[Longitudinal study on average craniofacial growth of skeletal C1. III girls in late adolescent period. Possibility of early orthognathic surgery].

The growth increments of Skeletal C1. III face during late adolescent period were investigated to estimate the possibility of earlier application of orthognathic surgery. Twenty C1. III Japanese girls, all requiring orthognathic surgery were investigated. Twenty C1. I girls were used as the control. The materials used in this study were lateral cephalometric X rays which were longitudinally taken at the age of 14 and 17 years respectively. Results were as follows: 1. The mean increments of maxilla and mandible showed no significant difference between C1. III and C1. I after the pubertal growth peak. 2. Ossification stage of the 3rd middle phalanx and the radium could be used as the maturity indicators for mandibular growth. Those were more reliable than the appearance timing of the menarche. Results are considered to be useful information for determining the timing of orthognathic surgery for Skeletal C1. III cases.