Chronic Sclerosing Osteomyelitis of the Mandible

Chronic sclerosing osteomyelitis of the mandible is a persistent low grade infection or inflammation of the bone that produces bone sclerosis in a localised area, usually related to a chronic dental or periodontal focus. Pus formation is minimal.

It occurs in adults, mainly in the posterior mandible, and it is less severe than acute suppurative disease. It is different from the diffuse, non-infective form that involves large parts of the mandible.

Pathophysiology. Chronic infection of low virulence, usually from periapical, periodontal or pericoronal disease, stimulates proliferation of the bone, with deposition of dense sclerotic bone and little necrosis.

A balance between bacterial load and host defence explains the persistence. Cultures are often negative or show mixed oral flora, and Actinomyces has been found in some cases.

Intermittent pain, swelling of the jaw, mild trismus and tenderness, with periods of quiet. Fever is uncommon. A sinus or exposed bone may be present. Teeth in the area may be decayed or periodontally involved.

Persistent pain and cortical expansion over months need exclusion of tumour.

• Panoramic radiograph and CT: focal sclerosis with a mixed pattern of lucency and opacity, cortical thickening and periosteal reaction, without large sequestra.
• MRI shows marrow oedema and enhancement in active disease.
• Bone scintigraphy shows increased uptake in the area.
• Bloods: C-reactive protein and ESR (often mildly raised), full blood count and glucose.
• Deep bone biopsy for histology and culture (aerobic, anaerobic, mycobacterial, fungal). Histology: sclerotic bone with chronic inflammatory cells, fibrosis and little suppuration.
• Dental assessment to find the focus of infection.

Differential diagnosis.

• Diffuse sclerosing osteomyelitis
• Garré osteomyelitis
• Chronic suppurative osteomyelitis
• Florid cemento osseous dysplasia
• Fibrous dysplasia and Paget disease
• Osteosarcoma and metastasis
• Condensing osteitis

• Remove the dental focus: extraction or root canal treatment, with debridement of adjacent diseased bone.
• Antibiotics for 4 to 6 weeks or longer after culture: amoxicillin 500 mg to 1 g orally three times daily with metronidazole 400 mg orally three times daily, or clindamycin 300 to 450 mg orally four times daily in penicillin allergy. Reduce amoxicillin to 500 mg every 12 hours at eGFR 10 to 30. Longer courses are used for refractory disease, based on limited evidence.
• Surgical decortication and removal of sclerotic and infected bone in persistent disease, with a graft if needed to restore contour.
• Hyperbaric oxygen is used for refractory disease with limited evidence.
• Analgesia: paracetamol 1 g every 6 hours (maximum 4 g daily) with ibuprofen 400 mg every 8 hours with food. Short term NSAIDs can relieve flares.

Monitoring. Review every 4 to 6 weeks during treatment, with C-reactive protein and imaging at 3 and 6 months, then annually for 2 years.

Referral and escalation. Refer to oral and maxillofacial surgery. Urgent referral for fracture, rapid progression, a destructive pattern or any suspicion of malignancy.