The study aimed to determine flap site recurrence rate in oral squamous cell carcinoma patients who had undergone reconstruction with submental island flap, to evaluate factors affecting flap site recurrence, particularly pathological level I lymph node status, and assess survival outcomes.

Fifty-six patients with squamous cell carcinoma of the oral cavity who underwent surgical resection and submental island flap reconstruction between October 2012 and February 2024 were enrolled onto the study. Tumor recurrence and survival outcomes were analyzed. A Kaplan-Meier estimate of locoregional recurrence-free survival (LRRFS), disease-specific survival (DSS), and overall survival (OS) was calculated. Factors affecting flap site recurrence and survival outcomes were assessed.

Most patients (78.57 %) were in the advanced stage (stage III-IV), and 21.43 % had pathological level I lymph node metastasis. Flap site recurrence rate was observed in 5.36 % of cases, without any identifiable factors predicting the recurrence, including pathological level I lymph node metastasis. The 5-year LRRFS, DSS, and OS rates were 60.28 %, 84.55 %, and 67.38 %, respectively. Positive resection margin, perineural invasion, and extranodal extension adversely affected LRRFS.

Submental island flap reconstruction in selected oral squamous cell carcinoma patients is oncologically safe regarding low flap site recurrence rate, satisfactory survival outcomes, and pathological level I lymph node metastasis did not affect the flap site recurrence.