Submental Flap in Intraoral Reconstruction After Pathologic Resections: Indications and Limitations

Abstract

Introduction

Submental flap is used to reconstruct intraoral and facial soft tissue defects. Submental flap is used for intraoral reconstruction in eighteen patients. Complications of this flap that includes local recurrence, remaining metastatic lymph node in the field of neck dissection, wound dehiscence at donor site and probability of transferring metastatic tissue are evaluated.

Materials and Methods

This flap is used as an alternative to free tissue transfer, and this article presents 18 cases after pathologic lesion resections, such as verrocous carcinoma (2 patients), odontogenic myxoma (1 patient), oral squamous cell carcinoma (SCC) (10 patients), adenoid cystic carcinoma (2 patients), leukoplakia (2 patients) as well as osteosarcoma in one patient.

Results

There was no case of local recurrence and remaining metastatic lymph node in the field of neck dissection. A case of metastatic lymph node involvement in posterior triangle of the neck, 2 years after surgery was occurred. One case of metastatic tissue transfer and a case of wound dehiscence in submental region are reported.

Conclusion

Submental flap is an useful aid for reconstruction of oral cavity mucosal defects. Its use in oral SCC reconstruction should be done in carefully selected cases.

Introduction

Submental flap was introduced in 1993 by Martin for facial skin and intraoral reconstructions [1]. Modifications of this flap are introduced based on blood supply (free or pedicle) [2, 3]. Orthograde and reverse flow are two known pedicle forms of this flap. The former is based on angular artery and depends on anastomosis between internal and external carotid arteries. The latter is the one mostly used for intraoral reconstructions [4, 5]. Free submental tissue transfer is not indicated for intraoral reconstructions because of vicinity of donor site to oral cavity.

Neck dissection in intraoral carcinoma (mainly squamous cell carcinoma) depends on clinical-radiographic and intraoperative findings [6, 7]. This article presents series of 18 cases with submental flap for intraoral reconstruction after pathologic resections. The advantages and limitations of the use of this flap are discussed.

Materials and Methods

Eighteen patients with Submental flap for intraoral reconstruction are considered for this study. Two types of submental flap which are variants of orthograde flow, (Martin and Patel modification) is used in our patients based on the thickness of the flap that is needed for reconstruction. Retrograde variant was used for reconstruction of palate in two cases of osteosarcoma and odontogenic myxoma (Fig. 1).

Fig. 1.

Retrograde variant of submental flap for increasing pedicle length to reach palate

Surgical Procedures [8, 9]

Martin’s original description of this flap is used for reconstruction of floor of mouth in two cases, in which there was need for thin structure. Thick submental flap was used in sixteen patients. Flap design in submental chin area is used in elliptical form, symmetric, and in two sides of the midline. Facial artery is identified and preserved. In Martin’s original submental flap, thickness of the flap composed of skin, subcutaneous tissue, and platysma muscle. In Patel’s modification of flap: the non pedicle side is the same as Martin’s submental flap but pedicle side of the flap contains anterior belly of digasteric and myelohyoid muscle that will protect submental artery and shelter submental perforators during flap dissection, eventually obtaining more bulky flap in paddle side (Figs. 2, 3). In oral squamous cell carcinoma (SCC) resection, submental flap accompanied with supraomohyoid neck dissection with preservation of facial artery and vein, was used. These vessels are identified then submandibular lymph nodes isolated and sent for frozen section. In patients with histologic metastatic node, this flap was not used for reconstruction. Donor site after harvesting submental flap with these two techniques are shown in Fig. 4.

Fig. 2.

Submental flap (Patel’s modification) with conservative neck dissection

Fig. 3.

Schematic picture of submental flap (Patel’s modification). Increased thickness in paddle side will improve blood supply and will preserve more perforators than original Martin’s submental flap

Fig. 4.

