Dental Anomalies II

Question 1

Gemination
(2)

Answer 1

 Attempt of a single tooth bud to divide, resulting in a bifid crown
 Affects deciduous and permanent dentition

Question 2

Gemination
Clinical and Radiographic features:
(3)

Answer 2

 Tooth count is normal when anomalous tooth is counted as one
 MC in the anterior maxilla
 RG: Bifid crown with shared root canal

Question 3

Fusion
(2)

Answer 3

 Union of two normally separate tooth buds → form a joined tooth
 Affects deciduous and permanent dentition

Question 4

Fusion
Clinical and Radiographic features:
(3)

Answer 4

 Tooth count reveals missing tooth when anomalous tooth is counted as one
 MC in anterior mandible
 RG: Separate canals usually present

Question 5

Concrescence

Answer 5

 Two fully formed teeth joined by root surfaces by cementum

Question 6

Concrescence
Clinical features:
 MC in
 Often involves
 May result from

Answer 6

posterior maxilla
2nd molar – root in close proximity to 3rd molar
postinflammatory/carious tooth

Question 7

Talon cusp
 Clinical features:

 Extends at least
 MC in — dentition
 MC in
 MC in

Answer 7

Well-delineated additional cusp located on the surface of an anterior tooth
half the distance between CEJ and incisal edge
permanent
maxillary lateral > central incisor
Asian, Inuit, Native Americans

Question 8

Dens evaginatus
 Clinical features:
(6)

Answer 8

 Cusp-like elevation of enamel
 central groove or lingual ridge of the buccal cusp
 Observed in posterior teeth (premolar MC)
 MC in mandible
 MC in Asian, Inuit, Native Americans
 May result in occlusal interferences

Question 9

Dens evaginatus
 Clinical features:
(1)

Answer 9

 Frequent association with shovel-shaped incisors

Question 10

Dens invaginatus
Dens in dente
 Clinical features:
(4)

Answer 10

 Deep surface invagination of the crown or root lined by enamel
 MC permanent maxillary lateral and central incisors
 “tooth within a tooth”
 Opening may become carious

Question 11

Enamel pearl
 Clinical features:
 Presence of
 MC
 MC at
 Precludes

Answer 11

enamel in an unusual location
max molars > mandibular molars
furcation area or near CEJ
normal periodontal attachment

Question 12

Taurodontism


 may be associated with

Answer 12

Enlargement of the body and pulp chamber of a multi-rooted tooth
Isolated or syndromic
cleft lip/palate

Question 13

Taurodontism
 Clinical features:
(4)

Answer 13

 Pulp chambers – increased apico-occlusal height
 Mild to severe cases
 MC in permanent teeth
 May appear bilateral

Question 14

Hypercementosis


 Generalized pattern: consider
 Associated with local factors like (2)

Answer 14

Non-neoplastic deposition of excessive cementum along the root
Isolated or involve multiple teeth
Paget disease
trauma, inflammation

Question 15

Hypercementosis
 Clinical and Radiographic features:

 MC in
 Frequency increases with

Answer 15

Thickening or blunting of the root surface
mandibular molars
age

Question 16

Dilaceration
(3)

Answer 16

 Abnormal angulation or bend in the root
 Majority arise following injury that displaces the calcified portion of the
tooth germ
 Idiopathic or syndromic

Question 17

Dilaceration
Clinical features:
MC where
bend
complications

Answer 17

 MC mand 3rd molars > max 2nd premolar > mand 2nd molar
 Bend occurs anywhere along the root
 Complications in extractions or endo

Question 18

Developmental alterations:
structure
(4)

Answer 18

 Amelogenesis imperfecta
 Dentinogenesis imperfecta
 Dentin dysplasia
 Regional odontodysplasia

Question 19

Amelogenesis imperfecta
(2)

Answer 19

 A large group of hereditary conditions that show alterations in the enamel
in the absence of systemic disease
 More than 14 different subtypes

Question 20

Amelogenesis imperfecta
 Alterations in the enamel may arise at any of the following stages:
(3)

