Hypodontia Flashcards
what is hypodontia?
CONGENITAL absence of one or more teeth
what is anodontia?
Complete absence of all teeth
[VERY VERY RARE]
what is severe hypodontia?
6 or more CONGENITALLY absent teeth
whats the prevalence of hypodontia?
approx 6%
what teeth are most affected by hypodontia?
8s, Lower 5s, Upper 2s, Upper 5s
Upper laterals common
what are some non-syndromic causes of hypodontia?
- Familial history of hypodontia
- Sporadic
- Mutations
what are some syndromic causes of hypodontia?
- Cleft lip & palate
- anhydrotic ectodermal dysplasia
what are some environmental causes of hypodontia?
- trauma
- radiotherapy/chemotherapy
How would a pt with hypodontia present with on a clinic?
- delayed or asymmetric eruption
- retained or intra-occluded deciduous teeth
- absent deciduous tooth
- tooth form
what are the associated problems with microdontia?
- malformation of other teeth
- short root
- impaction
- delayed formation/eruption of other teeth
- enamel hypoplasia
what problems can arise as a result of hypodontia?
- spacing
- drifting
- over-eruption
- aesthetic impairment
- functional problems
what is the hypodontia care pathway?
- GDP Recognition
- Referral to Specialist Orthodontist
- If appropriate, passed onto Hypodontia clinic (Ortho + Restorative input)
what investigations would be useful for a hypodontia patient?
- study models
- radiographs
- photographs
- Conebeam CT
what are the general treatment options for a pt with missing laterals?
- Accept
- Ortho alone
- Restorative alone
- Ortho & Restorative combined
if a pt has missing upper laterals what restorative tx options are available if there is an open space?
Common:
- resin bonded bridge
- implant
- partial denture
Less common:
- auto transplantation
- conventional bridgework
what are the advantages & disadvantages of a resin bonded bridge for a hypodontia patient?
Advantages
- simple
- non destructive
- aesthetically pleasing
Disadvantages
- it fails (comes off)
- appearance sometimes not ideal around gingival margins if high smile line
- pt needs good orthodontic retention so teeth dont drift
what are the key differences between a RBB vs Implant?
- cant do implant until pt has fully grown (21+)
- cost is high, lots of time needed
- sometimes bone graft required
- technique sensitive especially around gingival margins
- (spacing) implants need ~7mm space minimum so that the implant does not damage adjacent teeth roots
in a hypodontia tx plan, how do you make an upper canine look like a lateral incisor?
- fixed appliance that will EXTRUDE canine resulting in the gingival contour also changing to match a lateral incisor (lower gingival contour)
- significant reshape of canine (make more flat)
- bleaching (canines darker than laterals)
how do you make an upper premolar look like a canine?
- intrude premolar so gingival contour matches a regular canine. (higher gingival contour)
- rotate the tooth to take up space
- composite build up to match anatomy of canine
