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Dental Anatomy & Occlusion

Dental Anatomy & Occlusion

by chenny812, Jul. 2014

Subjects: anatomy dental, occlusion

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	A 1-year-old child is expected to have erupted which of the following primary maxillary and mandibular teeth? 1. lncisors and canines 2. lncisors and first molars 3. Central incisors and canines 4. Mandibular central and lateral incisors and maxillary central incisors	The correct choice is 2= INCISORS AND FIRST MOLARS . A 12-month-old child generally has all of the primary incisors and first molars. The primary mandibular central incisors erupt at 6 months, the mandibular laterals at 7 months, the maxillary centrals at 7-12 months, the maxillary laterals at 9 months, and the maxillary and mandibular first molars at 12 months, although the maxillary first primary molar may not erupt until about 14 months. Choices 1 and 3: A 1-year-old should have all of the primary incisors, but the cuspids do not & erupt until later: the mandibular cuspid at 16 months and the maxillary cuspid at 18 months. Choice #4: All of the teeth listed, which were the mandibular centrals and laterals and maxillary centrals, should be present in a 1-year-old, but so should the maxillary laterals and first primary molars. So, once again, the correct choice for question is 2.
	A 1-year-old child is expected to have erupted which of the following primary maxillary and mandibular teeth? 1. lncisors and canines 2. lncisors and first molars 3. Central incisors and canines 4. Mandibular central and lateral incisors and maxillary central incisors	INCISORS AND FIRST MOLARS The correct choice is 2. A 12-month-old child generally has all of the primary incisors and first molars. The primary mandibular central incisors erupt at 6 months, the mandibular laterals at 7 months, the maxillary centrals at 7-12 months, the maxillary laterals at 9 months, and the maxillary and mandibular first molars at 12 months, although the maxillary first primary molar may not erupt until about 14 months. Choices 1 and 3: A 1-year-old should have all of the primary incisors, but the cuspids do not & erupt until later: the mandibular cuspid at 16 months and the maxillary cuspid at 18 months. Choice #4: All of the teeth listed, which were the mandibular centrals and laterals and maxillary centrals, should be present in a 1-year-old, but so should the maxillary laterals and first primary molars. So, once again, the correct choice for question is 2.
	A branch of which of the following cranial nerves to the tongue may be anesthetized during administration of an inferior alveolar block? 1. V 2. VII 3. IX 4. XII	V The correct answer is choice 1. Let's review the cranial nerves to the tongue. Firstly, all intrinsic and extrinsic tongue muscles receive motor innervation from the hypoglossal nerve cranial nerve XII except the palatoglossus which is innervated by the pharyngeal plexus. The regular sensation of the anterior two-thirds of the tongue is provided by the lingual branch of the mandibular division of the trigeminal, cranial nerve V. Taste sensation of the anterior two-thirds of the tongue is provided by the chorda tympani, a branch of the facial nerve, cranial nerve VII. Taste and regular sensation of the posterior one third of the tongue is provided by the glossopharyngeal nerve, cranial nerve IX. It is the lingual nerve, a branch of the cranial nerve V, which is usually anesthetized during an inferior alveolar nerve block. Remember that this is the nerve block used when performing procedures involving mandibular teeth. When entering and leaving the area of the inferior alveolar nerve, some anesthetic will be deposited close to the lingual nerve, anesthetizing it also. So the correct answer to question is choice 1
	A deep invagination of the lingual pit in a maxillary lateral incisor can be called A. dilaceration B. fusion C. concrescence D. anodontia E. dens in dente	DENS IN DENTE The correct answer is choice E. The term "dens-in dente" refers to the"tooth within a tooth" appearance on radiograph of a lateral incisor with a deeply invaginated lingual pit. The pit may have the size and shape of a small tooth. Dilaceration refers to a sudden change of direction of a root. Fusion refers to the joining of two teeth by dentin. Concrescence is the joining of two teeth by cementum. Anodontia refers to the lack of development of all teeth.
	A developmental abnormality in which all teeth are absent is A. Microdontia B. Oligodontia C. Anodontia D. Exodontia E. Odontoma	ANODONTIA The correct answer is choice C. Anodontia is the absence of formation of all teeth. This may be due to a variety of genetic, metabolic or hormonal problems. Microdontia refers to the presence of teeth markedly smaller dentin than normal size. Oligodontia refers to the absence of many, but not all teeth. A few missing teeth are sometimes referred to as hypodontia. Supernumerary teeth can be referred to as hyperdontia. Exodontia is the procedure of removing teeth. Odontoma is a benign tumor of tooth tissue (enamel, dentin, cemetum etc.)in multiple tooth-like form (compound odontoma) or non-descript masses (complex odontoma).
	A hypoplasia of primary teeth which is limited to the incisal thirds of incisors, to the incisal tips of canines, and to the occlusal portions of molars, suggests which of the following? A. Tetracycline medication in early life B. Excessive fluorides in the drinking water C. A metabolic disturbance during the prenatal period D. A metabolic disturbance during infancy and the early childhood periods	A METABOLIC DISTURBANCE DURING INFANCY AND THE EARLY CHILDHOOD PERIODS The correct answer is choice C. Hypoplasia involves poor development and calcification of teeth. It can be caused by trauma or disease during a stage at which developing teeth are calcifying. Tetracycline staining will cause discoloration of teeth, and is caused by a mother taking tetracycline during pregnancy, with tetracycline being incorporated into tooth structure. It is not, however, hypoplasia. Fluorides do not cause hypoplasia either. Excess systemic fluoride well beyond the recommended lppm can cause fluorosis, a discoloration of enamel. So our choice is either C or D, depending on when incisal edges of primary incisors, canines and molars are calcifying. It turns out that they all begin calcification in utero between 4-6 months. A variable amount of crown enamel is complete by birth, and the rest shortly thereafter. Remember that incisal edges calcify first.
	A mandibular canine differs from a maxillary canine in which of the following? A. It is longer. B. It has a less pronounced cingulum. C. The crown is approximately the same length. D. It has a cusp tip more nearly centered mesiodistally when viewed from the facial.	IT HAS A LESS PRONOUNCED CINGULUM The correct answer is choice B. In general, the mandibular canine is smaller in all respects. Its cingulum is less pronounced, and the tooth crown appears to be somewhat assymetrical, with the mesial section of the facial area higher and narower than the distal. The distal section of the facial view looks somewhat bulbous and extends out farther. The mesial height of contour is also higher than the distal.
	A mandibular primate space is usually found in the primary dentition between 1. central incisors. 2. central and lateral incisors. 3. lateral incisor and canine. 4. canine and first molar. 5. first and second molars.	CANINE AND FIRST MOLAR molar. The maxillary primate space is found between the maxillary primary lateral incisor and canine. The primate space can occur in all other primates. When present, it usually allows the erupting mandibular first permanent molar to push forward and cause closure of the primate space. Then, the erupting maxillary first permanent molar can supposedly erupt directly into a class 1 "normal" molar relationship. If the primary dentition is crowded without spaces, the permanent first molars generally erupt end to end and the mandibular permanent molar cannot shift forward into a class 1 molar relationship until the primary mandibular second molar is replaced by the smaller permanent mandibular second bicuspid. This is referred to as a late mesial shift.
	A mental foramen would be found on x-ray closest to the root of which tooth? A. #19 B. #14 C. #29 D. #22 E. #4	#29 The correct answer is choice C. The mental foramen carries the mental nerve and artery through the mandible onto the skin overlying the mandible from the midline to the first premolar area. It also inervates buccal soft tissue and periosteum in the same area, as well as portions of the lower lip. Anesthetic is sometimes injected near the mental foramen to obtain anesthesia of these soft tissues. It is usually not possible to anesthetize teeth with a mental nerve block. The foramen is seen on x-ray as a lucent oval or circle most often near the apex of the mandibular second premolars (#20 and #29). It is possible in some cases to confuse the foramen with periapical pathology. Sometimes the foramen may be found slightly more mesially, toward the first premolar.
	A normal seven-year-old child will have how many teeth? A. 20 B. 22 C. 24 D. 26 E. 28	24 The correct answer is choice C. Fortunately, we do not really need to know here about replacement of deciduous teeth by permanents. At age seven, some of the primary incisors will have been replaced and some not. However, since there is a one-to-one replacement, it doesn't matter-if primaries or permanents are present. What is important is that the child has 20 primary teeth and that number of original tooth positions does not change as they are replaced. Only new teeth erupting distal to the original 20 will increase the total number. In this case, we expect that the four permanent first molars should erupt by about age six; therefore, four more than the original 20 teeth should be present, 24.
	All of the following are true of primary teeth, as compared to permanent teeth EXCEPT: A. Primary teeth are whiter in color B. Primary teeth have a smaller ratio of crown to root length. C. Primary teeth have a smaller ratio of mesial-distal width to crown height D. Primary molars have a smaller root trunk, relative to total tooth size E. Primary second molars closely model the anatomy of permanent first molars	PRIMARY TEETH HAVE A SMALLER RATIO OF MESIAL-DISTAL WIDTH TO CROWN HEIGHT The correct answer is choice C. The question reviews basic qualities or "set characteristics" of primary versus permanent teeth. In general, primaries are smaller than their permanent counterparts. They have the appearance of having very short crowns, because their crown is short, relative to their root size (small crown to root ratio). They also have the appearance of having "squat" crowns. This means that the crowns are flat, that is, they are relatively wide, but short in height (mesialdistal width to crown height ratio is LARGE. Primary molars have a very small root trunk, relative to the root trunk of the permanents. The root trunk is the area of combined root tissue. It is small in the primaries because that area is taken up by the developing permanent premolar crowns. Primary second molars are noted for their uncanny resemblance to permanent first molars (except in overal size).
	As compared with permanent teeth, the crowns of the primary teeth are A. larger. B. more bulbous and constricted. C. about the same size, but more bell-shaped cervically. D. narrower mesiodistally in comparison with their crown length in the anterior teeth.	MORE BULBOUS AND CONSTRICTED The correct answer is choice B. In general, primary teeth differ from permanents in a number of ways. They are generally smaller than their permanent counterparts in all dimensions. The are usually "squatter" in appearance, with their crowns shorter, relative to their mesio-distal length. They tend to have bulbous cervical ridges, on the buccal of molars, and both buccal and lingual of anteriors. They are whiter in color, and the enamel is relatively thinner.
	As the mouth is opened widely, the articular disk moves in what direction in relation to the articular eminence? A. Laterally B. Anteriorly C. Posteriorly D. Medially E. Superiorly	ANTERIORLY The correct answer is choice B. Fibers from the lateral pterygoid muscle enter the capsule and disc of the temperomandibular joint. Opening of the mandible involves the lateral pterygoid pulling the neck of the condyle and joint capsule forward toward the articular eminence. In addition, the disc may move slightly downward along the articular slope (inferiorly), but this is not an answer choice here.
	As you go from maxillary first to second to third molar, the MOST significant progressive change throughout the three teeth is A. loss of rhomboid shape B. loss of Carabelli cusp on the third molar C. decrease in size of one of the four major cusps D. loss of oblique ridge on the third molar	DECREASE IN SIZE OF ONE OF THE FOUR MAJOR CUSPS The correct answer is choice C. The distolingual cusp of the maxillary molar becomes less and less prominent as you go from first to second to third molar. The shape of maxillary molars is usually rhomboid, but it may be lost primarily in the third (but not second) molar. The Carabelli cusp (trait) is a small to medium-sized projection from the mesiolingual cusp of the first (but not second) molar. All three molars generally have an oblique ridge connecting the mesiolingual and distobuccal cusps, although it is much reduced in the third (but not the second) molar. So the size of only the distolingual cusp progressively changes as you go from first to second to third.
	At 9 years of age how many primary teeth remain in the mouth? A. 0 B. 4 C. 8 D. 12 E. 18	4 The correct answer is choice D. By nine years of age,the child has usually lost mandibular central (6-7 years), mandibular lateral (7-8 years), maxillary central (7-8 years) and maxillary lateral (8-9 years) incisors. The mandibular canine (9-10 years), first primary molar (10- 1 1 years). second primary molar (1 1-12 years) maxilary canine (I 1-12 years), first primary molar (10-1 l years) and second primary molar (10- 12 years) still remain. This amounts to 6 upper and 6 lower teeth.
	Because of the presence of a fissured groove cavity preparations MOST frequently need to be extended from the occlusal surface to the A. facial surface of maxillary molars. B. lingual surface of maxillary molars. C. lingual surface of mandibular molars. D. lingual surface of mandibular first premolars.	The correct answer is choice B. On the lingual surface of maxillary molars, the distolingual groove extends from the occlusal surface onto the lingual. This separates the distolingual and mesiolingual cusps. It is often deep, and when restored often cames the preparation onto the lingual surface. The facial groove generally does not extend deeply onto the facial surface so that it requires facial extension. The lingual groove of mandibular molars tends to stay on the occlusal surface, and not go deeply down onto the lingual. The lingual surface of mandibular first premolar often has a mesioloingual developmental groove. It is generally short and shallow and not commonly restored along with the occlusal surface.
