Clinical Radiology - Developmental Anomalies Flashcards
1
Q
What are the 4 categories of dental anomalies?
A
Eruption/position
Shape/size
Number
Structure
2
Q
Movement of a tooth from its position of development to its functional location in the mouth
A
Eruption
3
Q
After the tooth is in full occlusion, slight ___________ continues to compensate for normal attrition and continued __________ growth of the face
A
eruption; vertical
4
Q
Emergence has not occurred within 12 months of normal range or when 75% of root is formed
A
Delayed eruption
5
Q
What are the 2 systemic causes of delayed eruption?
A
Endocrine disorders
Syndromes (Gardner, cleidocranial dysplasia, ectodermal dysplasia, Down’s)
6
Q
What are the 3 local causes of delayed eruption?
A
Physical barrier
Abnormal position
Trauma
7
Q
Rare non-syndromic eruption disorder where the tooth fails to erupt in the absence of any mechanical obstruction
A
Primary failure of eruption
8
Q
Disturbance of tooth eruption that results from fusion of cementum or dentin with alveolar bone
A
Ankylosis
9
Q
Cessation of eruption because of mechanical interference caused by a physical barrier
A
Impaction
10
Q
Which 2 teeth are most affected by impaction?
A
3rd molars and canines
11
Q
What word is sometimes used as a synonym for non-erupted (embedded)?
A
Impaction
12
Q
What’s the ratio for location (labial/palatal) of impacted canines?
A
1/3 labial
2/3 palatal
13
Q
What are the 2 types of dental anomalies related to position?
A
Orientation (tooth axis)
Location
14
Q
What are the types of malpositions of teeth?
A
Mesially angulated
Distally angulated
Transverse (buccolingual)
Horizontal
Inverted
Rotated
15
Q
Tooth develops in ectopic location or does not follow its usual eruption course
A
Ectopic
16
Q
Where are ectopic teeth most commonly found?
A
Alveolar process
17
Q
Where are ectopic teeth found in rare cases?
A
Non-dentate regions
18
Q
Change in order/position between 2 adjacent teeth in the dental arch
A
Transposition
19
Q
Is transposition found in primary dentition?
A
No
20
Q
Which 2 teeth most commonly experience transposition?
A
Upper canines and 1st molars
21
Q
What category does “transposition” and “transmigration” fall under?
A
Ectopic
22
Q
Displacement of teeth across midline
A
Transmigration
23
Q
What teeth most commonly experience transmigration?
A
Lower canines
24
Q
Unassisted migration of teeth within alveolar process mesially, towards midline
A
Physiological drift
25
Tendency of teeth to move mesially to maintain contact between teeth
Physiological drift
26
Is physiological drift a developmental anomaly?
No!
27
What does physiological drift cause changes in?
Occlusal plane
28
Excessive # of teeth
Supernumerary teeth/hyperdontia
29
Missing teeth (does not include 3rd molars)
Agenesis
30
What are the 3 types of agenesis?
Hypodontia (1-5 missing)
Oligodontia (6+ missing
Andodontia (all 32 missing)
31
Supernumerary teeth are often __________ or _________
embedded; unerupted
32
Supernumerary teeth have variable numbers, size, and locations, and tend to have variable ____________
morphology
33
Supernumerary tooth in the incisor region of the maxilla
Mesiodens
34
Supernumerary tooth in the molar region of the maxilla
Paramolars
35
Supernumerary tooth posterior to the 3rd molars
Distomolars (also called 4th molars)
36
Unusually large
Macrodontia
37
Unusually small
Microdontia
38
Types of dental anomalies in regards to shape of crown
Dens invaginatus
Dens evaginatus
Enamel pearl
Fusion
Germination
39
Types of dental anomalies in regards to shape of root/pulp chamber
Concrescence
Supernumerary roots
Taurodontism
Dilaceration
40
"Tooth within a tooth" - dens in dente
Dens invaginatus
41
Invagination of the enamel surface into the interior aspect of the tooth
Dens invaginatus
42
What is the order for teeth most affected by dens invaginatus?
Lateral incisors > central incisors > premolars > canines > molars
43
What are teeth with dens invaginatus filled with during development? What happens after eruption?
Soft tissue; becomes necrotic after eruption
44
After a tooth with dens invaginatus erupts, there is a potential space for entrapment of food debris and bacteria, making this tooth prone to what? What does this lead to?
Caries -> leads to apical periodontitis
45
Which type of dens invaginatus?
Confined to crown
Type I
46
Which type of dens invaginatus?
Extends below CEJ as blind sac, +/- pulp
Type II
47
Which type of dens invaginatus?
Transverses root, perforates laterally
Type IIIa
48
Which type of dens invaginatus?
Transverses root, perforates apically
Type IIIb
49
Most severe form; anomalous shape
Dilated odontoma
50
Evagination of enamel, causing an additional tubercle or cusp
Dens evaginatus
51
Additional cusp on posterior tooth
Leong premolar, occlusal pearl, evaginated odontoma
52
Which teeth are most commonly associated with dens evaginatus?
