Dental malocclusion in native children of British Columbia, Canada.

Since 1972, the Medical Services Branch (MSB), Pacific Region of Health Canada, has conducted quadrennial surveys of the dental health status of Native children in British Columbia (B.C.), Canada. This paper will analyze the findings related to dental malocclusion. Data from the most recent survey in 1988 are compared to data from 1980, and also to similar data from the most recent B.C. Children's Dental Health Survey. Prevalences of abnormal and severe malocclusion are also compared to the original 1972 data. Methods used in the surveys were detailed in a previous paper (I). Significant decreases in the percentage of children with drifting due to premature space loss (P < 0.05), as well as a slight decrease in the percentage of children with crowding were observed. A trend towards an increase in Class II molar relationship was demonstrated, but was not consistent for all age groups. In contrast, there was a slight, but consistent, trend towards a decrease in the percentage of children with an anterior openbite. Comparisons between the age groups demonstrated an increased prevalence of abnormal molar relationship, drifting due to space loss, crowding, crossbite, and overjet greater than 4 mm in children older than 7 years. Native children had a significantly greater prevalence of Class III molar relationship, crossbite, crowding, negative overjet, and anterior openbite than other schoolchildren in B.C. (P < 0.05). However, percentage of Native children with a severe malocclusion decreased significantly from 1972 to 1988 for 7, 9, and 11 year old children (P < 0.05), but for 13 and 15-yr-olds. Improvement has occurred over time in some aspects of dental malocclusion in these Native Canadian children, but malocclusion continues to be a frequent problem, especially amongst adolescents.