Prevalence of malocclusion and occlusal traits among adolescents and young adults in Rivers State, Nigeria.

Background and aims: A systematic and well-organized dental care program for any target population in a community requires some basic information, such as the prevalence of the condition to be assessed. Thus, the aims of this study were to determine the prevalence of malocclusion among predominantly Rivers State adolescents and to compare the results with other authors.

Methods: The sample which was randomly selected from seven secondary schools comprised 620 schoolchildren, 297 (48%) males and 323 (52%) females aged 13-20 years old with a mean age of 16.74 +/- 2.0 (SD) years. The children were examined for occlusal traits which included the occlusal antero-posterior relationship (Angles classification), overjet, overbite, openbite, crossbite, spacing and crowding. The Index of Complexity, Outcome and Need (ICON) protocol was employed in their classrooms using wooden spatulae and orthodontic millimeter rulers under natural illumination. None of the subjects had undergone any form of orthodontic treatment.

Results: Results showed that about 11.8% had normal occlusions, 80.3% had Class I malocclusions, 6.3% had Class II malocclusions (Div 1, 3.9%; Div 11, 2.4%) and 1.6% had Class III malocclusions. About 70% had normal overjets, normal overbite was seen in about 56%, whilst in the maxillary arch 14.4% had crowding and 60% spacing. Open bite was present in 7.1% while crossbite was found in 17.1%. Significant gender differences were found for overbite, overjet and Angles classification (P < 0.05).

Conclusion: Angles Class I malocclusion is the predominant occlusal pattern among these students. This finding compares favorably with other studies done in other parts of Nigeria.