Osteomyelitis: Inflammation of the medullary portion or marrow space of the bone.
Broad Definition: Inflammatory process affecting the marrow, cortex, and periosteum.
Suppurative Osteomyelitis of the Jaw: Inflammatory process leading to edema and pus accumulation, increasing medullary pressure, obstructing blood supply, and causing bone necrosis.
Classification Systems
Multiple classification systems exist, leading to confusion.
Broad Categories:
Suppurative Osteomyelitis: Involves pus formation; has acute and chronic forms.
Non-suppurative Osteomyelitis: Chronic conditions without suppuration.
Includes chronic focal sclerosing, diffuse sclerosing, and Garre’s osteomyelitis.
Zurich System:
Categorizes into acute, primary chronic, and secondary chronic osteomyelitis.
Acute and secondary chronic relate to suppurative forms.
Primary chronic is synonymous with chronic diffuse sclerosing osteomyelitis.
Bone Histology
Structure:
Compact (cortex) bone and medullary (cavity) bone.
Periosteum lines the outside of compact bone.
Medullary cavity contains cancellous bone, marrow, and blood vessels.
Components:
Osteons: Basic metabolic units of bone.
Haversian Canals: Cylindrical canals with blood vessels and nerves.
Volkmann Canals: Interconnected with Haversian canals to nourish bone.
Suppurative Osteomyelitis
Stages:
Acute and chronic stages are the same disease, separated by a 4-week timeline.
Causes:
True infection by pyogenic microorganisms (Staphylococcus aureus, etc.).
Can result from radiation, injuries, or systemic and local conditions.
Primarily caused by infections from teeth or periodontium.
Pathophysiology:
Inflammatory response increases vascular permeability and thrombus formation.
Plasma fluid and pus accumulation increase medullary pressure and cause ischemia.
Pus compresses the inferior alveolar nerve, causing paraesthesia.
Necrotic bone fragments are called sequestra.
Clinical Presentation
Mandible is more affected than maxilla due to less blood supply.
Acute Symptoms:
Intense pain, swelling, trismus, fever, paraesthesia, and pus formation.
Chronic Symptoms:
Milder pain and swelling.
Fistula and sequestra formation with pus drainage.
Radiographic Appearance:
Acute: Radiolucent changes appear after 2 weeks.
Chronic: Sequestra appear as radiopaque masses.
Treatment
Antibiotics: Targeted after pathogen culture.
Surgical Intervention:
Debridement, drainage, and irrigation.
Sequestrum and diseased bone removal with possible bone replacement.