Hypodontia in down’s syndrome patients

الملخص EN

Background: The intention of this study was to quantify the occurrence of hypodontia in a group of individuals with Down syndrome.

Materials and method : the sample consisted of 164 subjects with Down syndrome with an age ranged 14-18 years, the subjects were examined clinically, when radiographs were in need, orthopantomograph, occlusal, or periapical were often taken to confirm the diagnosis.

Results : the results show a notably high prevalence of hypodontia in individuals with Down syndrome (45.2 %) being higher in females (47.4 %) than males (42.3 %), the hypodontia in the maxilla was higher than in the mandible and on the right side of females was higher than the left side, while males show on the left side was higher than the right side though this difference was not significant.

The number of congenitally missing teeth also in females was higher than in males ; the most congenitally missing teeth were the lower second premolars, upper lateral incisors, lower second premolars and lower lateral incisors respectively.

The distribution of peg–shaped lateral incisors was 15 % and more unilaterally than bilaterally.

Conclusions : this study reveals a high prevalence of hypodontia (missing teeth and peg-shaped lateral incisors) in patients with Down syndrome.

No explanation other than genetics is immediately available to explain why hypodontia should represent another phenotypic expression of this trisomy.