Dental Anomalies Flashcards
Conditions hyperdontia is associated with?
- Cleidocranial dysplasia
- Gardner syndrome
- Cleft lip and palate (-40% have supernumeraries in area of cleft)
Hyperdontia results in?
- Crowding
- Impede path of eruption of permanent teeth
- Resorption of root of adjacent teeth
- Cyst may develop around buried supernumerary teeth
Management of Hyperdontia
- Early diagnosis and treatment
- Removal by extraction or surgery before root of permanent tooth > 1/2 formed
Teeth most often absent in Hypodontia?
Terminal teeth of a series
- Third molars
- Mandibular 2nd premolar
- Maillary lateral incisors
- Maxillary 2nd premolar
- Mandibular central incisors
Etiology of Hypodontia?
- Environmental (trauma CT, RT)
- Genetic
- Non-syndromic: Mutations of PAX9, MSX1, AXIN2
- Syndromic: Ectodermal dysplasia, cleft lip/palate, trisomy 21
Management of Hypodontia
- Clinical and radiographic assessment -> Referral
- Regular preventive care
- Restore aesthetics/function -> Multi-disciplinary
Accessory roots are associated with what anatomical features?
Large cusp of Carabelli and paramolar tubercles
Accessory roots are more common in which teeth?
Lower 6s, canines and premolars
Reduction in root number are seen in which teeth?
<1% of 1st molars
15-40% of 2nd and 3rd molars
Most dental anomalies are more common in permanent teeth except?
Double tooth
Double tooth is most common in which teeth?
Incisors
Definition of Gemination
Budding of a second tooth from a single tooth germ
Features of Gemination
- One root canal present
- Bifid crown with single root and pulp chamber
- Familial inheritance
Definition of Fusion
Joining of two teeth of normal series or a normal tooth and supernumerary tooth by pulp and dentine
Features of fusion
- Two canals
- Number of teeth in dentition is normally reduced by 1 unit
Clinical Significance of Double Tooth
- Site of fusion may be at increased risk for plaque collection -> Caries or periodontal issues
- May retard eruption of permanent successor
Management of Double Tooth in Primary Dentition
- Fissure sealant in labial and palatal groove
- Monitor root resorption of primary double tooth to prevent delayed eruption of permanent successor
Management of Double Tooth in Permanent Dentition
- Permanent dentition: Surgical separation of fused teeth -> Orthodontic alignment and restorative treatment
- Reshaping or reduction of double tooth with single canal (gemination)
- Deliberate extraction and prosthodontic replacement
Definition of Concrescence
1.Joining of two teeth by cementum
- Fusion that occurs after root formation is complete
Concrescence is most common in which teeth?
Maxillary posterior region
Clinical significance of Concrescence?
Difficult extraction
What is a Talon Cusp?
Cusp projecting from cingulum of incisors
Talon Cusp is most common in which teeth?
Permanent incisors
Features of Talon Cusp
Consists of enamel, dentine and pulp horn
Accessory Cusps include?
- Paramolar cusp
- Cusp of carabelli
What is a Paramolar Cusp?
Extra cusp on buccal of molars
What is a Cusp of Carabelli?
Extra cusp on mesiopalatal of 6s, usually bilateral
Dens Invanginatus are most commonly seen in which teeth?
Maxillary lateral incisors
Types of Dens Invaginatus
Type 1: Above CEJ, Seal the groove
Type 2: Below CEJ
Type 3a: Communication laterally with periodontal ligament
Type 3b: Communication apically with periodontal ligament
Problems with Dens Invaginatus?
- Caries may develop in the invaginatus
- Enamel lining may be incomplete and dentin deficient in some areas → Direct communication with pulp → Acute dentoalveolar infection
Management of Dens Invaginatus
Prophylactic sealing of invaginatus soon after eruption
What is a Dens Evaginatus
Enamel covered tubercle projecting from tooth surface
Dens Evaginatus usually affects which teeth?
Premolars (Leong’s premolar), sometimes canines and molars
Problems with Dens Evaginatus?
Tubercle may fracture and cause pulpal infection
What condition is associated with Dens Evaginatus?
Rubinstein Taybi Syndrome
What is Taurodontism?
Describes a molar tooth with a pulp chamber that is vertically enlarged at the expense of the roots
What conditions is associated with Taurodontism?
- Ectodermal dysplasia (Hypodontia)
- Klinefelter’s Syndrome
- Tricho-dento-osseous syndrome
- 20% of A.I cases
What is dilaceration?
Abrupt deviation of long axis of crown or root portion
Etiology of dilaceration
- Trauma to primary dentition (2-5 yo)
- Idiopathic or developmental disturbances
Management of Dilaceration
If mild, the tooth may erupt then reshape for aesthetics
If fail to erupt, tracking tooth down orthodontically or remove surgically
What is a Hutchinson’s incisor?
- Barrel-shaped (Incisal-edge < cervical width)
- Incisal angles rounded, edge may be notched
What is a Moon’s molar?
Reduction of crown form towards occlusal surface of 6’s
What is a mulberry molar?
Hypoplasia of early mineralising part of 6’s
What is Globodontia?
Globular deformity of crowns of canines and posterior teeth of both dentitions
Associated conditions with Globodontia?
Otodental syndrome
- Rare, AD condition
- High frequency deafness from childhood
Microdontia is most common in which teeth?
Maxillary lateral incisors, 2nd premolars, 3rd molars
Microdontia is more common in permanent or primary dentition?
Permanent
What is the inheritance pattern of microdontia?
AD with incomplete penetrance