Prevalence and Correlates of Malocclusion in 12-14 Year-old Tanzanian Schoolchildren

Prevalence of occlusal deviation provides information on treatment need at an age when orthodontic treatment should have been rendered. Objectives: to assess the prevalence of malocclusion and its association with socio-demographic characteristics, dental caries experience and oral hygiene in Tanzanian schoolchildren residing in two socio-economically different districts and who have no history of orthodontic treatment. Methods: A stratified proportionate two stage cluster sampling design was utilized. One thousand six hundred and one children (mean age 13 years, 60.5% girls) in Kinondoni and Temeke districts participated in clinical examination and were interviewed in school settings. Results: A total of 63.8% (62.6% in Kinondoni and 66.0 % in Temeke) of the subjects had at least one type of occlusal anomaly, with midline shift (22.5%), spacing of at least 2 mm (21.9%) and open bite (16.1%) being most frequently recorded. Majority (93.6%) of the children showed a Class I molar relationship, Class II and III were registered in 4.5% and 2%, respectively. Multiple logistic regression analyses showed that the odds ratio (OR) for having any type of malocclusion, midline shift, Angle Class II/III and open bite were respectively 1.7, 2.1, 2.4 and 1.7 if having DMFT > 0. The OR for having midline shift and open bite were respectively 1.3 and 1.8 if being a resident of Temeke (less socio-economically privileged) as compared to being a resident of Kinondoni (more socio-economically privileged). Oral hygiene score did not vary systematically with malocclusion. Conclusion: Malocclusions are prevalent in Tanzanian primary schoolchildren and comparable with non-industrialized communities. The prevalence is higher in children with caries experience and those from less socio-economically privileged district (Temeke). The most prevalent malocclusion traits were midline shift, spacing and open bite indicating that early preventive measures should be recommended.

Supported by Faculty of Dentistry, University of Bergen, Norway