As it has been already discussed, osteomyelitis can be defined as the inflammation in the medullary portion of the bone. But this does not mean that the osteomyelitis of the jaws will be similar to that of long bones. According to several authors there exists a difference in the pathogenesis of osteomyelitis of long bones when compared with the jaws. This is considered important because the management of a particular disease depends upon the pathogenesis. Since the pathogenesis of osteomyelitis of jaws is considered different by certain authors as compared to the osteomyelitis of long bones, the treatment protocol of both these entities cannot be similar. This particular chapter will highlight the difference in the pathogenesis of osteomyeliis of long bones and the jaws.