Background and aims:  Patients with temporomandibular disorder(TMD) also complain about sleep disturbances frequently. The sleep-wake pattern and sleep quality could effect on orofacial pain condition. Therefore, this study investigated the sleep-wake pattern and sleep quality in TMD & orofacial pain patients and evaluate the association between the sleep-wake pattern and sleep quality and pain condition via questionnaire.
Methods:  We examined 3,276 patients with TMD, who visited the Orofacial Pain Clinic at Yonsei University College of Dentistry during January 1, 2015 to August 31, 2016. We conducted a survey using the Pittsburgh Sleep Quality Index questionnaire and classified TMD patients into two groups based on Diagnostic Criteria for Temporomandibular Disorders. For statistical analysis, we calculated the correlations between pain intensity and various factors such as sex, age, total sleep time, sleep efficiency, sleep latency, the number of awakening episodes and hypnotic medication use.
Results:  The result from statistical analysis showed correlations between pain intensity and several factors including age and sleep efficiency. No significant correlation was shown for other factors such as sex, total sleep time, the number of awakening episodes and hypnotic medication use. 
Conclusions:  The sleep-wake pattern and sleep quality are highly associated with TMD & orofacial pain. Therefore, a sleep deprivation can cause chronic pain in the orofacial area. We found statistically significant associations between sleep deprivation and orofacial pain. These results imply that clinicians treating patients with orofacial pain should also examine the patients´ sleep-wake pattern and sleep quality.

A QUESTIONNAIRE STUDY ON SLEEP-WAKE PATTERN AND SLEEP QUALITY IN TMJ & OROFACIAL PAIN CLINIC