Mandibular premolars
Maxillary incisors
53
Name the characteristics of premolars affected by dens evaginatus
Central groove or lingual ridge
Usually bilateral
Pulpal extension common (can lead to pulpal pathosis)
54
Additional cusp on anterior teeth
Talon cusp, Eagle's talon, supernumerary cusp
55
Which surface is the additional cusp usually found on for anterior teeth?
Lingual surface
56
In dens evaginatus, the extra cusp on anterior teeth extends at least ____ the distance from the CEJ to the incisal edge
1/2
57
Ectopic hemispherical bulging on root surface
Enamel pearl
58
Well defined, small, radiopaque nodule on root surface, usually at furcation
Enamel pearl
59
What is the order for teeth most commonly affected by enamel pearls?
Max molars > man molars > premolars and incisors
60
Which teeth are more often affected by enamel pearls: permanent or deciduous?
Permanent
61
Adjacent teeth connected with each other
Fusion
62
Rare union of 2 adjacent tooth germs during development
Fusion
63
In fusion, what parts are usually connected together?
Enamel + dentin (rarely just enamel)
64
Which teeth are more often affected by fusion: permanent or deciduous?
Both
65
Which teeth are most commonly associated with fusion?
Incisors and canines (rare in posterior teeth)
66
Total number of teeth diminished by 1
Fusion
67
Partial development of 2 teeth from 1 single tooth germ
Gemination
68
Abnormally formed tooth with usually one root canal
Gemination
69
Total number of teeth in the arch is normal
Gemination
70
What do both fusion and gemination result in?
Enlarged, anatomically correct teeth
Bifid crowns w/ separated roots
Bifid crowns w/ one enlarged root (single or double canals)
71
What is complete gemination called? What does it result in?
Twinning
Results in increased total # of teeth
72
What may fusion occur with in rare cases? What does it result in?
Supernumerary tooth
Results in normal total # of teeth
73
What are the potential complications of fusion and gemination?
Tooth malalignment
Spacing
Dental arch symmetry
Susceptible to caries and perio
Poor esthetics
Impaction of adjacent tooth
74
Connection by root cementum alone
Concrescence
75
When does concrescence occur?
After crowns are formed
76
Which teeth are most commonly associated with concrescence?
Maxillary 2nd and 3rd molars
77
What are 2 possible developmental problems with concrescence?
Space restriction
Local trauma
78
What is a possible post-inflammatory problem with concrescence?
Apical periodontitis followed by partial resolution (large caries w/ pulpal drainage) and cemental repair
79
Abnormal angulation or bend in the root and less frequently, the crown
Dilaceration
80
Displacement of crown/root from normal alignment with each other
Dilaceration
81
What are the causes for dilaceration?
Idiopathic
Local obstruction
Mechanical trauma to primary during development of permanent germ
82
What is the order for teeth most affected by dilaceration?
Man molars > max 2nd premolars > man 2nd molars > incisors
83
How common is dilaceration?
Common (1%)
84
What are the implications of dilaceration for endo, exo, ortho, and pros?
Endo - perforation
Exo - fracture
Ortho - resorption
Pros - stress to abutment
85
What is the order for teeth most affected by supernumerary roots?
Molars (especially 3rd) > man premolars & canines
86
Additional (supernumerary) root on a molar specifically
Radix entomolaris
87
Increased apico-occlusal height of pulp chamber
Taurodontism
88
What does the pulp chamber resemble in taurodontism?
Cud-chewing animals (bulls)
89
Taurodontism causes ___________ displacement of the furcation in multi-rooted teeth
apical
90
What conditions/syndromes can be associated with taurodontism?
Cleft lip/palate
Down syndrome
Ectodermal dysplasia
91
What treatment is implicated in taurodontism?
Endo
92
What treatments are implicated in supernumerary roots?
Endo and exo
93
What are the degrees for severity in taurodontism?
Hypotaurodontism
Mesotaurodontism
Hypertaurodontism
94
Which structure related dental anomalies have to do with enamel (ectoderm)?
Turner hypoplasia
MI hypomineralization
Amelogenesis imperfecta
95
Which structure related dental anomalies have to do with dentin (mesoderm)?
Dentinogenesis imperfecta
Dentin dysplasia
96
Which structure related dental anomaly has to do with enamel (ectoderm) and dentin (mesoderm)?
Regional odontodysplasia
97
What is the make-up of enamel?
98% minerals
2% organic matrix + water
98
What is enamel produced by?
Ameloblasts
99
What occurs in the secretory stage of enamel?
Secretion of matrix proteins
100
What occurs in the maturation stage of enamel?
Mineralization
101
What are the factors for developmental defects in enamel?
Inherited vs environmental
Systemic vs local
Timing (prenatal, perinatal, postnatal)
102
Name examples of systemic reasons for developmental defects in enamel
Metabolic disturbances, infections, chemicals
103
Name examples of local reasons for developmental defects in enamel
Infections, trauma, radiation
104
What would you expect if a developmental defect in enamel occurred during the secretory stage?
