[Do temporomandibular disorders really exist?]

Temporomandibular Disorders (TMD) is a collective term embracing a number of clinical problems that involve the muscles of mastication, the temporomandibular joint (TMJ) and associated structures or both. This group of disorders has been identified as the chief cause of pain, which is not of dental origin, in the orofacial area, and is defined as a subgroup in the category of musculoskeletal disorders. These disorders impair the quality of life of those suffering from them due to the extent of the pain and the chronic nature of its symptoms. It is known that chronic pain causes the development of psychological disturbances (anxiety, depression, etc.). The most common symptoms of TMD are the pain that usually appears as the result of mandibular activity (speaking or chewing), and is usually located in the masticulatory muscles, in the preauricular area and the temporomandibular joint (TMJ). Additional common symptoms are: a. restriction in jaw movement; b. asymmetry in jaw movement; c. noises from the joint. Patients suffering from TMD are likely to exhibit additional symptoms: hypertrophy of the muscles of mastication (an adaptive and asymptomatic phenomenon), abnormal occlusar erosion due to nighttime or daytime bruxism, or teeth grinding. Most functional temporomandibular disorders have similar signs and symptoms. As a result, diagnosis of the various disorders presents a serious problem. Functional temporomandibular disorders are often accompanied by mental symptoms such as depression, anxiety and/or somatization on various levels. One of today's accepted methods of classification also refers to the mental aspect and thus enables, for the first time, a suitable scientific comparison of the epidemiological, diagnostic and treatment data in the various studies. This method, initiated by Dworkin and LeResche (1992) is known as Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). The purpose of this method is to classify every subgroup of TMD according to agreed upon, clear and measurable diagnostic criteria, both from the physical (AXIS I) and the mental (AXIS II) aspect. The method includes a scale which grades the extent of severity, damage and limitations caused by the illness, in a manner which now can make scientific comparisons between the various studies and between the population of patients and the general population. Temporomandibular disorders are very common and affect between 30%-50% of the population, and appear to be more prevalent among women than among men. Studies conducted on youth revealed significant relationships between oral parafunctions (especially chewing gum and "jaw playing"), and functional temporomandibular disorders. The significance of this finding is in the need to warn young people of the possible risks of engaging in intensive oral practices. The high prevalence of signs and symptoms among the Israeli population obligates us, in our opinion, to change the physical examination for identification of these disorders, to a routine procedure in all dental clinics in Israel.