Pouch-Type Flap Configuration for the Reconstruction of Extensive Retromolar Defects

Retromolar trigone carcinoma is a relatively rare malignancy; however, owing to its complex anatomy, it is often diagnosed at an advanced stage. Surgical resection frequently results in complex defects of the maxilla, mandible, and buccal mucosa. Although free-flap reconstruction is commonly used for such defects, reports focusing on defect-oriented flap configuration strategies are limited. In this study, the authors aimed to evaluate the usefulness and clinical significance of a pouch-type flap configuration for the 3-dimensional reconstruction of extensive retromolar defects. Consecutive patients who underwent retromolar defect reconstruction using a pouch-type flap configuration at our institution between January 2022 and January 2025 were retrospectively reviewed. Postoperative outcomes were assessed by measuring maximal mouth opening and objective radiologic evaluation of cheek depression using computed tomography. Eleven patients were included, and complete flap survival was achieved in all cases. Postoperative maximal mouth opening ranged from 18 to 45 mm. Cheek contour evaluation demonstrated excellent outcomes in 5 cases, good outcomes in 3 cases, and fair outcomes in 1 case. The remaining 2 cases could not be evaluated because early tumor recurrence precluded postoperative follow-up. Patients who underwent postoperative radiotherapy tended to exhibit reduced mouth opening. The pouch-type flap configuration represents a useful reconstructive option for treating extensive retromolar defects through 3-dimensional reconstruction and addressing postoperative trismus and cheek depression.