Temporomandibular disorders and sleep disorders: which relationship?

The aim of this case-control study was to establish statistically significant associations between temporomandibular disorders (TMD) and obstructive sleep apnea (OSA) or excessive daytime sleepiness (EDS) using, respectively, the Douglass Sleep Disorders Questionnaire and the Epworth Sleepiness Scale.

A total of 100 patients affected by TMD and 100 age- and sex-matched controls randomly chosen from the general population, answered the 2 questionnaires, which investigated their sleep habits, sleep hygiene and sleep disorders. OSA was considered as present if the total Douglass questionnaire score reached or exceeded the cut-off point of 32 for women and 36 for men. The total score on the Epworth Sleepiness Scale was calculated for each subject, a total >10 considered to indicate the presence of EDS. The data were analysed by using the chi squared test.

EDS was found in 19% of the patients and in 10% of the control subjects, and OSA in 6 patients and in 4 control subjects. No statistically significant association emerged between TMD and OSA. EDS was more frequent in patients with myofascial pain. On the basis of the results of the first questionnaire, we were able to develop a profile of OSA patients: they are predominantly smokers, middle-aged (40-60 years old), overweight men.

Although most TMD patients complain of poor sleep quality, the age and sex prevalence of OSA was lower than that of TMD, and EDS was found to be present in only a few cases.