	Calcification of six-year molars begins A. at 6 years B. 6 months prenatal C. at birth D. 6 months postnatal E. at approximately 3 years of age	The correct answer is choice C. This question is commonly asked on NDB. It is the only tooth whose average beginning of calcification coincides with birth. It is also the first permanent tooth to begin calcifying. Calcification roughly, but not exactly, follows the order of eruption. Generally, teeth that begin to calcify first, erupt first, but there are many exceptions to this rule. An example of the rule, (and not the exception) is found in molars where the second molar begins calcifying at about 2-3 years and the third molar at 7-8 years. In both arches, canines calcify before first premolars, and first premolars calcify before second premolars.
	Contraction of the lateral pterygoid muscle produces 1. initial upward closure of the mandible. 2. forward movement of the condyle from the articular fossa. 3. posterior displacement of the condyle from the articular eminence. 4. final forceful closure of the molars through a bolus of food.	The correct choice is 2. The lateral pterygoid muscle moves the condyle forward, downward and medially. It originates on the lateral pterygoid plate and inserts on the neck of the condyle and the articular disk. Choice #1: Initial closure of the mandible is accomplished by the masseter and medial pterygoid muscles. The masseter originates on the zypomatic arch and inserts on the outer surface of the angle of the mandible. The medial pterygoid muscle originates on the lateral pterygoid plate and inserts on the inner surface of the angle of the mandible. Choice #3: Posterior displacement of the condyle is accomplished mostly by the posterior part of the temporalis muscle. Choice #4: Final forceful tooth closure is mainly due to the anterior part of the temporalis muscle. The temporalis muscle originates on the temporal crest of the cranium and inserts on the coronary process and the anterior ramus of the mandible.
	During a working movement of the mandible, the facial cusp ridges of the maxillary first premolar on the working side oppose which of the following mandibular structures? A. The facial embrasure between the canine and the first premolar B. The distal cusp ridge of the first premolar and the mesial cusp ridge of the second premolar C. The distal cusp ridge of the second premolar and the mesial cusp ridge of the first molar D. The mesiofacial groove of the first molar.	The correct answer is choice B. In a working movement (let's assume left working), the mandible will move left, and the left I maxillary first premolar facial cusp, which is a non-supporting cusp, will make contact with the mandibular facial surfaces as they move past. The mandibular teeth are positioned one half tooth mesial to the maxillary, so the maxillary first premolar should contact I both its counterpart, but also the tooth just distal to its counterpart. Therefore, both the first and second mandibular premolar facial surfaces will make contact.
	During nonmasticatory swallowing, teeth are usually 1. protruded. 2. in a working arrangement. 3. in contact in intercuspal position. 4. None of the above. This is a nonexistent act.	The correct choice is 3. The teeth are in the intercuspatory position when swallowing occurs. In fact, telling a patient to swallow is often a good way to get a patient into maximum intercuspation. Choice #4: Non-masticatory swallowing occurs throughout the day and night, more frequently when awake. Otherwise, a large amount of saliva would build up.
	During the eruption of permanent teeth, which bone processes occur? A. Both resorption and deposition B. Neither resorption nor deposition C. Resorption only D. Deposition only	The correct answer is choice A. This can be reasoned by noting that there must be bone resorption coronal to the emerging crown to have room for the crown to move into to approach the soft tissue (gingiva) above it. Bone deposition is also logical but less obvious. There must be bone deposition below the roots as the tooth moves coronally and bone deposition around the root to fully fill the shape of the alveolar socket surrounding the new root.
	Each of the following cusps of the maxillary molars is part of the maxillary molar primary cusp triangle EXCEPT one. Which one is this EXCEPTION? A. Mesiofacial B. Mesiolingual C. Distofacial D. Distolingual	The correct answer is choice D. Maxillary molars have a generally rhomboidal shape, and three major cusps forming a distinct triangular pattern, the primary cusp triangle. Note that primary here refers to important, not primary. as in primary (deciduous) I teeth. The three major cusps are the mesiobuccal, mesiolingual and distobuccal. Not included are the distolingual, which is small, and on the first molar, the cusp of Carabelli, which is even smaller, when present.
	Each of the following is a function of the periodontal ligament EXCEPT 1. sensory. 2. nutritional. 3. supportive via the fibers. 4. formative via its cellular elements. 5. maintenance of the epithelial attachment	The correct choice is 5. The periodontal ligament does not participate in the epithelial attachment to the tooth. This is maintained by the junctional epithelium of the gingival sulcus. The periodontal ligament carries nerves and blood vessels, which are the sensory and nutritive functions; it supports the tooth via the fibers; and has cementoblasts, osteoblasts and fibroblasts which make up the formative function. It has a fifth protective function to cushion the tooth against force. To summarize the five functions of the periodontal ligament: 1 ) sensory, 2) nutritive, 3) supportive, 4) formative, and 5) protective.
	Each of the following morphologic structures can be seen on any incisor EXCEPT one. Which one is this EXCEPTION? A. Cingulum B. Mesial marginal ridge C. Lingual fossa D. Transverse ridge	The correct answer is choice D. Incisors generally contain both mesial and distal marginal ridges, and a depression between them, the lingual fossa. Incisors, as well as canines contain a cingulum, or pronounced lingual bump near the cervical end of the crown. A transverse ridge is not present. This can be found on the mandibular fint premolar. It is a ridge seen on the linguallocclusal surface of the crown, connecting the buccal and lingual cusps.
	Exfoliation of primary canines is most likely to occur during the age range A. 6-7 B. 8-9 C. 10-11 D. 12-13	The correct answer is choice C. The canines erupt, as with most other teeth, in the order mandibular, then maxillary. The eruption of the maxillary is more predictable, with most occurring between 11 and 12. The mandibular may erupt as early as 9, but normally at 10-11. Eruption times, of course, are averages and are variable. So 10-11 is our closest answer. It is extremely rare to see a permanent canine at 8, so rule out choice B. Likewise, the mandibular canine is almost always erupted before 12, so rule out choice D.
	From a proximal view, which of the following describes the crown outline on a mandibular posterior tooth? A. It is designed to protect against root fracture by having the crown structure serve as root support. B. It is designed to allow for a minimum amount of chewing efficiency on the coronal surface of the tooth. C. It is usually rhomboidal and has a design flaw that encourages cusp fracture. D. It is usually trapezoidal and has a design flaw that encourages cusp fracture.	The correct answer is choice 1. A maxillary canine has an almost vertical inclination when viewed proximally. Maxillary lateral incisors, choice 2, lean slightly more buccally when viewed from the proximal and maxillary centrals slightly more. In actual degrees, the canines are 16 degrees off of vertical while the maxillary laterals and centrals are 26 and 28, respectively. Do not spend time remembering the numbers. The most vertical maxillary teeth are the first and second premolars, 5 and 6 degrees from vertical respectively. Mandibular centrals and laterals are 22 and 23 degrees off from vertical, respectively. The mandibular canine is more vertical than the mandibular incisors and as in the maxillary arch, the premolars are most vertical. In general, the order would be premolar, canine, incisor in order of decreasing vertical position. So the correct answer to question is choice 1.
	From the facial view, the maxillary first molar has its lingual root apex in line with which of the following? A. Facial groove B. Distofacial line angle C. Distofacial cusp tip D. Mesiofacial cusp tip E. Mesiodistal diameter midpoint	The correct answer is choice A. The palatal root of the maxillary first molar tends to diverge outwards in a palatal direction, but be approximately centered in the mesio-distal direction. Looking at it from the facial should place it behind the facial (buccal) groove. This groove separates the mesiobuccal and distobuccal cusps. Since the mesiobuccal cusp is larger, this groove is slightly distal to the mesio-distal midpoint.
	From the incisal aspect, the crown of a maxillary canine normally exhibits which of the following? A. A trapezoidal outline B. Symmetry between its mesial and distal portions C. A mesial portion that is thinner faciolingually than the distal portion D. A distal portion that displays some concavity in its facial outline E. Less faciolingual thickness than the crown of a mandibular canine	The correct answer is choice D. From the incisal, the crown of the maxillary canine is somewhat rhomboidal or diamond shaped. Its mesial portion is wider bucco-lingually than its distal portion, and is more bulbous and convex as well. The distal portion is narrower and concave on the labial surface, showing a depression there. In all dimensions, the maxillary canine is larger than its mandibular counterpart.
	How many cingula exist in each arch? A. 2 B. 4 C. 6 D. 8 E. 12	The correct answer is choice C. Cingula is the plural for cingulum, a rounded protuberance or elevation located on the lingual surfaces of anterior teeth. Therefore, central incisors, lateral incisors, and canines all have recognizable cingula. The cingulum, may be thought of as an undeveloped lingual cusp. When we view premolars in both arches, they no longer are said to have cingula, but instead have pronounced lingual cusps. In this case, each arch has two central incisors, two lateral incisors and two canines, for a total of six teeth.
	How soon after eruption of a permanent tooth is the apex usually fully developed? 1. Immediately 2. 3 months 3. 2 or 3 years 4. 5 or 6 years	The correct answer is #3. The apex of a permanent tooth is approximately one-half formed at the time of the eruption and the root is generally completed 2 to 3 years after eruption. This fact is important when treatment planning endodontic procedures in young people.
	If a permanent maxillary first molar has a fourth root canal, it will usually be found in A. Its own fourth root B. The mesiobuccal root C. The mesiolingual root D. The palatal (lingual) root E. It cannot be found: a maxillary first molar always has three root canals	The correct answer is choice B. The most common arrangement of root canals in the maxillary first molar is three, one in each root (mesiobuccal, distobuccal, palatal). A 4 canaled version is fairly common. The orifice to the canal is located in the area between the orifice to the mesiobuccal and palatal canals. The canal itself is located in the mesiobucccal root. It is estimated that 30-40% of maxillary first molars have this orifice, whether or not two canals end in one foramen or two. Endodontists often assume it to be there until proven otherwise.
	In a cervical cross section, which premolar(s) sometimes exhibit a root outline and a pulp chamber floor outline that are both kidneyshaped? A. Maxillary first B. Mandibular first C. Maxillary second D. Mandibular second E. All premolars	The correct answer is choice A. The maxillary first premolar may have a kidney shaped root outline and pulp outline because of the tendency of the tooth to have a deep mesial root concavity, which will indent that side. The other premolars listed will have cross sectional root shapes at the CEJ varying from oval to indented on both sides, giving a figure-8 appearance.
	In a Class II occlusal relationship, the tip of the facial cusp of a mandibular first premolar lies directly below the contacting area between which maxillary teeth? A. Canine and lateral incisor B. Canine and first premolar C. First and second premolars D. Second premolar and first molar	The correct answer is choice C. Lets look at a normal Class I relationship first. The facial cusp of the mandibular first premolar is a holding cusp that contacts the mesial marginal ridge of the maxillary first premolar and comes close to contacting the distal of the maxillary canine. In a Class II relationship, move the mandible backwards (distally), and the mandibular first premolar will now be between the first and second maxillary premolars.
	In a permanent mandibular first molar, what developmental groove separates the distofacial cusp from the distal cusp? A. Facial B. Buccal C. Distofacial D. Mesiofacial E. Oblique	The correct answer is choice C. The occlusal surface of the mandibular first molar consists of five cusps: MB, DB, ML, DL, and distal. There are three major pits: mesial, central, and distal. A central groove connects the mesial and central pits and also separates the MB and ML cusps. A mesiobuccal groove separates the MB from the DB cusp. A distobuccal (distofacial) groove separates the DB cusp from the distal cusp. A lingual groove separates the ML and DL cusps.
	In an acquired Class 3, crossbite relationship, as the mandible retrudes, the maxillary lateral incisor contacts which of the following teeth? A. Central incisor B. Lateral incisor C. Central and lateral incisors D. Canine and lateral incisors	The correct answer is choice D. In a Class III crossbite, the mandibular teeth are protruded beyond the maxillary counterparts. If these mandibular teeth are drawn in (retruded), then their lingual surfaces will contact the facial surfaces of the maxillary teeth. Since the mandibular teeth are narrower, the mandibular central contacts only the wider maxillary central. The mandibular lateral will contact both the distal part of the maxillary central and the mesial part of the maxillary lateral. The mandibular canine will contact the distal part of the maxillary lateral, and the mesial part of the maxillary canine.
	In an eight-year-old patient, which teeth are expected to be present? A. Permanent central and lateral incisors, premolars, and first molars, with primary canines B. Permanent central and lateral incisors, and first molars, with primary canines and molars C. Permanent central and lateral incisors, canines, and first molars, with primary molars D. All permanent teeth, except second and third molars	The correct answer is choice B. By age six, permanent first molars are usually present. By age seven, the mandibular incisors and the maxillary centrals are usually in. Maxillary laterals often erupt around ages seven to eight. Since canines usually erupt between 9 and 11 years, we still expect primary canines in our eight-year-old. Similarly, for premolars, the range may be from 9 years up to about 12 years, so primary molars, not premolars, should be present in our eightyear- old. Note that, as previously stated, the question must choose a pretty definitive age, such as eight. Choosing age 10 would lead to far too much variation and unpredictability, especially concerning canines and premolars.
	In an ideal intercuspal position, the distofacial cusp of a maxillary first molar opposes which feature on a mandibular first molar? A. The distal cusp B. The distofacial cusp C. The distofacial developmental groove D. The rnesiofaciai developmental groove	The correct answer is choice C. The facial cusps of maxillary molars are guiding cusps and oppose grooves on the facial surface of mandibular teeth. Since the mandible is about one half tooth forward of the maxilla, we look for a groove one half tooth distal to the distofacial area of the maxillary molar. This is the groove between the distobuccal and distal cusp of the mandibular molar.
