Changes in bite force and occlusal contact area after orthognathic surgeryfor correction of mandibular prognathism

Objective. This study examined the long-term changes of bite force and occl usal contact area in patients with prognathous after orthognathic surgery w ith a newly developed pressure-sensitive sheet (Dental-Prescale; Fuji Photo Film Co). Study Design. Fifty-seven patients with prognathous were examined. Bite for ce and occlusal contact area were measured just before operation and at 2 w eeks, 1 month, 3 months, 6 months, 1 year, 2 years, and 3 years after opera tion. Forty control subjects with normal occlusion were also measured. Results. The bite force and occlusal contact area of the patients were sign ificantly greater than the preoperative level at 1 year, 2 years, and 3 yea rs after operation. However, they were still significantly lower than the c ontrol subject level even at 3 years after operation. Conclusions. This study suggests that orthognathic surgery improves the bit e force and occlusal contact area of patients with prognathous. However, at 3 years from the time of operation, patients had not reached control subje ct levels.