ortho perspective on developmental anomalies Flashcards
are supernumeraries more common is men or women?
Men, twice as much as women
how are the conical-shaped teeth characterised and are they late forming or early forming?
peg shaped, early forming
how are the Tuberculate-shaped teeth characterised and are they late forming or early forming?
barrel shaped, late forming
name the different groups when classifying teeth by form/shape
1- Supplemental (extra tooth of normal (ish) form
3 - Conical – generally early forming and peg-shaped
3 - Tuberculate – generally late forming and barrel-shaped
4 - Odontome
what are the two different presentations of odontomas
- Compound – Containing many small separate tooth-like structures (denticles) –usually found anteriorly
- Complex – a large mass of disorganised enamel and dentine – usually found posteriorly
name the different groups when classifying teeth by site/ position
- Mesiodens – midline between the central incisors
- Paramolar / para premolar – adjacent to the molars/premolars
- Distodens/Distomolar – distal to the arch
where are the conical teeth usually found and what are the consequences on teeth appearance if they erupt
- they are usually found in the midline (mesiodens)
- if they erupt, they cause diastema
what is the risk of cystic formation and eruption impeding in the conical teeth
- low risk of impeding eruption and may erupt
- low risk of cystic formation or resorption
- Do Tuberculate teeth impede eruption?
- where does it usually found?
- is it fine to be left or does it need to be removed?
- yes they are more likely to impede eruption
- often found palatally
- need to be removed
what are the conditions associated with supernumerary?
- Gardner syndrome
- Cleidocranial dysostosis
- Cleft lip and palate
What does Gardner syndrome cause? and what condition of teeth is it associated with?
- associated with supernumerary
- a very rare inherited syndrome, which causes multiple precancerous polyps in the colon as well as tumours elsewhere, which can include osteomas in the skull.
- What does Cleidocranial dysostosis cause?
- What condition of teeth is it associated with?
- associated with supernumerary
- This condition which either inherited or a new mutation on the RUNX2 gene.
- Cleido – refers to the collarbones, and cranial refers to the skull.
- It causes the collarbones to be partly or completely missing, a hypoplastic maxilla making them usually look class III, and they will also often have multiple supernumerary teeth.
What are the problems with supernumerary teeth?
- Impede eruption of other teeth
- Cause displacement or rotation of erupted teeth
- Produce spacing between erupted teeth
- Contribute to crowding if they erupt
- Undergo cystic change
what genes associated with Hypodontia
MSX1
PAX9
AXIN2
what are the three different classifications of hypodontia and what do they mean
- Hypodontia – the absence of <6
- Oligodontia –the absence of ≥6 teeth
- Anodontia – the absence of all teeth
what are the conditions associated with Hypodontia?
- Cleft lip and palate
- Downs syndrome
- Ectodermal dysplasia
what is Ectodermal dysplasia? what does it cause and which condition of teeth is it associated with?
- a group of genetic disorders which involve defects of the hair, skin, nails, teeth, mucous
membranes and sweat glands. - Derived from the ectoderm
primary germ layer - Associated with Hypodontia
what is the treatment options for Hypodontia?
- Open up the space and add teeth as prosthetics
- Do ortho and close the gap to camouflage the missing teeth
what’s the definition of microdontia
Teeth which have smaller than average dimensions (more than 2 standard deviations) – range from mildly to severely
- Which tooth is mostly affected by microdontia?
- what treatment option is available for it?
- upper lateral (peg-shaped)
Treatment
- Accept – generally done if mild or in a less aesthetically challenging area e.g. upper 7s
- Create space to have the microdont teeth built up
- Extract the microdont tooth and close the space
Which teeth most commonly affected by macrodontia?
Upper 1s / lower 5s are most commonly affected – often bilateral
What is the treatment option for Macrodontia?
- Accept – generally done if mild or in a less aesthetically challenging area e.g. lower 5s
- Extract and reduce space for a normal-sized prosthesis
- Extract and close the space
- Camouflage restoratively to resemble 2 teeth e.g. if a very large upper 1 and missing upper 2 (crown will be put on top of 1 which has an attached 2)
What is the definition of Fusion?
fusion of 2 separate tooth germs leading to a reduced number of teeth in the arch (it looks like one tooth with a slight split in the middle)
What is the definition of Germination?
Developmental separation of a single tooth germ (one root but crown looks separated)
