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248 Cards in this Set
- Front
- Back
- 3rd side (hint)
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The two types of cells that give rise to teeth
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1. Ectodermal origin -> generate enamel
2. Ectomesenchymal origin -> generate dentin, cementum, and pulp |
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Stages of tooth development:
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1. Bud stage - epithelial ingrowth into ectomesenchyme
2. Cap stage - further epithelial growth 3. Bell stage - histo- and morpho-differentiation 4. Appositional stage - mineralization. formation of enamel and dentin of crown 5. Root formation - formation of dentin and cementum of root 6. Eruption |
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Cap stage
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Epithelial cells proliferate to form the enamel organ. Ectomesenchymal cells form two different structures: dental papilla and dental sac.
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Dental papilla forms these structures of the tooth:
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Dentin
Pulp |
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The Dental Sac gives rise to these structures:
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cementum
periodontal ligament alveolar bone connective tissues of gingiva |
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Tooth germ is composed of these 3 components:
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1. Enamel organ
2. Dental papilla 3. Dental follicle |
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the most important structure of the enamel organ
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Inner enamel epithelium.
It generates enamel. |
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transient structures
during cap stage |
Enamel knot
Enamel cord Enamel navel |
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stratum intermedium forms during what developmental stage?
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Bell stage
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represent layers of cells on the inner enamel epithelium that are derived from the retraction of stellate reticulum.
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Stratum intermedium
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the order of differentiation of tooth matrix forming cells:
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Preameloblasts -> Preodontoblasts ->
Odontoblasts -> Dentin -> Ameloblasts -> Enamel |
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As the mineralization of crown continues, the epithelial cells at the cervical loop proliferate and migrate downward to form...
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Hertwig epithelial rooth sheath (HERS)
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The root formation is initiated by...
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the disintegration of HERS
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Epithelial pearl
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remnants of dental lamina observed during the developmental stages
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Epithelial rests of Malassez
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Remnants of HERS
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The dental lamina:
A. appears at 12 weeks of gestation B. is synonymous with the vestibular lamina C. is derived from neural crest material D. is derived from ectoderm E. will give rise to cementum |
D. is derived from ectoderm
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Collagen in not the major component of matrix of:
A. dentin B. enamel C. cementum D. periodontal ligament |
B. enamel
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One of the following is not present in the bell stage of tooth development:
A. outer enamel epithelium B. inner enamel epithelium C. stellate reticulum D. stratum intermedium E. enamel knot |
E. enamel knot
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Cementogenesis starts prior to
A. amelogenesis B. dentinogenesis C. disintegration of dental lamina D. formation of apical foramen E. disintegration of Hertwig’s epithelial root sheath |
D. formation of apical foramen
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Two of the following are not products of the dental sac:
A. dentin B. cementum C. alveolar bone D. periodontal ligament E. enamel |
A. dentin
E. enamel |
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One of the following is not a component of tooth germ:
A. Dental papilla B. Enamel organ C. Dental follicle D. Vestibular lamina |
D. Vestibular lamina
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One of the following remains after the completion of tooth development:
A. amelogenin B. Hertwig’s epithelial rooth sheath C. ameloblasts D. odontoblasts |
D. odontoblasts
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Which one of the following is derived from ectomesenchyme?
Ameloblasts Odontoblasts Stellate reticulum Stratum intermedium Reduced enamel epithelium |
Odontoblasts
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Functions of Teeth:
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Incise and reduce food during mastication
Help in the development of the tissues that support them Esthetics Phonetics Psychological |
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Posterior teeth have contacts that are generally located ______ to the center of teeth when viewed from the occlusal
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buccal
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As you move from anterior to the posterior the contact areas move in a _______ direction
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cervical
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Mandibular Teeth: Contact their class counterpart and the tooth...
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mesial
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Maxillary Teeth: Contact their class counterpart and the tooth...
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distal
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The cervical embrasure ______ in size from anterior to posterior
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decreases
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The longest incisal embrasure
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embrasure of the maxillary lateral/canine
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The incisal embrasure with the widest angle
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The incisal embrasure of the maxillary canine/premolar
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The height of contour of the lingual surface of posterior teeth is located in the...
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middle or occlusal third
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The depth of the curvature of the CEJ on a tooth is greater on the _____ than on the _____ aspect
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mesial; distal
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All teeth are ______ inclined, with the possible except of the most distal maxillary teeth.
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mesially
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From the level of the occlusion the Curve of the maxillary arch is...
