Background

Temporomandibular disorders (TMD) are wide spread in the population: prevalence studies have reported that approximately 75 % of the population has at least one sign of joint dysfunction (women ratio is 4:1), while approximately 33 % experience at least one of its symptoms [1]. This means that TMD is, overwhelmingly, the most common chronic orofacial pain problem confronting dentistry. As a chronic disorder TMD, for many patients, is an enduring, recurrent condition, which may also resist treatment, [2,3]. Furthermore, as a chronic pain condition, TMD is no exception to this clinical picture and abundant evidence has established the presence of psychological distress and psychosocial disability as well as increased health care utilization in important segments of the TMD clinical population [4,5]. There are indications that many patients suffering from TMD may also show a reduced Oral Health Quality of Life (OHQoL) [6-8]. However, in the great majority of pertinent articles related to TMD patients, OHQoL was not specifically addressed; instead aspects such as psychological impairment – i.e. depressive preoccupation, anxiety – were used as a surrogate parameters for OHQoL [9]. Reisine and Weber in 1989 used many aspecifical instruments as the McGill Pain Questionnaire and the State-Trait Anxiety Inventory [10]; moreover, other Authors [11-13] used not-validated instruments. Short Form 36-item Health Survey (SF-36) is the most widely used questionnaire to evaluate the Health-related Quality of Life[14,15]; some authors have used it and its abbreviated version a