The Course of Temporomandibular Pain in Response to Mandibular Advancement Therapy Among Adults With Temporomandibular Disorder and Obstructive Sleep Apnea

Two chronic health conditions are treated with oral appliances during sleep. One condition is temporomandibular disorder (TMD); a musculoskeletal disorder characterized by pain in the masseter muscle and temporomandibular joint. TMD pain is treated with a stabilization splint which operates by limiting abnormal muscle activity. The other condition is obstructive sleep apnea (OSA). Mild to moderate OSA is treated with a mandibular advancement splint (MAS) which holds the mandible in a protruded position to increase the pharyngeal airway space and reduce upper airway collapsibility.

The comorbidity of the two conditions is high. Approximately one in four patients with clinically diagnosed TMD has OSA diagnosed by polysomnogram (PSG). This comorbidity poses a problem for management because neither appliance is considered effective in treating both conditions. In fact, mandible advancement is assumed to worsen TMD pain. However this assumption is not well supported by scientific evidence, with some studies finding that mandibular advancement actually reduces TMD pain, albeit after a transient increase in TMD pain in some patients. Furthermore, anecdotal evidence suggests that mandibular advancement reduces TMD pain. It is believed that by maintaining an open airway with the oral appliance, patients no longer have to clench their teeth in an effort to prevent the airway from collapsing during sleep.

The overall objective of this study is to characterize the temporal nature of TMD pain in adults with comorbid TMD/OSA treated with MAS therapy. It is the first study to monitor adherence to MAS therapy objectively in this study population, using a microsensor embedded in the MAS.

Recruitment and MAS therapy will be conducted at Lane and Associates Family Dentistry; a group of 27 dental practices located throughout the Triangle and Triad region of North Carolina. Advantages of using Lane & Associates are: large influx of new dental patients every month, fast recruitment, well-established protocols for screening for TMD and OSA and for referral of patients to sleep physicians for evaluation and PSG, standardized protocols for oral appliance therapy, and a Dental Sleep Medicine director who is highly experienced also in the management of TMD. The study coordinator is a dental hygienist in the University of North Carolina (UNC) School of Dentistry Dental Sleep Clinic who works in the School's Dental Sleep Medicine practice. She will travel to the Lane & Associates offices to assist in clinical and administrative activities and will manage all data collection for the 12 subjects. The Dental Sleep Clinic at the UNC School of Dentistry is not considered adequate to serve as the study site because it currently operates only one day a week and accepts referrals for only patients without TMD pain.

In the pre-enrollment phase, patients at Lane and Associates Family Dentistry will complete a standard TMD screening questionnaire. Those screening positive will be clinically examined against Research Diagnostic Criteria for TMD to confirm Group II: Masticatory Muscle Disorders, 1A: Myalgia. They will also be screened for OSA using the validated STOP-BANG questionnaire. Those at high risk will be referred for evaluation by a sleep physician and a diagnostic PSG, as is the standard of care at Lane and Associates. If the PSG reveals mild to moderate OSA (apnea-hypopnea index (AHI) ≥5 and <30), the patient is a candidate for oral appliance therapy, pending confirmation of the sleep physician, and thus eligible to enroll in the study.