Aetiology Of Malocclusion - Local Factors Flashcards
Give some local causes of malocclusion
Hyper/hypodontia
Variation in tooth size or form micro/macrodontia
Abnormalities of tooth position
Local ab normalities of soft tissues
Local pathology
How may there be a variation in tooth number?
Hyper/hypodontia
Variation in timing
- retained primary teeth
- early loss of primary teeth
- unscheduled loss of permanent teeth
What are the 4 types of supernumerary teeth?
Conical
Tuberculate
Supplemental
Odontome
What is a conical tooth? Where often found? Any issues?
Small and peg shaped
Close to midline
Usually 1/2
Tend to not prevent eruption but can displace teeth
What is a tuberculate tooth? Issues?
Paired and barrel shaped
Tend to remain unerupted
Often causes maxillary incisors to unerupt
What is a supplemental tooth? What teeth does this often happen to
Extra tooth of normal morphology
Maxillary laterals or lower incisors
What is an odontome? Issues?
Disorganised mass of dentine, pulp and enamel
Often prevent eruption and need extraction
What would this clinical presentation indicate?
Deciduous centrals remain but laterals erupted
Tuberculate supernumerary teeth preventing centrals to erupt
Or previous trauma damaged tooth germ
Define hypodontia
What teeth are most commonly found missing?
Developmental absence of one or more teeth
Maxillary laterals and 5s
When may alarm bells sound with regards to retention of deciduous teeth?
More than 6 months between Shedding of contralateral teeth
Why may deciduous teeth stay retained?
No successor beneath
Ectopic successor (abnormal position) - check for buccal canine bulge from 9yo onwards
Ankylosed primary molars (roots permanently fused to alveolar bone) - makes sharper sound and less mobile when tapped
Delayed development
Pathology or supernumerary teeth
What is balancing extraction?
Extracting same tooth on opposite side of same arch so midline shift is minimised
What is compensating extraction?
Extract tooth from opposing arch of the same side
- so occlusal relationship is maintained
What treatment would be considered for early loss of primary
Incisors
Canines
Molars
Incisor = little impact and no extraction
Canine = consider balanced extraction to minimise midline shift
Molar = more space loss in max vs man, Es lose more spacer than Ds
What would occur with a unscheduled loss of a central incisor?
What treatment would be ideal?
Early = drifting of teeth
Late = long term space
Maintain space with simple denture or reimplant tooth
What clinical presentations often occur with microdontia and macrodontia?
Micro
- spacing
- link to hypodontia
- poor aesthetics
Macro
- crowding
- asymmetry
- poor aesthetics
What clinical presentations may indicate a patient has ectopic canines?
Obvious bumps at 3
2s inlcined, mobile or discoloured
How are ectopic canines detected and treated?
2 radiographs needed
- OPT and upper anterior oblique occlusal
Management
- extract c
- surgical exposure and ortho alignment
- extraction
What may cause unerupted upper centrals?
- trauma to predecessor leading to ankylosis or displacement of germ
- supernumerary odontome or tuberculate teeth
What is a tooth transposition? Where most common? Treatment?
Interchange in the position of two teeth
Often 1st premolar and canine (maxilla)
Lower canine and incisors (mandibular)
Accept, extract, correct
What local abnormalities of soft tissues may occur?
Digit sucking
Fraenum
Tongue thrust
How may the labial fraenum affect tooth position?
Low fraenum can cause median diastema