Answer 20

 Matrix formation: Hypoplastic
 Mineralization of matrix: hypocalcified
 Maturation of the enamel: hypomaturation

Question 21

Amelogenesis imperfecta
inheritance
affects

Answer 21

 AD, AR, X-linked inheritance
 Affects deciduous and permanent dentition

Question 22

Amelogenesis imperfecta
 Clinical features:
 Hypoplastic type:
 Hypocalcified type:
 Hypomaturation type:

Answer 22

may see pits, rows of missing enamel
enamel is soft, “cheesy”, easily lost
enamel is soft

Question 23

 Hypocalcified type: enamel is soft, “cheesy”, easily lost

Answer 23

 Yellow, brown, orange

Question 24

 Hypomaturation type: enamel is soft

Answer 24

 Opaque white, brow

Question 25

Dentinogenesis imperfecta

 — gene mutation
 — inheritance
 Affects

Answer 25

Hereditary disturbance in the formation of dentin in the absence of any
systemic disorder
DSPP
AD
deciduous and permanent dentition

Question 26

Dentinogenesis imperfecta
 Clinical features:
 — teeth affected more severely
 Permanent teeth: MC in
 MC in — patients
 — discoloration, distinct translucence
 Enamel

Answer 26

Deciduous
incisors and 1st molars
White
Blue to brown
strips from poorly formed dentin

Question 27

Dentinogenesis imperfecta
 Radiographic features:
(4)

Answer 27

 Bulbous crowns, cervical constriction, thin roots
 Early obliteration of root canal and pulp chamber
 OR
 Normal to enlarged pulp chambers

Question 28

 Significantly enlarged pulp –

Answer 28

“shell teeth”

Question 29

Dentin Dysplasia I

 — inheritance
 Type II
 affected

Answer 29

Loss of organization of root dentin leads to shortened root length
AD
thought to be a variant of dentinogenesis imperfecta
Deciduous and permanent teeth

Question 30

Dentin Dysplasia I
 Clinical features:
 — well-formed
 — dentin loses organization → —
 (2)

Answer 30

Enamel and coronal dentin
Radicular, short roots
Tooth mobility and premature exfoliation

Question 31

Dentin Dysplasia I
 Radiographic features:
 Deciduous teeth:
 Permanent teeth:

Answer 31

little or no detectable pulp, very short roots
crescent shaped pulpal remnant, short root

Question 32

Regional odontodysplasia

 Most cases are
 May be due to

Answer 32

Nonhereditary developmental abnormality of teeth that affects enamel,
dentin, and pulp
idiopathic, some syndromic
alteration of vascular supply

Question 33

Regional odontodysplasia
 — affected
 MC in
 Dx at
 Affects

 Erupted teeth are
 — of overlying soft tissue

Answer 33

Enamel, dentin, and pulp
maxillary anterior teeth
time of eruption of primary and permanent
several teeth, quadrant distribution
Impacted teeth, delayed eruption
malformed, caries rampant
Hyperplasia

Question 34

Regional odontodysplasia
 Radiographic findings:
(3)

Answer 34

 Extremely thin enamel and dentin
 Enlarged pulp chambers – ghost teeth
 Short roots may be observed

Question 35

Segmental odontomaxillary dysplasia

Answer 35

 Developmental disorder, affects jaw and overlying soft tissue

Question 36

Segmental odontomaxillary dysplasia
 Clinical features:

 Usually dx during —
 — of overlying gingiva
 Primary teeth may be —
 — teeth may be missing

Answer 36

Painless, unilateral enlargement of maxillary bone
childhood
Hyperplasia
hypoplastic
Maxillary premolar

Question 37

Segmental odontomaxillary dysplasia
 Radiographic features:
(3)

Answer 37

 Thickened trabeculae, often vertically oriented
 Radiopaque, granular appearance
 Maxillary sinus may be smaller

Question 38

Segmental odontomaxillary dysplasia
 Treatment:
(2)

Answer 38

 Remains relatively stable, may not require tx
 Surgical recontouring