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convex
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From the level of the occlusion the Curve of the mandibular arch is...
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concave
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the _____ incisal edge of the maxillary central is close to 90 degrees, while the the _____ incisal edge is more rounded
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mesial; distal
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The distal contact of the maxillary central is in...
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the junction of the incisal/middle third
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maxillary central: the mesial marginal ridge is slightly _____ than the distal marginal ridge
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longer
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curvature of CEJ on the mesial is the greatest of any tooth
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Maxillary Central
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widest anterior tooth in a mesiodistal dimension
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Maxillary Central
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time of eruption of permanent Maxillary Central
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7-8 years
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mesial contact of the maxillary lateral is in the...
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junction of the incisal/middle 1/3
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distal contact of the maxillary lateral is in the...
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middle 1/3
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Possible lingual pit on this anterior tooth
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maxillary lateral incisor
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There may be a groove on the lingual surface that extends to the root (palatoradicular groove) of this anterior tooth
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maxillary lateral incisor
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May vary in form more than any other tooth except the 3rd molar
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maxillary lateral incisor
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Which canines generally have sharper cusp tips?
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maxillary canine s
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maxillary canine :
Mesial is... Distal is... |
straight; bulbous
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maxillary canine:
The cusp tip is _____ in a mesial/ distal dimension |
centered
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the mesial cusp ridge > distal cusp ridge
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permanent maxillary premolar
primary maxillary canine |
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maxillary canine :
The incisal edge is _____ to a line that bisects the root |
facial
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Widest anterior tooth in a facial -lingual dimension
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maxillary canine
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Smallest and most narrow of all the teeth
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mandibular central
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Mesial and Distal aspects are mirror images of each other
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mandibular central
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first succedaneous tooth to erupt, 5-6 years of age
most symmetrical tooth |
mandibular central
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Distal contact of the mandibular lateral incisor:
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incisal 1/3
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the crown appears to be twisted on the root
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mandibular lateral
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Which canine has the longer crown?
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mandibular canine
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Mesial contact of the mandibular canine
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incisal 1/3
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Distal contact of the mandibular canine
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middle 1/3
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mandibular canine: incisal edge is _____ to the labiolingal midpoint
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lingual
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Which canine is One continuous arc from cusp tip to root apex?
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mandibular canine
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the only anterior tooth that may have a bifurcated root
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mandibular canine
if this is the case the roots are positioned facial and lingual |
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Longest tooth from cusp tip to root apex
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maxillary canine
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mandibular canine erupts when?
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between 9-10 years of age
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What is the composition of enamel?
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It is composed of 96% mineralized substances and 4% organic material and bound water.
The mineralized substance is calcium hydroxyapatite. The organic material is mostly enamelin. |
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Enamel rods are arranged in such a fashion that they radiate from...
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the DEJ
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The ____ is believed to be the actual enamel rod, whereas the ____ is considered to be interrod enamel.
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head; tail
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Enamel Crystals located within the center of the rod are arranged _____ to the longitudinal axis of the rod, whereas crystals at the periphery of the rod are arranged ______ to the longitudinal axis of the rod.
Crystals located within the center of the tail of the enamel rod are arranged _______ to the longitudinal axis of the rod. |
parallel; oblique; perpendicular
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resultant developmental disturbanances recorded in enamel. They are composed of sequential groups of hypocalcified or normally calcified enamel rods.
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Striae of Retzius
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A special form of daily imbrication lines present in those teeth whose crowns were being formed at the time of birth.
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neonatal lines
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At the tooth surface, Striae of Retzius overlap each other, forming parallel shallow grooves known as _____, and parallel elevations known as ______ ______ __ ________.
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perikymata; imbrication lines of Pickerill
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Enamel spindles
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short spindle-like structures that are the ends of dentinal tubules that are trapped in enamel.
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Enamel tufts
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hypocalcified enamel rods that resemble tufts of grass
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False enamel lamellae
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cracks in enamel and frequently extend into the dentin
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True enamel lamellae
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hypocalcified enamel rods that are poorly calcified or uncalcified due to developmental disturbances affecting the ameloblasts.
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located deep to the cusps and is a region where the enamel rods intertwine as they pass from the DEJ to the tooth surface.
It protects the enamel from the formation of cleavage planes. |
Gnarled enamel
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Hunter- Schreger bands: The dark bands are ______. The light bands are ______.