	In an ideal intercuspal relation in a normal dentition, each of the following teeth contacts each other EXCEPT one. Which one is this EXCEPTION? A. Maxillary first premolar and mandibular second premolar B. Maxillary first molar and mandibular second premolar C. Maxillary second premolar and mandibular first molar D. Maxillary second molar and mandibular third molar	The correct answer is choice B. Maxillary posterior teeth generally contact their own counterpart in the mandibular arch, and the tooth just distal to it. Maxillary first premolars contact mandibular first and second premolars. Maxillary first molars contact mandibular first and second molars. Maxillary second premolars contact mandibular second premolars and first molars. Maxillary second molars contact mandibular second molars and third molars.
	In an ideal intercuspal relation, the mesiofacial cusps of the mandibular second molars contact the maxillary molars in (on) the A. distal fossae of the second. B. central fossae of the second. C. lingual embrasures between the first and second. D. facial embrasures between the first and second. E. mesial marginal ridges of the second.	The answer is choice E. Facial cusps of mandibular teeth are supporting cusps and occlude on marginal ridges of the maxillary teeth except for the distobuccal cusp of the molars which occludes with the central fossa of the maxillary molars and the distal cusp of the mandibular first molar which occludes with the distal triangular fossa of the first maxilary molar. So the mesiofacial cusp of the mandibular second molar should contact the distal marginal ridge of the maxillary first molar and mesial marginal ridge of the maxillary second molar.
	In an ideal intercuspal relation, the mesiolingual cusp of the maxillary first molar contacts the mandibular first molar in (on) the A. central fossa. B. distal fossa. C. mesial fossa. D. mesial marginal ridge. E. distal marginal ridge.	The correct answer is choice A. This reminds us of our general rule: maxillary posterior cusps make contact on mandibular marginal ridges EXCEPT for the mesiolingual cusps of the maxillary first and second molars which occlude in the central fossae of the corresponding mandibular teeth.
	In an ideal intercuspal relation, the oblique ridge of the maxillary first molar opposes which structure of the mandibular molar? A. The interproximal area between first and second B. The developmental groove between the mesiofacial and distofacial cusps of the first C. The developmental groove between the mesiolingual and distolingual cusps of the first D. The developmental groove between the distofacial and distal cusps of the first	The correct answer is choice D. The distolingual cusp of the maxillary first molar occludes with the mesial marginal ridge of the second molar and the distal marginal ridge of the first molar. Therefore, the oblique ridge, which is slightly mesial to the distolingual cusp of the maxillary first, should occlude with something slightly mesial to the area just mentioned. This would be the area between the distal cusp and distobuccal cusp of the first molar. This is the distobuccal groove area.
	In an ideal occlusion, maxillary posterior tooth buccal cusps oppose A. marginal ridges only B. marginal ridges and fossae C. grooves and embrasures D. grooves and marginal ridges	The correct answer is choice C. Maxillary LINGUAL cusps and mandibular buccal cusps are holding (support) cusps, whereas maxillary BUCCAL cusps and mandibular lingual cusps are guiding cusps. Therefore, the maxillary buccal cusps lie slightly buccal to the mandibular buccal cusps and will fit into grooves and embrasures, such as the buccal grooves of mandibular molars. These guiding cusps have a function only during horizontal mandibular movements.
	In carving an occlusal amalgam restoration in a permanent mandibular second molar, which of the following shapes is the most typical groove pattern? 1. H 2. L 3. U 4. Y 5. +	The correct choice is #5, a plus or cross shape. The permanent mandibular second molar generally has four cusps with a cross groove pattern. Choices #1 and 3: H and U shapes are not common groove patterns, although the mandibular second premolar may exhibit these patterns as variations. Choice #2: An L-shaped groove pattern is typical of the mesial occlusal grooves of the maxillary molars. Choice #4: A Y-shaped groove pattern is characteristic of the mandibular second premolar.
	In cervical cross-section, the root of a mandibular canine is described as A. triangular. B. roughly conical. C. flattened in a mesiodistal direction. D. broader mesiodistally on the lingual than on the facial.	The correct answer is choice C. In cross section mandibular canine roots are roughly oval. They are longer bucco-lingually. and narrower mesio-distally. They are slightly wider towards the buccal. The pulp canal tends to be ovalish as well. Maxillary canine root sections tend to be more similar, and slightly more elongated in the bucco-lingual direction.
	In contrast to maxillary canine crowns, mandibular canine crowns have which of the following anatomically? A. Greater measurements, mesiodistally B. Greater measurements, faciolingually C. More accentuated marginal ridges D. Well-defined lingual pits E. Less-pronounced cingula	The correct answer is choice E. In general, when comparing maxillary and mandibular canines you will find that the mandibular canines are smaller (mesio-distally AND bucco-lingually), they lack lingual pits, (maxillary canines have them as rare variants) have smaller cingula, and less pronounced marginal ridges. Mandibular canines are more symmetrical when viewed from the occlusal.
	In extraction of premolars, the dentist may sometimes use a rotation or circular motion. Which premolar should NEVER be extracted with this type of motion? A. Maxillary first B. Maxillary second C. Mandibular first D. Mandibular second	The correct answer is choice A. The choice of direction of movement used by the dentist in extracting a tooth depends greatly on the likely root form of the tooth involved. Teeth with circular or conical shaped roots can easily be rotated during extraction. To a lesser extent, a slightly oval shaped root could also be rotated during extraction. Multi-rooted teeth and teeth with extremely broad, flat, fused roots cannot be rotated without fracture of the root or crown. While there is much variation in root form among the premolars, the maxillary first premolar almost invariably has two roots, a buccal and lingual, and whether fused or not, will not rotate without breaking. Maxillary seconds can have two roots but usually do not and the one root can be conical. Similarly, both mandibular premolars are usually single rooted and potentially can be rotated out. Of the two, the mandibular first premolar is more likely to have a second root.
	In normal occlusion, and in a left working movement, the mesiofacial cusp of the maxillary left second molar passes through which of the following mandibular structures? A. The embrasure between the left first and second premolars B. The embrasure between the left first and second molars C. The facial groove of the left first molar D. The facial groove of the left second molar E. The distofacial groove of the left first molar	The correct answer is choice D. The mesiofacial cusp of the maxillary second molar is a guiding cusp. It will pass through an area on the facial surface of a mandibular tooth. Since the mandible is about one half tooth forward relative to the maxilla, look for a surface on the mandibular second molar facial area, slightly distal to the area of the mesiobuccal cusp. This is the facial groove of the second molar.
	In protrusive movement, the mandibular canines in a Class II occlusal relationship articulate with which of the following maxillary teeth? A. Canines only B. Lateral incisors only C. Canines and lateral incisors D. Canines and first premolars	The correct answer is choice C. Remember that the mandibular teeth are located about one half tooth mesial to the corresponding maxillary teeth. So although they are not normally in contact in centric occlusion, the mandibular canine is located in the area of the mesial half of the mandibular canine and the distal half of the lateral incisor. When the mandible protrudes, the teeth will contact in that position.
	In relation to maxillary canines, maxillary first premolars usually erupt: A. before canines B. after canines C. at nearly the same time as canines	The correct answer is choice A. Although there is some variation in eruption times, the most usual order of eruption in the maxillary arch is first premolar, second premolar, canine. In the mandibular arch it is most often canine, first premolar, second premolar. The mandibular version generally erupts before the maxillary. Two year ranges for the teeth in question are: maxillary first premolar (10-11), maxillary second premolar (10-11), maxillary canine (11 -12), mandibular first premolar (10-11), mandibular second premolar (11-12), mandibular canine (9-10). The maxillary arch is generally more predictable than the mandibular.
	In the comparison of the rhomboidal and heart-shaped crown outlines of maxillary molars, the crown portion that differs MOST in contour and size is the A. mesiofacial. B. distofacial. C. mesiolingual. D. distolingual.	The correct answer is choice D. Most maxillary molars have a rhomboidal occlusal crown outline due to the presence of four cusps. As one of the cusps, the distolingual, becomes less prominent, or absent, the occlusal outline changes and becomes more heart shaped. The smaller distolingual cusp is sometimes a variety of tooth form, and is more common as you go from first to second to third molar. The third molar most commonly has this heart shaped form.
	In the diagram of Posselt's envelope of motion, maximum intercuspal position is the 1. lowest point. 2. most anterior point. 3. most posterior point. 4. most superior point.	The correct choice is #4. On the diagram of [Posselt's] envelope of motion, the intercuspal position is the most superior point labelled #3 on the diagram. Choice #1: The lowest point is #8 which is the position of maximum opening. Choice #2: The most anterior point is #1, the maximum protruded position. Choice #3: The most posterior point is #4, the retruded contact position.
	In which of the following molars is the mesial fossa most distinctly separated from the remainder of the occlusal table by a transverse ridge? 1. Maxillary first 2. Mandibular first 3. Maxillary second 4. Mandibular second	The correct choice is 2. The triangular ridges of the mesiobuccal and mesiolingual cusps of the mandibular first molar join to form a transverse ridge which separates the mesial fossa from the rest of the occlusal table. This transverse ridge is not quite as prominent in the mandibular second molar which is choice #4. Choices #1 and 3: In the maxillary molars, the central fossa is separated from the distal fossa by the oblique ridge running from mesiolingual to distobuccal cusps.
	In which of the following teeth is the mesial portion MOST distinctly separated from the remainder of the occlusal table by a transverse ridge? A. Primary maxillary first molar B. Primary mandibular first molar C. Primary mandibular second molar D. Mandibular second premolar E. Mandibular first molar	The correct answer is choice B. Transverse ridges are most noticeable in two teeth, the permanent mandibular first premolar, and the primary first mandibular molar. A transverse ridge connects buccal and lingual sections of a tooth and separates mesial and distal. In the primary mandibular first molar, the transverse ridge connects the large mesiobuccal and mesiolingual cusps. This structure is more common and more noticeable on the primary first molar than on the permanent first premolar. The other teeth listed do not have transverse ridges.
	Mandibular lateral translation (Bennett movement) occurs during the A. earliest stage of lateral movement. B. latter stage of protrusive movement. C. middle stage of retrusive movement. D. hinge axis movement of the mandible. E. ending stage of exhibiting a border movement.	The correct answer is choice A. The Bennett movement involves whole body movement of the mandible in a lateral direction. Lets use process of elimination for our answers. In lateral movement, both rotation and translation occur. Translation occurs particularly on the working side of the TMJ, in combination with some rotation, primarily rotation around a vertical axis. The translation component is known as the Bennett shift, and is a whole body shift of the working side of the mandible of about 1 mm laterally. Protrusive movement is primarily translation caused by the lateral pterygoid muscle, but forward and not lateral. Similarly. retrusive movement is translation backwards, not laterally, and is caused primarily by the temporalis muscle. Hinge axis movement of I the mandible refers to opening. The beginning of opening is rotational around a horizontal axis through the TMJ. Later siages of opening involve translation, to the maximal opening possible.
	Maxillary tooth crowns exhibit concavities on which of the following surfaces? A. The mesial of central incisor and first premolar B. The mesial of canine and first molar C. The distal of first premolar and the mesial surface of second molar D. The mesial of first premolar and the distal of first molar E. The distal of the first molar and the mesial of the second molar	The correct answer is choice D. The most well known mesial concavity on both crown and root is on the mesial of the maxillary first premolar. So we are most likely going to choose between choices A and D. The central incisor does not have a mesial crown concavity, although a root groove may be present. Likewise, the canine often has proximal root concavities that do not extend to the crown. Second premolars and distals of first premolars also may have this trait, but again, it does not extend to the crown. The cervical third of the mesial surface of the first molar sometimes exhibits a concavity not found normally on the second molar, or on the distal of the first, which is usually quite convex.
	Mesial inclination of lingual cusps is present in which maxillary premolars? 1. First premolars only 2. Second premolars only 3. Both first and second premolars 4. Neither first nor second premolars	The correct answer is choice 3. Mesial inclination of lingual cusps is present on both maxillary premolars. This means that when viewed from the lingual, the lingual cusp tends to lean towards the mesial and most of the lingual cusp is mesial to the midline. t It is a characteristic of the maxillary premolars and not consistently found in either the mandibular first or second premolar. In the mandibular first premolar, the lingual cusp may be midline or mesial or distal to the midline. In the mandibular second premolar, often gd two lingual cusps are present. So the correct answer to question is choice 3.
	Mesiolingual grooves can be found on which of the following permanent teeth? A. Maxillary canines B. Mandibular first premolars C. Maxillary first molars D. Mandibular second molars	The correct answer is choice B. Mandibular first premolars often have a mesiolingual developmental groove which begins on the occlusal and extends down the mesiolingual surface. Maxillary first molars have distolingual grooves but not mesiolingual. Mandibular molars have lingual grooves.
