Purpose: Paramedial mandibulotomy facilitates access for the resection of tumors in the oral and oropharyngeal space; however, severe complications related to surgical techniques and radiotherapy have been reported for this procedure. This study evaluated whether preservation of the periosteum during a mandibulotomy would decrease postoperative complications owing to the increased healing capacity provided by preserving more tissue. Materials and Methods: Patients who underwent mandibulotomy for surgical tumor ablation from 2007 through 2012 were included in a retrospective controlled cohort study. The trial was comprised of 2 groups: 1 group underwent subperiosteal and 1 group underwent supraperiosteal surgical dissection in the area of the mandibulotomy. The primary predictor variable was surgical technique and the primary outcome variable was surgical complications. The groups were matched according to tumor type, age, and gender. Clinical and radiographic follow-up was performed 12 months after surgery. Complications regarding bone exposure, plate exposure, osteoradionecrosis, nonunion, infection of the soft tissue flap, abscesses, fistulas, and gingival necrosis were recorded. Recordings of other factors, such as age, smoking habits, and timing of radiotherapy and chemotherapy, were performed and the 2 groups were compared for postoperative complications. Data analysis used the c2 test (Fisher exact test) to compare the sub- and supraperiosteal groups for postoperative complications. Results: Thirty-two patients were included (16 per group; 14 women and 18 men; mean age, 56 yr). Thir- teen patients in the subperiosteal group and 7 in the supraperiosteal group showed complications during the first 12 months. Seven patients had complications that persisted to the 12-month follow-up (6 in the subperiosteal group and 1 in the supraperiosteal group); however, the difference was not statistically relevant. Conclusion: This study found more persistent complications in the subperiosteal group compared with the supraperiosteal group at 12-month follow-up, which could imply that a more tissue-preserving surgical technique promotes mandibular healing in patients undergoing mandibular access osteotomy in combination with radiotherapy.