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diazones; parazones
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Level of fluoride that can cause fluorosis
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>ppm
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Composition of dentin
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65-70% mineralized substances
20-25% organic material 10% bound water The mineralized :calcium hydroxyapatite. The organic material :collagen and ground substance. |
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Which portion of dentin has more curvature?
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Coronal portion
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Circumpulpal dentin
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the remaining and the bulk of primary dentin.
more mineralized than mantle dentin |
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Mantle Dentin
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first formed dentin. It is located in both the crown underlying the DEJ and the root of the tooth
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Dead Tracts
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empty dentinal tubules that lead directly to pulp
Due primarily to caries |
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Deciduous teeth: dentin formation complete...
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~18 months post
eruption |
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Permanent teeth: dentin formation complete...
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~2-3 years post
eruption. |
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Globular Mode of Calcification of dentin occurs in...
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the Crown of the tooth
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Contour Lines of Owen
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Wide arcs of rings in dentin
Result from metabolic disturbances during development |
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An exaggerated Line of Owen
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Neonatal Line
Demarcates trauma experienced during birth |
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Granular layer of Tomes
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A granular appearing layer of dentin underlying the
cementum that covers the root. Viewed under transmitted light in ground sections. Located in the peripheral most layer of radicular dentin. |
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The clear layer between the granular layer of Tomes and cementum is known as
the... |
Hyaline layer of Hopewell-Smith.
Facilitates the adherence of cementum and dentin. |
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Functions of premolars
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Assist in tearing food
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Transverse ridges =
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the union of 2 triangular ridges
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Facial /Lingual and Proximal Geometric Shape of maxillary premolars
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trapezoidal
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MBCR is longer than the DBCR
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Maxillary 1st Premolar
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This will always help you distinguish right from left Maxillary 1st Premolars
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Mesial marginal ridge groove with a depression on the radicular surface
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Cross section of the root resembles a “Figure 8” at the cervical portion
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Maxillary 1st premolar
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Occlusal shape of Maxillary 1st premolar
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hexagon
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Maxillary 1st premolar: Shape of Occlusal table
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trapezoidal
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Maxillary 1st premolar erupts when?
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10-11 years of age
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Maxillary 2nd Premolar: Cusps are _____ in a mesiodistal direction
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centered
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Maxillary 2nd Premolar:
True/False? The buccal and lingual cusps are of equal height |
True
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Maxillary 2nd Premolar: Shape of Occlusal profile
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Oval
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Proximal Geometric Shape of Mandibular Premolars
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rhombus
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Mandibular 1st Premolar:
Cusp tip is slightly ______ to a line that bisects the tooth in a mesial – distal dimension |
mesial
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Premolar with Mesio-lingual developmental groove
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Mandibular 1st Premolar
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Mandibular 1st Premolar:
Shape of occlusal profile |
diamond
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Smallest of all premolars
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Mandibular 1st Premolar
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Y” shaped groove pattern in the version with 2 lingual cusps and 3 cusps in total
In the tooth with 2 cusps there is an “H” shaped groove pattern |
Mandibular 2nd Premolar
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Mandibular 2nd Premolar:
shape of the occlusal profile |
square
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Roundest of all the premolars in cross-section
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Man 2nd Premolar
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Maxillary 1st molar:
Oblique ridge-connects the... |
DB and ML cusps
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Maxillary 1st molar:
Shape from the facial view |
trapezoidal
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Maxillary 1st molar;
Largest cusp |
ML cusp
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Maxillary 1st molar:
Shape from the Occlusal view |
rhomboidal
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Maxillary 1st molar:
Mesial contact position |
junction of the middle/occlusal
1/3rds |
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Maxillary 1st molar:
Lingual groove extends onto the occlusal surface and becomes the... |
disto-oblique developmental groove
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Maxillary 1st molar:
smallest in bulk of the 4 major cusps |
DL cusp
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Maxillary 1st molar:
True/False? The lingual surface is wider then the buccal surface |
True
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Only tooth wider lingually than facially.
