Evaluation of bone resection margins of segmental mandibulectomy for oral squamous cell carcinoma

Resection margins are frequently studied in patients with oral squamous cell carcinoma and are accepted as a constant prognostic factor. While most evidence is based on soft tissue margins, reported data for bone resection margins are scarce. The aim of this retrospective study was to evaluate and determine the utility of surgical margins in bone resections for oral cavity squamous cell carcinoma (OCSCC). The status of bone resection margins and their impact on survival was investigated in patients who had undergone segmental mandibulectomy for OCSCC. Medical records were retrieved for the years 2000–2012; 127 patients were identified and included in the study. Tumour-positive bone resection margins were found in 21% of the patients. The 5-year overall survival was significantly lower in this group (P < 0.005). Therefore, there is a need for intraoperative feedback on the status of bone resection margins to enable immediate additional resection where necessary. Although the lack of intraoperative methods for the evaluation of bone tissue has been addressed by many authors, there is still no reliable method for widespread use. Future research should focus on an objective, accurate, and rapid method of intraoperative assessment for the entire bone resection margin to optimize patient outcomes.     

Evaluating the accuracy of resection planes in mandibular surgery using a preoperative,intraoperative, and postoperative approach

In mandibular surgery, three-dimensionally printed patient-specific cutting guides are used to translate the preoperative virtually planned resection planes to the operating room. This study was performed to determine whether cutting guides are positioned according to the virtual plan and to compare the intraoperative position of the cutting guide with the resection performed. Nine patients were included. The exact positions of the resection planes were planned virtually and a patient-specific cutting guide was designed and printed. After surgical placement of the cutting guide, intraoperative cone beam computed tomography (CBCT) was performed. Postoperative CT was used to obtain the final resection planes. Distances and yaw and pitch angles between the preoperative, intraoperative, and postoperative resection planes were calculated. Cutting guides were positioned on the mandible with millimetre accuracy. Anterior osteotomies were performed more accurately than posterior osteotomies (intraoperatively positioned and final resection planes differed by 1.2 ± 1.0 mm, 4.9 ± 6.6°, and 1.8 ± 1.5°, respectively, and by 2.2 ± 0.9 mm, 9.3 ± 9°, and 8.3 ± 6.5° respectively). Differences between intraoperatively planned and final resection planes imply a directional freedom of the saw through the saw slots. Since cutting guides are positioned with millimetre accuracy compared to the virtual plan, the design of the saw slots in the cutting guides needs improvement to allow more accurate resections.     

Lateral segmental mandibulectomy reconstruction with bridging reconstruction plate and anterolateral thigh free flap: a case series of 30 consecutive patients

Lateral posterior segmental mandibular defects present a reconstructive challenge and an osseous flap would be the gold standard to reconstruct such a defect. However, combining a mandibular reconstruction plate (MRP) with a soft-tissue free flap (to restore mucosal integrity and provide durable coverage of the plate itself) offers an alternative option for posterior segmental mandibular defects in patients who are not suitable for osseous reconstruction, or do not choose it. We retrospectively reviewed 30 consecutive patients (19 male and 11 female) who underwent reconstruction of a segmental mandibulectomy defect using a bridging MRP and anterolateral thigh (ALT) free flap. The mean (range) age was 67 (31-87) years. The American Society of Anesthesiologists’ (ASA) status of the study population comprised Grade 1 (n = 10), Grade 2 (n = 18), and Grade 3 (n = 2). The majority of patients had oral cavity squamous cell carcinoma (n = 26) involving the mandible, two had osteoradionecrosis, and two mucoepidermoid carcinoma. Four patients had complications specific to the reconstruction, and flap loss occurred in one (96.7% success rate). Metalwork infection occurred in three, including one plate extrusion and one plate fracture. The median length of stay was 10 days, and mean (range) duration of follow up 23.3 (1-96) months. This technique is an alternative reconstructive option for the non-tooth-bearing mandible. Reconstructing a posterolateral segmental mandibulectomy defect with a bridging MRP and ALT free flap offers a robust reconstructive alternative with a favourable complication profile.     

A technique of tongue fixation after total mandibulectomy: the Oji spatula

When ameloblastoma presents late, as is often the case in Nigeria, it can affect the whole mandible. The treatment of choice is total mandibulectomy. The procedure may necessitate the resection of the musculature of the floor of the mouth to which a large portion of the tongue is attached. In our hospitals, immediate reconstruction is not undertaken for various reasons. Consequently, the musculature of the floor of the mouth cannot be reattached to a graft. The purpose of this paper is to illustrate a simple and patient-friendly method for fixation of the tongue after total mandibulectomy to achieve a secure airway. The tongue is tied to a wooden spatula, which stretches horizontally across the mouth. It is in contrast to the conventional technique of rigid fixation of the tongue to the pectoral muscle. This technique was used for 11 patients with large ameloblastomas. For the purpose of comparison, the conventional technique was used in 4 patients. The method of using a wooden spatula as a means of tongue fixation is known in the maxillofacial unit of the University of Nigeria Teaching Hospital, Enugu as the Oji spatula after the surgeon who developed it. All 11 patients tolerated this method well, but the 4 patients who had their tongues tied to the pectoral muscle complained of pain and discomfort. All the patients survived the procedure without postoperative blockage of the airway by the tongue. Follow-up for up to 6 months established that the patients had no respiratory problems.     

Development of a novel resection and cutting guide for mandibular reconstruction using free fibula flap

Introduction

The authors developed a semi-standardised resection and cutting guide for mandibular reconstruction with free fibula flap based on data of mandible sizes and angles.

Marginal or segmental mandibulectomy: treatment modality selection for oral cancer: a systematic review and meta-analysis

Surgery is the most well established mode of initial definitive treatment for the majority of oral cancers. The most important decision in terms of tumour ablation in oral cancers when the jaws are potentially involved is the management of the mandible. The aim of this study was to explore the differences in survival rate and disease control between patients undergoing marginal mandibulectomy and patients undergoing segmental mandibulectomy using a systematic review and meta-analysis approach. A total of 15 cohort studies, including 1672 participants, were identified. Meta-analysis provided weak evidence in favour of segmental mandibulectomy for local control. Segmental mandibulectomy gave 73% better disease-free survival than marginal mandibulectomy when the marrow was invaded (P = 0.04). The overall survival rate was evaluated, and no statistically significant difference was found between the two different mandibulectomy approaches, although the results showed a trend in favour of segmental mandibulectomy which could increase the overall survival by 23%. Based on these findings regarding the survival rate and efficacy of disease control, this study indicates that a marginal mandibulectomy may be recommended for cases with no invasion or superficial invasion of the mandibular cortex, and a segmental mandibulectomy may be a more reasonable choice for patients with extensive mandibular cortex invasion or medullary invasion.