230 Theories and techniques of oral implantology

Osteomyelitis. Osteomyelitis is a bone infection caused by pyogenic microorganisms, usually Staphylococcus aureus and Streptococcus pyogenes. The microorganisms may be circulated to the bone or invade it directly during a fracture or some other traumatic injury.

The bone marrow is affected first in osteomyelitis. Local necrosis of the approximating tissues occurs and soon spreads. When the center of the infection is near the bone's surface, a subperiosteal abscess may result. If the infection is close to a joint, the joint becomes inflamed because of synovial congestion and an increase in the fluid of the joint. If the infection penetrates the joint, a purulent exudate is formed in the joint cavity, causing early destruction of the articular cartilage. When the jaws are affected, the bone around the teeth may be destroyed, leaving the teeth loose. A fetid breath is also symptomatic of mandibular or maxillary osteomyelitis.

The symptoms of osteomyelitis include sudden pain in the affected bone accompanied by a sudden rise in temperature and tenderness in the area. Swelling appears. Leukocytosis is usually present. Radio-graphic diagnosis is not always conclusive in the early stages, since bone destruction will not be visible until the disease has been active a few weeks. Then the x-rays show irregular areas of bone destruction separated by what appears to be normal bone (Fig. 6-36) .

Fig. 6-36. Osteomyelitis, showing irregular areas of bone destruction with apparently normal bone. (From Kolas, S., and others: Radiographic patterns of resorption seen in some gnathodental hard-tissue disturbances, Dent. Clin. N. Amer., November, 1968.)

New bone begins forming in a haphazard manner, not along normal stress lines, in response to the infection. Once the infection is controlled and necrotic tissues disappear, this bone is replaced by new bone that forms along normal stress lines. Small pieces of dead bone may become separated from the parent bone (Fig. 6-37). These sequestra may be absorbed by healthy bone or broken down and eliminated.

Osteomyelitis responds well to chemotherapy in its early stages. An antibiotic, preferably penicillin, should be administered at the first suspicion of the disease and continued for at least 1 week after all signs of pain, tenderness, and swelling have disappeared and the body temperature has been normal. Delaying treatment complicates the condition be-cause the bone becomes necrotic and the antimicrobial agent cannot reach the dead bone to combat the organisms within it. The necrosed bone should be curetted, and drains may be necessary. Antibiotics should also be administered. If large sequestra are trapped within the bone, they should be surgically removed, as it may otherwise take years for them to be broken down and eliminated.

If an implant is contemplated in an area where osteomyelitis has occurred, the dentist must wait at least 1 year after complete bone "fill-in" to ensure that the new bone is firmly established and healthy

Fig. 6-37. A late stage of extensive osteomyelitis. A great deal of bone destruction has occurred, leaving numerous dense sequestrae. (From Worth, H. M.: Principles and practice or oral radiographic interpretation. Copyright 1963 by Year Book Medical Publishers, Inc. Used by permission.)