Prevalence of malocclusion among adolescents in Ibadan, Nigeria.

The objective of this study was to determine the prevalence of malocclusion among predominantly Yoruba adolescents in Ibadan, Nigeria, and to compare the results with those of other authors. The sample for this epidemiological survey comprised 636 secondary school students, (334 [52.5%] boys and 302 [47.5%] girls), aged 12-17 years (mean age, 14.72 +/- 1.16 SD). The subjects were randomly selected, and none had received previous orthodontic treatment. Occlusal anteroposterior relationships were assessed based on the Angle classification. Other variables examined were overjet, overbite, crowding, and midline diastema. The results showed that about 24% of the subjects had normal occlusions, 50% had Class I malocclusions, 14% had Class II malocclusions, and 12% had Class III malocclusions. Over 66% had normal overbites, and 14% and 9% had increased and reduced values, respectively. Overjet relationship was normal in 66%, increased in 16%, and decreased in 8%. Crowding was observed in 20% of the subjects and midline diastema in 37%. No statistically significant differences were observed for any occlusal variables (P > .05). Class I malocclusion is the most prevalent occlusal pattern among these Nigerian students. Different patterns of Class II and Class III might be present for the dominant ethnic groups in the country. Therefore, a survey of the occlusal pattern in southeastern Nigerians (Ibo ethnic group) would appear to be worthwhile.