Developmental Dental Anomalies Flashcards
What are the 5 categories of dental anomalies
Eruption/Position
Shape/size
Number
Structure
Movement of a tooth from its position of development to its functional location in the mouth
Eruption
After the tooth is __, slight eruption continues in order to compensate for normal attrition and continued vertical growth of the face
full occlusion
Know the difference between the dental papilla and dental follicle
dental papilla is found at the apex of the tooth and the dental follicle is found near the crown (Pic in powerpoint)
Movement of eruption when the first part of the cusp or crown is visible through the gingiva. This process normally occurs when the dental root is approximately 2/3 its final length
Emergence
When emergence has not occurred within 12 month of the normal range or when 75% of root is formed
Delayed eruption
What are some systemic causes of delayed eruption
endocrine disorders
syndromes
Local causes of delayed eruption
Physical barrier
Abnormal position
Trauma
Rare non-syndromic eruption disorder where the tooth fails to erupt in the absence of any mechanical obstruction
Primary failure of eruption
Disturbance of tooth eruption that results from the fusion of cementum or dentin with the alveolar bone
Ankylosis
Cessation of eruption because of mechanical interference caused by a physical barrier
Impaction
What teeth are the most affected with impaction
3rd molars and canines are the most affected teeth
Impaction is sometimes used as synonym for __
non-erupted (embedded)
With impaction whats the average amount that is palatal and labial
1/3 labial
2/3 palatal
(if the tooth looks more enlarged its most likely palatal)
What are the different malpositions possible
Horizontal
Inverted
Rotated
Mesially angulated
Distally angulated
Transverse (Buccolingual)
Change in orientation of the tooth axis
Malpositions
What tooth most commonly has malpositions
Impacted 3rd molars
Tooth develops in ectopic location or does not follow its usual eruption course
Ectopic
Ectopic teeth are most commonly in the
alveolar process
(Rare cases in non-dentate regions)
Change in order/position between two adjacent teeth in the dental arch
Transposition
Transposition is most common in
upper canines and 1st premolars
Is transposition reported in primary dentition
NO
Displacement of teeth across the midline
Transmigration
Transmigration is most common in
lower canines
Unassisted migration of teeth within the alveolar process mesially, towards the midline
Physiological Drift
Physiological Drift is the tendency of teeth to move __
mesially to maintain contact between teeth
Physiological drift is associated with __ tilting , and changes in __
mesial
occlusal plane
Excessive number of teeth (>32)
Supernumerary teeth
Hyperdontia
Missing teeth
Agenesis (not 3rd molars)
Missing 1-5 teeth
Hypodontia
Missing 6+ teeth
Oligodontia
Missing all 32 teeth
Anodontia
Variable numbers, size, and locations, and tend to have variable morphology. Often embedded or unerupted
Supernumerary teeth
Supernumerary teeth in the incisor region
Mesiodens
Supernumerary teeth in the molars region (buccal or lingual)
Paramolars
Supernumerary teeth posterior to 3rd molars
Distomolars or 4th molars
Unusually large teeth
Macrodontia
Unusually small teeth
Microdontia
Tooth within a tooth
Dens invaginatus (Dens in dente)
Invagination of the enamel surface into the interior aspect of the tooth
Dens invaginatus (Dens in dente)
Most common teeth for Dens invaginatus
Lateral incisors> Central inc > Premolars > Canines > Molars
Dens invaginatus: filled with soft tissue during dental development, which becomes __ after eruptions
necrotic
After eruption, potential space for entrapment of food debris and bacteria, prone to dental caries leading to apical periodontitis
Dens invaginatus
Classification of Dens invaginatus
Type I = confined to crown
Type II = Extends below the CEJ as a blind sac, +/- pulp
Type IIIa/IIIb = Transverses root, perforates laterally (a) or apically (b)
Most severe form of Dens invaginatus, anomalous shape
Dilated Odontoma
Evagination of the enamel. Additional tubercle or cusp
Dens evaginatus
ADditional cusp of a posterior tooth (Leong premolar, occlusal pearl, evaginated odontoma)
Dens evaginatus
Dens evaginatus is most commonly seen where
Premolars in the mandible
Dens evaginatus is usually in the __, unilateral or bilateral? A __ is common
Central groove or lingual ridge
Bilateral
Pulpal extension
A dens evaginatus on an anterior tooth’s palatal surface, common in the maxillary lateral or central incisors
Talon cusp (eagles talon or supernumerary cusp)
A talon cusp extends at least __
1/2 the distance from the CEJ to the incisal edge
Ectopic hemispherical buldging on root surface
Enamel Pearl
Well defined, small, radiopaque nodule on root surface, usually at a furcation
Enamel Pearl
Are enamel pearls more common on permanent or deciduous teeth
Permanent
Where are enamel pearls most common
Max molars> man molars» premolars and incisors
Adjacent teeth connected with each other
Fusion
Rare union of 2 adjacent tooth germs during development
Fusion
Fusion is usually between
Dentin and enamel (rarely just enamel)