	Moving the mandible from a maximum intercuspal position to a retruded contact position usually results in 1. increased occlusal vertical dimension. 2. increased horizontal overlap. 3. decreased vertical overlap. 4. all of these.	posterior to centric occlusion or maximum intercuspation. It also represents a position where the condylar head is located closer to the distal section of the glenoid fossa. Because retruded contact implies that the teeth are not in complete occlusion which is the greatest intercuspation and smallest vertical dimension, they are therefore slightly farther apart with a greater vertical dimension. If the mandible moves posteriorly, there will be greater distance from the mandibular anteriors to the maxillary anteriors or slightly increased horizontal overlap. If the teeth are slightly more separated vertically, there will be less vertical overhang of the maxillary anteriors over the mandibular. So all three choices, 1.2 and 3 are all correct and the correct answer to question is choice 4.
	On a maxillary molar, which of the following ridges is formed by the union of the distal cusp ridge of the mesiolingual cusp and the triangular ridge of the distofacial cusp? A. Cuspal B. Central C. Marginal D. Oblique E. Transverse	The correct answer is choice D. The oblique ridge is found on maxillary molars. It connects the distobuccal and mesiolingual cusps. It also separates the distolingual cusp from the main cusp triangle of the molar. Just distal to it is the distolingual groove.
	On the crowns of maxillary canines, which lobe includes the cusp tip? A. Mesiolingual B. Distofacial C. Mesiofacial D. Lingual E. Middle facial	The correct answer is choice E. The maxillary canine is often described as having three facial lobes, mesial, distal and middlc The cusp tip is located almost centrally. on the middle lobe, slightly to the mesial of center. The lingual lobe contains the cingulum.
	On the occlusal surface of a maxillary first molar, the total number of pits is normally the same as found on the occlusal surface of which premolar? A. Maxillary first B. Mandibular first C. Maxillary second D. U-type mandibular second E. Y-type mandibular second	The correct answer is choice E. The maxillary first molar has three pits, the mesial, distal and central. The maxillary first premolar generally has two, a mesial and a distal, as does the maxillary second. The mandibular first generally has the same two. The U type mandibular second premolar is the two cusped type, with the same two pits. However, the Y type is the three cusped type, which contains a central pit in addition to the mesial and distal.
	Perikymata are the result of 1. enamel hyperplasia. 2. enamel hypoplasia. 3. interstitial growth. 4. normal enamel apposition. 5. early ameloblastic degeneration.	The correct answer is choice 4. Perikymata are normal enamel features. Line of Retzius which form early in enamel formation complete an arc of enamel and return to the dentinal enamel junction. Later lines of Retzius do not complete an arc-like pattern and terminate on the enamel surface. They form a series of grooves and elevations at the enamel surface. The grooves are known as imbrication lines and the elevations are known as perikymata. So the correct answer to question is choice 4.
	Primary molars differ from permanent molars in that primary molars 1. have heavier root trunks. 2. tend to have less pronounced cervical ridges. 3. have thicker enamel compared to the total bulk of crowns. 4. have flatter facial and lingual surfaces extending from the occlusal to the cervical ridge.	The correct answer is choice 4. Let's review them one by one. Primary molars generally have lighter, thinner root trunks. The roots are smaller due to the smaller size of the tooth and the widespread position of the roots to surround the developing crown of the succedaneous tooth. So choice 1 is incorrect. Choice 2 is also incorrect. A number of primary molars have pronounced cervical ridges, including the primary maxillary first molar and primary mandibular first molar. Choice 3 is incorrect. Primary teeth are generally characterized by thinner enamel. Choice 4 is our correct answer. The facial and lingual outline of the primary molars are usually straight from the occlusal surface to cervical ridge and then bulbous at the cervical ridge. The permanent molars facial and lingual surfaces tend to be more completely and regularly convex without a straight surface. So the correct answer to question is choice 4.
	Prominent cervical ridges or bulges are noted on which surfaces of primary teeth? A. Linguals of molars and buccals of incisors B. Buccals and linguals of molars and buccals of incisors C. Linguals of incisors and buccals of molars D. Buccals and linguals of incisors and buccals of molars E. Buccals of molars and buccals of incisors	The correct answer is choice D. Prominent cervical ridges are characteristic of certain primary teeth. There is a constriction of the tooth at the cervical line, giving a bulge or ridge effect immediately incisal to the CEJ. These cervical ridges are found on the buccal and lingual of primary anteriors, and the buccal only of molars. In molars, the cervical ridge makes the occlusal table look constricted as the tooth is viewed from the occlusal.
	Protrusive movement is produced primarily because of contracture of which of the following muscles? A. Masseter B. Mylohyoid C. Temporalis D. Medial pterygoid E. Lateral pterygoid	The correct answer is choice E. The masseter and medial pterygoid act primarily to close (elevate) the mandible. They form the "masseteric sling". The temporalis can both elevate and retract the mandible, depending on which fibers are contracted. The mylohyoid can play a very small role as an accessory in opening (depressing) the mandible. The lateral pterygoid is the primary protruder and opener (depresser) of the mandible.
	The anterior tooth LEAST likely to have a mesial or distal root concavity is the: A. Maxillary central incisor B. Maxillary canine C. Mandibular canine D. Mandibular central incisor E. Mandibular lateral incisor	The correct answer is choice A. Root concavities are grooves running vertically along the proximal side of a root. They may be shallow or deep, and if deep, may make the teeth appear double rooted. All of the mandibular anteriors can have this groove. It can be especially deep in mandibular canines, approaching a double-rooted appearance. It is also common in maxillary canines, although rarely as deep. It is almost never found on maxillary central incisors, whose root form is usually roundish, triangular and convex.
	The apices of a mandibular second molar are located A. posteriorly to the pterygomandibular raphe. B. inferiorly to the mylohyoid muscle insertion. C. inferiorly to the masseter muscle insertion. D. inferiorly to the medial pterygoid muscle insertion.	The correct answer is choice B. The pterygomandibular raphe joins the buccinator and superior constrictor muscles. It is anterior and superior to the second mandibular molars. The mylohyoid line is the attachment of the mylohyoid on the medial side of the mandible. It moves in an upward slanting direction, getting higher on the mandible as you move more posterior. By the second 1 and third molar area, it is superior to the molar root apices. Both the masseter and medial pterygoid insert on the angle and ramus, below the second molar root apices.
	The Bennett movement is best described as the 1. medial shift of the working condyle. 2. lateral movement of the non-working condyle. 3. bodily shift of the mandible in the direction of the working condyle. 4. bodily shift of the mandible in the direction of the non-working condyle.	The correct answer is choice 3. Let's review the terminology of lateral or working movements. The side to which the mandible moves is known as the working side and the condyle of that side is the working condyle. The opposite side is known as the nonworking or balancing side. The working condyle exhibits a small sliding lateral movement during lateral excursions and this is known as the Bennett movement. So the correct answer to question is choice 3.
	The cemental union of two fully formed teeth that were originally separate entities is 1. fusion. 2. concrescence. 3. dilaceration. 4. dens in dente. 5. hypercementosis.	The correct answer is choice 2. Let's define the five terms. Choice 1, fusion, is incorrect. Fusion is the result of two adjacent teeth joined by a union of dentin. The result is a large crown or double crown with two distinct root canals. Choice 2 is correct. Concrescence is the joining of roots of two teeth by cementum. This usually occurs after the teeth are formed and have most implications in terms of the difficulty of extraction. Choice 3 is incorrect. Dilaceration of a root refers to a sharp angular deviation of the root from its normal long axis. Choice 4 is incorrect. Dens in dente refers to an inpocketing of the enamel organ into the pulp during tooth formation resulting in an enamel lined pit. This is most commonly found in the maxillary lateral incisor. Choice 5 is incorrect. Hyprcementosis refers to excess cementum development near the apex of the root but not involving union of the teeth. So the correct answer to question is choice 2.
	The concept of using a lateral checkbite record to set a respective condylar inclination implies which of the following? A. That the non-working side condyle has traveled against the posterior wall of the fossa B. That the working side condyle has traveled down the slope of the articular eminence C. That the non-working side condyle has moved anteriorly and medially D. That the working side condyle has moved toward the medial wall of the glenoid fossa	The correct answer is choice C. At this stage (pre-prosthodontics), we can ignore the discussion of the lateral checkbite and just look to see which of our answer choices are true. In a working (lateral) movement, the mandible moves toward the working side. The condyle rotates and translates on the working side, and moves slightly laterally (Eliminate choice D). The condyle will only travel down the slope of the articular eminence during the translation phase of opening (depression). (Eliminate choice B). During a working movement, the non-working condyle moves forward and medially, not posteriorly (Eliminate choice A).
	The contraction of the lateral pterygoid muscle causes 1. the initial upward closure of the mandible. 2. forward movement of the condyle from the articular fossa. 3. posterior displacement of the condyle from the articular eminence. 4. the final forceful closure of the molars through a bolus of food.	The correct answer is choice 2. Let's review the functions of the lateral pterygoid. This muscle extends from the pterygoid plate to the neck and condyle of the mandible and also contributes fibers to the articular disk. Its function is to depress or open the mandible, to move the mandible sideways in working movements, and to protrude the mandible or cause the mandible to move forward. When this occurs, the condyle moves anteriorly from its place in the articular or glenoid fossa. So choice 2 is correct. Choices 1 and 4 are incorrect because they deal with closure or elevation of the mandible. The lateral pterygoid does not elevate. The chief elevator muscles are the masseter, medial pterygoid and to some extent the temporalis. Choice 3 is incorrect because it involves backward posterior movement or retrusion. The lateral pterygoid is involved in protrusion while the chief retruder muscle is the temporalis. So the correct answer to question is choice 2.
	The dentist instructs the patient, who has a severed left lateral pterygoid muscle, to open wide. The patient's mandible will move in which direction? A. To the left B. To the right C. In a straight protrusive direction D. In a retrusive direction	The correct answer is choice A. As a rule, the mandible will move TOWARD the injured side. Imagine both lateral pterygoids ; contracting and attempting to pull both condyles forward. However, only the right side can move. The right side of the mandible will move forward and medially as the left condyle stays in the same position. The mandible essentially rotates left instead of protruding or opening.
	The facial masticatory mucosa (attached gingiva) is narrowest on which mandibular tooth? 1. First molar 2. Second molar 3. First premolar 4. Central incisor	The correct choice is 3. The narrowest zones of attached gingiva are located at the mandibular and maxillary first premolars. Choice #4: The widest zones of attached gingiva are found in the maxillary and mandibular incisor regions. Of course, these facts are only true in a normally aligned, periodontally healthy dentition.
	The glenoid fossa is an oval cavity or a depression in the 1. maxilla, just anterior to the malar process. 2. temporal bone, just anterior to the auditory canal. 3. mandible, just posterior to the internal oblique ridge.	The correct choice is 2. The glenoid or articular fossa is located in the temporal bone just anterior to the auditory canal. It is the depression into which the mandibular condyle fits to form the temporomandibular joint.
	The healthy free gingiva aids in the selfcleansing process by 1. directing food particles toward the occlusal surface. 2. forcing particles away from the proximal space. 3. deflecting particles away from the free gingiva onto the interdental papillae. 4. adhering closely to the tooth surface below the height of contour of the cervical enamel.	The correct answer is choice 4. The free gingiva when healthy and not inflamed forms a snug fitting soft tissue collar around the tooth. It prevents food and debris from entering the sulcus. It cannot direct food to the occlusal surface, choice 1. This is done partially by the cheeks and tongue. Choices 2 and 3 are also incorrect. Gingiva cannot force food particles in any direction as it is not a movable tissue. So it does not force food either into the interproximal area or away from it. Note also that forcing food interproximally would not aid the self cleansing process but instead would make self cleansing more difficult. So the correct answer to question is choice 4.
	The largest incisal/occlusal embrasure is located between which of the following teeth? A. Maxillary central and lateral incisors B. Mandibular central and lateral incisors C. Maxillary lateral incisor and canine D. Mandibular lateral incisor and canine E. Maxillary canine and first premolar	The correct answer is choice C. Small incisal embrasures are noted between incisors (choice A and B) due to the high contact areas and right angle-type line angles at the mesio-incisal and disto-incisal. The low contact between the lateral incisor (middle third) and canine (junction of incisal and middle third) makes for a large incisal embrasure there. We do not find a large embrasure on the mandibular counterparts because of the higher contact area of the incisor and canine in that arch (incisal third on both teeth). Likewise, the contact of the maxillary first premolar (on the mesial) is high (incisal third).
	The lingual cusp(s) on which of the following mandibular posterior teeth is (are) approximately 2/3 the height of the respective facial cusp(s)? A. First premolar B. Second premolar C. First molar D. Second molar E. Third molar	The correct answer is choice A. The mandibular tooth which has the most noticeable size difference between its buccal and lingual cusps is the mandibular first premolar. The tooth is very canine-like in form and unlike the three other premolars which have buccal and lingual cusps of similar size.
	The lingual cusps of a mandibular first molar must be restored to accommodate 1. centric relation. 2. working movement. 3. non-working movement. 4. protrusive position. 5. maximum intercuspation.	The correct answer is choice 2. Lingual cusps of mandibular molars are nonsupport cusps. The supporting cusps, the buccal cusps of mandibular teeth and lingual cusps of maxillary teeth are involved in both centric occlusion or maximum intercuspation. choice 5. and centric relation or retruded contact. choice 1 . Nonsupport cusps, such as mandibular linguals, are not involved. They will be involved in working movements. choice 2. For example, in a left working movement, the mandible shifts left and the lingual cusps of the left mandibular teeth will be involved in chewing. On the nonworking side, the right side in this case, the lingual cusp moves left away from contact and are not involved. So choice 3 is incorrect. Choice 4 is incorrect. In protrusive movements anterior teeth contact while posterior teeth separate. Lingual cusps of mandibular teeth are not involved. So the correct answer to question is choice 2 .
