SOFT-TISSUE RESPONSE TO ORTHOGNATHIC SURGERY IN PERSONS WITH UNILATERAL CLEFT-LIP AND PALATE

Individuals with cleft lip and palate often require orthognathic surge ry to establish facial harmony and optimal occlusal function. Surgery to the skeletal components of the face can accomplish predictable alte rations in jaw relations. The soft tissue response to those skeletal m ovements, however, is difficult to predict, as it is also for the nonc left individual. In addition there is the variability of the repaired cleft lip. The study included 30 persons with complete unilateral clef t lip and palate, operated for midface deficiency using a Le Fort I ma xillary advancement at a mean age of 18.0 years. Some relapse occurred in the immediate postoperative period, but after 1 year the mean adva ncement of the maxilla was 4.9 mm (best fit of anterior maxilla) and 5 .6 mm (incisal edge). Both skeletal and soft tissue changes were negli gible after that time. The ratio of upper lip advancement to underlyin g incisor advancement was 0.65 to 1. Although the lip response was hig hly correlated to the underlying bony movement, the variation was suff icient to preclude accurate prediction. The upper lip thinned with max illary advancement, but this was not related to the original lip thick ness. Coincident mandibular surgery had no appreciable effect on upper lip movement.