An approach to marginal mandibulectomy and reconstruction for lower gingival carcinoma: A case report

Abstract

Introduction

The patients with early stage, clinically node-negative oral squamous cell carcinomas are usually treated with oral surgical excision of primary tumor. Marginal mandibulectomy of posterior mandible is difficult with an adequate safety margin via an intraoral. The cheek-splitting incision allows marginal resection at the posterior mandible under direct vision and it can avoid invasion to the neck region. The Buccal fat pad flap (BFP) grafting is considered feasible for the reconstruction of surgically induced defects, because of it has a high success rate due to BFP’s rich vascularity, proximity to the recipient site, low donor-site morbidity, and simple surgical procedure for grafting. The combination of BFP and The mucosal defect covered with fibrin glue and polyglycolic acid sheet (MCFP technique) can makes early intake after surgery, excellent wound-healing and pain-relieving effects.

Case report

We reported a case of squamous cell carcinoma arising at the posterior mandibular gingiva that was treated by marginal mandibulectomy via a cheek-splitting transbuccal approach, reconstructed the defect after surgery using a BFP covered with MCFP technique.

Conclusion

A major advantage of this approach is that it obtains an adequate margin of the posterior site without requiring a cervical incision thus allowing early intake after surgery and excellent wound-healing and pain-relieving effects.

Highlights

  • The cheek-splitting incision allows marginal resection at the posterior mandible under direct vision and it can avoid invasion to the cervix.

  • The combination of BFP and MCFP technique can makes early intake after surgery, excellent wound-healing and pain-relieving effects.

  • Cheek-splitting transbuccal approach and reconstructed using a buccal fat pad covered with MCFP technique are options for the treatment of c squamous cell carcinoma arising at the posterior mandibular gingiva.

Introduction

Patients with early stage, clinically node-negative oral squamous cell carcinoma (OSCC) are usually treated by the oral surgical excision of the primary tumor. Marginal mandibulectomy is considered an acceptable method to treat OSCC of the mandibular gingiva [ ]. The intraoral approach to marginal mandibulectomy of the anterior mandible offers an adequate safety margin. Conversely, it can be challenging to obtain an adequate margin by performing marginal mandibulectomy of the posterior mandible via the intraoral approach because of difficulties with instrumentation and the obstructed view of the surgical site. Consequently, the submandibular approach is frequently used to gain sufficient access to tumors arising from the posterior mandible [ ]. For patients with early stage tumors who do not require neck dissection, submandibular incision should be avoided to conserve the normal anatomy including lymph flow in the neck. The cheek-splitting incision was first described in 1988 as a surgical technique to remove the posterior lesions of the alveolar ridge and floor of the mouth via a transbuccal approach [ ]. This incision type allows marginal resection at the posterior mandible under direct vision [ ]. Buccal fat pad (BFP) flap has been used for the reconstruction of maxillary defects since it was first reported in 1977 [ ], and more recently, it has been adapted for use in various oral defects [ ]. The mucosal defect covered with fibrin glue and polyglycolic acid sheet (MCFP technique) is another method for wound coverage in the oral region [ ]. The combination of BFP and MCFP technique enables early intake after surgery as well as excellent wound-healing and pain-relieving effects.

We report here a case of OSCC arising from the posterior mandibular gingiva that was treated using marginal mandibulectomy via the cheek-splitting transbuccal approach, followed by the reconstruction of the defect using a combination of BFP and the MCFP technique.

Case report

A 68-year-old woman was referred to the Department of Oral and Maxillofacial Surgery, Gifu Prefectural Tajimi Hospital, owing to a complaint of an intractable ulcer around the left posterior mandibular gingiva since approximately 1 month. Clinical examination revealed a 12 × 10-mm mass with ulceration in the posterior part of the second molar gingiva of the mandible ( Fig. 1 ), which indicated dominant invasion in the lingual side without a palpable mass in the neck. In the T2-weighted magnetic resonance imaging (MRI) findings, the enhanced area showed a 10 × 10 mm mass ( Fig. 1 B). In computed tomography (CT) findings, bone resorption was not observed in the mandible. No metastatic lymph node was detected by MRI, CT, ultrasound (US), or positron emission tomography (PET) findings. An incisional biopsy revealed a well-differentiated SCC, and patient’s illness diagnosed an OSCC on the left mandibular gingiva (T1N0M0, stage I). Because the patient had early stage, clinically node-negative OSCC of the posterior mandible, we planned surgical resection of the primary tumor. She underwent marginal mandibulectomy via the cheek-splitting transbuccal approach and reconstruction using a combination of BFP and the MCFP technique under general anesthesia. Skin was incised starting from the left side of the lower lip, 5 mm anterior from the left angulus oris, and then continued 25 mm downward with a slight curve. The incision was then continued 15 mm upward along the nasolabial fold, followed by 15 mm in the posterior direction ( Fig. 2 ). Tumorectomy was performed with an adequate surgical margin of 10 mm; the extent of resection included parts of the buccinator, anterior masseter, inferior temporalis muscle, and superior pharyngeal constrictor muscle. Marginal mandibulectomy was performed using a reciprocating saw via a cheek incision. No malignant cells were observed in the intraoperative frozen specimen harvested from two points of the remaining tissue margin after the excision. The area of the surgical defect that was reconstructed using a combination of BFP and the MCFP technique was 35 × 25 mm. BFP was reached by passing through the posterior region of the exposed buccinators via blunt dissection. After achieving wound hemostasis, a small amount of fibrin glue (fibrinogen) was sprayed onto the wound. Next, the wound was covered with a PGA sheet that were cut into 5–10-mm-wide pieces and applied in manner to minimize overlapping, and a mixture of fibrin glue and thrombin was sprayed onto the sheet and the surrounding area using a specialized spray kit. Histopathological examination revealed a well-differentiated SCC with negative margin. In the postoperative phase, oral ingestion was initiated 3 days after surgery. Acetaminophen used for 2 days after surgery for pain relief. At 3 months after surgery, a linear scar was observed at the reconstructed site along with a slight cicatricial contracture at the donor site; however, no trismus or facial nerve palsy was noted. The wound was barely visible with little esthetic disturbance ( Fig. 3 ). However, 5 months after the initial surgery, an examination revealed multiple neck metastases, for which the patient underwent modified radical neck dissection. Histopathological examination revealed multiple nodal metastases (level IB and IIA) without extracapsular spread; thus, the patient received no postoperative treatment. No local or regional recurrence or distant metastasis was noted at 13 months after the secondary surgery.

Mar 21, 2021 | Posted by in Oral and Maxillofacial Surgery | Comments Off on An approach to marginal mandibulectomy and reconstruction for lower gingival carcinoma: A case report

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