Nbde Released-Dental Anatomy/occlusion

Front 1

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

Back 1

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.

Front 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

Back 2

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.

Front 3

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

Back 3

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

Front 4

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

Back 4

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.

Front 5

A developmental abnormality in which all teeth are absent is
A. Microdontia
B. Oligodontia
C. Anodontia
D. Exodontia
E. Odontoma

Back 5

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).

Front 6

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

Back 6

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.

Front 7

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.

Back 7

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.

Front 8

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.

Back 8

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.

Front 9

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

Back 9

#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.

Front 10

A normal seven-year-old child will have how many teeth?
A. 20
B. 22
C. 24
D. 26
E. 28

Back 10

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.

Front 11

Anodontia

Back 11

Lack of development in a tooth

Front 12

Dens in dente

Back 12

Tooth within a tooth

Front 13

Anodontia

Back 13

Is the absence of formation of all teeth