Dental Anomalies Part II Flashcards
what is amelogenesis imperfecta
- inherited genetic mutation
- isolate or syndromicc
- enamel is affected in all or nearly all teeth
what dentition is affected in amelogenesis imperfecta
primary and permanent
what is type 1 alemogenesis imperfecta
hypoplastic type: thinner but hard enamel
what is type 2 amelogenesis imperfecta
hypomaturation type: relatively hard but colored (not translucent)
what is type III amelogenesis imperfecta
hypomineralized or hypocalcified: softer rough colored undermineralized enamel
what is type IV amelogenesis imperfecta
hypoplastic- hypomature with taurodontism
describe the type 1 hypoplastic type amelogenesis imperfecta
- thin bur mineralized enamel. looks radiopaque
- quantitative enamel defect: failure during enamel matrix secretory stage (enamel agenesia is rare)
- generalized or localized, pits, striae, groove defects
- diffuse smooth or rough
- teeth appear white to yellow-brown, small, and square shaped
- open contacts “picket fence” appearance. flat occlusal surface, low cusps
- delayed eruption and increased impaction
describe type II amelogenesis imperfecta
- normal thickness of enamel. a qualitative defect
- soft enamel - as radiodense as dentin
- less translucid enamel: cloudy white, yellow or brown color
- hard and protective
describe type III amelogenesis imperfecta
- enamel of normal thickness but soft, porous and shedding easily from the dentin. normal shape at eruption
- these teeth are very sensitive even to physical contact with a toothbrush
- soft enamel that is less dense than dentin in radiographs
- grossly worn teeth to gingival level
- the color of enamel can range from white to creamy yellow-brown
describe dentinogenesis imperfecta
- primary dentition more severely affected
- amberlike translucency (yellow to blue-gray)
- enamel separates easily from dentin (faulty DEJ)
- accelerated attrition -> anterior open bite
- cervical constriction -> bulbous crown
- short and slender roots
- partial or complete obliteration of pulp chambers and canals
- types I, II and III
describe type I dentinogenesis imperfecta
- associated with osteogenesis imperfecta
- mutation in collagen synthesis genes
describe type II dentinogenesis imperfecta
- no skeletal defects
- enlarged pulp chambers in primary teeth (occasional)d
describe type III dentinogenesis imperfecta
- brandywine isolate
- found in people originating from southern maryland
- enlarged pulp chambers
- pulp exposure
what are the acquired abnormalities
- attrition
- abrasion
- erosion
- third molar impaction
what is attrition
physiologic wear of teeth
what is abrasion
mechanical wear of teeth
what is erosion
chemical wear of teeth
what are the ways third molars can be impacted
full impaction and partial impaction
what are the orientations for third molar impactions
- vertical
- inverted
- mesioangular
- distoangular
- horizontal
- inverted mesioangular
- inverted distoangular
