Facial mobility after bimaxillary surgery in class III patients: a three-dimensional study.

Quantifying soft tissue changes after orthognathic surgery is increasingly important in surgical planning, but little is actually known about the changes in facial mobility after surgery. In the current study, we investigated facial mimics in patients before and after orthognathic surgery. Eleven patients with jaw discrepancy requiring maxillary and/or mandibular surgery were considered. Facial landmarks were applied, and facial surface data were acquired using a three-dimensional laser scanner before surgery and after 3, 6, and 12 months. The facial movements were frowning, eye closure, grimace, smiling, and lip purse. They were described in terms of surface and landmark displacements. Mean and SD were calculated for the right and left sides of the face and compared with normal values previously obtained in control subjects. We compared the results in 4 groups of patients: all the patients together (group A), bimaxillary surgery (group B), basal surgery without ancillary procedures (group C), and basal surgery plus rhinoplasty and/or genioplasty (group D). After surgery, modifications of symmetry were evident in many subjects, but after 1 year, facial movements were statistically similar to presurgical registrations. In smiling, the single case observations revealed a postsurgical improvement of amplitude in 8 subjects. In conclusion, orthognathic surgery did not significantly modify facial mobility in the long term. On the contrary, the amplitude of movement during smiling seems to increase in the majority of subjects. Our evaluation of three-dimensional laser scanning of facial movement showed that it can detect small posttreatment changes on soft tissues.