	The most external layer of alveolar bone is the: A. Spongy bone B. Spicule bone C. Cortical bone D. Woven bone E. Cribriform plate	The correct answer is choice C. Cortical bone refers to the outer layer of compact bone (usually with Haversian systems). Inner bone is usually spongy, with spicules of bone surrounded by marrow, and the spongy bone is not organized into Haversian systems. The term bundle bone refers to cortical bone with embedded collagen fibers, as in the periodontal ligament. Woven bone refers to early stages of bone formation by the intramembranous method. Remember that bone is formed intramembranously on a primitive connective tissue model, or through bony replacement of a cartilagenous model.
	The most symmetrical primary tooth, when viewed from the labial or lingual, is the: A. Maxillary central B. Maxillary lateral C. Mandibular central D. Mandibular lateral	The correct answer is choice C. The most symmetrical primary tooth, when viewed from the labial or lingual is the mandibular central incisor. The incisal edge is straight and horizontal. The mesio-incisal and disto-incisal angles are close to 90 degrees. In the mandibular lateral, the body of the crown is slightly rotated, and the incisal edge tilts downward distally. The maxillary central incisor has a decidedly rounded disto-incisal angle, as opposed to the sharp mesio-incisal angle. This characteristic is even more pronounced in the maxillary lateral, so both of these teeth are not symmetrical in a labial or lingual view.
	The parotid duct is called A. Stensen's duct, and empties near the maxillary second premolar B. Wharton's duct and empties through the floor of the mouth C. Wharton's duct and empties near the maxillary second molars D. Stensen's duct and empties near the mandibular second molars E. Stensen's duct and empties near the maxillary second molars	The correct answer is choice E. Stensen's duct empties the parotid gland into the buccal vestibule near the location of the buccal side of the maxillary second molar. Wharton's duct empties the submandibular gland, and some secretions from the sublingual gland, into the floor of the mouth underneath the tongue. The sublingual gland empties into the floor of the mouth through a series of openings in the plica sublingualis.
	The periodontal ligament fibers are primarily composed of which of the following connective tissues? A. Hyaline B. Elastic C. Collagenous D. Fibrocartilagenous	C. Collagenous The correct answer is choice C. The periodontal ligament fibers are primarily composed of collagen. Hyaline cartilage is found on bone joint surfaces, in the trachea and nose, elastic connective tissue can be found in walls of arteries, and fibrocartilagenous tissue in many areas of the body. The collagen fibers of the periodontal ligament (known as principal fibers) connect the cementum of the tooth root to the alveolar bone.
	The premolar that most frequently has a single central pit is the 1. maxillary first. 2. maxillary second. 3. mandibular first. 4. mandibular second.	4. mandibular second. The correct choice is 4. The mandibular second premolar typically has a Y-shaped groove pattern with mesial, distal and lingual grooves intersecting in a single central pit. The incorrect choices: Choice #I : The maxillary first pre-molar usually does not have a central pit, but a central groove with mesial and distal pits at each end. This is also true of choice #2, the maxillary second premolar, although a variation of the occlusal surface may be seen where the typical groove pit pattern is replaced by a single central pit. Choice #3: The mandibular first premolar typicaily has mesial and distal pits separated by the transverse ridge joining the buccal and lingual cusps.
	The primary maxillary canine is usually exfoliated between the ages of 1. 6 and 7 years. 2. 8 and 9 years. 3. 10 and 11 years. 4. 12 and 13 years.	3. 10 and 11 years. The correct answer is choice 3. Primary maxillary canines are usually exfoliated between ages 10 and 11. Let's review exfoliation of other primary teeth. Primary central incisors are generally lost at approximately age 6 for mandibulars and age 7 for maxillaries. Laterals are lost at approximately 7 for mandibular and 8 for maxillaries. Canines are lost at about 10 for mandibular and 11 for maxillary. First molars are lost at approximately 10 for both arches and second molars at approximately 11 for both arches. As a general rule, mandibular teeth are lost first although they are at approximately the same time for the molars. So the correct answer to question is choice 3.
	Prominent cervical ridges or bulges are noted on which surfaces of primary teeth? A. Maxillary first molar B. Maxillary second molar C. Mandibular first molar D. Mandibular second molar	C. Mandibular first molar The correct answer is choice C. The primary mandibular first molar has the most prominent buccal cervical ridge. The "pot belly" is most visible as the tooth is viewed from the mesial side. It is also seen prominently on occlusal view as a bulge on the mesial-buccal.
	The primary purpose of dental pulp is: A. Sensation B. Proprioception C. Enamel formation D. Dentin formation E. Inflammatory response	D. Dentin formation The correct answer is choice D. The odontoblasts, present in the outer layer of the pulp tissue, produce dentin. Dentin is the primary structural material of teeth, and attaches to both other dental tissues, cementum and enamel. No pulp means no dentin, and no dentin means no teeth! Some of the other functions listed are secondary. Sensation, in particular of pain, is a protective function, and can help prevent people from doing damage to the teeth. Proprioception, in general, is viewed as a protective response. Pulp can possibly be viewed as having a slight proprioceptive function. Proprioception is defined as the sense of position or space of a body part. Jaw position is determined partially by sensation of tooth contact, which is felt through the periodontal ligament, and to a lesser extent, through the pulp. This would hardly be the major function of pulp tissue. Enamel is formed by ameloblasts, not odontoblasts. Ameloblasts are never located in the pulp. Inflammatory response in the tooth pulp is brief and destructive, due to the confined space inside the pulp cavity. Little repair can occur through inflammation, and prolonged inflammation usually leads to pulpal necrosis. So inflammation is certainly not a major function of the pulp.
	The proximal contact of posterior teeth creates wear patterns that eventually cause 1. gingival recession. 2. increased length of clinical crowns. 3. decreased length of anatomic crowns. 4. reduced interproximal embrasure spaces.	4. reduced interproximal embrasure spaces. The correct answer is choice 4. Slow gradual wear occurs interproximally at the contact point of adjacent posterior teeth. As this occurs over a lifetime, the mesiodistal width of the teeth become slightly less. The teeth become closer and the interproximal embrasure space becomes narrower. Choice 1 is incorrect because interproximal wear on teeth would not have a direct impact on gingival recession. Gingival recession is often related to periodontal disease andlor traumatic abrasion of the gingiva. Choices 2 and 3 are incorrect. Wear between teeth on the mesial and distal directions will not cause changes in occlusal or cervical height. As a reminder, anatomic crown is defined as the area of the tooth above the cementoenamel junction while clinical crown is that area of the tooth visible in the mouth above the gingival margin. Anyway, the correct answer to question is choice 4.
	The root tip most likely to be forced into the maxillary sinus during surgical removal is that of a 1. maxillary first premolar. 2. permanent maxillary canine. 3. permanent maxillary first molar. 4. permanent maxillary central incisor. 5. primary maxillary second molar at age 12.	3. permanent maxillary first molar. The correct answer is choice 3. Maxillary first molar roots are most in danger of entering the maxillary sinus. In general, the three teeth in the vicinity of the sinus are the second premolar. first molar and second molar. The first molar root is more likely to enter the sinus than roots of the other two teeth. Choices 1. 2 and 4 are all incorrect because they are not normally located near the sinus. Choice 5 is incorrect because a primary maxillary second molar which will be replaced by a permanent second premolar. It usually exfoliates by age 17 and if not exfoliated will certainly have most of its root resorbed by that age. So the correct answer to question is choice 3.
	The root tip MOST likely to be forced into the maxillary sinus during surgical removal is that of a maxillary A. central incisor. B. canine. C. first premolar. D. first molar.	A. central incisor. The correct answer is choice D. The maxillary sinus is a membrane lined air space found in the maxilla. The tooth nearest to the sinus in most people is the maxillary first molar. During extractions, a root of this tooth can sometimes be accidentally forced into the sinus through thin bone or membrane. Although a majority of tooth roots forced into the sinus are from the first molar, a small number are from the second molar, and an even smaller number from the second premolar. The other teeth listed are too far anterior.
	The spacing between anterior teeth in a 5-year-old child is MOST frequently caused by A. the presence of an excessive maxillary anterior frenum. B. the pressure from succedaneous teeth. C. thumb-sucking. D. tongue thrusting. E. the growth of the dental arches.	E. the growth of the dental arches. The correct answer is choice E. Spacing is common in the primary dentition. Remember that the maxilla and mandible must both grow sufficiently to contain the larger size of the permanent dentition, as compared to the smaller primary dentition. The other choices listed CAN cause spacing. An excessive anterior frenum can prevent the maxillary anteriors from contacting. The pressure from permanent teeth erupting may move the primary teeth at various angles. Thumb sucking and tongue thrust can also move anterior teeth apart. However the MOST COMMON cause is normal arch growth to accommodate the permanent teeth.
	The spacing between anterior teeth in the primary dentition is most frequently caused by 1. thumb-sucking. 2. tongue thrusting. 3. the growth of the dental arches. 4. the pressure from succedaneous teeth.	3. the growth of the dental arches. The correct answer is choice 3. Spacing between primary teeth and lack of contact between them is a natural, normal condition and not due to any parafunctional habits such as thumb sucking or tongue thrusting. So choices 1 and 2 are incorrect. As the arches grow in the child, the previously positioned anterior teeth will become farther apart and additional needed space for the wider permanent teeth will be provided. So choice 3 is correct. Choice 4 is incorrect. Succedaneous teeth are those permanent teeth which will eventually replace primary teeth. They include the incisors, canines and premolars. However, they do not pressure the primary dentition in any way which causes spaces between primary teeth. So the correct answer to question is choice 3.
	The tissue found above the condylar head and below the articular fossa of the TMJ is called the A. acapsule B. temporomandibular ligament C. articular disk D. sphenomandibular ligament E. lateral pterygoid muscle	C. articular disk The correct answer is choice C. The articular disk is the piece of fibrous connective tissue that acts as a cushion between the condylar head and the articular (glenoid) fossa of the temporal bone. It also separates the upper and lower compartments of the joint. The articular capsule is the fibrous connective tissue structure that surrounds the entire joint structure. The temperomandibular ligament, also known as the lateral ligament, connects the capsule to the zygoma and neck of the mandible. The sphenomandibular ligament connects the sphenoid bone to the lingual and ramus of the mandible, whereas the stylomandibular ligament connects the styloid process of the temporal bone to the posterior border of the ramus. These two ligaments are sometimes assigned a slight protective function. The superior head of the lateral pterygoid muscle inserts into both the articular disk and capsule.
	The tooth showing the LEAST amount of anatomic variability is the: A. Maxillary third molar B. Mandibular first molar C. Maxillary lateral incisor D. Mandibular third molar	B. Mandibular first molar The correct answer is choice B. Mandibular first molars, like all teeth, have a significant number of anatomical variations. However, the other three teeth listed are considered to be the most variable in the mouth. Third molars have extreme varieties in crown shape, root shape, root number etc. They may look like first or second molars, or may be mere pegs. They are often missing. Variation in maxillary laterals is extreme as well, and is discussed in question 13. Mandibular first molar variations are less extreme. Some common ones include: 4 cusped instead of 5 (no distal cusp), and large extremely distally curved mesial roots. A rare variety may have 2 distal roots.
	The wear facets on the incisal edges of the mandibular lateral incisors are caused by occlusion with the 1. maxillary central incisors only. 2. maxillary central and lateral incisors 3. maxillary lateral incisors and canines.	2. maxillary central and lateral incisors The correct answer is choice 2. Mandibular lateral incisors are situated slightly mesially to the maxillary lateral. As a rule, the mandibular teeth are one half tooth mesial to the maxillary so the mandibular lateral will contact the mesial part of the maxillary lateral and the distal part of the maxillary central, both areas, of course, on the lingual surface of the maxillary teeth. So the correct answer to question is choice 2.
	What condylar movement is performed as the mandible moves from a pure protrusive movement from maximum intercuspal position to a maximum protruded position? A. Translation B. Rotation C. Hinge D. Oblique E. Medial and foward	A. Translation The correct answer is choice A. The mandible moves by rotation around the axis of the temperomandibular joint and also by translation (movement of the whole body of the mandible). In protrusion, the lateral pterygoids act together to pull the mandible forward without rotation. Rotation is partly involved in both opening and in working movements, but not in protrusion.
