The use of the mental foramen as a guide for marginal mandibulectomy in oral squamous cell carcinoma patients with tumor-free margins: experience of 15 years

BACKGROUND: Preserving an adequate residual mandibular height during marginal mandibulectomy is essential to reduce the risk of postoperative fracture while maintaining oncologic safety in patients with oral squamous cell carcinoma (OSCC). PURPOSE: The aim of this study was to evaluate the oncologic outcomes of marginal mandibulectomy guided by the mental foramen and to assess its relevance as an anatomical landmark for osteotomy. MATERIAL AND METHODS: Patients treated for OSCC by marginal mandibulectomy with localization of the mental foramen between 2007 and 2022 were retrospectively included. The primary endpoint was bone resection margin status. Secondary endpoints included local recurrence-free survival, disease-free survival, and overall survival. An anatomical analysis of the mental foramen position relative to the inferior osteotomy line was performed using postoperative computed tomography. RESULTS: A total of 150 patients met all inclusion criteria. Clear bone margins (R0) were achieved in 98 % of cases. Bone invasion (pT4) was observed in 41.3 % of patients. At 5 years, local recurrence-free survival, disease-free survival, and overall survival were consistent with outcomes reported for selected OSCC treated by marginal mandibulectomy. No immediate postoperative mandibular fractures were observed. The inferior osteotomy line showed a consistent relationship with the mental foramen. CONCLUSION: Marginal mandibulectomy guided by the mental foramen allows reproducible bone resection while achieving satisfactory oncologic outcomes. The mental foramen constitutes a reliable anatomical landmark for osteotomy in carefully selected patients with OSCC.