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32 Cards in this Set
- Front
- Back
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what are the 3 stages of tooth development?
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- bud stage
- cap stage - bell stage |
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What happens in the cap stage?
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the round form starts to invert and there is the appearance of a cap = cap stage
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How are buds formed?
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epithelial thickening (dental lamina) starts at 6-8 weeks of fetal development and the lamina differentiates into tooth buds
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how do buds appear in the bud stage?
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round or ovoid
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what happens in the bell stage?
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-concavity deepens = bell stage
-most of enamel and coronal dentin laid down; DEJ identifiable -connection w/ dental lamina disintegrates permanent tooth bud starts forming |
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bell stage ends with what?
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formation of CE line
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enamel organ differentiates into hertwig's sheath, which forms the what?
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root structure
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when the root is completed what happens to the apical foramen?
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it is constricted
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root is completed in deciduous teeth at about age _____
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3, one year from eruption to completion
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active eruption
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entry of tooth into oral cavity until contact w/ opposing tooth
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passive eruption
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continuing adaptation of tooth to changing occlusal relationships, continues throughout life
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Deciduous eruption sequence
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1. central incisors
2. lateral incisors 3. 1st molars 4. canines 5. 2nd molars *mandibular precedes maxillary |
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permanent anteriors develop ________ to primary roots
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lingual
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premolars develop w/in ______ of primary molars
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root furcations
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when do the mandible/maxilla start growth spurt?
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age 5 to make room for the first permanent molars that erupt at age 6
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which teeth are the cornerstones in permanent occlusion
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1st molars
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what are the ages of mixed dentition?
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6-12 yrs old
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ankylosis
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root is fused to bone, disrupts resorption and exfoliation - especially if permanent tooth bud does not form
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describe resorption process
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starts at least 1 yr prior to exfoliation; permanent teeth start resorption of primary roots (osteoclastic process) b/c of the pressure of permanent teeth coming in
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describe exfoliation
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-root structure mostly resorbed, tooth is loose
-mandibular teeth precede maxillary except: primary 2nd molars all 4 are lost about same time (11-12 yrs) |
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deciduous dentition is important in maintaining what?
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arch space for permanent dentition
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how many deciduous teeth and what is the dental formula?
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20 (A-T); I 2/2 C 1/1 M 2/2
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primary dentition crowns are ______ M-D relative to height and _______ relative to total tooth length
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wider; shorter
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in primary dentition the facial and lingual HOC are closer to the ________
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cervical line
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primary crowns exhibit more _____ convexity
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F and L
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primary crowns are more constricted ______ and ______ in F-L dimensions
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cervically and occlusally
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there is a presence of a __________ on facials of all primary teeth and linguals of anteriors
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cervical ridge
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do primary teeth or permanent teeth have fewer anomalies and more consistent shapes?
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primary
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do primary or permanent teeth have longer roots relative to crown height?
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primary, but primary roots are smaller in other dimensions
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T or F apices of anterior roots are facially inclined
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T
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to provide more space for permanent buds, molar roots are ________
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flared
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Do primary roots have root trunks?
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no, branching occurs close to crown
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