Bony Union in Maxilla and Mandible Free Flap Reconstruction: A Systematic Review and Meta-Analysis.

[BACKGROUND] Bony nonunion is an important complication in head and neck reconstruction, but its definition, incidence, and treatment are not well-reported.

[METHODS] MEDLINE, Embase, CENTRAL, and Web of Science were searched from October 1st, 1990 to January 6th, 2025 for studies reporting bony union for maxilla or mandible reconstruction with vascularized free flap.

[RESULTS] The search strategy yielded 5985 abstracts and 52 were included in the review. Definitions of bony nonunion varied and were reported in 20 studies. Higher pooled rates of complete union were observed in reconstructions of the maxilla, reconstructions using the radius, and surgeries aided by virtual surgical planning. Treatment for nonunion was reported in 11 studies.

[CONCLUSIONS] Virtual surgical planning has the potential to improve union outcomes and reduce the need for revision surgeries in nonunion cases. The heterogeneity of the studies necessitates randomized controlled trials for further analysis of the nonunion risk factors and consequences.