Mouth opening after fibula free flap reconstruction: Impact of radiation and implications for prosthodontic rehabilitation

Why clinicians should know about it

• Picked for Plastic and Reconstructive Surgery (paper of the day, 10 October 2026): Fibula free flap reconstruction and radiation impact

Abstract

STATEMENT OF PROBLEM: Mandibular mobility is critical for prosthodontic rehabilitation following maxillofacial reconstruction, especially in a procedure like Jaw-in-a-Day (JIAD) that needs accurate pre-operative planning. The fibula free flap (FFF) reconstruction enables the restoration of appearance and function after benign or neoplastic tumor resection, but some complications, such as trismus, present in a delayed manner or worsen after radiotherapy (RT). The specific magnitude of reduction in maximum incisal opening (MIO) following these procedures is poorly quantified, potentially compromising the feasibility of definitive prosthetic delivery, maintenance, and long-term survivability. PURPOSE: The purpose of this cross-sectional clinical study was to evaluate and quantify the postoperative reduction in MIO in patients undergoing FFF reconstruction with or without RT. MATERIAL AND METHODS: This IRB-approved study evaluated 30 participants (n=10 per group, 80% power, α=.05). Three cohorts were compared: a control group (Group C), patients after FFF reconstruction without RT (Group FFF), and those with FFF with RT (Group FFF+RT). MIO was measured in millimeters using a TheraBite range-of-motion scale. Functional mouth opening was assessed using the 3-finger test. One-way ANOVA with Tukey post hoc testing was used for MIO comparisons, and the Kruskal-Wallis test was used for the 3-finger test. Pearson correlation analysis evaluated the association between variables (α=.05). RESULTS: A statistically significant difference was identified among groups (P<.001). No significant difference was found between control and Group FFF (P=.593), whereas Group FFF+RT demonstrated significantly reduced MIO compared with both groups (P=.005). The greatest reduction was observed in Group FFF+RT, which demonstrated an approximate 30% reduction in MIO compared with the control. A strong positive correlation was also observed between MIO and functional mouth opening (r=.73, P<.001). CONCLUSIONS: Mandibular mobility was significantly reduced in Group FFF+RT, demonstrating an approximately 30% decrease in MIO compared with controls. Reconstruction alone did not significantly impair mandibular opening. Functional limitations paralleled objective measurements. These findings underscore the impact of RT on mandibular function and highlight the importance of anticipating restricted mouth opening during prosthodontic planning for complex reconstructions, including JIAD protocols.

Abstract as published, via PubMed.