Correlation between chronological age and skeletal maturity in different malocclusions: A retrospective study

The timing of initiation and duration of the pubertal peak is important in dentofacial orthopaedics as the mandible expresses maximum growth during the pubertal peak. The aim of the study was to compare the mean chronological age with skeletal age in three skeletal jaw relations.

The sample consisted of 787 cephalograms divided into class I, class II, and class III skeletal relationship, in which cervical vertebrae stages were assessed. Dunn test was used to compare different types of malocclusion. Pubertal peak duration was assessed by comparing the respective 95% CI.

There was no statistically significant difference in the mean chronological age in all three malocclusion groups at CS2, CS3, CS4 and CS5. There was no significant difference in the mean age of boys and girls at each CVM stage, but class III boys have significantly delayed maturity during the pubertal spurt at CS4 (14.6 years±0.98) compared with girls (13.3 years±1.48) with P=0.02. The pubertal peak duration was 1.27 years (CI: 0.77-1.76) in the class I children, 0.96 (CI: 0.58-1.34) in the class II children and 1.15 years (CI: 0.26-2.0) in the class III children. In the class III children, the duration of the pubertal peak was higher for boys, 1.74 years (CI: 0.66-2.82) compared with girls, 0.8 years (CI: 0.42-2.82).

There was positive correlation between chronological age and CVM stages in each skeletal jaw relation. Average time of attaining of a pubertal spurt is similar in class I, class II and class III children. Class III girls reach puberty slightly earlier than boys and puberty ends lately in class III boys. Class II boys have the shortest duration of the pubertal peak and class III boys have the longest duration of the pubertal peak.