Epidemiological surveys of dysfunction of the masticatory system.

Findings in epidemiologic studies referred to in this review appear to warrant the following conclusions: 1. Symptoms of dysfunction of the masticatory system are very common in unselected materials - much more common than hitherto assumed. This implies that dentists in the future must interest themselves more than hitherto for diagnosis and treatment of functional disturbances of the masticatory system in general practice. 2. There are no differences in frequency of dysfunction between men and women in the general population. Why women dominate in patient materials has not been convincingly explained in the literature. 3. Symptoms of mandibular dysfunction have been found in perons in all age groups. The slight differences as to age distribution reported, indicate more frequent symptoms in old individuals than in young ones. 4. No predominant etiologic factor of dysfunction of the masticatory system has been found in the population studies. Various factors are obviously involved in the etiology of functional disorders. A certain correlation between the degree of dysfunction and the general state of health and the number of residual teeth has, however, been demonstrated. Besides occlusal disturbances and psyhic factors the general health therefore should be observed as an important variable in mandilular dysfunction. 5. In order to faciliate future comparisons between different materials and interpretation of results it is necessary to use the same dignostic criteria and to collect data by reference to suitalbe induces permitting assessment of the prevalence of different symptoms with their severity. 6. With the aid of a generally accepted dysfunction index it should be possible further to elucidate the still many obscure aspects of the etiology and further course of dysfunctional diseases of the masticatory system in clinical materials and population studies. 7. More epidemiologic research of different populations is necessary to increase our knowledge in this field.