Salivary fistulas are frequent complications in oral oncological reconstructive surgery by means of pedicled or free flaps. The most common risk factors are malnutrition, advanced disease, and healing alterations due to radiation therapy or infections. However, they can be observed also in healthy patients where the flap suture breakdown is the only cause. During the reconstructive phase, flaps are anchored to the remnant tongue, hyoid bone, and residual gingival mucosa; the last structure often does not offer suitable margins for a strong suture. The aim of this study was to propose a transmandibular fixation of the flap that allows, in a safe, efficient, and unexpensive way, the creation of a saliva-proof neofloor of the mouth, independently from the quality and thickness of residual gingival mucosa.