SAPHO syndrome in the mandible: A 17-patient-based experience

Abstract

SAPHO (Synovitis, Acne, Pustulosis, Hyperostosis and Osteitis) syndrome is a rare inflammatory bone disorder with a remarkably low incidence. The condition's impact on the mandible is exceptionally uncommon, often resulting in a high rate of misdiagnosis and an extended duration of illness. The objective of this study was to assess patients with SAPHO syndrome in the mandible in across various stages and to dissect their distinctive features, aiming to provide future clinical experience for the disease.

Methods: A retrospective analysis was performed on a cohort of 17 patients diagnosed with SAPHO syndrome affecting the mandible at the Second Affiliated Hospital of Zhejiang University from January 2020 to March 2023. Data including clinical presentations, imaging characteristics, and laboratory results were collected.

Results: The median age at disease onset was 25, with a diagnostic interval of 26 months. Notably, seven individuals were prepubescent (under the age of 14). Seven patients (41.18 %) exhibited polyostotic involvement, while eight patients (47.06 %) presented with dermatological manifestations either concurrently with or subsequent to the osseous lesions. Condyle involvement was identified in six patients (35.29 %), and bilateral mandibular affection was noted in an equivalent number. The majority of patients (sixteen patients, 94.12 %) reported symptomatic relief following treatment with nonsteroidal anti-inflammatory drugs (NSAIDs). Glucocorticoids were instrumental in managing severe pain and extreme limitations in mouth opening. For patients with refractory disease, tumor necrosis factor-alpha (TNF-α) inhibitors, Janus kinase (JAK) inhibitors and bisphosphonates were employed. Ultimately, effective pain management was achieved in the entire cohort.

Conclusion: The diagnosis of SAPHO syndrome involving the mandible is exclusionary. It is important to improve diagnostic accuracy among oral and maxillofacial surgeons (OMFS), dentists, and rheumatologists to avoid unnecessary surgery and tooth extraction. TNF-α inhibitors, JAK inhibitors and bisphosphonates are recommended as third-line drugs.