Donor site in submental flap. a Martin’s modification. b Patel’s modification, that anterior belly of digastric and myelohyoid muscle are transferred with the flap.*sign, points out to one of submental artery perforators in nonpedicled side which is cut

Results

Table 1 shows demographic information of eighteen patients after pathologic resections and reconstruction with submental flap. Eighteen patients (8 males and 10 females) aged between 8 and 75 years, after pathologic lesion resections, such as verrocous carcinoma (2 patients), odontogenic myxoma (1 patient),oral SCC (10 patients), adenoid cystic carcinoma (2 patients), leukoplakia (2 patients) as well as osteosarcoma (1 patient) were operated and immediately reconstructed with submental flap, and followed up between 1 and 4.5 years.

Table 1.

Demographic information of eighteen patients after pathologic resections and intraoral reconstruction with submental flap

Case	Age/sex	Diagnosis	Location	Follow up (years)	Defect size	The last information
1	53/F	SCC	Buccal	3	T 3	Alive. Recurrent SSC at base of flap
2	50/M	SCC	Buccal	2.5	T 4	Alive with no disease
3	25/F	SCC	Tongue	4	T 3	Died–Neck Metastasis (posterior triangle)
4	67/F	SCC	Tongue	4	T 3	NR-NM
5	60/F	SCC	Mandibular alveolar ridge	4	T 3	Alive with no disease
6	72/M	VC	Palate	4.5	T 4	Alive with no disease
7	35/F	ACC	Palate	2	Hemimaxillectomy	NR-NM
8	37/M	SCC	Buccal	3	T 3	NR-NM
9	68/F	Leukoplakia	FOM	2	T 4	Alive with no disease
10	70/F	SCC	FOM	3	T 3	NR-NM
11	75/M	VC	Palate	2	T 4	Alive with no disease
12	43/F	ACC	Palate	1	Maxillectomy distal to right canine	NR-NM
13	75/M	SCC	Palate	1	T 3	NR-NM
14	64/F	Leukoplakia	FOM	1	T 4	Alive with no disease
15	8/F	Osteosarcoma	Palate	1	Right hemimaxilla	NR-NM
16	68/M	Papillary SCC	Buccal and palate	1	T 4	NR-NM
17	65/M	SCC	Maxillary alveolar ridge	1	T 4	NR-NM
18	56/M	Odontogenic myxoma	Maxilla	1	Right hemimaxilla	Without recurrence

SCC Squamous cell carcinoma, VC Verrocous carcinoma, ACC Adenoid cystic carcinoma, FOM Floor of mouth, NR-NM: No recurrence-No metastasis

The patient with alveolar ridge SCC had undergone preoperative radiotherapy and chemotherapy. Martin’s original flap was used for leukoplakia ablation to reconstruct floor of mouth because of its thin nature, this modification is a good choice and Patel’s modification of submental flap, that is thicker was used for intra oral reconstruction of tongue, buccal mucosa, alveolar ridge, and palate. In the present article, submental flap is used for reconstruction of most part of oral cavity. There was no case of marginal mandibular nerve palsy due to flap harvest and all flaps survived. There was no case of local recurrence and remaining metastatic lymph node in the field of neck dissection. A case of metastatic lymph node involvement in posterior triangle of the neck two years after surgery was observed. One case of metastatic tissue transfer with this flap is shown. A case of wound dehiscence in submental area occurred.

• A.The patient was a 53-year-old female with squamous cell carcinoma on left buccal mucosa and radiographic/clinical NO neck. Submandibular lymph node was not involved in frozen sections. Wide surgical resection with clear safety margins and supraomohyoid neck dissection with preservation of facial artery and vein was performed; finally submental flap was used for reconstruction. Post operative chemo-radiotherapy was done. After one year recurrence of SCC was revealed in flap base (Fig. 5).
• B.Donor site dehiscence: A 50-year-old man, who was a heavy smoker, presented with a squamous cell carcinoma on the right buccal mucosa. Supraomohyoid neck dissection with preservation of facial and submental artery was used for immediate reconstruction. One week later the patient returned with dehiscence of donor site (Fig. 6). Reclosure of the wound was unsuccessful, so daily wet-dry dressing was prescribed. Healing by secondary intension filled the defect in two weeks.

Fig. 5.

