In a follow-up study of 24 patients with mesial bite operated on at the Department of Oral and Maxillofacial Surgery, University of Innsbruck Medical School, relations between the outcome of sagittal splitting and myofunctional disorders were investigated. Orofacial imbalances of variable extent were found to be present in 16 of the patients followed up. Effects of myofunctional factors on occlusal position, occlusion, overbite and overjet are reviewed. Five patients with particularly severe myofunctional disorders underwent detailed logopedic and myofunctional evaluation. Results are presented. As myofunctional factors may profoundly affect the late results of surgery, it is concluded that patients with myofunctional disorders should undergo adjuvant myofunctional rehabilitation before or at least after surgery in order to prevent relapses.