I J Pre Clin Dent Res 2015;2(1):38-43 International Journal of Preventive & January-March Clinical Dental Research All rights reserved Myofascial Pain - Dysfunction Syndrome: A Dilemma for the Clinicians Abstract Ravi Patel1, Himanshu Arora2, The MPD syndrome is a psychophysiologically altered condition 3 4 involving the muscles of mastication and cervical group of muscles. The Sarfaraz Memon , Usha Sharma , Ramjee Lal Raigar5, Anant Raghav condition characterized by dull aching, radiating pain often results in 6 muscle spasm and restricted movements. Frequently, myofascial pain is Sharma overlooked as a common cause of chronic pain because of frequent 1General Practitioner, Dr Ravi’s Dental Clinic, association with joint dysfunction and other pain disorders. Thus, the Surat, Gujarat, India therapy should be directed towards reducing stress, rehabilitating the 2Senior Lecturer, Department of occlusion and relaxing the muscles to alleviate the condition. Prosthodontics, Crown and Bridge Key Words Implantology, Manubhai Patel Dental College, Vadodara, Gujarat, India Myofascial; pain; temporomandibular joint 3Senior Lecturer, Department of Prosthodontics, Crown and Bridge Implantology Manubhai Patel Dental College, Vadodara, Gujarat, India 4Senior Lecturer, Dept. of Oral Pathology, KM Shah Dental College & Hospital, Vadodara, Gujarat, India 3 Post- Graduate Student, Department of Prosthodontics, Crown and Bridge Implantology, RUHS College of Dental Science, Jaipur, Rajasthan, India 4Senior Lecturer, Department of Periodontics, Pacific Dental College, Udaipur, Rajasthan, India INTRODUCTION Temporomandibular joint pain dysfunction Facial pain and its diagnosis have always posed a syndrome is a term covering a variety of problems dilemma for the clinicians. The complex anatomy of which include the entire scope of the region compounded with the variability of temporomandibular joint disorders originating symptoms involved, present a challenging situation either intra articular or extra articular.[1] Myofascial during the management of orofacial pain. The study pain-dysfunction syndrome is a psychophysiologic of temporomandibular joint appears to hold an disease that primarily involves the muscles of uncommon fascination for clinicians of many mastication. The condition is characterized by dull, disciplines. The dysfunction of these joint results in aching, radiating pain that may become acute during a large proportion of complaints presented to the use of the jaw, and mandibular dysfunction that dentists. With ever increasing refinements in generally involves a limitation of opening.[2] diagnostic and treatment modalities, dramatic Frequently, myofascial pain is overlooked as a advances have been made in understanding the common cause of chronic pain because of frequent causes of facial pain related to joint and surrounding association with joint dysfunction and other pain musculature. Still the mystery exists regarding the disorders. precise diagnosis and treatment of facial pain. ETIOLOGY Differentiation between temporomandibular The myofascial pain-dysfunction syndrome has a joint pain-dysfunction syndrome and myofascial multicausal etiology and the knowledge about the pain-dysfunction syndrome probable etiological factors seem to have improved over a period of time. Goodfriend (1933),[1] Costen 39 Myofascial Pain-Dysfunction Syndrome Patel R, Arora H, Memon S, Sharma U, Raigar RL, Sharma AR Fig. 1: Etiology of the myofascial pain-dysfunction Fig. 2: The concept of “etiologic circle” is useful to syndrome understand the mechanism of TMJ dysfunction Fig. 3: Pathophysiology of this stress disorder of skeletal Fig. 4: Medication Thearpy muscles (1934)[1] and many others initially advocated the facial pain occurred when Laskin (1969)[1] probable etiologies for the dysfunction syndrome. presented a comprehensive explanation of the Pathologies of temporomandibular joint, trauma, problem and proposed his psychophysiological occlusal disharmony and many other factors have theory. He suggested that though mechanical factors been proposed by different authors. Lot of related to occlusion may cause this condition by confusion existed until, Travell and Rinzler[1] first producing muscular overextension or suggested that skeletal muscles in spasm could be overcontraction leading to muscle fatigue but the source of pain. They described about the painful psychophysiologically motivated oral habits is the areas within the muscles and called them as frequent cause of painful spasm. To stress the role “Trigger areas” which were associated with pain, played by muscles, it was suggested that the term spasm, tenderness and dysfunction. Schwartz myofascial pain dysfunction syndrome is a more (1955)[1] adapted Travell’s work and postulated the accurate term to describe the condition than term temporomandibular joint pain-dysfunction temporomandibular joint pain-dysfunction syndrome. He reported that majority of patients syndrome. Laskin pointed out the key elements of with pain in the region of temporomandibular joint the theory of MPD dysfunction.