Bone Abstracts

Introduction: Cranialfacial fibrous dysplasia (CFD) presents with pain, facial asymmetry and/or neurological complications. It has been suggested that patients with CFD respond favourably to treatment with bisphosphonates, by a decrease in pain and arrest of progression. Therefore, we performed a retrospective study of 56 patients with CFD in our center.

Methods: We assessed clinical characteristics and disease course. Furthermore, clinical and biochemical response on bisphosphonate treatment was assessed. Prognostic factors for treatment outcome were identified.

Results: Most patients had monostotic CFD (n=36.68%), eight had polyostotic FD (14%) and 10 (18%) McCune–Albright syndrome (MAS). Mean age at diagnosis was 23.8±16.1 years and 4.2±4.0 years in MAS, mean follow-up was 16.5 years (range 1–61). Most affected sites were the frontal, sphenoid and maxillary bone, 43, 36 and 32% respectively. Reported symptoms were headaches (26%), visual problems (21.4%), hearing loss (4%), vertigo (4%) and loss of smell (4%). MAS-patients had significantly higher SBS of the skull. In MAS patients GH-excess was diagnosed in 60% solely in patients with a high SBS score of the skull (P<0.001) vs patients without GH-excess. In monostotic CFD mean alkaline phosphatase was 114.7±73 U/l at time of diagnosis and 195.3±58 U/l and 630.0±257 U/l in PFD and MAS respectively. Forty-two surgeries were performed in 19 patients (33 surgeries in monostotic CFD, 1 in PFD and 8 in MAS patients), 48% for cosmetic reasons, 14% for pain reduction and 12% for nerve compression. Forty-one patients were treated with bisphosphonate and 96% of the monostotic CFD patients, 75% in the PFD and 20% in MAS had a good response to treatment. High SBS of the skull and GH-excess were risk factors for reduced treatment response.

Conclusion: In patients with CFD, treatment with bisphosphonates reduces pain and clinical symptoms, especially in those with monostotic CFD. GH-excess and high SBS of the skull appear to be risk factors for treatment failure.