	What is the most reliable and consistent way to distinguish maxillary first, second and third molars? A. number of cusps B. size of the distobuccal cusp C. inclination of the roots D. extent to which the roots are fused E. size of the distolingual cusp	E. size of the distolingual cusp The correct answer is choice E. The maxillary molars differ from each other in several ways, although the general patterns of morphology are shared. As you go from 1st to 2nd to 3rd, the teeth become smaller in overall dimension. Most maxillary molars have four cusps, however, the first molar may have a 5th cusp, the Carabelli cusp. This cusp is sometimes large and cusp-like, but sometimes small and unnoticeable. It is sometimes referred to as the Carabelli trait, and is highly variable. The Carabelli trait can be found on the mesiolingual cusp. The third molar may sometimes have a distolingual cusp so reduced in size, that the tooth is essentially three-cusped. So, sometimes, the first, second and third molars might have 5,4, and 3 cusps respectively. This is not always the case, and cannot reliably differentiate between the teeth. Third molars commonly have fused roots, however, second and first molars rarely do. This will not distinguish all three molars from each other. Roots tend to incline more distally from 1st to 2nd to 3rd molar, however, this is not universally found. The most reliable way to distinguish the three molars is by the size of the distolingual cusp. The MB, ML and DB cusps in all maxillary molars form the trigon, or major cusp triangle. The distolingual cusp by itself, is the talon cusp, and gets progressively smaller from first to second to third molar. As stated previously, it may be absent in third molars.
	What is the most reliable and consistent way to distinguish maxillary first, second and third molars? A. number of cusps B. size of the distobuccal cusp C. inclination of the roots D. extent to which the roots are fused E. size of the distolingual cusp	E. size of the distolingual cusp The correct answer is choice E. The maxillary molars differ from each other in several ways, although the general patterns of morphology are shared. As you go from 1st to 2nd to 3rd, the teeth become smaller in overall dimension. Most maxillary molars have four cusps, however, the first molar may have a 5th cusp, the Carabelli cusp. This cusp is sometimes large and cusp-like, but sometimes small and unnoticeable. It is sometimes referred to as the Carabelli trait, and is highly variable. The Carabelli trait can be found on the mesiolingual cusp. The third molar may sometimes have a distolingual cusp so reduced in size, that the tooth is essentially three-cusped. So, sometimes, the first, second and third molars might have 5,4, and 3 cusps respectively. This is not always the case, and cannot reliably differentiate between the teeth. Third molars commonly have fused roots, however, second and first molars rarely do. This will not distinguish all three molars from each other. Roots tend to incline more distally from 1st to 2nd to 3rd molar, however, this is not universally found. The most reliable way to distinguish the three molars is by the size of the distolingual cusp. The MB, ML and DB cusps in all maxillary molars form the trigon, or major cusp triangle. The distolingual cusp by itself, is the talon cusp, and gets progressively smaller from first to second to third molar. As stated previously, it may be absent in third molars.
	When alveolar bone fuses to the cementum of a root, it is known as A. gemination B. ankylosis C. hypercementosis D. gomphosis E. dilaceration	B. ankylosis The correct answer is choice B. Ankylosis refers to fusion or union of cementum to tooth root. Clinically, this may be important because ankylosed teeth are difficult to extract, and bone may be removed with the root. Additionally, ankylosed teeth often fail to fully erupt and sometimes remain below the plane of occlusion as the surrounding teeth erupt normally. Gemination refers to two tooth crowns emerging from one root. Hypercementosis is a nonpathological condition of additional cementum being deposited on a root surface. It does not fuse with bone, however. A gomphosis is the term for the immovable joint between tooth and alveolar bone. It refers to a normal, nonankylosed state. Dilaceration refers to a sudden change in direction of a tooth root.
	When anesthetizing the mandibular arch, the inferoir alveolar nerve block is usually performed. However, local infiltration may be effective. It is most likely to be effective in the area of the: A. Molars B. Premolars C. Canines D. Incisors E. Local infiltration is generally effective throughout the arch.	D. Incisors The correct answer is choice D. The primary anesthetic injection for mandibular teeth for both restoration and extraction is the inferior alveolar nerve block. It is supplemented variously by the lingual nerve block, mental nerve block, long buccal nerve block or local infiltration. Local infiltration can occasionally be effective by itself in areas where thin bone (or very little bone) is present. The facial surface of mandibular incisors is composed of thin dentine and often is a site of periodontal disease, leaving even less bone than previously present. Extractions of mandibular incisors can sometimes be accomplished through local infiltraton alone. Mandibular bone is usually too thick in other areas of the arch.
	When compared with maxillary first premolars, the central developmental groove of maxillary second premolars is A. longer with less supplementary grooves. B. shorter with less supplementary grooves. C. longer with multiple supplementary grooves. D. shorter with multiple supplementary grooves.	D. shorter with multiple supplementary grooves. The correct answer is choice D. One of the differences in the occlusal views of maxilary first and second premolars is the groove pattern. First premolars tend to have longer central grooves, few or no supplemental grooves, and a predictable groove pattern. Second premolars have shon central grooves (sometimes reduced to a pit), many supplemental grooves, and an unpredictable groove pattern. Sometimes the supplemental grooves will form an X radiating from the central pit-like groove. Other anomalies include an occasional distal transverse ridge.
	When hypoplasia of primary teeth is found but is limited to cusp tips and incisal edges of incisors, canines, and molars, it is most likely due to A. fluorosis B. insufficient systemic fluoride C. tetracycline intake D. metabolic disturbance in embryonic period E. metabolic disturbance in infancy	D. metabolic disturbance in embryonic period The correct answer is choice D. Let's rule out choices. Fluorosis, or staining from excess systemic fluoride, is generalized discoloration and blotchiness throughout the enamel. Tetracycline staining is generalized yellow-brownish staining throughout the dentin and enamel (moreso dentin). There is no hypoplasia in either condition. Insufficient fluoride intake will affect caries susceptibility but does not have a distinctive clinical appearance. Hypoplasia is usually caused by a metabolic disturbance. The effect of the disturbance depends on timing. The crown tips and incisal edges of primary incisors, canines, and molars are formed from three to six months in utero, and crowns are completed during the first two (incisor) to 10 (second molar) months. So metabolic disturbances in infancy occur after the crown tips and incisal edges of these teeth are already formed.
	Which extrinsic muscle of the tongue functions to retract the tongue? A. Hyoglossus B. Styloglossus C. Genioglossus D. Palatoglossus	B. Styloglossus The correct answer is choice B. Hyoglossus, attached to the hyoid bone, tends to pull the side of the tongue downward and also aids in retraction. With genioglossus, it can depress the tongue. Styloglossus is attached to the styloid process and stylomandibular ligament. It is the main retractor of the tongue, and can also elevate it. With genioglossus, it can raise the sides of the tongue and leave the middle depressed. Genioglossus connects to the mental spine of the mandible and can depress the tongue. Anterior fibers can retract the tongue tip while posterior fibers can protrude it. Palatoglossus attaches to the palatine aponeurosis. It can help to pull the posterior part of the tongue upwards.
	Which incisor is MOST frequently markedly concave on the lingual surface? A. Maxillary central B. Mandibular central C. Maxillary lateral D. Mandibular lateral	C. Maxillary lateral The correct answer is choice C. The maxillary lateral incisor is one of the most highly variable teeth in the mouth. It has a high incidence of being congenitally missing, can often appear in a peg form, and has a large variety of shape and size anomalies. A concave lingual surface is found commonly, and may range from small pit to deep depression. In clinical dentistry, large lingual pits or depressions on these teeth are sometimes restored with sealant or composite fillings.
	Which muscle is primarily involved when the mandible makes a RIGHT WORKING movement? A. Right medial pterygoid B. Left medial pterygoid C. Right lateral pterygoid D. Left lateral pterygoid	D. Left lateral pterygoid The correct answer is choice D. In a right working movement, the mandible moves to the right side. This movement occurs as the left lateral pterygoid pulls the left condyle forward while the right condyle stays stationary. In- general, lateral pterygoid muscles move the mandible forward (protrude) when acting jointly. They also act jointly to open the jaw (depress the mandible). When acting separately, the left lateral pterygoid moves the jaw right, while the right later pterygoid moves the jaw left. Medial pterygoids are closing muscles (elevators) and are not involved in protrusion or lateral movement.
	Which of the following anatomic features of a maxillary lateral incisor will most likely complicate root planing? 1. A root bifurcation 2. A mesial concavity 3. A distolingual groove 4. An extreme distal cervical line curvature	3. A distolingual groove The correct answer is choice 3. In the maxillary lateral incisor, which is probably the most variable tooth in the mouth, a variation exists where a groove may cross from the cingulum over the mesial or distal margin onto the surface of the crown and down the mesial or distal surface of the root. This is known as a lingual marginal groove or distal lingual groove or mesial lingual groove. The groove is often deep and narrow and extremely difficult to scale or root plane. So choice 3 is correct. Choice 1 is incorrect as the maxillary lateral is invariably single rooted and does not contain a bifurcation. Choice 2 is incorrect. The maxillary lateral root does not normally possess a mesial concavity and if present, would not be as difficult to root plane as the narrow distal lingual groove. Choice 4 is incorrect. In general, the cervical curve of the lateral incisor is less than that of the central. However, the CEJ cervical line curvature does not have great significance for root planing. So the correct answer to question is choice 3.
	Which of the following BEST describes the Curve of Spee? A. The spherical configuration of the composite arrangement of the occlusal surfaces and incisal edges of the teeth of both dental arches B. The facial-lingual curvature resulting from the facial cusps being the longest in the mandibular arch, and the lingual cusps being the longest in the maxillary arch C. The anterior-posterior curvature of the occlusal surfaces of the teeth, as seen in a facial view D. The inclination of the teeth in relation to the vertical long axis of the body E. The composite arrangement of the facial crown surface heights of contour of all the teeth in any quadrant	C. The anterior-posterior curvature of the occlusal surfaces of the teeth, as seen in a facial view The correct answer is choice C. The curve of Spee is an imaginary curve connecting the cusp tips of the mandibular teeth as seen from the lateral (facial side of the posterior teeth). The curve of Spee prevents protrusive interferences. The curve of Wilson is an imaginary curve connecting cusp tips as seen from the front of the face. This curvature helps to eliminate lateral interferences. These curves are part of a theory known as the spherical theory of occlusion.
	Which of the following best describes the root lengths of a maxillary molar? 1. The lingual root is the longest and the distofacial root is the shortest. 2. The lingual root is the longest and the mesiofacial root is the shortest. 3. The mesiofacial root is the longest and the distofacial root is the shortest. 4. All roots are the same length.	1. The lingual root is the longest and the distofacial root is the shortest. The correct answer is choice 1. Maxillary molars are three rooted with mesial buccal or mesial facial, diaobuccal or distofacial, and palatal or lingual roots. Palatal is longest and generally curved and widest when viewed from the buccal or lingual. This is also termed flattened buccal lingually. The mesial buccal is second largest, not usually curved and widest when viewed proximally or mesiodistallly flattened. The distobuccal is usually shortest. So the correct answer to question is choice 1.
	Which of the following can adversely affect the self-cleaning quality of a dentition in normal alignment? A. Contact of adjacent teeth B. Efficient use of a toothbrush C. Friction of food material during mastication D. Too great a contour of the cervical enamel ridge	D. Too great a contour of the cervical enamel ridge The correct answer is choice D. Contact of adjacent teeth leads to a healthy self-cleansing of the teeth by preventing interproximal food impaction. Efficient use of a toothbrush will help the self-cleansing properties of teeth by aiding in plaque removal. Friction of rough or abrasive foods can also scrape plaque off of teeth. Prominent cervical enamel ridges or bulges can interfere with self-cleansing actions of the mouth by trapping plaque underneath the bulge, near the gingival margin. In prosthodontics, this is similar to overcontouring of prosthetic crowns which can lead to the same negative result.
	Which of the following characterizes a temporomandibular joint? 1. It is immune to arthritis. 2. It has one synovial cavity. 3. It has two synovial cavities. 4. It has no synovial cavities.	3. It has two synovial cavities. The correct answer is choice 3. The temperomandibular joint has an unusual structure in which two compartments exist, an upper and a lower. The upper compartment exists in the area above the articular disk and below the articular or glenoid fossa. The lower compartment exists between the articular disk and the head of the mandibular condyle. Both compartments are synovial cavities in which synovial fluid eases the motion of the joint. In general, rotational movement is thought to involve primarily the lower compartment while translational movement involves primarily the upper compartment. Choices 2 and 4 are incorrect as noted already. Choice 1 is incorrect as arthritis is an occasional cause of TMJ pain and dysfunction. Arthritis is sometimes linked to trauma of the TMJ. So the correct answer to question is choice 3.
	Which of the following covers the articulating osseous structures of the temporomandibular joint? 1. Synovial membrane 2. Hyaline cartilage only 3. Vascular fibrous connective tissue 4. Dense avascular fibrous connective tissue 5. Dense avascular elastic connective tissue	4. Dense avascular fibrous connective tissue The correct choice is 4. The articulating surfaces of the temporomandibular joint are covered by a dense avascular fibrous connective tissue. The articular disk is also made up of dense fibrous connective tissue. The incorrect choices: Choice #1: The synovial membrane forms the joint capsule of the temporomandibular joint and secretes the synovial fluid. Choice #2: The temporomandibular joint is one of very few joints in the body that does not have hyaline cartilage on its articular surfaces. The head of the condyle has some hyaline cartilage where bone growth takes place, under the articulating fibrous connective tissue. Choice #3: Vascular connective tissue makes up some of the periphery of the articular disk, but its main portion is avascular as is the fibrous connective tissue of the articulating surfaces. So, once again, the correct answer is 4.
