COMPLETE SOLUTIONS GRADED A+
QUESTIONS AND ANSWERS
What layer do neural crest cells develop from? ANSWER -Ectoderm
At what embryonic age does the dental lamina begin to develop? ANSWER -6 weeks
What are the three components of the tooth bud? ANSWER -Enamel Organ
Dental papilla
Dental sac
What are the three morphologic stages of a developing tooth bud? ANSWER -Bud stage
Cap stage
Bell stage
During the bell stage invagination of the epithelium occurs, which layer is essential for
enamel production? ANSWER -Stratum intermedium
Which cells does the stellate reticulum support and protect? ANSWER -Ameloblasts
What do remnants of Hertwig's epithelial root sheath persist as? ANSWER -Rests of
Malassez
What is the origin of the dental papilla? ANSWER -Neural crest cells
What does the dental papilla differentiate in to? ANSWER -Dentin and primordium of pulp
What are enamel pearls? ANSWER -Cells of epithelial root sheath that remain attached to
dentin. Differentiate into ameloblasts and produce enamel
,What are the 7 steps (in order) of histophyisological differentiation of a tooth bud?
ANSWER -Initiation
Proliferation
Histodifferentiation
Morphodifferentiation
Apposition
Mineralization
Maturation
During which stage of tooth development may problems that lead to anomalies of tooth
number occur? ANSWER -Initiation
Which three stages of tooth development encompasses the bud, cap, early bell and late bell?
ANSWER -Proliferation
Histodifferentiation
Morphodifferentiation
Disruptions of proliferation may result in what type of tooth anomalies? (4) ANSWER -
Size
Proportion
Numbers
Twinning
Which stage of tooth development may lead to anomalies of the enamel, dentin, and
cementum? ANSWER -Morphodifferentiation
What is the incidence of hyperdontia? Males vs females? ANSWER -0.3 - 3%
Males 2:1 females
Is hyperdontia more common in maxilla or mandible? More common in primary teeth or
permanent teeth? ANSWER -Maxilla 90%
Permanent dentition 5x more common that primary
,Which permanent teeth are most frequently missing? List in order from most to least
common ANSWER -Third molars
Mandibular second pre molars
Maxillary lateral incisors
Maxillary second pre molars
Name 9 syndromes that may be associated with supernumerary teeth ANSWER -Apert
Cleidocranial dysplasia
Gardner syndrome
Crouzon syndrome
Sturge Weber syndrome
Orofacialdigital Syndrome I
Hallermann-Strieff Syndrome - A
Cleft lip and palate
Down syndrome
Which syndrome is associated with shovel shaped incisors?
A. Sturge Weber Syndrome
B. Cleidocranial dysplasia
C. Apert syndrome
D. Hallermann Strieff Syndrome-A ANSWER -C. Apert Syndrome
Narrow high palate
Cleft of soft palate
Delayed or ectopic eruption
Shovel shaped incisors
Hypoplastic midface
Which syndrome is associated with osteomas of the jaw?
, A. Orofiaciodigital Syndrome I
B. Apert Syndrome
C. Crouzon Syndrome
D. Gardner Syndrome ANSWER -D. Gardner Syndrome
Delayed eruption
Supernum teeth
Osteomas of the jaw
Agensis of third molars is associated with agenesis of which permanent tooth? ANSWER -
Maxillary lateral - either one or both
What is the inheritance pattern for non syndromic hypodontia? ANSWER -Autosomal
dominant
Which teeth (from most to least) commonly present as microdontia? ANSWER -Lateral
incisors
Second pre molars
Third molars
Which tooth anomaly is characterized by: abortive attempt by single tooth to divide; bifid
crown with single root and pulp chamber? ANSWER -Gemination
Which tooth anomaly is characterized by: complete cleavage of single bud results in
supernum mirror image tooth? ANSWER -Twinning
Which race is fusion of teeth most commonly seen? ANSWER -Japenese (5%)
Which tooth anomaly is characterized by: dental union of 2 embryologically developing
teeth two separate pulp chambers; separate or fused canals appear as large bifid crown with
one chamber; dentin is always confluent? ANSWER -Fusion