Mandibular mobility and the occurrence of occlusal interferences were assessed in a group of 42 subjects, all of whom underwent orthognathic surgery without maxillomandibular fixation. A minimum period of 3 months (mean of 12.9 months) had elapsed since surgery. Mandibular advancement (n = 8) and bimaxillary advancement procedures (n = 8) resulted in significantly greater end-of-treatment overjet than did Le Fort I (n = 12), mandibular setback (n = 3), or maxillary advancement with mandibular setback (n = 11). Mean maximum protrusion (5.9 mm) and mean maximum excursions to right and left (6.8 and 6.1 mm, respectively) were significantly higher after Le Fort I osteotomy. The frequency of right lateral, but not left lateral, non-working-side contacts was significantly greater in the mandibular setback group and the maxillary advancement with mandibular setback group. The mandibular setback group exhibited the only severe interference between r etruded contact position and intercuspal position.