Dental abnormalities Flashcards
(45 cards)
Anomalies occurring during dental lamina formation stage? (induction & proliferation)
Hypodontia/oligodontia/anodontia Supernumerary teeth Double teeth (fused/geminated) Odontomes (complex/compound) Odontogenic tumors (ameloblastic fibroma/fibrodentinoma/fibro odontoma) Odontogenic keratocysts
Anomalies occurring during histodifferentiation? (dental tissue dev.)
Regional odontodysplasia
Anomalies occurring during morphodifferentiation? (size & shape)
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Macrodondia
Microdontia
Dens invaginatus
Dens evaginatus
Carabelli trait
Talon cusp
Taurodontism
Hutchinson’s incisors and mulberry molars in congenital syphilis
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Anomalies occurring during matrix deposition?
Enamel: Amelogenesis imperfecta Chronological enamel hyperplasia Molar-incisor hypoplasia Enamel opacities Fluorosis
Anomalies occurring during matrix deposition?
Dentine: Dentinogenesis imperfecta Dentinal dysplasia Vitamin-D resistant rickets Pre-eruptive intracoronal resorptive lesions
Anomalies occurring during eruption & root development?
Premature eruption
Natal & neonatal teeth
Delayed eruption
Ectopic eruption
Eruption cyst
Transposition of teeth’
Impactions
Arrested root development from systemic illness or treatment thereof
Failure of eruption in: amlg. imperf., cleidocranial dysplasia, cherubism
Failure of eruption associated with inflammatory follicular cysts
Most common teeth to be affected in hypodontia?
Primary dentition:
- Maxillary central>lateral incisors
Permanent dentition:
- Maxillary lateral incisors
- Mandibular 2nd premolars
- Mandibular central incisors
Hypodontia can be manifested in many syndromes:
Ectodermal dysplasia Dento-alveolar clefting Incontinentia pigmenti Trisomy 21/down syndome Chondro-ectodermal dysplasia (Ellis van Creveld syndrome) Reiger syndrome
Ectodermal dysplasia
X-linked recessive defect Defects in: sparse, brittle, light hair; -dry, pale, scaly, sensitive skin; -nails thick/thin, abnormally shaped, discolored, brittle; -sweat glands missing or malfunctioning Teeth: hypodontia or peg-shaped/pointed Hypoplastic enamel, deficient ridge Full lips, small nose
Cleft lip & palate also possible in severe conditions, with most teeth missing in primary & permanent dentition
Solitary median maxillary central incisor syndrome (SMMCI)
One incisor located in maxillary midline
Mutation in chr 7 - sonic hedgehog gene
Associations: hypoplasia of sella turcica, pituitary disfunction, GH def and shortness
Can present with other midline disturbances: Cleft palate, choanal stenosis/atresia, imperforate anus, umbilical hernia
Treatment: ortho- & prosthodontic
Hyperdontia
Supplemental - extra normal tooth
Supernumerary - dysmorphic and/or reduced (small, conical)
Associated syndromes:
Cleft lip & palate
Cleidocranial dysplasia
Apert syndrome, Gardner syndrome, Down syndrome, Crouzon disease, Sturge-Weber syndrome, Hallermann-Streiff syndrome
Hyperdontia (supernumerary) related complications
Ectopic eruption
Dentigerous cyst formation
Pericoronal space ossification
Crown resorption
Microdontia can be associated with?
Associated with: Hypodontia (often affects max lat. inc & 3rd molar) Congenital hypopituitarism Ectodermal dysplasia Down syndrome
Microdontia has 2 forms:
True generalized microdontia:
Teeth have normal structure but smaller than normal teeth
Occur in pituitary dwarfism
Generalized relative microdontia:
Teeth have normal size, but jaw is larger than usual, therefore they appear relatively small
Macrodontia
General: involves all teeth
Pituitary gigantism
Local - unilateral congenital hemifacial hypertrophy:
Can look like fusion or gemination of adjacent teeth
Most common: maxillary incisor
Rhizomicry
Small root-to-crown size
Systemic conditions: Osteoporosis, dentinal dysplasia
Local factors: trauma, pulpal infection, radiation during root development, root resorption
Accessory cusps:
Talon & carabelli’s cusp
Talon:
Cusp-like cingulum on maxillary anterior teeth (most common central incisors)
Treatment: reduce height over time –> allow reactionary dentine to form inside pulp
Carabelli:
Permanent: maxillary 1st molar
Primary: maxillary 2nd molar
Double tooth
fusion, gemination, concrescence
Radiology necessary to determine pulpal fusion
More common anteriorly than posteriorly
Double tooth in primary often follows by aplasia of successor teeth
Associations:
Down syndrome
Thalidomide embryopathy
Cleft palate
Gemination vs Fusion vs Concrescence
Gemination:
One bud gives rise to two teeth (joined crowns) with one root, being counted as one tooth.
Fusion:
Two buds develop separately and join later, having two canals, thus the tooth count is reduced
However if a normal tooth is fused to a supernumerary, the tooth number is still normal
Concrescence:
Two teeth joined by the cementum
Evagination/dens evaginatus
Small tubercle on occlusal part, central on fissure
When fractured during normal wear and tear –> pulpal exposure & involvement
Premolars most common, then molars
Treatment: grinding over time to allow formation of reactionary dentine in pulp, removal of tubercle and partial pulpotomy
Dens invaginatus
Invagination of dental papilla during development, infolding of enamel
Dentine can start from tip of cusps or foramen cecum and extend deep into root
Most commonly maxillary lateral incisors
Taurodontism
Body of tooth and pulp chamber are elongated vertically, while the roots are short and underdeveloped, the furcation having moved far down apically
Failure of Hertwig’s epithelial root sheath to invaginate at horizontal level
Affects molars
Qualitative defects of dental hard tissue?
Opacity - hypomineralization
Demarcated opacity - well demarcated, white, yellow, brown
Diffuse opacity - no clear boundaries
Quantitative defects of dental hard tissue?
Hypoplasia - deficient enamel formation
Enamel is thin, pitted, grooved, even missing
Associated with: Down syndrome Epidermolysis bullosa Tuberous sclerosis Treacher Collins syndrome Phenylketoneuria Lesch-Nyhan syndrome Fanconi syndrome Strurge-Weber syndrome Turner syndrome
