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