Soft tissue response to orthognathic surgery in persons with unilateral cleft lip and palate.

Individuals with cleft lip and palate often require orthognathic surgery to establish facial harmony and optimal occlusal function. Surgery to the skeletal components of the face can accomplish predictable alterations in jaw relations. The soft tissue response to those skeletal movements, however, is difficult to predict, as it is also for the noncleft individual. In addition there is the variability of the repaired cleft lip. The study included 30 persons with complete unilateral cleft lip and palate, operated for midface deficiency using a Le Fort I maxillary advancement at a mean age of 18.0 years. Some relapse occurred in the immediate postoperative period, but after 1 year the mean advancement 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 negligible after that time. The ratio of upper lip advancement to underlying incisor advancement was 0.65 to 1. Although the lip response was highly correlated to the underlying bony movement, the variation was sufficient to preclude accurate prediction. The upper lip thinned with maxillary advancement, but this was not related to the original lip thickness. Coincident mandibular surgery had no appreciable effect on upper lip movement.