Radiological Study of Experimental Osteomyelitis : Differences of Radiological Findings between the Jaw Bones and the Long Bone

The behavior of osteomyelitis in the maxilla differs from that in the mandible radiologically and clinically. The mandibular osteomyelitis tends to be more diffuse and wide-spread lesion, but in the maxillary osteomyelitis the lesion is usually localized. In this study, the difference in radiographic findings of osteomyelitis between in the maxilla and the mandible is demonstrated by using dogs experimentally. The difference between jaw bones and the tibia is also clarified. The experimental osteomyelitis was caused by an injection of 4-Nitroquinoline-N-oxide (4NQO) into the bone marrow of the individual bones. The results obtained are as follows : 1. An experimental osteomyelitis in the individual bones was successfully caused by the application of 4NQO. 2. There were no radiographic changes in the jaw bones and the tibia one week after the injection of 4NQO. Two weeks after the injection of 4NQO, radiographic findings appeared in the maxilla, mandible, and tibia. 3. The severity of the maxillary bone destruction due to the osteomyelitis was less than that in the mandible and the tibia. The bone destruction of the maxilla did not progress with time but was localized around the 4NQO injected area. The bone destruction of the mandible and the tibia was accelerated with time, and its severity increased. 4. Osteosclerosis in the tibial osteomyelitis was more severe than in the mandible. No osteosclerosis was seen in the maxillary osteomyelitis. 5. The sequestrum formation was seen to be almost the same in the maxilla, and tibia. 6. The periosteal new bone formation occurred more frequently in the tibial osteomyelitis than in the mandibular osteomyelitis, but there was no statistical significance. The periosteal new bone formation did not develope in the maxillary osteomyelitis. 7. As the first bony changes of osteomyelitis, the bone destruction and the periosteal new bone formation occurred two weeks after 4NQO injection. Osteosclerosis and the sequestrum formation were mostly seen three or four weeks after 4NQO injection. 8. In the mandibular and tibial osteomyelitis, the lesion spread more widely with time, but in the maxillary osteomyelitis the lesion was still localized. 9. The mandibular and tibial osteomyelitis revealed more radiographic findings than the maxillary osteomyelitis.