Osteomyelitis is an exhaustive disease whose main feature is an inflammation of inner part of bone, bone marrow. In oral and maxillofacial area, we have maxillary and mandibular osteomyelitis and the latter is dominant because of its impaired blood supply. The main cause of osteomyelitis is a bacterial infection and the ways of infections are by periapical odontogenic infection, fracture, post-operative complication, and periodontal disease. The predominant etiologic factor is periapical odontogenic infection mostly caused by advanced dental caries. It is generally believed that periodontal disease could be a cause of osteomyelitis. But periodontal disease is usually confined to the alveolar bone area and not extends to the underlying bone marrow. Accordingly periodontal infection per se rarely cause produce oseomyelitis. Even though osteomyeltis could be occurred by periodontal disease, its virulence of infection is milder than periapical odontogenic infection. So it usually provokes sclerosing or hyperplastic osteomyelitis rather than suppurative type. We had a case of suppurative osteomyelitis caused by periodontal disease and treated it with periodontal and oral and maxillofacial surgical method.