SCC at the base of submental flap (after surgical resection).The patient had previous buccal mucosal SCC. Recurrence of the cancer occurred at facial skin opposite to transferred flap. After surgical resection deep margins were free of tumoral cells

Fig. 6.

Dehiscence at submental donor site. (one week postoperatively)

Discussion

Submental flap had wide skin paddle so it is a suitable choice for reconstruction of intraoral medium to large mucosal defects [10]. Submental flap is excellent for intraoral soft tissue pathologic lesions without neck dissection [11]. In patients with verrucous carcinomas, adenoid cystic carcinoma and extensive leukoplakias good results were obtained. It gave the surgeon the opportunity of wide resection with safety margins and immediate reconstruction. The submental flaps are used for reconstructing surgical defects after resection of soft tissue sarcomas [12]. Our experience with this flap in management of upper jaw osteosarcoma showed good result in wide resection with safety margins and immediate reconstruction. One of our patients is the youngest patient (8-years) with submental flap in the literature (Fig. 7). Because of axial blood supply it can be used in patients with preoperative chemoradiotheraphy similar to our patient with alveolar ridge SCC [13, 14]. In patients with intraoral SCC, that is the most prevalent oral carcinoma, neck management is an integral part of treatment [15, 16]. Literature recommended that this flap is not suitable for clinical N+ neck [17]. But in NO neck patients this flap with preservation of facial artery and conservative neck dissection is recommended [18]. Retrograde submental flap can be used in management of neck positive patients. Sacrifice of facial artery and vein have no negative effect on flap perfusion because of reverse flow of bloodstream through anastomosis of external and internal carotid arteries via angular artery [19, 20].

Fig. 7.

Submental flap for reconstruction of maxilla in 8 year old girl with upper jaw osteosarcoma

We realized that in patients with oral SCC and clinical NO neck submental flap has some limitations, including:

• A.The samples can not send enblock for histopathologic examination. The samples include (a) Submental lymph nodes, (b) Submandibular lymph nodes, (c) Submandibular salivary gland and (d) Main sample. Consequently there is a risk of ignoring remaining metastatic tissue in neck. Discontinuous neck dissection is not to be recommended in oral cancer although some authors believe that it does not to affect oncologic results [21, 22].
• B.In patients with supraomohyoid neck dissection where facial vein-artery should be persevered and protected, the procedure may be difficult and time consuming. In this situation submental flap technique is not rapid and simple [23]. In such cases axial vessels should be skeletonized and soft tissue cuff surrounding them should be as thin as possible, this renders the flap more prone to ischemia and increase the risk of flap failure.
• C.There is possibility of metastatic soft tissue transfer with the submental flap (case A).
• D.The submental flap has large paddle size so it is a suitable choice for reconstruction of T3–T4 oral SCC [24, 25]. Although it has the capacity to replace small mucosal defects, it is more possible that these tumor sizes (advanced oral SCC) have occult neck metastasis than T1–T2 oral SCC, so neck dissection should be done more comprehensive in them than conservative [26].

Hairy nature of this flap in males and the need for second operation for hair removal is another limitation of this flap. De-epithelialized variant is a good solution for this topic (Fig. 8). Wound contracture from secondary epithelialization process is prevalent [27].

Fig. 8.

De-epithelialized variant is a good solution for hairs in males

Submental flap passages through subcutaneous tunnel for reconstruction of buccal mucosa and palate will increase soft tissue facial fullness and slight asymmetry that is noticed by the patients. This bulging is more prominent over lower mandibular border (Fig. 9).

Fig. 9.

Soft tissue bulging is resulted from transfer of submental flap in subcutaneous tunnel

Donor site dehiscence occurred in one patient. Review of the intraoperative photographs revealed that the width of submental flap in submental region exceeded the limits than that determined by pinch test. Heavy smoking habit of the patient may be the other contributing factor.

Oncologic safety of submental flap in management of oral SCC should be evaluated in multicenter studies with large number of patients.

Conclusion

Submental flap is a useful aid for reconstruction of oral cavity mucosal defects after pathologic resections. Its use in oral SCC should be done in carefully selected cases.