Changes in temporomandibular joint dysfunction after orthognathic surgery.
PURPOSE: We sought to evaluate the effects of orthognathic surgery on temporomandibular joint (TMJ) dysfunction in patients with known presurgical TMJ internal derangement who underwent double-jaw surgery for the treatment of dentofacial deformities. PATIENTS AND METHODS: Treatment records of 25 patients with magnetic resonance imaging and clinical verification of preoperative TMJ articular disc displacement who underwent double-jaw surgery only were retrospectively evaluated, with an average follow-up of 2.2 years. Signs and symptoms of TMJ dysfunction, including pain, range of mandibular motion, and presence/absence of TMJ sounds, were subjectively (visual analog scales) and objectively evaluated at presurgery (T1), immediately postsurgery (T2), and at longest follow-up (T3). Surgical change (T2-T1) and long-term stability of results (T3-T2) were calculated using the superimposition of lateral cephalometric and tomographic tracings. RESULTS: Presurgery, 16% of the patients had only TMJ pain, 64% had only TMJ sounds, and 20% had both TMJ pain and sounds. Postsurgery, 24% of the patients had only TMJ pain, 16% had only TMJ sounds, and 60% has both TMJ pain and sounds. Thus, presurgery 36% of the patients had TMJ pain, and postsurgery, 84% had pain. Average visual analog scale pain scores were significantly higher postsurgery and none of the patients with presurgery TMJ pain had relief of pain postsurgery. In addition, 6 patients (24%) developed condylar resorption postsurgically, resulting in the development of Class II open bite malocclusion. CONCLUSIONS: Patients with preexisting TMJ dysfunction undergoing orthognathic surgery, particularly mandibular advancement, are likely to have significant worsening of the TMJ dysfunction postsurgery. TMJ dysfunction must be closely evaluated, treated if necessary, and monitored in the orthognathic surgery patient.