The status of the developing occlusion of 8-9 year-old children from a lower socio-economic group in a developing...

The aim of this study was to determine the percentage of developing malocclusions that are present at the age of 8-9 years. This data will be used for a follow-up study on the same sample two years hence, in order to formulate soundly based recommendations to Public Health Authorities on the implementation of a community directed, preventive and interceptive orthodontic programme. A total of 936 children were examined by 3 investigators, at 9 primary schools in the lower socio-economic suburbs of a large urban area. The majority of subjects (66.5 per cent) presented with Class I malocclusions. A significantly higher percentage of white children however, presented with Class II malocclusions, while black children showed a higher tendency toward Class III malocclusion. Well circumscribed anterior openbites were found in 27.8 per cent of black children, but no specific causative factors could be identified. Early loss of primary molars and canines occurred in both groups. There was a statistically significant difference (p < 0.05) between the mean posterior arch lengths of the two groups, the black children having on average 2.2 mm longer arch lengths.