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Maxillary 1st molar
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Maxillary 2nd Molars:
A line drawn thru the __ cusp will bisect the apex of the lingual root |
DL
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Maxillary 2nd Molar:
__ root is larger than the __ root |
MB; DB
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Maxillary 2nd Molar:
True/False The roots are within the confines of the tooth from all angles |
True
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Maxillary 2nd Molar:
Occlusal outline is less rhomboidal and more heart shaped because of... |
the decrease in size of the DL cusp
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#6
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Sella turcica
hold the pituitary gland |
Ros the cowboy sits on the saddle
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3 buccal cusps (MB > DB > Distal) and 2 lingual cusps
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Mandibular 1st molar
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Mandibular 1st molar
MB groove ends in a... |
buccal pit
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Mandibular 1st molar
Mesial contact: |
junction of occlusal and middle 1/3rd
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Mandibular 1st molar
Roots curve... |
distally
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Mandibular 1st molar:
__L cusp is longer/larger than the __L |
ML; DL
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First permanent tooth to erupt
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Mandibular 1st molar
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Mandibular 1st molar:
Can only see the mesial aspect of the occlusal surface from this view |
Mesial view
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Mandibular 1st molar:
Which marginal ridge is lower? |
DMR is lower, thus you can see more of the occlusal table for the distal view
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Mandibular 1st molar:
Occlusal shape |
Pentagon
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Mandibular 1st molar:
begin calcification when? |
8 mos. prenatally
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Mandibular 2nd molars:
Concavity on the root on this side |
mesial
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Mandibular 2nd molars:
Occlusal shape |
Rectangular
Groove pattern is a “+” sign |
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Mandibular 2nd molars:
___ outline is very bulbous |
MB
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Smallest molar
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Mandibular 3rd molar
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Primary Teeth are smaller in all dimensions than the teeth they are succeeded by except...
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the mandibular molars that are wider M-D than the permanent premolars
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Primary Teeth are wider ___ in relation to their height so they appear ‘short and squatty’
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M-D
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Primary or Permanent?
the enamel rods in the apical aspect curve incisal/occlussally |
Primary
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MCR > DCR on what primary tooth?
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MAX canine
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Primary tooth that the occlusal resembles a premolar, 2 very prominent cusps
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Primary Maxillary 1st Molar
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Primary tooth that resembles the Maxillary Permanent 1st Molar
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Primary Maxillary 2nd Molar
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Primary tooth that resembles nothing else in the permanent dental arch
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Primary Mandibular 1st molar
MB and ML have a transverse ridge MB largest and longest cusps |
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Primary tooth that resembles the Permanent Mandibular 1st Molar
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Primary Mandibular 2nd molar
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Primary incisors erupt at
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6 months
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Primary teeth show evidence of calcification when?
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in utero (2nd trimester)
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artery that supplies all maxillary posterior teeth
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Posterior superior alveolar artery
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artery that supplies all maxillary anterior teeth
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Anterior superior alveolar artery
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All teeth are supplied by branches of what artery?
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Maxillary artery
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artery that supplies all mandibular teeth
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Inferior alveolar artery
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All mandibular incisors drain into the _______ lymph nodes
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submental
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Maxillary and mandibular third molars drain into what lymph nodes?
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upper deep cervical nodes
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All maxillary teeth(except third molars), the mandibular canines and all posterior teeth (with the possible exception of the third molar) drain into what lymph nodes?
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the submandibular lymph nodes
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All teeth drain into what vein?
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The facial vein
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All teeth are innervated by branches of the...
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Trigeminal nerve
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Pulp morphology of max anterior teeth
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One root, one canal
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Pulp morphology of Maxillary First Premolar
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2 roots, 2 canals: 57%
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Pulp morphology of Maxillary 2nd Premolar
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1 canal: 50-65%
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Pulp morphology of Maxillary First Molar
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3 roots, 4 canals: 59%
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Pulp morphology of Maxillary 2nd Molar
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3 roots, 3 canals: 60%
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Pulp morphology of mandibular anterior teeth and man. premolars:
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Usually 1 root, 1 canal
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Pulp morphology of Mandibular First and Second Molars
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2 roots, 3 canals
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Apical constriction
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most narrow point of the root
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Function of pulp:
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Sensory, protection and maintenance of dentin
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Structure of the Dental Pulp:
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Dentin ->
Predentin -> Odontoblasts -> Subodontoblastic plexus of Raschkow - Cell free zone - Cell rich zone -> Pulp proper |
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Most Common Cell in the Cell-Rich Zone
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Fibroblasts
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Location of Dendritic Cells in the pulp
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Below OB Zone
Cell Processes between odontoblasts |
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Collagen types in pulp
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Type I & III (ratio 55:45) produced by pulp fibroblasts
Also, small amount of Type V |
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Zone of Viel.
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Cell Free zone
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Responsible for dull aching pain in the pulp
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unmyelinated C fibers
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Responsible for sharp, localized pain in the tooth
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myelinated A delta sensory axons
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Opacity of pulp chamber suggests the formation of...
