The effect of orthognathic surgery on head posture

Changes in resting head and neck posture were studied in 201 patients following five different orthognathic surgery procedures: (1) LeFort I osteotomy for superior repositioning (intrusion) of the maxilla (n = 45); (2) bilateral sagittal split ramus osteotomy for mandibular advancement (n = 78); (3) mandibular setback (n = 19); (4) combined maxillary intrusion and mandibular advancement (n = 46); (5) combined maxillary intrusion and mandibular setback (n = 13). Head and neck posture were measured on standardized serial cephalograms taken in natural head position prior to, immediately after, and 1 year after surgery for each subject. Immediately after surgery, there was flexion of the head as measured by the craniovertical and craniocervical angles in all of the groups except the mandibular setback group, which showed little change. By 1 year post-surgery, the mean craniovertical and craniocervical angles were approximately the same as before surgery in the groups with one-jaw surgery. Statistically significant head flexion at 1 year (P less than 0.05) was observed in the combined maxillary intrusion and mandibular advancement group, and with maxillary intrusion plus mandibular setback, there was a trend toward persistent flexion. Neck posture showed no significant short- or long-term changes in any of the surgical groups.