Prevalence of malocclusion and orthodontic treatment need in children and adolescents in Bogota, Colombia. An epidemiological study related to different stages of dental development

The aim of the study was to assess the prevalence of malocclusion in a popu lation of Bogotanian children and adolescents in terms of different degrees of severity in relation to sex and specific stages of dental development, in order to evaluate the need for orthodontic treatment in this part of Col ombia. A sample of 4724 children (5-17 years of age) was randomly selected from a population that attended the Dental Health Service; none had been or thodontically treated. Based on their dental stages the subjects were group ed into deciduous, early mixed, late mixed and permanent dentition. The reg istrations were performed according to a method by Bjork et al (1964). The need for orthodontic treatment was evaluated according to an index used by the Swedish National Board of Health. The results showed that 88 per cent of the subjects had some type of anomly , from mild to severe, half of them recorded as occlusal anomalies, one-thi rd as space discrepancies, and one-fifth as dental anomalies. No clear sex differences were noted, except for maxillary overjet, spacing, tooth size t all more frequent in boys), and crowding (more frequent in girls). Occlusal anomalies and space discrepancies varied in the different dental developme ntal periods, as did tipped and rotated teeth. Little need for orthodontic treatment was found in 35 per cent and moderate need in 30 per cent. A great need was estimated in 20 per cent, comprising children with prenormal occlusion, maxillary overjet, or overbite (>6 mm), posterior unilateral crossbite with midline deviation (>2 mm), severe crow ding or spacing, congenitally missing maxillary incisors, impacted maxillar y canines or anterior open bite (>3 mm in the permanent dentition). Urgent need for treatment was estimated to be 3 per cent, comprising subjects with extreme post- and pre-normal occlusion, impacted maxillary incisors or ext ensive aplasia.