This study investigated the soft tissue profile change of the chin following genioplasty. The subjects were 20 females who underwent genioplasty. They were divided into two groups depending on the directions of surgical displacement of the chin. In 11 patients anterior repositioning was made (forward movement group) and in 9 patients posterior repositioning was made (backward movement group).
For each patient, lateral cephalograms taken preand postoperatively were traced and superimposed, and then linear measurements were obtained.
The results were as follows: 1. There were differences in soft tissue reaction to hard tissue displacement between the forward movement group and backward movement group.
2. In the forward movement group, the size of the chin increased as a result of further forward displacement of soft tissue pogonion in spite of forward displacement of lower labial sulcus. In the backward movement group, the size of the chin decreased as a result of backward displacement of soft tissue pogonion and forward displacement of lower labial sulcus.
3. The horizontal displacement ratio of soft tissue pogonion to pogonion was 148% in the forward movement group, and 33% in the backward movement group.
4. There was a significant positive correlation between the horizontal change of pogonion and soft tissue pogonion, horizontal change of menton and soft tissue menton, horizontal change of pogonion and the size of the chin, and horizontal change of menton and the size of the chin. On the other hand, in the forward movement group, there was no correlation between skeletal changes and soft tissue changes of the chin.