An oral defect after oncologic resection, especially in the upper jaw, is an extremely complex problem in terms of reconstructive surgery. Herein, we report 2 patients who were diagnosed with oral mucosal squamous cell carcinoma. In one patient, the lesion was present on the right side of the hard palate, invading the maxillary bone. In the other patient, the lesion was present in the left retromolar trigone region. Reconstruction of the postsurgical defects was successfully done using a temporalis muscle flap. Both patients were discharged after ensuring the absence of any postsurgical complications. Furthermore, the postoperative functional and esthetic outcomes were adequate. These case reports highlight the usefulness and reliability of a temporalis muscle flap for the immediate reconstruction of oral and maxillary defects after oncologic resection.