An epidemiological survey of 972 children, 566 females (58.2%) and 406 males (41.8%) was conducted. The sample population was 11 - 12 year old (mean age 11.84 years) in high schools across the country. None of the subjects were undergoing or had previous orthodontic treatment. Occlusal and anterior posterior relationships were assessed based on BSI 1983 definitions. The two conditions that made up bimaxillary protrusion, bimaxillary prognathism and bimaxillary proclamation, were assessed using extraoral and intraoral parameters respectively.
Results:
Bimaxillary prognathism and proclination were found with 64.4% and 68.8% prevalence respectively. Both conditions were found across all ethnic groups but with significantly different prevalence rates. There was an association between oral habits and ethnicity. Class 1 incisor relationship, class 1 canines and average overbite were the most common occlusal relationships found.