Incidence and Recovery of Front Tooth Numbness After Nasoseptal Flap with Nasal Floor Extension

Introduction: The advancement of endoscopic endonasal approaches (EEAs) has expanded surgical access to skull base lesions but has also increased the frequency of skull base defects. Nasoseptal flap (NSF) is widely used for repair, and larger defects often require nasal floor extension to cover larger defects. While floor extension necessitates sacrificing the nasopalatine nerve, potentially causing front tooth numbness, the actual incidence and risk factors remain unknown.

Methods: This retrospective cohort study analyzed 52 patients who underwent a transsphenoidal approach using NSF with floor extension at a single center from June 2024 to January 2025. The primary outcomes were the incidence and recovery rate of front tooth numbness. Subjective numbness was evaluated at postoperative day 1 and at 1, 3, and 5 months after surgery.

Results: In patients with NSF and floor extension, the mean age was 50.2 (SD = 16.4) years, and 55.8% were male. Tumor pathology included pituitary adenoma (65.4%), craniopharyngioma (25.0%), and meningioma (3.8%). Immediate postoperative front tooth numbness occurred in 16 patients (30.8%). Of these, 12 patients showed complete recovery at 3 months (recovery rate = 75.0%), while 4 patients had persistent numbness (persistent numbness rate at 3 months = 7.7%). Comparison between patients with front tooth numbness and those with intact sensation showed no significant differences in sex, age, intraoperative cerebrospinal fluid grade, tumor pathology, or surgeon.

Conclusions: Despite complete nasopalatine nerve transection in NSF with floor extension, most patients showed no immediate numbness or recovered within 3 months, suggesting effective compensation through the contralateral nasopalatine nerve collateral system. As no specific risk factors for numbness were identified and the recovery rate was favorable, floor extension should not be avoided when necessary, but preoperative counseling regarding potential temporary numbness is recommended.