Fusion can be seen on primary and permanent dentitions and is usually between __ and is rare in __
incisors and canines
Posterior teeth
Clinical appearance of a large and wide tooth
Fusion
With fusion the number of teeth changes how
Diminished by 1
Partial development of two teeth from one single tooth germ
Gemination
Abnormally formed tooth with usually one root canal
Gemination
How is the total number of teeth different with gemination
Total number of teeth in arch is normal
Tooth may present the same for both of these, so thats why its important to count teeth to see if number is normal or if one is missing
Fusion or gemination
__, referred to as twinning, will result in increased number of teeth (rare)
Complete gemination
Fusion may occur with a __ giving a normal tooth count for fusion, but its still not gemination
supernumerary
Connection by root cementum alone
Concrescence
Concrescence occurs after __
roots have been formed (Thicker cementum layer unites roots)
What teeth most commonly show concrescence
Maxillary 2nd/3rd molars
Possbile etiologies for concrescence
Developmental
Post Inflammatory
Abnormal angulation or bend in the root and less frequently the crown
Dilaceration
Displacement of crown/root from normal alignment with each other
Dilaceration
Out of all the dental anomalies a dilaceration is the most __
idiopathic (don’t know what caused it)
Dilacerations are common/uncommon? Where do we see it occur
Common (1%)
Mand molars > Max 2nd premolars > Man 2nd molars > incisors
Where do we most often see supernumerary roots
Molars (especially 3rd) > mand premolars/canines
Name for a 1st molar with an extra disto-lingual root
Radix Entomolaris
Increased apico-occlusal height of the pulp chamber
Taurodontism
Resembles shape of cud-chewing animals - bull tooth
Taurodontism
With Taurodontism there is apical displacement of the __ in a __ tooth
furcation
multirooted tooth
Common with cleft lip/palate, down syndrome or ectodermal dysplasia
Taurodontism
Taurdontism has implications for __ treatment
endodontic
3 types of taurodontism
Hypo-
Meso-
Hyper-
(Look at pics)
Produced by ameloblasts- specialized, end-differentiated cells
Enamel
Secretion of matrix protein by ameloblasts
Secretory stage
Mineralization of the matrix
Maturation stage
Enamel developmental defects can be caused by what 4 things and can occur at what 3 times
inheritied, systemic, enviornmental, local
Prenatal, perinatal, postnatal
Broad term for reduction in enamel thickness
Enamel hypoplasia
Reduced thickness of enamel results from changes occurring during the stage of __
Matrix formation
Enamel hypoplasia is caused by a source of __ to organism or hereditary
stress
Localized quantitative enamel defect on permanent teeth caused by trauma or periapical disease of deciduous
Turner’s Hypoplasia
With Turners hypoplasia, Extension of defect depends on the __
severity of the infection or trauma
Turners hypoplasia is more common in __ and __
premolars (infection)
anterior maxillary (trauma)
Spectrum of developmental qualitative hypomineralization enamel defects affecting the permanent first molars and incisors
MIH - Molar-incisor hypomineralization
MIH has variable severity
One to all four 1st molars and incisors (localized to extensive defects)
MIH has considerable higher risk of __
caries
MIH is currently a __ especially in __
global concern
School-age kids
Genetically inherited condition (absence of systemic disorder or known local factors). Defective enamel formation and/or calcification
Amelogenesis imperfecta
What type of teeth are usually involved in amelogenesis imperfecta
both the deciduous and the permanent dentitions
Clinically presents as small, discolored teeth with enamel defects
Amelogenesis imperfecta
4 main types of amelogenesis imperfecta
Hypoplastic
Hypomaturation
Hypocalcified
Hypomaturation-hypocalcifies
Produced by odontoblasts- specialized, end-differentiated cells
Dentin
Rare hereditary developmental disturbance of the dentin
Dentinogenesis Imperfecta
(Impacts deciduous and/or permanent dentition)
Opalescent teeth, amber-blue, wear / enamel fractures, bulbous crowns, pulp canal obliteration
Dentinogensis imperfecta
Types of dentinogenesis imperfecta
Type I - Associated with osteogenesis imperfecta
Type II and III - without other inherited disorders
Bulbous crowns due to cervical restriction. Short thick roots. Pulp obliteration (see no pulp tissue)
Dentinogensis imperfecta types I and II
Shell teeth - normal thickness enamel with extremely thin dentin and enlarged pulp chambers. More common in primary dentition
Dentinogenesis imperecta type III
Rare genetic condition characterized by normal enamel but atypical dentin with abnormal pulpal morphology
Dentin Dysplasia
Type I vs Type II Dentin dysplasia
Type I effects root
Type II effects crown
Thistle tube shape pulp chamber
Type II crown dentin dysplasia
Rare developmental anomaly of both ectodermal (enamel) and mesodermal (dentin, pulp, cementum) dental components
Regional Odontodysplasia
Has a localized occurrence within a segment or quadrant of the dentition.
Region odontodysplasia
Characterized by ghost teeth, unerupted or erupted
Regional odontodysplasia