Hypodontia Flashcards
Definition of hypodontia
congenital or developmental absence of one or more teeth
definition of anodontia
complete absence of teeth
definition of severe hypodontia
six or more congenitally absent teeth
what is the prevalence of hypodontia in the general population
6%
are more females or males affected by hypodontia
F>M
(6.3% : 4.6%)
is hypodontia more or less common in the primary denition - what is the % prevalence
hypodontia less common in primary dentition (<1%)
What teeth are most likely to be affected by hypodontia?
Lower 5’s
Upper 2’s
Upper 5’s
Lower incisors
(third molars - but not included in definition of hypodontia)
which teeth are most commonly dealt with by orthodontists?
upper lateral incisors
What % of the population have missing upper laterals
1-2%
What % of all missing teeth do lateral incisors account for?
upper lateral incisors account for 20% of all missing teeth
(therefore, most cases seen have missing U2’s)
What other problems are missing upper laterals associated with?
ectopic maxillary canines
3 aetiologies of hypodontia
- Non-syndromic
- Syndromic
- Environmental
How can the Non-Syndromic aetiology of hypodontia be described and divided?
Mutations in at least 3 genes associated with missing teeth in non-sporadic hypodontia
- familial (hereditary)
- sporadic (no FH)
How can Syndromic aetiology of hypodontia be described and name some syndromes associated
Missing teeth part of a bigger cranio-facial syndrome
examples:
- cleft lip and palte
- anhidrotic ectodermal dysplasia
- van der Woude
- Goldenhar
Give 2 examples environmental aetiologies of hypodontia
- trauma
- radiotherapy / chemotherapy at an early stage in life
