Hypodontia Flashcards
hypodontia - define
congenital absence of one or more teeth
anodontia - define
complete absence of teeth
severe hypodontia - define
6 or more congenitally absent teeth
hypodontia prevalence
approx 6%
- excluding 8s
0.9% primary dentition
hypodontia most commonly affected teeth
- lower second premolars
- upper lateral incisors
- upper second premolars
- lower incisors
prevalence of missing upper lateral incisors
1-2% population
- approx 20% of all missing teeth
- associated with ectopic canines
hypodontia aetiology
non syndromic
- mutations in at least 3 genes associated with missing teeth in non-syndromic hypodontia
- familial
- sporadic
syndromic
- 100 craniofacial syndromes associated
- cleft lip and palate
- anhydrotic ectodermal dysplasia
environmental
- trauma
- radiotherapy or chemotherapy
hypodontia clinical presentation
delayed or asymmetric eruption
retained or infra occluded deciduous teeth
absent deciduous tooth
tooth form may be abnormal
hypodontia - associated dental problems
microdontia
malformation of other teeth
short root anomaly
impaction
delayed formation or eruption of other teeth
crowding or malposition
taurodontism
enamel hypoplasia
altered craniofacial growth
maxillary canine or first premolar transportation
hypodontia - potential consequences
spacing
drifting
over eruption
aesthetic impairment
functional problems
hypodontia care pathway
GDP recognition
referral to specialist orthodontist
hypodontia - missing upper lateral incisors - early intervention
extraction URb, ULb
sectional fixed appliance to close space between upper central incisors
allows eruption UR3 and UL3
hypodontia assessment and planning
history
extra oral exam
intra oral examination
- orthodontic aspects
- restorative aspects
investigations
problem list
definitive plan
retention and maintenance
hypodontia investigations
study models
planning models
radiographs
photographs
CBCT
missing upper lateral incisors - management options
accept
restorative alone
orthodontics alone
combination of ortho and restorative
ideal restorative option for a missing upper lateral incisor
resin bonded bridge
what is the ideal abutment for a resin bonded bridge (to fill the gap of a missing lateral) and why?
canine
- root length
- crown dimensions
- less shine through
resin bonded bridge advantages
relatively simple
can be done at young age
non-destructive
aesthetics
can be placed on semi-permanent basis
disadvantages of a resin bonded bridge
failure rate
orthodontic retention needs are high
can sometimes have poor appearance
Implant - indications
growth must have stopped
- must be over 21
require minimum 7mm space
often need bone graft
implant disadvantages - compared to RBB
significant extra time to do
significant cost
How to make a canine look like a lateral
extrusion of canine
significant reshape of U3
bleaching
how to make a first premolar look like a canine
intrude U4 to give correct gingival architecture
rotate to take up more space e
composite build up or veneer
vertical height and ‘caninise’ U4
Keys to successful hypodontia management
inter-disciplinary team
joint assessment and treatment planning with precise aims
joint collaboration at transitional stages of treatment
follow up of treated cases