[3] Fig. 1 shows were suffering from functional disorders involving Etiology of the myofascial pain-dysfunction painful spasm of masticatory musles. He syndrome. Although there are three means of entry hypothesized that stress was a significant cause of into the syndrome. The darker arrows indicate that clenching and grinding habits which resulted in most common pathway. The explanation of this muscle spasm. Occlusal abnormalities were found mechanism is termed the psychophysiologic theory. to play a secondary role. The next significant Laskin’s theory is an outgrowth of work of development towards understanding this aspect of Schwartz and is based on premise that MPD 40 Myofascial Pain-Dysfunction Syndrome Patel R, Arora H, Memon S, Sharma U, Raigar RL, Sharma AR syndrome is primarily a result of emotional rather myospasm is triggered by emotional disturbances than occlusal or mechanical factors. The and may be due to a combination of psychologic masticatory muscle spasm is the primary factor stress and muscle incordination secondary to responsible for signs and symptoms of pain- malocclusion. To complete the understanding for dysfunction syndrome. Spasm can be initiated in etiology of MPD syndrome, it is essential to one of the three ways: 1) muscular over extension, eliminate the possibility of medically linked factors, 2) muscular overcontraction, or 3) muscle fatigue. recent major surgical operations or trauma to head The myofascial pain syndrome so produced not only and neck which can give signs and symptoms of causes pain and limitation of movement but also MPD syndrome. produces changes in jaw position so that teeth don’t PATHOPHYSIOLOGY OF MPD SYNDROME occlude properly (occlusal disharmony). In addition As explained by Travell (1960),[5] the it may also cause organic changes such as pathophysiology of this stress disorder of skeletal degenerative changes in the TMJ and muscle muscles is outlined on Fig. 3. It has been observed contraction which is a manifestation of long-term that whenever the pain associated with skeletal spasm. These organic changes result in an altered muscle spasm is very severe, it is referred to a site chewing pattern with attendant reinforcement of the from the muscle that is its source. The pain is original spasm and pain. The changes in referred from a small area of hypersensitivity neuromuscular control of mandible produced due to located within the muscle or the fascia. These areas occlusal disharmony has been supported by many are termed as Trigger areas. The response of researchers. Irregularities in occlusion appear to be muscles against the injury tends to gain momentum the precipitating factor in pathogenesis of MPD and results in a self representating cycle of spasm- syndrome. Occlusal interferences, posterior bite pain-spasm which limits the movements and result collapse, deep overbite/overjet and many other in fibrosis of tissues. factors tend to restrict movement and predispose the Clinical Features patients to increased parafunctional activity Incidence resulting in overuse and thus fatigue of muscles. Women are affected by MPD syndrome more Moreover Bruno (1971)[1] found that the resulting frequently than men, with the ratio ranging from 3:1 pain in muscles will be concentrated in areas of to 5:12. The greatest incidence appears to be in the fascia which upon palpation demonstrated 20 to 40 years age group.[2] The patients suffering tenderness and pain and these areas were referred to from MPD syndrome usually present with as trigger areas. According to Weinberg (1974),[1] complaint of: every patient has got adaptation to a situation which Pain in a zone of reference (most important is determined by his psychological make up. In a problem that causes patients to seek given patient, an occlusal interference may trigger treatment). the patient’s acute symptoms while another factor, Trigger points in muscles which cause pain on [2,3] such as emotional stress may sustain them. stimulation. Evidence that nocturnal parafunction may be Taut muscle band. involved in MPD syndrome stemmed from studies Limited jaw opening. [4] by Trenouth (1978) who observed that jaw pain Associated symptoms. and limitation of movement were often noted to be Presence of contributing factors for onset of Christensen [4] worse on awakening. (1981) and pain. Yemm (1979)[4] demonstrated that in chronic cases No tenderness in temporomandibular joint. of MPD syndrome, an inflammatory