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pulp stones
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types of Denticles (pulp stones)
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1. Free denticles - located free in the pulp
2. Attached denticles - attached to the wall of pulp chamber 3. Interstitial denticles - wholly within wall of pulp chamber 4.True denticles (formed by odontoblasts) - rare and when present, located in radicular pulp 5. False denticles - Do not posess odontoblasts. |
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ginglymoid joint
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Hinging movement in one plane
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arthrodial joint
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Gliding movements
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The TMJ is a ____________ joint
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Ginglymoarthrodial
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Masseter muscle
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Elevates the mandible
Superficial portion- aids protrusion Stabilizing muscle |
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Temporalis muscle
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Elevates the mandible
Posterior fibers can retrude the mandible (along with the suprahyoid and infrahyoid muscles) Stabilizing muscle |
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Medial Pterygoid muscle
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Elevates the mandible
Stabilizing muscle Aids in protrusion |
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Lateral Pterygoid muscle
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Active in protrusiong and lateral movement and sustained activity during opening
Two Heads Superior Head: Stabilizing muscle Inferior Head: jaw-opening and protrusion only |
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Depressor Muscles of the mandible
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Myly Digs Graves
Mylohyoid, Digastric, Geniohyoid muscles |
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Elevator Muscles of the mandible
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Meat Makes Tasty LuncheS
Masseter, Medial pterygoid, Temporalis, Superior head of Lateral pterygoid |
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The inferior belly of the lateral pterygoid muscles constrict in unison to...
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move the mandible forward.
Protrusion |
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The contra lateral inferior belly of the lateral pterygoid muscle constricts with superficial portion of the masseter muscle for a ________ movement
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Lateral
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Centric Relation is an orthopedically stable muscular position where the condyle rests in a _______ ________ position against the posterior wall of the articular eminence with the articular disk interposed
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superior anterior
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A purely rotational movement can occur for the first ____ mm of jaw opening.
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20-25
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tooth position when the TMJ is in CR and the teeth first touch on closing
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Centric Occlusion
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the position of the teeth when there is maximum contact of teeth in occlusion.
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Maximum intercuspation
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The outer limits of the mandible’s range of motion are called...
They are limited by the... |
border movements
ligaments of the TMJ. |
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FACTORS INFLUENCING THE DISTANCE BETWEEN CR AND MI
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1. Steepness of cuspal inclines of the posterior teeth.
2. Amount of vertical and horizontal overlap of anterior teeth. 3. Lingual morphology of maxillary anterior teeth 4. General inter arch relationships of the teeth |
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most superior non-
occluding position in the FRONTAL PLANE BORDER MOVEMENTS envelope. |
Rest Position
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When the mandible is at rest, it is typically ___ mm below MI
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2-4
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POSSELT ENVELOPE OF MOTION
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Three Dimensional Border
movement with function occurring within the borders |
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The mesiobuccal cusp of the mandibular first molar occludes in the embrasure area between the maxillary second premolar and first molar
The mesiobuccal cusp of the maxillary first molar is aligned directly over the buccal groove of the mandibular first molar |
Angle’s Class I
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In Angle’s Class I each mandibular tooth occludes with it’s counterpart and the...
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adjacent tooth mesial to it.
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Tooth + Tooth =
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33
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The B-O line of the mandible occludes with ____ of the maxilla
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C-F
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Horizontal Overlap=
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Overjet
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Vertical Overlap=
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Overbite
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Maxillary teeth are advanced one half tooth labially of mandibular teeth, the opposite of Class I occlusion.
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Angle's Class II
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Mandibular teeth are one full tooth ahead of maxillary teeth.
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Angle's class III
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Three basic eccentric movements:
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1. Laterotrusive
2. Protrusive 3. Retrusive |
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rotating side is the
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working side
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Articular disc is made of what?
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dense fibrous connective tissue; no nerves or blood
vessels so it can endure heavy forces without damage or pain. |
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Axial Loading:
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the process of directing occlusal forces through the long axis of the tooth
With proper contact, posterior teeth receive force along the vertical or long axis in MI |
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Axial loading accomplished in two ways:
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1. Development of tooth contacts on cusp tips or flat surfaces, perpendicular to the long axis of the tooth (marginal ridges, bottom of fossae)
2. Tripodization – each cusp contacting a fossa in such a way that three contacts points are made |
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Cuspids are best suited to accept horizontal forces of Occlusion because...
