Bilateral sagittal split surgery is not a predictable treatment for temporomandibular dysfunction in patients with retrognathia

ObjectiveA prospective study to clarify the impact of forward bilateral sagittal split osteotomy (BSSO) on temporomandibular dysfunction (TMD).Study DesignWe examined and interviewed patients with BSSO before and at 1 year after surgery to evaluate the changes in TMD symptoms. A well-known TMD index, which incorporated two complementary subindices—the objective functional Helkimo dysfunction index (Di) and the subjective symptomatic anamnestic index (Ai)—was used. Patients with a forward movement of the mandible and osteosynthesis with titanic miniplates were included.ResultsForty patients (26 females and 14 males, mean age of study population 36.9 years) retrognathia completed the study. There was no change in TMD symptoms in 24 patients (60%), as measured by the Di, and 26 (65%), as measured by the Ai. Twelve patients improved (30%), according to the Di scores and 10 (25%) according to the Ai scores. Four patients had more TMD symptoms at follow-up (10%), as measured by both Di and Ai.ConclusionsSurgery for orthognathia is a predictable treatment for improving aesthetics and occlusion but less predictable for alleviating TMD symptoms in patients with retrognathia. TMD symptoms should therefore be treated independently.