Bone Abstracts

Background: Diffuse sclerosing osteomyelitis (DSO) of the mandible is a rare chronic inflammatory disorder causing pain, swelling, and progressive sclerosis on imaging. Diagnosis is often difficult because clinical, radiological, microbiological, and histopathological findings may evolve over time. There is no standard treatment, and management is commonly multidisciplinary; osteoporosis specialists may become involved because bisphosphonates are frequently prescribed.

Case report: A woman in her late 60s presented with severe pain and swelling of the right lower mandible/submandibular region. Symptoms persisted despite extraction of the lower right first molar. She later reported worsening right-sided facial pain affecting sleep, painful chewing and yawning, right earache, headaches, and intermittent tingling along the right tongue border. Examination showed tenderness buccal and lingual to the right mandibular body, inferior to the mandible and over the right temporomandibular joint, and later a bony hard swelling over the right mandibular body. X-ray showed subtle changes suspicious for osteomyelitis.

Results: Initial treatment under oral surgery with doxycycline for 28 days produced early improvement. Symptoms recurred after stopping treatment, and further courses of doxycycline and co-amoxiclav provided only partial or temporary benefit. Cone beam CT demonstrated progressive diffuse sclerosis of the right hemimandible with periosteal new bone formation and cortical disruption, without fracture or sequestrum. A bone biopsy confirmed osteomyelitis with secondary bony sclerosis; no malignancy was identified with negative cultures. Oral alendronate gave only transient benefit. After referral for specialist metabolic bone input, vitamin D deficiency was corrected and 2 doses of intravenous pamidronate 60mg 1 month apart were given with limited clinical response. Following MDT discussion, it was decided to switch to intravenous ibandronate. An initial 6mg dose was given resulting in good improvement in both pain and local tenderness; 2 further 3mg doses have subsequently been given.

Conclusion: This case highlights the chronic, relapsing nature of mandibular DSO and challenges in early diagnosis and optimal management. A number of case reports / case series have reported good symptomatic improvement with different bisphosphonates including alendronate, clodronate, ibandronate and zoledronate, however the optimal treatment regime has not been established and long term data are lacking.