TEMPORO-MANDIBULAR JOINT. THE FEATURES OF FUNCTIONAL ANATOMY AND HISTOLOGICAL STRUCTURE DURING THE DYSFUNCTION OF TMJ

Abstract

The question of structural organization, function and diagnosis of the diseases of temporomandibular joint (TMJ) has attracted the attention of various specialists for a long time. To date, there is no data about morphological and functional status of tissues and organs of maxillofacial region during the TMJ dysfunction and different defects, accompanied by a decrease in the height of the lower third of the face. TMJ dysfunction is found with a frequency of 5 to 85% of the population, including the young people. TMJ dysfunction with the pain syndrome is a type of chronic facial pain present in 12% of people, while in 20-80% of adults at least one of its sign is present. Women have this disease more frequently than men. Currently three main theories of the origin of dysfunction are considered: the theories of occlusive disorders, muscle imbalance, physiological phenomenon. During the interaction of these factors, there is overactivity of masticatory muscles with the appearance of the fatigue, pain, limitation of joint movement. Impaired functions of neuromuscular complex are caused by various reasons: psychogenic factors, CNS diseases, parafunctions of masticatory muscles, occlusion disorders, abnormalities of the bite, premature contacts, and errors in prosthetics. In 30-40% of cases there is a combination of TMJ diseases with osteochondrosis of the cervical spine. The vast majority of patients have such a cause of pain dysfunction syndrome of TMJ as various irregularities in the dentition that resulted from malocclusion after prosthetics, tooth fillings or extractions, operations with widely open mouth, pathological abrasions of teeth, and in some cases, bruxism. Also odontogenic disorders are the cause of activation of muscle trigger points in 67% of cases. Of these, in 75% there is occlusion dysfunction and partial secondary adentia with one-sided type of chewing. Hypertone of masticatory muscles causes significant compression of articular tissues. This degrades the functional state of the joint and contributes to the pathological process. To date, not much attention is paid to the morphology of the temporomandibular joint and processes of arthrogenesis. There is also no consensus about the structure of the joint as a whole and its individual structure elements. There are only few studies devoted to the change of its structural elements under pathological conditions. During the analysis of the literature a huge number of scientific papers about TMJ pathology are revealed, much less attention is paid to the problems of the structural organization of the individual elements. To date, practically there are no works devoted to comprehensive assessment of the TMJ and the changes that occur in its structure during different occlusal disorders. The question of compensatory changes in the joint that occur in different types of occlusal disorders is not fully studied.

Keywords

• temporo-mandibular joint, functional anatomy, dysfunction, muscle imbalance.