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Long, thick roots
Better crown/root ratio Surrounded by dense bone Extensive periodontal ligament Most proprioceptively sensitive tooth in the mouth |
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Group function
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when several posterior teeth on the working side contact during excursions
No contact on non-working side during excursions |
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mutually protected occlusion
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Posterior teeth should contact slightly more heavily than anterior teeth in centric occlusion
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Three Types of Occlusal Interferences:
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1. Excursive interference - interference to the desired Occlusal scheme (Canine Guidance/Group function)
2. Prematurity (usually a high restoration) 3. Deflective Occlusal Contact (centric interference-usually natural) |
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Christensen’s effect
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When the mandible moves in protrusive position, there should be adequate tooth-guided contacts on the anterior teeth to disocclude all posterior teeth immediately
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What is an articulator?
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A mechanical instrument that represents the temporomandibular joints and jaws, to which maxillary and mandibular casts may be attached to simulate some or all mandibular movements
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THE STEEPER THE Articular eminence and medial WALLS of the mandibular fossa...
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THE TALLER THE CUSPS
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COUPLING
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The steepness of the anterior teeth (Anterior Guidance AG) MUST exceed the posterior condylar inclination (Condylar Guidance CG)
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Increase overbite (VO) =
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increase cusp height (which increases vertical dimension during protrusion)
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The Greater the Overjet:
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The Shorter the Cusps MUST Be since there is less space in the posterior during protrusion
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“The Flatter” the Occlusal plane or the Curve of Spee...
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taller the cusp height can be.
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THE BENNET MOVEMENT
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A bodily side shift of the condyle on the working side in conjunction with rotation.
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BENNET ANGLE
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The angle made by the Sagittal plane and a line drawn from the point of origin of the balancing condyle to the final position.
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The Greater the Side Shift
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the Shorter the Cusps Will Be
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The articulator we use at UMB:
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Hanau Modular Semi Adjustable Arcon Articulator
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Bite registration sets the angle of the...
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horizontal condylar guidance
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Dental Anomalies
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An anomaly is a deviation from normal usually related to embryonic development which may result in absence, excess or deformity of body parts
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Anodontia
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absence of teeth
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third most common site of missing teeth
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Missing mandibular second premolar
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Ninety percent of extra teeth occur in the...
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maxilla
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mesiodens
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an extra tooth located between the maxillary incisors
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The most common site of extra teeth in the mandible is...
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the second premolar region
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The most common maxillary site of extra teeth is the...
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third molar area
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Gemination or Twinning
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Caused by the splitting of a single tooth germ
Usually there is only a single root and one pulp chamber |
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Fusion
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Fused teeth originate from two separate tooth germs
They have separate roots and pulp spaces Fusion may be caused by pressure between developing teeth |
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Hutchinson’s Teeth
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Notched incisors are characteristic of Hutchinson’s Teeth
These abnormalities result from congenital syphilis The appearance of the occlusal surface of molar teeth gave rise to the name mulberry molar |
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Carabelli’s Trait
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Carabelli’s trait refers to accessory cusps or tubercles on teeth
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Enamel Pearls
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Enamel Pearls are most common in the furcation of maxillary molars
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Talon Cusps
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Are small enamel projection in cingulum area of anterior permanent teeth
The projection may contain a pulp horn They sometimes cause occlusal interferences |
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Dens in Dente
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Dens in dente or “tooth within a tooth” results from an invagination of the enamel organ within the crown of the tooth
It usually appears as a deep pit or groove in the cervical area of incisors Maxillary lateral incisors are most often affected |
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Concrescence
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The joining of two teeth at the roots through cementum
It differs from fusion in that only the cementum is involved Occurs after eruption |
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Hypercementosis
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This is the excessive formation of cementum around a tooth root after eruption
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Enamel Dysplasia
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Abnormal enamel development
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“Turner’s tooth”
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Enamel Hypoplasia that occurs as a result of a deciduous tooth infection
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Enamel hypoplasia
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occurs due to a disturbance of the ameloblasts during enamel matrix formation
It may be caused by either disease or trauma |
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Enamel hypocalcification
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results from a disturbance in the maturation of the enamel matrix
Insufficient mineral deposition causes a white spot |
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Dentinogenesis Imperfecta
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hereditary disorder affects both dentitions
The teeth may appear blue-gray to yellow and opalescent The teeth may show a complete lack of pulp chambers and root canals The teeth are weak and prone to fracture |
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Transposition
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results from misplaced tooth buds that develop in the wrong place
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