Clinical evaluation of the temporomandibular joint and masticatory muscles 10-15 years after mandibular setback surgery and six weeks of inter-maxillary fixation

Abstract

Objectives. The purpose of this study was to clinically evaluate the TMJs and masticatory muscles 10-15 years after orthodontic-surgical treatment of mandibular prognathism. Material and methods. Thirty-six patients where included in this study. All patients had been operated with the intraoral vertical ramus osteotomy (IVRO) technique and subsequent inter-maxillary fixation (IMF) for six weeks. Mean follow-up period after surgery was 12.5 years, and mean age at the long-term follow-up examination was 34.1 years (range 27.2 – 59.8 years). At the long-term follow-up consultation, the masticatory muscles and TMJs were examined according to the Helkimo clinical dysfunction index. The participants also completed a questionnaire. Results. Mean maximum unassisted mouth opening 10-15 years after surgery was 50.1 mm, (range 38-70 mm, SE 1.2). Statistically significantly greater in males compared to females (p=0.004). Mean Helkimo Dysfunction group was 1.5. None of the patients reported to have pain while chewing or opening the mouth on a weekly or daily basis. However, eight patients reported weekly (n=6) or daily (n=2) difficulties with maximum opening of the mouth. Conclusion. The results of the present study show that 10-15 years after IVRO setback surgery and subsequent IMF for six weeks, mandibular range of movement is satisfactory and the patients report few functional limitations or symptoms related to the TMJs and/or masticatory musculature.