Congenital absence of one or more teeth due to a developmental defect. Dental agenesis is the most common dental anomaly, with prevalence ranging from 1.6 % to 9.6 %. The main genes associated with syndromic and non-syndromic dental agenesis are : EDA, EDAR, EDARADD, MSX1, PAX9, IRF6, GREM2, AXIN2, LRP6, SMOC2, LTBP3, FGFR1, IRF6, LRP6, PITX2, WNT10A, WNT10B.

Dental agenesis must be confirmed by radiographs and includes :

-        hypodontia: absence of 1 to 5, usually permanent, teeth. This anomaly is common in the population (wisdom teeth in particular). Hypodontia is more frequent in permanent dentition (around 5 %) than in temporary dentition (0.4 to 0.9 %). In addition to the third molars (highest prevalence at 20 % of the population), the most commonly missing teeth are 2nd premolars (2.9 % - 3.2 %), followed by maxillary lateral incisors (1.5 % - 1.8 %).

-        anodontia is the total absence of teeth. It is always syndromic.

-        oligodontia, characterized by the congenital absence of more than 6 temporary/permanent teeth (excluding wisdom teeth). Oligodontia affects 0.14 % of the population.

It can be :

-                isolated

-                associated with other manifestations as part of certain syndromes.

The syndromes most often associated with oligodontia are (see these terms):

-        Hypohidrotic Ectodermal Dysplasia.

-        incontinentia pigmenti

-        EEC syndrome (Ectrodactyly- ectodermal dysplasia clefting syndrome)

-        trisomy 21

-        Kabuki syndrome

-        blepharo-cheilo-odontic syndrome

-        Axenfeld-Rieger syndrome

-        Van der Woude syndrome

-        Johanson-Blizzard syndrome

-        ulnar-mammary syndrome

-        Sotos syndrome

-        tuberous sclerosis of Bourneville

-        Zlotogora-Ogur syndrome (cleft lip and palate-ectodermal dysplasia syndrome)

-        Witkop syndrome (hypodontia-nail dysplasia syndrome).

Apart from esthetic and orthodontic problems, the main problem is the major risk of early cancer in cases of hypodontia or anodontia: hepatoblastoma (< 3 years of age, HR 4.20), neuroblastoma (< 3 years of age, HR 4.20), nephroblastoma (< 3 years of age, HR 4.59), osteosarcoma (10-20 years of age, HR 2.19), colorectal cancer (< 40 years of age, HR 2.81) or bladder cancer (< 30 years of age, HR 3.35).

Anesthetic implications:

none

References : 

-        Eiset SE, Schraw J, Vrelits Sorensen G, Gregersen PA, Rasmussen SA, Ramlau-Hansen CH, Lupo PJ, Hasle H.
Congenital tooth agenesis and risk of early-onset cancer.
JAMA Network Open. 2024;7(3):e240365. doi:10.1001/jamanetworkopen.2024.0365

Updated: April 2024