Prevalence of occlusal deviations and orthodontic treatment in the Northern Finland Birth Cohort of 1986

OBJECTIVE: To investigate the prevalence of occlusal deviations and received orthodontic treatment in a Finnish adult population, and to assess variation by sex. MATERIALS AND METHODS: The data (n = 1,746) are part of the Northern Finland Birth Cohort 1986 (NFBC1986). A clinical oral examination, including 3D intraoral scanning and self-completed questionnaires was carried out when the subjects were 33-35 years old. Registration of occlusion was done in connection with clinical oral examinations and from 3D dental models. RESULTS: Over half of the subjects (52.5%) had received orthodontic treatment, and it was more common among females compared to males. Almost half (47.5%) had at least one occlusal deviation, with the most common deviations being increased overbite ≥ 5 mm (26.3%), increased overjet ≥ 5 mm (9.2%), anterior crossbite at least in one tooth (5.0%), and lateral crossbite (4.9%). The prevalence of occlusal deviations was higher among males and subjects with orthodontic treatment history compared to females and the untreated group. CONCLUSIONS: Occlusal deviations and orthodontic treatment history were common, although severe deviations were relatively rare. Occlusal deviations were slightly more prevalent among males and in the treated group, whereas orthodontic treatment history was more common among females.