Developmental Dental Anomalies II Flashcards
What is gemination?
- Attempt of a single tooth bud to divide, resulting in a bifid crown
- Affects deciduous and permanent dentition
What are the clinical/radiographic features of gemination?
- Tooth count is normal when anomalous tooth is counted as one
- MC in the anterior maxilla
- RG: Bifid crown with shared root canal
What does this show?
gemination
What is fusion?
- Union of two normally separate tooth buds → form a joined tooth
- Affects deciduous and permanent dentition
What are the clinical and radiographic features of fusion?
- Tooth count reveals missing tooth when anomalous tooth is counted as one
- MC in anterior mandible
- RG: Separate canals usually present
What does this show?
fusion
Fusion or gemination?
fusion
Fusion or gemination?
gemination
What is concrescence?
Two fully formed teeth joined by root surfaces by cementum
What are the clinical features of concrescence?
- MC in posterior maxilla
- Often involves 2nd molar – root in close proximity to 3rd molar
- May result from postinflammatory/carious tooth
What are the clinical features of a talon cusp?
- Well-delineated additional cusp located on the surface of an anterior tooth
- Extends at least half the distance between CEJ and incisal edge
- MC in permanent dentition
- MC in maxillary lateral > central incisor
- MC in Asian, Inuit, Native Americans
What does this show?
talon cusp
What are the clinical features of dens evaginatus?
- 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
- Frequent association with shovel-shaped incisors
What does this show?
dens evaginatus
What are the clinincal features of dens invaginatus (dens in dente)?
- 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
What does this show?
dens invaginatus (dens in dente)
What are the clinical features of an enamel pearl?
- Presence of enamel in an unusual location
- MC max molars > mandibular molars
- MC at furcation area or near CEJ
- Precludes normal periodontal attachment
What does this show?
enamel pearl
What is taurodontism?
- Enlargement of the body and pulp chamber of a multi-rooted tooth
- Isolated or syndromic
- may be associated with cleft lip/palate
What are the clinical features of taurodontism?
- Pulp chambers – increased apico-occlusal height
- Mild to severe cases
- MC in permanent teeth
- May appear bilateral
What does this show?
taurodontism
What is hypercementosis?
- Non-neoplastic deposition of excessive cementum along the root
- Isolated or involve multiple teeth
- Generalized pattern: consider Paget disease
- Associated with local factors like trauma, inflammation
What are the clinical/radiographic features of hypercementosis?
- Thickening or blunting of the root surface
- MC in mandibular molars
- Frequency increases with age
What does this show?
hypercementosis
What is a dilaceration?
- Abnormal angulation or bend in the root
- Majority arise following injury that displaces the calcified portion of the tooth germ
- Idiopathic or syndromic
What are the clinical features of dilaceration?
- MC mand 3rd molars > max 2nd premolar > mand 2nd molar
- Bend occurs anywhere along the root
- Complications in extractions or endo
What are the different types of developmental alterations of structure?
- Amelogenesis imperfecta
- Dentinogenesis imperfecta
- Dentin dysplasia
- Regional odontodysplasia
What is amelogenesis imperfecta?
- A large group of hereditary conditions that show alterations in the enamel in the absence of systemic disease
- More than 14 different subtypes
- AD, AR, X-linked inheritance
- Affects deciduous and permanent dentition
In amelogenesis imperfecta, alterations in the enamel may arise at any of the following stages:
- Matrix formation: Hypoplastic
- Mineralization of matrix: hypocalcified
- Maturation of the enamel: hypomaturation
What are the clinical features of amelogenesis imperfecta?
- Hypoplastic type: may see pits, rows of missing enamel
- Hypocalcified type: enamel is soft, “cheesy”, easily lost
— Yellow, brown, orange - Hypomaturation type: enamel is soft
— Opaque white, brown
What disorder is this?
amelogenesis imperfecta
What disorder is this?
amelogenesis imperfecta
What is dentinogenesis imperfecta?
- Hereditary disturbance in the formation of dentin in the absence of any systemic disorder
- DSPP gene mutation
- AD inheritance
- Affects deciduous and permanent dentition
What are the clinical features of dentinogenesis imperfecta?
- Deciduous teeth affected more severely
- Permanent teeth: MC in incisors and 1st molars
- MC in White patients
- Blue to brown discoloration, distinct translucence
- Enamel strips from poorly formed dentin
What are the radiographic features of dentinogenesis imperfecta?
- Bulbous crowns, cervical constriction, thin roots
- Early obliteration of root canal and pulp chamber
OR
- Normal to enlarged pulp chambers
— Significantly enlarged pulp – “shell teeth”
What disorder is this?
dentinogenesis imperfecta
What disorder is this?
dentinogenesis imperfecta
What is dentin dysplasia I?
- Loss of organization of root dentin leads to shortened root length
- AD inheritance
- Type II thought to be a variant of dentinogenesis imperfecta
- Deciduous and permanent teeth affected
What are the clinical features of dentin dysplasia I?
- Enamel and coronal dentin well-formed
- Radicular dentin loses organization → short roots
- Tooth mobility and premature exfoliation
What are the radiographic features of dentin dysplasia I?
- Deciduous teeth: little or no detectable pulp, very short roots
- Permanent teeth: crescent shaped pulpal remnant, short roots
What disorder is this?
dentin dysplasia I
What is regional odontodysplasia?
- Nonhereditary developmental abnormality of teeth that affects enamel, dentin, and pulp
- Most cases are idiopathic, some syndromic
- May be due to alteration of vascular supply
What are the clinical findings for regional odontodysplasia?
- Enamel, dentin, and pulp affected
- MC maxillary anterior teeth
- Dx at time of eruption of primary and permanent
- Affects several teeth, quadrant distribution
- Impacted teeth, delayed eruption
- Erupted teeth are malformed, caries rampant
- Hyperplasia of overlying soft tissue
What are the radiographic findings for regional odontodysplasia?
- Extremely thin enamel and dentin
- Enlarged pulp chambers – ghost teeth
- Short roots may be observed
What disorder is this?
regional odontodysplasia
What is segmental odontomaxillary dysplasia?
Developmental disorder, affects jaw and overlying soft tissue
What are the clinical features of segmental odontomaxillary dysplasia?
- Painless, unilateral enlargement of maxillary bone
- Usually dx during childhood
- Hyperplasia of overlying gingiva
- Primary teeth may be hypoplastic
- Maxillary premolar teeth may be missing
What are the radiographic features of segmental odontomaxillary dysplasia?
- Thickened trabeculae, often vertically oriented
- Radiopaque, granular appearance
- Maxillary sinus may be smaller
What is the treatment for segmental odontomaxillary dysplasia?
- Remains relatively stable, may not require tx
- Surgical recontouring
What disorder is this?
Segmental odontomaxillary dysplasia
