Changes in dentoalveolar and facial heights during early and late growth periods: a longitudinal study.

This longitudinal study examined the dentoalveolar structures during early and late growth periods in 62 subjects (26 male, 36 female) with normal facial patterns and acceptable occlusions. Hand-wrist radiographs were assessed and subjects grouped accordingly as either early stage (group 1) or late stage (group 2). Group 1 comprised 30 subjects with skeletal development maturation stages between PP2= and MP3=, H or S. Group 2 comprised 32 subjects with skeletal development maturation stages between MP3u and Ru. Skeletal and dentoalveolar measurements and ratios were assessed at the beginning and end of the observation periods. Differences in measurements and ratios within each group were examined using paired t-tests. Differences between the 2 groups were evaluated using Student's t-tests. Increases in alveolar heights (except for upper posterior alveolar heights) differed between the groups. Vertical alveolar dimensions increased substantially in group 1 in comparison with group 2. With the exception of upper anterior alveolar heights, all increases in group 2 were statistically significant. As a result of differential growth in alveolar dimensions, lower facial ratio (Co-Go/ANS-Me) and overbite remained constant in both stages. Vertical alveolar growth exhibited regional differentiation according to the pubertal growth periods. Although this growth plays a role in the establishment of normal facial patterns and occlusion, it should also be considered with respect to the treatment and treatment stability of patients showing vertical facial discrepancies.