Anomalies In Dentition Flashcards
What classifications of dental anomalies are there?
- Number
- Form
- Size
- Structure
- Colours
- Others
What anomalies in tooth number are there?
- Hypodontia
- Hyperdontia
- Variation in root number
How many teeth are there in primary dentition?
20
What is hyperdontia?
Where are they mostly found?
Are they mostly erupted?
Increase in tooth number. Presence of supernumeraries
Mostly found in premaxilla (90%) more common in males, permanent teeth.
Mostly unerupted (75%), usually incidental findings in radiograph
What are other names for supernumerary teeth?
Mesiodens (midline), paramolars (buccal/palatal of molar region), distomolars (distal of molars)
What is a supplemental supernumerary tooth?
Similar shape/size/form of tooth in the area that is found- may not be able to decide which is the supernumerary.
What are the forms of supernumerary teeth?
Conical, supplementary, tuberculate
What medical/dental conditions have higher association with supernumeraries
Cleidocranial dysostosis (have no collar bone): have a lot of supernumeraries but many remain unerupted Cleft palate (40% have supernumeraries in area of cleft due to disturbance of development of developing tooth buds)
What are the associated problems that supernumeraries cause?
- Impede/deflect path of eruption of permanent teeth
- Resorption of roots of adjacent teeth- buried supernumerary causing root resorption of nearby tooth
- Cyst @ buried supernumerary
What is the management for supernumeraries?
- Removal (extraction or surgery) Make sure the crown of associated tooth is fully formed- if not may cause hypoplastic permanent tooth, or dilaceration. Just have to extract before permanent tooth erupt, Scar tissue from extraction may cause difficulty in eruption
- Leave alone and review (if tooth is buried, not causing problem) X-ray every 5 years to see if any cystic changes
What is hypodontia?
Congenital absence of teeth
Oligodontia- 6 or more missing teeth
Anodontia- no teeth at all
Hypodontia associated with microdontia in severe cases
Is hypodontia more common in males or females?
Females
Which teeth are most often missing in hypodontia?
Caucasians- lower 5s followed by upper 2s
Mongoloids- lower incisors
What related syndromes/conditions are associated with hypodontia
Ectodermal dysplasia- scanty hair, eyebrows, pouty lips, bat ears
Ellis van Creveld Syndrome
Down’s syndrome
Cleft
What is the management for hypodontia?
Clinical and radiographic assessment
Regular preventive care (to prevent further loss of teeth)
Restore aesthetics/function
What extra/accessory root is common on lower 6s
Distolingual root
Which teeth commonly have extra/accessory roots?
Lower 6s, canines, premolars, teeth with large cusp of Carabelli (mesiopalatal of upper 6s/7s)
What dental treatment does extra roots affect and how?
Extractions- iatrogenic fracture/difficult to remove
Ortho- tooth might not move
Endo- missing root canal during endo will cause persistent infection
Which teeth are more affected by reduced root numbers
Single, pyramidal root form
<1% of 1st molars
15-40% of 2nd and 3rd molars
What are the two kinds of double teeth?
Fusion- 2 tooth buds join together, fewer total number of teeth
Gemination- 1 tooth germ splitting into 2, total tooth number correct
Which teeth are most commonly affected by double tooth
Incisors
What are implications of primary double tooth?
double permanent tooth, hypodontia or hyperdontia possible
Caries at joint
Resorption affect exfoliation and eruption
What are the management options for double tooth
Place fissure sealant if deep grooves present.
Monitor root resorption of primary double tooth to prevent delayed eruption of permanent successor
May need to divide tooth for aesthetic/ortho reasons (if they have separate pulp chambers)
When to intervene for double tooth
When permanent tooth supposed to be erupting
Where is talons cusp most prominent
Upper central incisors
How can you classify anomalies affecting enamel and dentine?
Genetic- enamel/dentine only OR systemic?
Environmental- localised or generalised?
Where is cusp of carabelli located
Mesiopalatal of upper 6, may also be seen on upper second primary molar
Usually bilateral
Implication of cusp of carabelli
May have associated root if large, be careful during exo
What is paramolar cusp
Extra cusp on buccal of molars
What are characteristics of hypomineralised AI
- Initial normal thickness of enamel
- Dark yellow/brown/chalky white depending on degree of hypomin
- Enamel may wear away to expose rough sensitive dentine
- Xray: difficult to distinguish enamel and dentine–> moth eaten appearance
- Hypomaturation- snowcapped teeth, some parts chalky white
What is dens in Dante
Severe form of dens invaginates, look like tooth within a tooth
Complications of dens invaginatus
Caries may develop in invaginatus
Enamel lining may be incomplete or very thin, dentin deficient hence when there are caries there is rapid involvement of th pulp —> direct communication with pulp leading to acute dental alveolar infection
Characteristics of X-linked AI
- males more severely and uniformly affected (no normal x chrom to balance out)
- females vertical bands of normal/abnormal enamel (1 normal x chrom)
- no male-to-male transmission
- heterozygous females may pass trait to children of any sex
Dens invaginatus more common in males or females
Males
What is dens evaginatus
Enamel covered tubercle projecting from tooth surface, usually occlusal
Which teeth are more likely to have dens evaginatus
Premolars
Canines, molars
Lower more likely than upper
Usually bilateral
Management of Leong’s premolar
PRR soon after eruption, reinforce tubercle with CR. This is to prevent fracture, allow slow natural attrition, allowing pulp to recede and lay down reactionary dentine
If evaginatus in occlusion, PRR with pulpal protection (always assume pulp exposed). Compare with baseline 6 months later on xray to check for continued root development ie vitality
Management of dilacerated tooth
If mild, tooth may erupt, then you can reshape for aesthetics
If fail to erupt, track down orthodontically or remove surgically.
What are the dental changes in a patient with congenital syphilis
Moon/mulberry molar
Hutchinson’s incisor
What is management for Molar-incisor hypomin
- SSC for molars if not suitable for CR/GIC
- CR veneers for incisors if aesthetics compromised
- If molars severly compromised, analyse occlusion, KIV extraction (timing to allow 7s to erupt in place of 6, extract when 7s’ furcation beginning to form)
What is moon’s and mulberry molar
Moon’s molar: reduction/narrowing of crown form towards occlusal surface of 6s
Mulberry: hypoplasia of early mineralising parts of 6s, cusps and fissures cannot be seen clearly
What syndrome is globodontia associated with
Otodental syndrome
How can you classify anomalies affecting enamel?
Genetic- enamel only OR systemic?
Environmental- localised or generalised?