Florid Cemento-Osseous Dysplasia

Florid cemento osseous dysplasia is a benign, non-neoplastic fibro osseous condition of the tooth bearing jaw, with multifocal sclerotic lesions that involve two or more quadrants and replace normal bone with dense, poorly vascularised tissue. It is usually discovered on radiographs.

It is most frequent in women of African and Asian descent in the fourth to sixth decades. The posterior mandible is often involved, with symmetrical lesions.

Pathophysiology. The cause is unknown. A reactive process of the periodontal ligament cells is proposed, with replacement of bone by fibrous tissue, cementum like material and woven bone, which then matures to dense sclerotic mass.

The sclerotic bone has limited blood supply, so infection after extraction or exposure to the mouth can lead to chronic osteomyelitis and sequestration.

Usually no symptoms and no swelling. Some report dull ache or discomfort, and secondary infection produces pain, swelling, discharge and exposed sclerotic bone, especially after extractions or under dentures that traumatise the ridge.

The teeth are vital, with normal mobility. Simple bone cysts may coexist in the area.

• Panoramic radiograph: multiple dense radiopaque masses with a thin radiolucent rim, in two or more quadrants, usually in the posterior jaw and bilaterally, in a tooth bearing or former tooth bearing area, sometimes with a mixed lucent and opaque pattern in early lesions.
• Cone beam CT: extent of lesions, relation to the inferior alveolar canal and cortex, and exclusion of bone expansion.
• Pulp sensibility tests: teeth are vital and no periapical pathology is present.
• Biopsy is avoided when the radiographic picture is typical, because of the risk of infection and poor healing.
• Serum calcium, phosphate, alkaline phosphatase and parathyroid hormone when the lesions are atypical, to exclude Paget disease and other metabolic bone disease.

Differential diagnosis.

• Chronic diffuse sclerosing osteomyelitis
• Paget disease of bone
• Periapical cemento osseous dysplasia (limited to the mandibular incisors)
• Cementoblastoma and osteoma
• Odontomas and ossifying fibroma
• Fibrous dysplasia
• Gardner syndrome with multiple osteomas

• No treatment is needed for asymptomatic lesions. Reassure and record the finding to prevent unnecessary surgery.
• Prevent infection: excellent oral hygiene, regular scaling, fluoride use, and avoidance of extractions and surgery wherever possible. Dentures should fit well and avoid pressure on the ridge. Teeth should be restored and treated endodontically when needed, preferring root canal treatment to extraction.
• When an extraction is unavoidable: use an atraumatic technique with minimal bone removal and prophylactic antibiotic, such as amoxicillin 2 g orally 1 hour before the procedure and amoxicillin 500 mg three times daily for 5 to 7 days after, or clindamycin 300 mg four times daily in penicillin allergy. Reduce amoxicillin to 500 mg every 12 hours at eGFR 10 to 30.
• Infected sclerotic bone or osteomyelitis: culture directed antibiotics, such as amoxicillin 500 mg to 1 g three times daily with metronidazole 400 mg three times daily for 4 to 6 weeks after debridement, with sequestrectomy and saucerisation for exposed necrotic bone. Longer courses are directed by specialist advice.
• Analgesia: paracetamol 1 g every 6 hours (maximum 4 g daily) with ibuprofen 400 mg every 8 hours with food.

Monitoring. Annual clinical review and radiographs every 1 to 2 years, with early assessment of any pain, swelling or exposed bone.

Referral and escalation. Refer to oral and maxillofacial surgery for infection, sequestrum or planned surgery. Refer to oral medicine for atypical presentation. Urgent referral for fever, facial swelling or spreading infection.