Temporomandibular Joint Defects: Etiology and Reconstruction Strategy: A Narrative Review.

Temporomandibular joint (TMJ) defects primarily arise from congenital malformations, bony ankylosis, and radical tumor resection. As a pivotal structure for regulating maxillofacial development and maintaining stomatognathic homeostasis, the anatomical restoration and functional reconstruction of the TMJ are essential for rehabilitating the dentofacial complex. Distinct from standard mandibular reconstruction, TMJ reconstruction is inherently more complex, with treatment heavily dependent on etiology, age, defect extent, and coexisting dentofacial deformities-factors that invariably require patient-specific protocols. This review systematically evaluates current reconstructive paradigms, including free bone grafting (costochondral and coronoid process grafting, vertical ramus osteotomy), vascularized free flaps (vascularized fibula, vascularized medial femoral condyle, and deep circumflex iliac artery flaps), mandibular ramus distraction osteogenesis, and total joint replacement. We provide a critical analysis of their respective clinical indications, advantages, and limitations, while discussing emerging trends and future perspectives in the field.