Dental Anomalies I Flashcards
ameloblasts are extremely sensitive to:
external stimuli
enamel defect may be caused by:
local or systemic factors
enamel remodeling does not occur until after:
initial formation
abnormalities are _____ on tooth surface
etched permanently
what are the stages of enamel development
- matrix formation: enamel proteins laid down
- mineralization: minerals deposited, original proteins removed
- maturation: final maturation, remaining original proteins removed. hard, translucent enamel
the timing of the enamel injury affects:
location and appearance of defect
the final enamel is a record of
all significant insults received during tooth development
what are the clinical features of enamel hypoplasia
- large areas of missing enamel
- pits, fissures, grooves
what are the clinical features of enamel opacities
- areas of enamel hypomaturation
- diffuse or demarcated
- white, yellow, brown
what is turner hypoplasia
periapical inflammatory disease or trauma of overlying deciduous tooth
what are the clinical and radiographic features of turner hypoplasia
- observed in permanent teeth- MC premolar
- traumatic cases- max central incisors
- focal areas of white, yellow, brown discoloration
- extensive hypoplasia- may involve entire crown
- RG: lack of enamel, irregular surface dentin
what does antineoplastic therapy cause
- developmental abnormalities from use of radiation or chemotherapy
- severity dependent on age of treatment, form of therapy, dose and field of radiation
- radiation therapy- more severe alterations
what are the clinical features of antineoplastic therapy from radiation and chemotherapy
- radiaiton: hypodontia, microdontia, radicular hypoplasia, enamel hypoplasia
- chemotherapy: enamel hypoplasia, microdontia, occassionally radicular hypoplasia
describe dental fluourosis
- ingestion of excessive FL -> significant enamel defects
- retention of amelogenin proteins in enamel -> hypomineralized enamel
- dose dependent
what are the clinical features of dental fluorosis
- white, opaque enamel with areas of brown/yellow discoloration
- affected teeth are caries resistant
- bilateral, symmetrical distribution
what is the treatment for enamel defects
- most defects are cosmetic
- focal loss of enamel- increased prevalance of caries
- composite restorations, veneers, full crowns
when is tooth wear considered pathologic
when the degree of destruction creates functional, aesthetic or dental sensitivity problems
what is attrition
loss of tooth structure due to tooth to tooth contact
- poor quality/absent enamel can accelerate the process
what are the clinical features of attrition
- incisal and occlusal surfaces
- large, flat, smooth and shiny wear facets
- slow loss of tooth structure, reparative secondary dentin forms
what is abrasion and what is the most common cause
- pathologic wearing of tooth structure secondary to an external agent
- toothbrushing is the most common cause
what are the clinical features of abrasion
- dependent on cause
- toothbrushing: horizontal cervical notches on buccal surface
- tobacco pipe and bobby pins: V shaped notches on incisal edge
what is erosion and what is it caused by
- loss of tooth structure caused by a non bacterial chemical process
- exposure to acidic source, reduced salivary flow
what are the clinical features of erosion
- cupped lesion, central depression of dentin surrounded by elevated enamel
- may create concave sloping areas on palatal surfaces
what is the treatment for tooth wear
- multifactorial cause
- detailed diagnosis, preventative measures
- erosion: may consider limiting toothbrushing to 1x daily
- restorative treatment: composite, veneers, full corwn
what are extrinsic stains, what are they caused by and what is the treatment
- arises from the surface accumulation of exogenous pigment
- tobacco, bacterial stains, food and beverages, iron, restorative materials, medications
- can be removed with surface tx usually
what are instrinsic stains, what are they caused by and what is the tx
- arises from endogenous materials that are incorporated into enamel and dentin
- amelogenesis imperfecta, dentinogensis imperfecta, dental fluorosis, hyperbilirubinemia, trauma, medications
- cannot be removed by prophylaxis
what is internal resorption
- loss of tooth structure on the dentinal walls of the pulp
- commonly arises secondary to inflammatory reaction
- continues if vital pulp tissue remains
what are the clinical and radiographic features of internal resorption
- inflammatory resorption
- replacement resorption
- coronal pulp affected -> pink tooth of mummery
what happens in inflammatory resorption
resorbed dentin replaced by inflamed granulation tissue
- RG: well circumscribed radiolucent enlargement of pulp chamber
what happens in replacement resorption
- pulpal dentinal wall is resorbed with bone and cementum like bone
- RG: partial obliteration of canal by bone - radiopacity
what is external resorption, what are the common causes
- loss of tooth structure along external surface of root
- exposure of adjacent mineralized cementum to cementoclasts
- common causes: localized pressure (ortho), excessive occlusal forces, tumors
what are the clinical and radiographic findings of external resorption
- “moth eaten” loss of tooth structure
- over pulp chamber, radiolucency superimposed
what is ankylosis and what is it caused by
- anatomic fusion of tooth cementum with the alveolar bone
- may be caused by trauma, chemical/thermal irritation, genetically decreased PDL
what are the clinical features of ankylosis
- most common in 1st-2nd decade
- most common mandibular primary first molar
- mandible 10:1
- ankylosis of permanent teeth uncommon
- sharp, solid sound upon percussion
what are the radiographic features of ankylosis
- absence of PDL space (difficult to detect)
- adjacent teeth inclined towards affected tooth
- supraeruption of opposing tooth
what is the treatment for ankylosis
for primary teeth (lack of exfoliation) -> extraction
what is anodontia
total lack of development of teeth
what is hypodontia
lack of development of one or more teeth
what is oligodontia
lack of development of 6 or more teeth
what is hyperdontia
development of an increased # of teeth
more than ____ genes associated with odontogenesis
200
tooth number anomalies are ____ and _____
syndromic and non syndromic
what are the genes most commonly implicated in tooth number anomalies
- PAX9
- MSX1
- AXIN2 genes
what is the prevalance of hypodontia and what is the associated syndrome
- prevalence of 3-10% in permanent teeth
- syndrome associated : ectodermal dysplasia
absence of primary teeth correlates strongly with:
missing successor
what are the clinical features of hypodontia
- after 3rd molars, most common in 2nd premolar and lateral incisor
- most common in females
most cases of hyperdontia represent as a:
single tooth supernumerary
what are the syndromes associated with hyperodntia
cleidocranial dysplasia and gardner syndrome
hyperdontia is positively correlated with:
macrodontia
what are the clinical features of hyperdontia
- single tooth hyperdontia: most common in anterior maxilla- mesiodens
- acessory 4th molar: distomolar/distodens
- 2:1 male
describe microdontia and the conditions associated with it
- presence of unusually small teeth
- genetic and environmental factors play a role
- isolated cases more common than diffuse cases
- conditions: down syndrome, pituitary dwarfism
what are the clinical features of microdontia
- isolated microdontia: MC in maxillary lateral- peg lateral
- most common in females
describe macrodontia and the conditions associated with it
- teeth larger than average
- genetic and enivronmental factors play a role
- conditions: pituitary gigantisim, XYY males, pineal hyperplasia, hyperinsulinism
- isolated cases more common than diffuse caseswh
what are the clinical features of macrodontia
- isolated macrodontia: MC in incisors or canines
- MC in males