	Which of the following groups of fibers of the periodontal ligament is most likely to be found in the middle third of the root? 1. Apical 2. Oblique 3. Horizontal 4. Transseptal 5. Alveolar crest	2. Oblique The correct answer is choice 2. Oblique fibers of the periodontal ligament are directed from the alveolar bone downward obliquely at an angle toward the cementum. They are found primarily in the middle third of the root. Choice 1, apical fibers, as the name implies are found primarily in the apical third of the root. Horizontal fibers which horizontally rather than obliquely connect bone to cementum are found primarily in the coronal third of the root. Transeptal fibers connect the cementum of two adjacent teeth above the level of alveolar bone and thus are also in the coronal third of the root. Finally, alveolar crest fibers connect obliquely from the coronal area of the cementum to the apical crest. They are also found in the coronal third of the root. So from the top down, our answers would be apical, middle, coronal, coronal, and coronal, and the correct answer to question is choice 2.
	Which of the following incisal angles of maxillary teeth exhibits the greatest convexity? A. Mesioincisal of the central B. Distoincisal of the central C. Mesioincisal of the lateral D. Distoincisal of the lateral	D. Distoincisal of the lateral The correct answer is choice D. It is best to view the term convexity as it refers to roundness, or an arc-like shape. In general both the mesio-incisal and disto-incisal line angles of the maxillary central incisor are more angular and less rounded than the corresponding line angles of the lateral. Within the lateral, the disto-incisal angle is more rounded than that of the mesio-incisal. Think of the maxillary lateral as a smaller more delicate and rounded version of the central.
	Which of the following incisors has its mesial and distal contact areas at the same incisocervical level? A. Maxillary central B. Mandibular central C. Maxillary lateral D. Mandibular lateral	B. Mandibular central The correct answer is choice B. In maxillary centrals, the mesial contact (near the mesio-incisal line angle) is more incisal ( than is the distal contact. Likewise, in the maxillary lateral, the mesial contact is more incisal (near the junction of the incisal and middle thirds), while the distal contact is near the middle of the crown. The mandibular central incisor is generally symmetrical in crown shape when viewed from the labial, and this includes contact points which are both located in the incisal thirds. In the mandibular lateral, the distal contact area is more cervical.
	Which of the following is correct regarding the contact relationship of maxillary central incisors and maxillary lateral incisors? A. Contacts are centered faciolingually. B. Contacts are centered incisocervically. C. Facial embrasures are wider than lingual embrasures. D. lncisal embrasures are larger than gingival embrasures.	A. Contacts are centered faciolingually. The correct answer is choice A. When viewed from the occlusal, the contact area of the maxillary central and lateral is centered in the labio-lingual direction. The contact is not centered inciso-cervically, being located more toward the incisal, at the junction of the incisal and middle thirds. Facial embrasures are fairly flat, while the lingual are deeper. Gingival embrasures extend up to the contact point, which is incisally located. Therefore they are larger than the rather small incisal embrasures, located incisal to the contact point.
	Which of the following is NOT found in mature pulp? A. neurons B. blood vessels C. leukocytes D. cells capable of forming primary dentin E. odontoblasts	D. cells capable of forming primary dentin The correct answer is choice D. Pulp is a connective tissue containing fibroblasts, blood vessels, nerves (carrying pain sensation), and odontoblasts. Since pulp contains blood vessels, it will also have leukocytes. Odontoblasts will line the perimeter of the pulp, and are capable of producing dentin. However, this dentin is of the secondary or reparative variety. Primary dentin is that which is first produced as the tooth is originally formed. Primary dentin cannot be produced by a mature pulp already inside a tooth.
	Which of the following is the first succedaneous tooth? A. Maxillary central incisor B. Mandibular central incisor C. Maxillary lateral incisor D. Mandibular first molar	B. Mandibular central incisor The correct answer is choice B. The definition of a succedaneous tooth is one that replaces another tooth. Therefore, all permanent molars are NOT succedaneous. The first primary tooth to be lost is generally the mandibular central, so the first succedaneous tooth is the permanent mandibular central incisor.
	Which of the following is the longest root? A. Root of a maxillary canine B. Root of a mandibular canine C. Lingual root of a maxillary first molar D. Lingual root of a maxillary second molar E. Mesial root of a mandibular first molar	A. Root of a maxillary canine The correct choice is 1. The maxillary canine has the longest root of any tooth in the dentition as you will find out when you try to extract one. It averages 17 millimeters from cemento-enamel junction to apex. Choice #2: The mandibular canine has an average cemento-enamel junction to apex root length of about 15 mm. Choices 3 and 4: The lingual roots of the maxillary first and second molars are the longest of the three roots in the molars and they average 12 and 11 mm, respectively. And choice #5: The mesial root of the mandibular first molar averages 14 mm. from CET to apex and is roughly the same length as the distal root.
	Which of the following jaw positions is determined almost exclusively by the behavior of the mandibular musculature? 1. Postural 2. Terminal 3. lntercuspal 4. Retruded contacting 5. Protruded contacting	1. Postural The correct choice is 1. The postural or rest position, where freeway space is present between the teeth, is primarily determined by the musculature. Choice #2: The terminal position is mostly determined by how far the condyle can go posteriorly in the articular fossa. Choices 3,4 and 5: Any position where the teeth are in contact is primarily determined by the teeth themselves.
	Which of the following jaw positions is determined almost exclusively by the behavior of the musculature? A. Postural B. lntercuspal C. Retruded contact D. Protruded contact	A. Postural The correct answer is choice A. Three of the four positions listed are determined by a combination of muscular and dental factors. lntercuspal position is held in place by muscles in a position determined by the intercuspation (occlusion) of the two arches. The muscles may pull the mandible forward or backward into protruded or retruded contact positions, but the actual position is again determined by how the teeth intercuspate (occlude). Postural or rest position is determined by musculature alone. Teeth are slightly out of contact and the distance between the arches is determined by the habitual position or comfort level of these muscles.
	Which of the following ligaments has an outer oblique portion which limits the extent of jaw opening and initiates translation of the condyle down the articular eminence? A. Capsular B. Collateral C. Stylomandibular D. Temporomandibular	D. Temporomandibular The correct answer is choice D. The temperomandibular (lateral) ligament reinforces the lateral aspect of the joint capsule. Its other functions include limiting the amount of opening, limiting the amount of retrusion, and due to its initial tautness, initiating the downward motion of the condyle. The capsular ligament surrounds the disc and synovial compartments of the joint. The stylomandibular ligament connects the styloid process and the ramus. The sphenomandibular ligament connects the sphenoid bone to the ramus. The function of these ligaments is not clear. They are sometimes referred to as collateral (accessory) ligaments.
	Which of the following maxillary teeth has the largest cervico-occlusal crown height? A. First premolar B. Second premolar C. First molar D. Second molar	A. First premolar The correct answer is choice A. The maxillary first premolar is notable for its large cervico-occlusal length (height). It is generally slightly larger than the second premolar. Both premolars are larger in height than the molars, which decrease in crown height from the first to the second to the third.
	Which of the following molars MOST frequently have only 3 cusps? A. Maxillary first B. Mandibular first C. Maxillary third D. Mandibular third	C. Maxillary third The correct answer is choice C. The maxillary third molar often lacks a distobuccal cusp. This cusp is generally smaller as one goes from the first to the second to the third molar. This leaves the third molar as a three cusped tooth. The maxillary first usually has four cusps, or five if a Carabelli cusp is present. The mandibular first usually has five cusps (including a small distal cusp). A mandibular third usually resembles the mandibular second in having 4 cusps (no distal cusp such as that on the first mandibular).
	Which of the following muscles is NOT an elevator of the mandible? 1. Temporal 2. Masseter 3. Medial pterygoid 4. Lateral pterygoid	4. Lateral pterygoid The correct choice is 4. The lateral pterygoid acts to help open or depress the mandible as well as being active in lateral mandibular movements. The digastric muscles also assist in depressing the mandible. Choices 1, 2 and 3: The temporal, masseter and medial pterygoid muscles all elevate or close the mandible.
	Which of the following normally describes the general crown form of canines when viewed from the facial or lingual aspect? A. 3-sided B. 4-sided C. 5-sided D. 6-sided E. 7-sided	C. 5-sided The correct answer is choice C. The labial or lingual view of the maxillary canine crown form is pentagonal. The bottom of the pentagon is the CEJ. From the CEJ, the crown outline moves upward and outward on both the mesial and distal sides, until reaching the height of contour. Then, both sides turn inward and upward until reaching a point at the cusp tip.
	Which of the following normally describes the pulp cavity in a mesiodistal section of a maxillary canine? A. It exhibits 2 pulp horns. B. It is widest at its incisal limit. C. It is pointed at its incisal limit. D. It is widest at the midroot level. E. It is generally wider than in a faciolingual section.	C. It is pointed at its incisal limit. The correct answer is choice C. The pulp of the maxillary canine, in mesio-distal section, will follow the outline of the tooth. It will be highest and pointed underneath the buccal cusp, and slant cervically downward toward both the mesial and distal directions. It is widest at about CEJ level, or slightly below, and will be considerably wider buccolingually than mesiodistally.
	Which of the following occurs when the distofacial cusp of a permanent mandibular right first molar moves through the facial groove from the central fossa of the maxillary right first molar? A. Direct lateral excursion to the left B. Direct lateral excursion, to the right C. Direct protrusive mandibular excursion D. Lateral-protrusive excursion to the left E. Lateral-protrusive excursion to the right	B. Direct lateral excursion, to the right The correct choice is #2, a direct lateral excursion to the right. The distofacial cusp of the right mandibular first molar occludes in the central fossa of the right maxillary first molar and moves through the facial groove of the maxillary first molar in a right lateral excursion.
	Which of the following permanent posterior teeth has a mesial marginal ridge that is located more cervical than its distal marginal ridge? 1. Maxillary first premolar 2. Maxillary second molar 3. Mandibular first premolar 4. Mandibular second molar	3. Mandibular first premolar The correct answer is #3, the mandibular first premolar. This is the only tooth that exhibits a mesial marginal ridge more cervically placed than the distal marginal ridge. The mandibular first premolar is also the only tooth where the occlusal table is not roughly parallel to the occlusal plane. The occlusal table is tilted so far lingually that virtually the whole table is visible when the tooth is viewed from the lingual.
	Which of the following permanent teeth normally have a mesiolingual groove? A. Maxillary canine B. Maxillary first molar C. Mandibular first molar D. Mandibular canine E. Mandibular first premolar	E. Mandibular first premolar The correct answer is choice E. The mandibular first premolar is the only tooth to have a mesiolingual groove. It is found between the mesial marginal ridge and the mesiolingual cusp ridge. It begins in the mesial pit and crosses the marginal ridge and onto the proximal surface. This trait is highly variable. Note that a similar groove is NOT found on the distal side of this tooth or on the mandibular second premolar.
	Which of the following positions would yield the smallest measurement of vertical dimension? 1. Reverse overlap 2. Edge-to-edge 3. Retruded contact 4. Maximum intercuspation	4. Maximum intercuspation The correct answer is choice 4. Maximum intercuspation or centric occlusion is the position in which the teeth are most fully contacted with each other. As such the jaws are most fully closed and therefore the vertical dimension is the least. Choice 1.2 and 3 as not being in maximum intercuspation or contact. are going to be slightly more separated and at greater vertical dimension. Choice 1. reverse overlap. refers to a protruded mandible position. Choice 2. edge to edge, refers to the meeting of the mandibular and maxillary anterior incisal edges. At this point. posterior teeth will be slightly separated. Choice 3. retruded contact or centric relation, is a mandibular position slightly posterior to maximum intercuspation. But again, slightly more separated and thus at slightly greater vertical dimension. So the correct answer to question is choice 4.
	Which of the following premolars frequently has only one pulp horn? 1. Maxillary first 2. Mandibular first 3. Maxillary second 4. Mandibular second	2. Mandibular first The correct choice is 2. The mandibular first premolar has two cusps, but the lingual is so small that it usually has no pulp horn. The maxillary premolars, choices 1 and 3, have two well-developed cusps, each with its own pulp horn. The mandibular second premolar, choice 4, generally has three cusps and two pulp horns: buccal and lingual.
	Which of the following primary molars has an occlusal surface that most often bears the greatest resemblance to a premolar? 1. Maxillary first 2. Maxillary second 3. Mandibular first 4. Mandibular second	1. Maxillary first The correct choice is 1. The primary maxillary first molar bears the closest resemblance to a premolar. There are usually three cusps, but the mesiobuccal and mesiolingual cusps are much more prominent than the distobuccal which may even be absent. The incorrect choices: Choice 442: The primary maxillary second molar resembles the permanent maxillary first molar from the occlusal. Choice #3: The primary mandibular first molar does not really resemble any of the permanent teeth. Choice #4: The primary mandibular second molar resembles the permanent mandibular first molar.
	Which of the following represents the geometric form of anterior teeth when viewed from the mesial or distal aspect? A. Rhomboidal B. Trapezoidal C. Elliptical D. Triangular E. Square	D. Triangular The correct answer is choice D. Not a great question, in our opinion, however triangular is better than the rest. An incisor, when viewed from the mesial or distal can be viewed as roughly triangular, with one side the lingual slope, the second side the lingual edge of the root, and the third side made up of the entire buccal surface, both root and crown. Rhomboidal and square are definitely not correct, as they imply four equal sides, and elliptical is oval, with no distinct sides. Trapezoidal implies two parallel and two nonparallel sides, and this is not true for a mesial or distal view of an incisor. So while it might be stretching things a bit to see this I tooth view as triangular, it is still a better answer than the others.
