Diffuse sclerosing osteomyelitis of the mandible: a new concept of its etiology. Diffuse sclerosing osteomyelitis of the mandible is a disease of unknown etiology. The clinical and radiographic findings suggest an infectious origin, but bacteriologic and histologic findings do not support this concept. Analysis of clinical symptoms, localization of the condition, and posttreatment findings in a group of 27 patients suggest a chronic tendoperiostitis due to muscular overuse as an etiologic factor in diffuse sclerosing osteomyelitis of the mandible. This hypothesis was supported by the initial results of muscle relaxation treatment in 13 of these patients. 