Osteomyelitis is an inflammatory reaction to an infection of the bone caused by pyogenic bacteria. The condition was first described by REES in 1947. It initially involves the periosteum and rapidly spreads to involve the Haversian system, then extending to the medullary portion of the bone. Osteomyelitis is mostly of odontogenic origin, such as infection from the root canal or root apex, periodontal infection, or from the extraction site. It can also be due to trauma or infection from the fracture site. It is more common in the mandible rather than the maxilla. This is because the maxilla has a profuse blood supply, and its thin cortical plates dissipate pus, discharging it into the adjacent soft tissue and paranasal sinuses.