Prevalence of malocclusion among 12-15-year-olds in Moshi, Tanzania, using Bjork's criteria.

OBJECTIVE To assess the prevalence of malocclusion in 12-15 -year-olds in Moshi, Tanzania. DESIGN Cross-sectional study. SETTING Moshi Municipality, Kilimanjaro region, Tanzania. SUBJECTS Two hundred and eighty nine randomly selected primary school children (153 males and 136 females) had a clinical examination for malocclusion traits done. RESULTS The overall prevalence of malocclusion was 97.6%. Angle's Class II and III malocclusion occurred in 6.9% and 11% of the sample respectively. Crowding was encountered very frequently in both jaws, especially in the lower anterior segments. Anterior open bite occurred in 6.2% and the deep bite in 10.7% of the sample. There was no significant gender difference in either the overall prevalence of malocclusion or in the occurrence of the different occlusal traits. CONCLUSION It was noteworthy that some of the malocclusion traits recorded were relatively minor deviations from the normal occlusion. Hence the high prevalence of malocclusion did not necessarily imply a heavy burden of need and demand for orthodontic treatment.