We mailed questionnaires to all patients who had had sagittal split osteotomies alone (n= 84) or in combination with genioplasty (n = 37) between 1995 and 2000, to find out the incidence of postoperative sensory disturbances. The patients with sagittal split osteotomies alone reported sensory disturbance in 48/131 (37%) operated sides. When combined with genioplasty patients experienced them in 20/54 (37%) operated sides. The incidences were 36/101 (36%) for mandibular advancement and 12/30 (40%) for mandibular setback. Out of the patients with sagittal split osteotomies alone, 59/66 (89%) were satisfied with the result of the operation, and when combined with the genioplasty the corresponding figure was 23/27 (85%). We conclude that differences in the incidence of sensory disturbance after sagittal split osteotomy for mandibular advancement and setback were not significant. The combination with genioplasty did not increase the incidence of sensory disturbance. Sensory changes after the osteotomies do not serve to be the main determinant of the patients' satisfaction.