The longitudinal development of malocclusion in postnormal children with little respectively urgent need for orthodontic treatment.

The development of overjet, overbite and first molar relationship was followed longitudinally in 30 children with Class II malocclusion. They received no orthodontic treatment during the 7-year registration period. Models were taken each year between 7 and 14 years of age. The need for orthodontic treatment was defined using a 4-grade treatment priority index issued by the National Swedish Board of Health. The postnormal children were classified into two groups according to the need for treatment at the time when the first model was taken (age 7). The "treatment index 1" group (= group 1) consisted of 18 mild postnormal cases with little need for treatment. The "treatment index 3" group (= group 3) consisted of 12 cases with urgent need for treatment according to the priority index. All cases were Class II:division 1 with proclined incisors. For group 1 a significant increase in overjet and overbite was found over years. No uniform pattern in the longitudinal development of overjet and overbite was found for group 3. No clear changes in the first molar relationship in either group were found. Interceptive treatment in the mixed dentition is suggested favourable in postnormal cases, even when the malocclusion initially is mild in order to avoid an increase in overjet and overbite.