Platysma myocutaneous flap for reconstruction of intraoral defects following excision of oral sub mucous fibrosis: A report of 10 cases.

Various surgical procedures are available for treating oral submucous fibrosis, but all of them have their inherent drawbacks. The superiorly based platysma myocutaneous flap is a common reconstruction option for intraoral defects followed after excision of fibrous bands in oral submucous fibrosis. The superiorly based flap has an excellent blood supply, but less efficient venous drainage when compared with posteriorly based flap. We present our results of using a superiorly based flap in the treatment of oral submucous fibrosis. Of 10 patients eight had no postoperative complications, one patient developed partial skin loss and other developed venous congestion which was managed conservatively.

Platysma myocutaneous flap was first used for reconstruction of intraoral defects by Futrell in 1978.[1] After that, it has been used for reconstruction of various head and neck defects. Platysma myocutaneous flap is easy to harvest, thin and pliable, promoting three-dimensional reconstruction, and there is a limited donor site morbidity with primary closure of the neck. The advantages of platysma flap include good color match, easy access to the donor site in the same operative field with minimum morbidity of donor site, ease in closing the donor site primarily, and appropriate flap thickness for oral facial defects.

Oral submucous fibrosis is chronic and disabling disease with obscure etiology that affects the complete oral cavity occasionally with the pharynx, and rarely involving the larynx. It is characterized by blanching and stiffness of the oral mucosa, which causes progressive limitation of mouth opening and intolerance to hot and spicy food.

It's precancerous nature was described by Paymaster,[2] who recorded that, in one-third of patients with squamous cell carcinomas has a slow onset of growing. Murti et al.[3] reported the malignant transformation of oral submucous fibrosis.

The purpose of this report is to examine the experience and results obtained with the use of reconstruction of intraoral defects with platysma myocutaneous flap. When considering the complications that can occur when adopting this technique one has to include total or partial necrosis of skin island, fistula, dehiscence, hematoma, and cellulitis with rates ranging from 18% to 45%.(Cannon, et al., 1982). We think that platysma myocutaneous flap is a better option that an extended nasolabial flap in terms of extraoral facial scar for the management of oral submucous fibrosis.[4]

Patients and Methods

Ten patients with oral submucous fibrosis were treated with superiorly based platysma myocutaneous flap. Six men and four women aged between 20 and 45 years were selected for this study after getting approval from Institutional Ethics Committee. Patients with oral submucous fibrosis falling in grades 3 and 4 were only selected for the study [Table 1].

Table 1

Number of patients with site of defect and complications

Surgical Technique

Superiorly based platysma myocutaneous flap was raised as described by Gupta[4] and used for reconstruction of the intraoral defects. With the neck hyperextended the proposed skin paddle was outlined on the ipsilateral neck, below the inferior border of the mandible [Figure 1]. The superior incision was made first and a plane superficial to the platysma muscle was dissected carefully cephalic to the inferior border of the mandible. A Skin incision was then made at the inferior line of the skin paddle, with additional exposure of the platysma muscle inferiorly. The platysma muscle was transected sharply at least 1 cm inferior to the edge of the skin paddle, and a subplatysmal plane of dissection developed just below the inferior border of the mandible. If the cervical branch of the facial nerve was to be incorporated, it was necessary to identify the nerve in the superficial layer of the deep cervical fascia and carefully dissect and preserve its proximal portion. Once the plane of dissection was fully developed, the platysma flap was transected vertically, anteriorly and posteriorly for full mobilization. The flap was introduced into the oral defect by creating an approximately sized soft tissue tunnel [Figures 2–4]. The harvested flap was sutured to the defect which was created by the release of fibrous band [Figure 5]. The donor site was easily closed in layers to obtain an acceptable cosmetic result [Figures 6 and 7].

Figure 1

Marking platysma flap outline

Figure 2

Submandibular incision to provide

Figure 4

Rt flap in position

Figure 5

Lateral thoracic flap in position

Figure 6

Pre op mouth opening

Figure 7

Post op mouth opening

Harvesting the flap

Results

Eight patients encountered no problems during wound healing process. Partial skin loss occurred in one patient. In this patient, healing occurred by secondary intention, that result in an excellent re-epithelization because of the good blood supply from surrounding tissues. These complications need prolonged nasogastric nutrition for 15 days. In another patient, there was venous congestion in the early postoperative period but resolved after a maximum of 48 h. No flaps failed, and all patients had overall good cosmetic results. There was no donor site morbidity in any patient.

Discussion

The goal of reconstruction is restoration form and function to allow a good quality of life. Oral and facial reconstruction after ablative surgery may be achieved in a variety of ways including skin grafts. Pedicled myocutaneous flaps and free flaps. Flap choice is related to the patient's condition and to the surgeons experience and ability.

We have found that superiorly based progressive massive fibrosis (PMF) can be used safely for reconstruction of intraoral defects following excision of fibrotic bands. The main complication of using a superiorly based PMF is venous congestion. In our study, one patient had venous congestion and the other had a partial skin loss. However, this was minimal and was managed by conservative measures only. The main venous drainage of platysma muscle is through the external jugular and submental veins.[56] Utmost care should therefore be taken to preserve these vessels and this can be achieved easily.

The primary blood supply to PMF derives from submental artery which branches from a facial artery, additional blood supply comes inferiorly from the cervical transverse vessels, medially from thyroid vessels and laterally from occipital and postauricular vessels. This is a multiaxial blood supply as it has multiple anastomoses with ipsilateral and contralateral mental, labial and sublingual arteries.[78]

In this study, platysma myocutaneous flap is avoided, if the muscle is thin because the blood supply to the skin island does not strictly depend on musculocutaneous perforating vessels, it is more of a fasciocutaneous with little muscle and it is technically difficult to set up.

Although various surgical options are available success rate varies with these procedures. Fibrous bands excision and propping the mouth open to allow secondary epithelization causes rebound fibrosis during healing. Split thickness skin grafting after excising fibrous bands results in high recurrence rate from contracture. Full thickness skin grafts rarely survive. Palatal island flap recommended by Khanna and Andrade[9] has its own limitations including involvement of donor tissue with limited reach of the flap and maxillary second molar needs to be removed to lower the defect so that flap is not under tension.

Tongue flap causes severe dysphagia, disarticulation, and risk of postoperative aspiration. Stability of tongue flap is questionable and dehiscence and uncontrolled tongue movements are the common postoperative complications.[10]

Buccal fat pad can also be used, but the anterior reach of it is inadequate and the region near canine cannot be covered, hence heals by secondary intention and subsequent fibrosis leads to gradual relapse.[11]

Temporal myotomy or coronoidectomy recommended by Caniff, et al.[12] to release severe trismus following atrophy of temporalis tendon secondary to the severity of submucous fibrosis.

We recommend the use of platysma muscle flap for reconstruction of intraoral defects after release of submucous fibrosis as the incision is some away from the face, the scars get hidden beneath collars and the patients are very comfortable.