	Which of the following represents the largest cusp of the mandibular first molar? A. Distal B. Mesiofacial C. Mesiolingual D. Distofacial E. Distolingual	B. Mesiofacial The correct answer is choice B. The order of size of cusps in the mandibular first molars, from largest to smallest is:mesiobuccal, mesiolingual, distolingual. distobuccal and finally, distal. The distal can be remembered as the smallest simply by realizing that it is so small that it is often absent, so that one variety of mandibular first molar is a four cusped version. In mandibular second molars, cusps are much more equal in size.
	Which of the following represents the MOST common anatomic feature that complicates periodontal maintenance in a maxillary first premolar? A. Deep concavity on the mesial surface of the tooth B. Intermediate furcational ridge C. Mesiolingual developmental groove D. Excessive convexity of the facial root	A. Deep concavity on the mesial surface of the tooth The correct answer is choice A. On the mesial surface of the crown of the maxillary first premolar, there is a mesial developmental groove, which travels from the occlusal downward along the mesial crown surface, and then joins into the mesial root concavity, which extends down most of the mesial surface of the mesial root. This concavity often lends itself to plaque and calculus accumulation, overhanging restorations, and difficult cleaning of the area. Note that the mesiolingual developmental groove is found on the mandibular first premolar.
	Which of the following represents the normal eruption age (years) of the maxillary lateral incisors? A. 4-5 years B. 6-7 years C. 8-9 years D. 10-11 years	C. 8-9 years The correct answer is choice C. As a reminder, normal eruption times for the permanent incisors are: mandibular centrals at 6- 7 years. mandibular laterals at 7-8 years, maxillary centrals at 7-8 years and maxillary laterals at 8-9 years.
	Which of the following represents the tissue formed in response to stimuli produced by carious penetration of a tooth? A. Predentin B. Primary dentin C. Secondary dentin D. Interglobular dentin	C. Secondary dentin The correct answer is choice C. Secondary, or reparative, dentin, is formed in response to carious penetration or excessive mechanical stimulation (abrasion). It is sometimes viewed as a protective response. Predentin is non-mineralized precursor organic material laid down by odontoblasts. It is primarily collagen fibers. Primary dentin is all originally formed dentin in the tooth(excluding secondary dentin). Interglobular dentin refers to small uncalcified areas of dentin where collagenous matrix exists without mineralization.
	Which of the following roots is most likely to have a concavity on either or both its facial and lingual surfaces? 1. Root of a maxillary second premolar 2. Lingual root of a maxillary first molar 3. Mesial root of a mandibular first molar 4. Distal root of a mandibular second molar 5. Mesiofacial root of a maxillary first molar 6. Distofacial root of a maxillary first molar	2. Lingual root of a maxillary first molar The correct choice is 2. Of all the roots listed, only the lingual root of the maxillary first molar has a concavity on its lingual and/or facial surfaces. Choices 1, 3 and 4: The root of the maxillary second premolar and the mesial and distal roots of the mandibular molars are usually characterized by mesial and distal concavities down the sides of the roots. These concavities are most prominent on the maxillary second premolar and the mesial root of the mandibular molars. Choices 5 and 6: The mesiobuccal and distobuccal roots of the maxillary first molar generally do not exhibit any consistent concavities. They are slightly wider buccolingually than mesiodistally.
	Which of the following teeth has its mesial contact area located within the incisal or the occlusal one-third? 1. Maxillary canine 2. Maxillary first molar 3. Mandibular second premolar 4. Mandibular central incisor	4. Mandibular central incisor The correct answer is choice 4. The mesial surface of the mandibular central incisor contacts the mesial surface of the other mandibular central. They contact in the incisal third. All mandibular incisal contacts with each other or with the mesial of the canine are within the incisal third. Choice 1 is incorrect. Contact of the maxillary canine with the maxillary lateral incisor is in the middle third. Choice 2 is incorrect. Contact of the maxillary first molar with a maxillary second premolar is within the middle third. Choice 3 is incorrect. Contact of the mandibular second premolar with the mandibular first premolar is in the middle third. So the correct answer to question is choice 4.
	Which of the following teeth have long axes positioned with their root apices facial and their crowns lingual? A. Maxillary incisors B. Mandibular incisors C. Maxillary premolars D. Maxillary molars E. Mandibular molars	E. Mandibular molars The correct answer is choice E. The question looks for teeth that lean lingually. That is, the root tips point facially, and the crowns lingually. In general, both maxillary and mandibular incisors have their root tips facing lingually and their crowns facially. (Opposite to what the question is looking for). Maxillary premolars generally are straight, and not buccally or lingually inclined. Maxillary molars, like the incisors, lean so that their crowns tip facially and root apices palatally. Only mandibular molars,of the teeth listed, tip in the lingual direction, with facially located roots.
	Which of the following teeth have sharp demarcations between pulp chambers and pulp canals? 1. Mandibular canines 2. Maxillary lateral incisors 3. Maxillary first premolars 4. Mandibular second premolars	3. Maxillary first premolars The correct choice is 3. The maxillary first premolar generally has easily visualized beginnings of the pulp canals because 85% of the time, it has two canals, one each in the buccal and lingual roots. Choices 1. 2 and 4 are all single-rooted teeth, almost always with a single canal continuing apically from the pulp chamber. So it is difficult to see where the chamber ends and the single canal begins.
	Which of the following teeth in the permanent dentition normally have bifurcations? A. Mandibular canines B. Mandibular second premolars C. Maxillary molars and maxillary first premolars D. Mandibular molars and maxillary first premolars E. Maxillary first and second molars	D. Mandibular molars and maxillary first premolars The correct answer is choice D. Bifurcations are divisions of roots or root trunks into two sections. We should be looking here for two rooted teeth. The mandibular canine is generally single rooted, as is the mandibuar second premolar. Maxillary molars are generally three-rooted. Mandibular molars are generally two-rooted. So our answer is mandibular molars and maxillary first premolars usually have bifurcations.
	Which of the following teeth in the permanent dentition normally have trifurcations? 1. Mandibular molars only 2. Mandibular second premolars 3. Mandibular molars and maxillary first premolars 4. Maxillary molars and maxillary first premolars 5. Maxillary first and second molars and some maxillary third molars	5. Maxillary first and second molars and some maxillary third molars The correct choice is 5. The maxillary molars are the only permanent teeth that normally have trifurcations. To have a trifurcation in the root trunk, three roots must be present. Choice #1: Mandibular molars. normally having two roots. therefore have a bifurcation. Choice #2: Mandibular second pre-molars normally are single rooted. Choices #3 and 4: Maxillary first premolars usually have two roots and a bifurcation, although the bifurcation may be well down the roots towards the apices of the roots.
	Which of the following teeth is MOST likely to have a distal coronal concavity that can pose special problems in matrix placement? A. Maxillary first premolar B. Mandibular first premolar C. Maxillary first molar D. Mandibular first molar	C. Maxillary first molar The correct answer is choice C. The maxillary first molar may show a slightly flattened section of the crown in the cervical third of the distobuccal area. Note that the maxillary first molar often has a mesial concavity, as does the mandibular first molar, with a coronal concavity extending down to and meeting a root concavity.
	Which of the following teeth would most likely be congenitally absent? 1. Maxillary canine 2. Mandibular canine 3. Maxillary central incisor 4. Mandibular central incisor 5. Maxillary lateral incisor 6. Mandibular lateral incisor	5. Maxillary lateral incisor The correct answer is choice 5. The most commonly congenitally missing tooth is the maxillary lateral incisor, choice 5. Others include third molars, either maxillary or mandibular and second premolars, maxillary or mandibular. Canines are rarely congenitally missing. A general rule related to this question is that congenitally missing teeth are usually the distal teeth of a certain I type, that is the lateral incisors more often than the central, second premolars more than first premolar and the third molars more than the other molars. Anyway, the correct answer to question is choice 5.
	Which position of the mandible is determined primarily by tooth position? A. intercuspal B. centric relation C. physiologic rest D. retruded contact	A. intercuspal The correct answer is choice A. Intercuspal position is also centric occlusion. The teeth are in contact and the mandible is neither protruded nor retruded. There is no leeway space (space between the teeth). The position centric relation and the position retruded contact are positions sometimes used in prosthodontics to give a reproducible jaw relation. The mandible is pushed slightly backwards to where the condyle is in its most posterior position. This position is determined by the condyle, muscles, teeth and the dentist. Retruded contact is generally a few millimeters distal to centric occlusion. Physiologic rest is the position of the mandible when the jaws are at rest. Teeth are generally slightly separated and the amount of separation is determined by the comfortable stretch or contraction of the facial muscles. The position is thus determined primarily by soft tissue and not by teeth.
	Which premolar has a facial cusp with a triangular ridge so uniquely prominent as to frequently separate its mesial pit from its distal pit? A. Maxillary first B. Mandibular first C. Maxillary second D. Mandibular second	B. Mandibular first The correct answer is choice B. The triangular ridge is the surface inclining downward from the buccal and lingual cusps of the premolars. In the mandibular first premolar, these ridges are often very prominent, meet in the middle and become a pronounced transverse ridge, which separates the mesial from the distal half of the tooth. This transverse ridge is unique to the mandibular first premolar.
	Which premolar is the largest? A. mandibular first B. mandibular second C. maxillary first D. maxillary second	C. maxillary first The correct answer is choice C. In general, the premolars are very similar in overall size. All four premolars are similar in mesial-distal width, and the maxillary premolars are larger than the mandibulars in buccal- lingual width. Between the two maxillary premolars, the major difference is in overall tooth length, including root. The first premolar is approximately 1mm longer on average.
	Which premolar MOST likely possesses a crescent-shaped central developmental groove? A. Maxillary first B. Mandibular first C. Maxillary second D. Mandibular second	D. Mandibular second The correct answer is choice D. The mandibular second premolar often contains a Y shaped or crescent shaped central developmental groove. The three variations of the central groove pattern of this tooth are often referred to as the Y, H and U patterns. The mandibular first premolar tends to have no central pit, and lacks the Y shaped developmental central groove. The maxillary first tends to have a longer straight central groove with few supplementary grooves, while the maxillary second usually has a shorter central grove with more supplementary grooves.
	Which primary tooth most closely resembles its successor? A. Mandibular first molar B. Maxillary second molar C. Mandibular central incisor D. Maxillary first molar E. Mandibular second molar	C. Mandibular central incisor The correct answer is choice C.
	Which root is most likely to have a divided root canal? A. Maxillary central incisor B. Mandibular central incisor C. Maxillary canine D. Mandibular canine	D. Mandibular canine The correct answer is choice D. Maxillary central incisors, mandibular central incisors and maxillary canines almost invariably have single roots. Maxillary centrals and canines generally have a single root canal within the single root. Mandibular centrals may have two canals, but usually have one apical foramen. The mandibular canine is the most likely of the group to have two roots and/or two canals within the one or two roots.
	Which teeth usually have trifurcations? A. maxillary and mandibular molars B. maxillary molars and premolars C. maxillary first, second and sometimes third molars D. mandibular first, second and sometimes third molars E. None. Teeth can have bifurcations but not trifurcations	C. maxillary first, second and sometimes third molars The correct answer is choice C. This is a basic definition question. The term trifurcation refers to the area where any three roots join together. This is opposed to the more common term bifurcation found wherever two roots come together. Only a three rooted tooth can have a trifurcation, so maxillary molars should immediately come to mind. The area underneath the common root trunk where the mesiobuccal, distobuccal and palatal roots meet is the trifurcation.
	Which tooth can almost always be rotated during extraction, without danger of fracturing the root? A. Mandibular canine B. Maxillary first premolar C. Maxillary second premolar D. Mandibular first premolar E. Maxillary central incisor	E. Maxillary central incisor The correct answer is choice E. In extraction, teeth with conical or rounded roots can be extracted with a rotational movement in addition to buccal-lingual luxation. You should avoid this movement with any teeth likely to have two roots, either separate or fused. Many teeth may have one root, but it is more flattenned than round, or a usually one rooted tooth may occasionally have two roots. The mandibular canine is generally one rooted, but may have two roots occasionally, with a split into buccal and lingual sections near the apex. Its root may also be somewhat flattened. Maxillary first premolars generally have two roots and are never rotated. MaxiHary second premolars are usually one-rooted, but the root may be ovalish or flattened rather than round. Mandibular first premolars are usually one rooted, occasionally double rooted, and the root is often flattened. Maxillary central incisors invariably have one root, usually oval or rounded. There is rarely a complication when they are rotated during extraction.
	Which tooth has the greatest mesio-distal diameter? A. Mandibular first molar B. Maxillary second molar C. Mandibular central incisor D. Maxillary second molar	A. Mandibular first molar The correct answer is choice A. The permanent mandibular first molar is the largest tooth in the mesiodistal direction. In general, the mandibular molars are wider mesiodistally than their maxillary counterparts. The mandibular first molar is slightly longer than the mandibular second molar, partially due to the presence of a fifth cusp, the distal cusp. This cusp is absent in the second molar. It should be noted that within the molars, in general, size decreases from 1st to 2nd to 3rd within both arches.

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