Craniomandibular disorders in adult populations of West Bothnia, Sweden.

A randomly selected sample of 1992 adults (995 men and 997 women) representing four equally sized age groups of 25-, 35-, 50-, and 65-years-old inhabitants of West Bothnia were studied for prevalence of symptoms and clinical signs of mandibular dysfunction. Of the sample 79% completed a questionnaire and a clinical examination. The chewing inability increased with age. Recurrent headaches (once a week or more often) were reported to occur in 11% to 15% of the four age groups, and the duration of headaches was generally more than 2 years. Tooth-clenching, which was the most frequent oral parafunction, was reported significantly more often in women, whereas attrition was more severe in men. The commonest clinical finding was temporomandibular joint clicking, which varied between 13% and 35% in the different age groups. Crepitation was observed more often in women and increased with age. The jaw muscles were more frequently tender to palpation in women and the elderly. The mean maximal mouth opening capacity varied between 55 mm and 44 mm, decreasing with age, and was for the whole sample significantly higher among men. Since signs and symptoms of craniomandibular disorders were common findings in all age groups, routine dental examination should always include functional evaluation of the stomatognathic system.