A Management Strategy for Idiopathic Bone Cavities of the Jaws

Idiopathic bone cavities (IBCs) are benign osseous pseudocysts of unclear etiology. Their clinical course and response to treatment are poorly understood. The purpose of this study was to present a case series of patients with IBC with long-term follow-up.

A retrospective case series of patients with IBC of the jaw was implemented. Medical records were reviewed for data on presentation and imaging. All patients underwent surgical exploration to confirm the diagnosis. Follow-up radiographs were evaluated for resolution or persistence after the procedure. Descriptive data were summarized.

The sample included 45 patients (60% girls) with 47 IBCs who presented at a mean age of 13.5 ± 0.35 years (range, 9 to 17 yr). All lesions were asymptomatic and discovered as incidental findings; the average size was 2.0 cm (range, 0.8 to 7 cm). Most (n = 44) were solitary lesions of the mandible presenting within the body (n = 27), symphysis (n = 15), or ramus (n = 2). One patient had synchronous bilateral mandibular and maxillary IBCs. Common radiographic features included scalloping without root resorption or displacement and cortical thinning without expansion or perforation. Intraoperative findings showed an empty bone cavity often filled with blood-tinged serous fluid or blood. The histopathology of scrapings from the bony wall showed benign mixed fibrous tissue and no epithelial lining. Average radiographic follow-up was 32.7 ± 6.7 months (range, 0 to 9 yr). After exploration and curettage, 43% of patients had complete bone fill within 2 to 5 years. The other 57% had no change in lesion size at an average of 2.25 years (range, 2 to 9 yr). No patients developed symptoms, had enlargement of the lesion, or had pathologic fracture.

Many IBCs persist for years despite exploration and curettage. Nonetheless, unresolved lesions did not enlarge or cause harm. A single procedure to confirm the diagnosis is sufficient for management.