Periapical lesions of mandibular bone: difficulties in early diagnostics. It is often difficult to establish a correct diagnosis on the basis of initial clinical and roentgenologic symptoms in mandibular bone disease. In this paper these problems are discussed, and some suggestions are made to overcome them. The discussion is based on cases of osteogenic sarcoma, histiocytic lymphoma, and chronic osteomyelitis. The patients were a boy and two middle-aged women, all of them with primary clinical symptoms of pain and swelling, diffuse roentgenologic changes in mandibular bone, uncertain response to treatment, and an unusual progress of the disease. 