Comparison of Bony and Soft Tissue Free Flaps in the Management of Osteoradionecrosis of the Mandible and Maxilla

BACKGROUND/OBJECTIVE: Advanced (Notani III) osteoradionecrosis (ORN) often requires microvascular free-flap (MVFF) reconstruction, yet comparative outcomes by flap category and the effect of peri-oncologic factors on postoperative events remain uncertain. We compared outcomes after bony versus soft-tissue MVFF and evaluated potential risk factors for reconstructive failure (RF) and acute and late complications. METHODS: This single-center retrospective cohort study included adults with Notani III ORN who underwent MVFF reconstruction at a tertiary hospital between 2008 and 2024. Twenty-three patients were included: 9 bony free flaps and 14 soft-tissue free flaps. Primary endpoints were total flap loss and RF. RF was defined as major RF requiring salvage flap and/or hardware removal or minor RF requiring return to the operating theater without new flap/hardware removal. Secondary endpoints included acute complications during index admission and late complications ≥3 months post-reconstruction. Fisher's exact test and exploratory logistic regression were used. RESULTS: The mean age of patients was 60.3 years, and 74% were male. There were no total flap losses. RF occurred in 26% (major 9%, minor 17%), with no significant differences between bony and soft-tissue flaps in either group. Acute complications occurred in 39% of patients and late complications in 52%. Pre-radiotherapy (RT) dental interventions were associated with a statistically significant increase in acute complications (OR 2.13, 05% CI 1.28-3.52, P=0.04). Prior immunotherapy was associated with lower odds of acute complications (OR 0.30, 95% CI 0.15-0.59, P=0.04). CONCLUSIONS: MVFF provided durable reconstruction for Notani III ORN with no flap failures and a low rate of major RF. Outcomes did not differ by flap category. Pre-RT dental interventions and prior immunotherapy modify perioperative risk and warrant validation in larger, multicentre cohorts.