Ten patients with mixed connective tissue disease (MCTD) were examined for signs and symptoms in the masticatory system. The study included clinical, radiological, histological and immunohistochemical examinations. The status of the teeth and periodontium did not seem to differ from that found in the general Finnish population. All 10 patients showed clinical dysfunction, and 7 had additional radiographic changes of the temporomandibular joints. Sialopenia was observed in 7 patients, and histological examination revealed sialoadenitis with a focus score exceeding 1 in the labial salivary glands in 9 patients. Only 1 patient had clinically detectable mucosal lesions. However, in 5 of 6 patients with normal-appearing mucosa, histological examination revealed chronic inflammation. Three of the 10 patients had clinically atrophic and erythematous oral mucosa; histological examination again revealed chronic inflammation. The signs and symptoms appearing in the masticatory system of these 10 MCTD patients were many and varied and indicate the importance of closely examining all oral structures. As with other connective tissue diseases, MCTD should be treated on a multidisciplinary basis.