Clinical and scintigraphic improvement of mandibular involvement associated with chronic nonbacterial osteitis following an interleukin-23 inhibitor: a case-based literature review.

Chronic nonbacterial osteitis (CNO) occasionally presents with severe and refractory mandibular involvement, conventionally called as diffuse sclerosing osteomyelitis. While conventional treatments such as bisphosphonates and tumor necrosis factor (TNF) inhibitors are utilized, optimal management remains challenging due to heterogeneous responses. Here, we report a 59-year-old male with CNO associated with palmoplantar pustulosis who developed refractory mandibular osteitis. Following recurrent relapses under conventional therapies, he was treated with guselkumab, an interleukin (IL)-23 inhibitor. His clinical symptoms and abnormal tracer uptake on bone scintigraphy markedly improved within three months without any adverse events. Furthermore, we conducted a case-based literature review to evaluate the effectiveness of potential therapies, such as IL-17/IL-23 inhibitors and Janus kinase (JAK) inhibitors, for CNO-associated mandibular involvement. The review identified five additional cases treated with these agents. Clinical improvement was observed across all cases, while radiological progression was noted in two patients treated with JAK inhibitors. Although the precise immunopathogenesis of mandibular CNO requires further elucidation, our findings suggest that IL-23, IL-17, and JAK inhibitors may be potential therapeutic options, particularly for patients experiencing treatment failure or paradoxical reactions to conventional biologic agents.