Although the oncologic validity and perioperative complications of midline mandibular osteotomy are well described, little attention has been directed toward the long-term functional problems that may be associated with its use. Thirty-one patients who had undergone this procedure were examined to assess postoperative sensation, temporomandibular joint (TMJ) function, occlusion, and cosmesis. The majority (27 of 31) patients had some sequelae but these were minor in nature. Twenty of 31 patients had abnormal sensation, 24 of 31 noted a changed occlusion, and 15 of 31 had signs or symptoms of TMJ myofascial pain. Although patients should be advised of the potential for functional problems with this procedure, they can be reassured that these are likely to be relatively minor in significance. If technically feasible and if an exact restoration of occlusion is a priority, a prefabricated lingual splint should be used.