Bilateral hypodontia is more common than unilateral hypodontia in children with Down syndrome: a prospective population-based study.

BACKGROUND

In individuals with simple hypodontia, congenital absence of teeth commonly affects just one tooth of a pair, not both. However, patterns of hypodontia have not been fully explored in children with Down syndrome (DS).

OBJECTIVE

We describe the frequency and left-right symmetry of hypodontia in the permanent dentition of 8- to 9-year-old Norwegian children with DS.

MATERIALS AND METHODS

This population-based cross-sectional study was part of a national prospective study evaluating upper airway function, hearing, dental, and craniofacial characteristics in a cohort of children with DS born in 2002. The cohort consisted of 29 children with DS and represented 57 per cent of all children born with DS in Norway in 2002. Hypodontia was assessed using panoramic and/or dental radiographs. Data were collected prospectively at TAKO-Centre, National Resource Centre for Oral Health in Rare Medical Conditions, Lovisenberg Diakonale Hospital, Oslo, Norway.

RESULTS

Hypodontia of permanent teeth, excluding third molars, was found in 61.5 per cent of the 26 children included in the final sample. Among the 16 children with hypodontia, 75.0 per cent were missing two or more permanent teeth. Two children (7.7 per cent) had severe hypodontia (oligodontia). The teeth most often missing were the maxillary lateral incisors, followed by the mandibular second premolars and maxillary second premolars. Most (68.9 per cent) cases of hypodontia occurred bilaterally.

CONCLUSIONS

The majority of the children with DS were missing one or more permanent teeth. Unlike in the general population, bilateral hypodontia was more common than unilateral hypodontia in this sample of children with DS.