The thickness of enamel would be reduced
105
What would you expect if a developmental defect in enamel occurred during the maturation stage?
The quality and mineralization of enamel would be reduced
106
Reduced thickness of enamel presenting as pits, grooves, thin, or missing enamel; affects 1 or more teeth
Enamel hypoplasia
107
Results from changes occurring during the stage of matrix formation in enamel (ameloblasts)
Enamel hypoplasia
108
What can cause enamel hypoplasia?
Stress (nutritional, trauma, infection)
Genetics
109
Localized quantitative enamel defect on permanent teeth caused by trauma or periapical disease of deciduous teeth
Turner's hypoplasia
110
What does the extent of the enamel defect in Turner's hypoplasia depend on?
Severity of infection or trauma
111
What teeth are most commonly affected by Turner's hypoplasia?
Premolars (infection)
Anterior maxillary teeth (trauma)
112
Spectrum of developmental qualitative hypomineralization enamel defects affecting the permanent 1st molars and incisors
Molar-incisor (MI) hypomineralization
113
Molar-incisor (MI) hypomineralization has variable severity, meaning what?
Can affect 1 to all 4 1st molars + incisors
114
Patients with Molar-incisor (MI) hypomineralization have a higher risk for what?
Caries
115
How common is Molar-incisor (MI) hypomineralization?
More common than we once thought - highly prevalent across the globe
116
Genetically inherited condition (absence of systemic disorder or known local factors); defective enamel formation and/or calcification
Amelogenesis imperfecta
117
Which teeth are more often affected by amelogenesis imperfecta: permanent or deciduous?
Both
118
Describe the genetic inheritance of amelogenesis imperfecta
Autosomal, X-linked
Dominant or recessive
119
What disease?
Small, discolored teeth
Enamel defects (pits, grooves, prone to wear, caries, breakage)
Amelogenesis imperfecta
120
What are the main types of amelogenesis imperfecta?
Hypoplastic
Hypomaturation
Hypocalcified
Hypomaturation-hypocalcified
121
What type of amelogenesis imperfecta?
Vertically reduced crown height
Reduced overall enamel thickness
Smooth appearance
Dentin, pulp chambers, roots may appear normal
Hypoplastic
122
What type of amelogenesis imperfecta?
Loss of coronal enamel
Rough appearance
Enamel and dentin have a similar density on X-rays
Hypocalcified
123
What is dentin produced by?
Odontoblasts
124
What is the make-up of dentin?
70% minerals
20% organic matrix + water
125
The ECM of dentin shares similar proteins with ________
bone
126
Mutations in genes coding for proteins common to both dentin and bone (type 1 collagen) lead to what types of defects?
Dentin and skeletal defects
127
T/F: Odontoblasts continue to function throughout life
True!
128
Rare hereditary developmental disturbance of dentin
Dentinogenesis imperfecta
129
Which teeth are more often affected by dentinogenesis imperfecta: permanent or deciduous?
Both
130
Describe the genetic inheritance of dentinogenesis imperfecta
Autosomal
Dominant or rescessive
131
What disease?
Opalescent teeth (amber/blue color)
Wear/enamel fractures
Bulbous crowns
Pulp canal obliteration
Dentinogenesis imperfecta
132
Which forms of dentinogenesis imperfecta?
Generalized (primary dentition more affected in type I)
Bulbous crowns due to cervical restriction
Pulpal obliteration
Short, thick roots
Dentinogenesis imperfecta types I and II
133
Which disease?
More common in primary dentition
Shell teeth - normal thickness of enamel with extremely thin dentin and enlarged pulp chamber
Dentinogenesis imperfecta type III
134
What are the types of dentinogenesis imperfecta?
Type I - associated with osteogenesis imperfecta
Types II and III - without other inherited disorders
135
Rare genetic condition characterized by normal enamel but atypical dentin with abnormal pulpal morphology
Dentin dysplasia
136
Which teeth are more often affected by dentin dysplasia: permanent or deciduous?
Both
137
Describe the genetic inheritance of dentin dysplasia
Autosomal dominant
138
What are the types of dentin dysplasia?
Type I - root
Type II - crown
139
What type of dentin dysplasia?
Short, abnormally shaped root
Merged roots
Complete or partial obliteration of pulp chambers
Dentin dysplasia type I
140
What type of dentin dysplasia?
Teeth are normal in color, shape, size
Abnormal pulp chambers - looks like a thistle tube
Leads to pulp stones/partial obliteration
Dentin dysplasia type II
141
Rare developmental anomaly of both ectodermal (enamel) and mesodermal (dentin, pulp, cementum) dental components
Regional odontodysplasia
142
Which teeth are more often affected by regional odontodysplasia: permanent or deciduous?
Both
143
Is regional odontodysplasia localized or systemic?
Localized within a segment or quadrant
144
What disease?
Look like "ghost teeth"
Hypoplastic/hypomineralized enamel
Defective layers of enamel + dentin
Enlarged pulp
Unerupted or erupted teeth
Regional odontodysplasia
