Osteoradionecrosis of the jaw (ORNJ) remains one of the most severe late complications of head and neck radiotherapy. Current evidence suggests that ORNJ is a progressive and biologically heterogeneous disorder driven by microvascular injury, chronic hypoxia, oxidative stress, fibro-atrophic remodeling, impaired bone turnover, immune dysregulation, and systemic susceptibility factors. Within this complex pathogenic network, heat shock protein 27 (HSP27) emerges as a biologically plausible but unexplored mediator. HSP27 regulates multiple stress-response pathways, including redox homeostasis, cytoskeletal stabilization, endothelial protection, apoptosis control, fibroblast activation, and osteoblast–osteoclast function, all of which overlap with key mechanisms implicated in ORNJ. However, no studies have directly investigated HSP27 expression, activation, or functional significance in irradiated mandibular tissues or ORNJ-specific cohorts. This review summarizes current knowledge of ORNJ pathobiology, examines potential mechanistic links with HSP27, and outlines future research priorities involving biomarker development, tissue-level characterization, preclinical modeling, and therapeutic targeting. Integrating HSP27 into ORNJ research may improve understanding of pathogenesis, risk stratification, and the development of novel preventive and therapeutic strategies.
Topkan et al. (Mon,) studied this question.