Orthodontic treatment needs in an urban Iranian population, an epidemiological study of 11-14 year old children.

OBJECTIVES A preliminary study to investigate the orthodontic treatment need and its gender distribution in urban Iranian schoolchildren. STUDY DESIGN A cross-sectional study was carried out at the school premises. SUBJECTS AND METHODS For this survey, 502 subjects attending 6 different schools in the city of Isfahan, Iran (253 females and 249 males, aged 11-14 years) were randomly selected and examined, including those who were wearing an orthodontic appliance at the time of the survey (1 female and 5 males). IOTN (DHC and AC) scores were recorded for those who were not undergoing orthodontic treatment. One examiner, who had been formally calibrated in the use of occlusal indices, screened all schoolchildren. IOTN scores was calculated from direct examination. Gender dimorphism was evaluated by the Chi-square test (AC and DHC components of IOTN index). The prevalence of most severe occlusal traits in those who scored DHC 4 and 5 was calculated. RESULTS At the time of the survey, 1.1% of subjects were wearing an orthodontic appliance, 36.1% had definite need (DHC 4 or 5) for orthodontic treatment, 20.2% borderline need (DHC 3) and 43.8% showed slight or no need for treatment (DHC 1 or 2). Reviewing the AC scores, 17.9% of the studied subjects showed definite need (AC 8-10) for orthodontic treatment, 36.1% borderline need (AC 5-7) and 46% showed slight or no need for treatment (AC 1-4). The prevalence of the four most severe occlusal traits in those with definite orthodontic treatment need were: severe maxillary crowding (43.6%), increased overbite (39.1%), increased overjet (35.8%) and severe mandibular crowding (27.4%). No gender differences were found for AC (P>0.05) and DHC (P>0.05) of IOTN index. CONCLUSION Approximately one-third of Iranian school children were in need of orthodontic treatment, as determined by the index of orthodontic treatment need.