Developmental Dental Anomalies I Flashcards
1
Q
Ameloblasts are extremely sensitive to ______ stimuli
A
external
2
Q
Does enamel remodeling occur after initial formation?
A
No… Abnormalities etched permanently on tooth surface
3
Q
What are the stages of enamel development?
A
- (1) Matrix formation: enamel proteins laid down
- (2) Mineralization: minerals deposited, original proteins removed
- (3) Maturation: final mineralization, remaining original proteins removed
4
Q
What is enamel hypoplasia?
A
large areas of missing enamel
- Pits, fissures, grooves
5
Q
What are enamel opacities?
A
areas of enamel hypomaturation
- diffuse or demarcated
- White, yellow, brown
6
Q
What is turner hypoplasia?
A
Periapical inflammatory disease or trauma of overlying deciduous tooth
7
Q
What are the clinical/radiographic features of turner hypoplasia?
A
- 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
8
Q
What does this show?
A
turner hypoplasia
9
Q
What is antineoplastic therapy?
A
- Developmental abnormalities secondary to use of radiation or chemotherapy
- Severity dependent on age of treatment, form of therapy, dose and field of radiation
- Radiation therapy – more severe alterations
10
Q
What are the clinical features of antineoplastic therapy?
A
- Radiation: Hypodontia, microdontia, radicular hypoplasia, enamel hypoplasia
- Chemotherapy: enamel hypoplasia, microdontia, occasionally radicular hypoplasia
11
Q
What does this show?
A
antineoplastic therapy
12
Q
What is dental fluorosis?
A
- Ingestion of excessive FL → significant enamel defects
- Retention of amelogenin proteins in enamel → hypomineralized enamel
- Dose dependent
13
Q
What are the clinical features of dental fluorosis?
A
- White, opaque enamel, with areas of brown/yellow discoloration
- Affected teeth are caries resistant
- Bilateral, symmetrical distribution
14
Q
What does this show?
A
dental fluorosis
15
Q
What is the treatment for enamel defects?
A
- Most defects are cosmetic
- Focal loss of enamel – increased prevalence of caries
- Composite restorations, veneers, full crowns
16
Q
What is the definition of tooth wear?
A
Considered pathologic when the degree of destruction creates functional, aesthetic, or dental sensitivity problems
17
Q
What is attrition?
A
- Loss of tooth structure due to tooth-to-tooth contact
- Poor-quality/absent enamel can accelerate process
- Clinical features:
— Incisal and occlusal surfaces
— Large, flat, smooth and shiny wear facets
— Slow loss of tooth structure, reparative secondary dentin forms
18
Q
What type of tooth wear is shown?
A
attrition
19
Q
What is abrasion?
A
- Pathologic wearing of tooth structure secondary to an external agent
- Toothbrushing MC
- Clinical features:
— Dependent on cause
— Toothbrushing: horizontal cervical notches on buccal surface
— Tobacco pipe, bobby pins: V-shaped notches on incisal edge
20
Q
What type of tooth wear is shown?
A
abrasion
21
Q
What is erosion?
A
- Loss of tooth structure caused by a non-bacterial chemical process
- Exposure to acidic source, reduced salivary flow
- Clinical features:
— Cupped lesion, central depression of dentin surrounded by elevated enamel
— May create concave sloping areas on palatal surfaces
22
Q
What type of tooth wear is shown?
A
erosion
23
Q
What is the treatment for tooth wear?
A
- Multifactorial cause
- Detailed diagnosis, preventative measures
- Erosion: may consider limiting toothbrushing 1x daily
- Restorative treatment: composite, veneers, full crown
24
Q
What is an extrinsic stain?
A
- Arises from the surface accumulation of exogenous pigment
- Usually can be removed with surface treatment
- Tobacco, bacterial stains, food + beverages, iron, restorative materials, medications
25
What is an intrinsic stain?
- Arises from endogenous materials that are incorporated into enamel and
dentin
- Cannot be removed by prophylaxis
- Amelogenesis imperfecta, dentinogenesis imperfecta, dental fluorosis, hyperbilirubinemia, trauma, medications
26
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
27
What are the clinical/radiographic features of internal resorption?
- Inflammatory resorption: resorbed dentin replaced by inflamed granulation
tissue
--- RG: well-circumscribed radiolucent enlargement of pulp chamber
- Replacement resorption: pulpal dentinal wall is resorbed with bone and
cementum-like bone
--- RG: partial obliteration of canal by bone (radiopacity)
- Coronal pulp affected → pink tooth of Mummery
28
What is shown here?
internal resorption
29
What is shown here
Internal resorption where coronal pulp affected → pink tooth of Mummery
30
What is external resorption?
- Loss of tooth structure along external surface of root
- Exposure of adjacent mineralized cementum to cemetoclasts
- Common causes: localized pressure (ie: orthodontic therapy), excessive occlusal forces, cysts, tumors
- Common!
31
What are the clinical/radiographic findings for external resorption?
- “moth-eaten” loss of tooth structure
- Over pulp chamber, radiolucency superimposed
32
What is shown here?
external resorption
33
What is ankylosis?
- Anatomic fusion of tooth cementum with the alveolar bone
- May be caused by trauma, chemical/thermal irritation, genetically decreased PDL
34
What are the clinical featurs of ankylosis?
- MC 1st-2nd decade
- MC mandibular primary first molar
- Mandible 10:1
- Ankylosis of permanent teeth uncommon
- Sharp, solid sound upon percussion
35
What are the radiographic features of ankylosis?
- Absence of PDL space (difficult to detect)
- Adjacent teeth inclined towards affected tooth
- Supraeruption of opposing tooth
36
What is the treatment for ankylosis?
For primary teeth (lack of exfoliation) → extraction
37
What is anodontia?
total lack of development of teeth
38
What is hypodontia?
lack of development of one or more teeth
39
What is oligodontia?
lack of development of 6 or more teeth
40
What is hyperdontia?
development of an increased # of teeth – supernumerary
41
Does tooth number anomalies have a genetic component?
YES!
- More than 200 genes associated with odontogenesis
- Syndromic and non syndromic
- MC genes implicated: PAX9, MSX1, AXIN2 genes (hypodontia)
42
What is the prevalence of hypodontia?
3-10% in permanent teeth
43
Absence of primary teeth correlates strongly with missing...
successor
44
What sydrome is associated with hypodontia?
ectodermal dysplasia
45
What are the clinical features of hypodontia?
- After 3rd molars, MC in 2nd premolar and lateral incisor
- MC in females
46
What does this show?
hypodontia
47
What are most cases of hyperdontia?
single-tooth supernumerary
| Positively correlated with macrodontia
48
What syndromes are associated with hyperdontia?
Cleidocranial dysplasia, Gardner Syndrome
49
What are the clinical features of hyperdontia?
- Single tooth hyperdontia: MC in anterior maxilla – mesiodens
- Accessory 4th molar: distomolar/distodens
- 2: 1 male
50
What is microdontia?
- Presence of unusually small teeth
- Genetic and environmental factors play a role
- Conditions: Down syndrome, pituitary dwarfism
- Isolated cases more common than diffuse cases
51
What are the clinical features of microdontia?
- Isolated microdontia: MC in max lateral – peg lateral
- MC in females
52
What is macrodontia?
- Teeth larger than average
- Genetic and environmental factors play a role
- Conditions: pituitary gigantism, XYY males, pineal hyperplasia, hyperinsulinism
- Isolated cases more common than diffuse cases
53
What are the clinical features of macrodontia?
- Isolated macrodontia: MC in incisors or canines
- MC in male
