Submental Flap

Overview

Vascular Anatomy

• Arterial supply: The submental artery, a branch of the facial artery, arises deep to the submandibular gland. It is 1-2 mm in diameter and courses anteriorly between the anterior belly of the digastric muscle and the mylohyoid muscle. Perforating branches supply the submental skin from both the medial and lateral borders of the anterior digastric.
• Venous drainage: The submental vein drains into the facial vein, the external jugular vein, or both. The venous drainage is variable and this is the main source of complications (venous congestion).
• Pedicle length: The maximum pedicle length is approximately 8 cm via anterograde flow (facial artery → submental artery). Pedicle length can be extended by ligating the facial artery proximal to the takeoff of the submental artery, thereby creating retrograde flow from the facial artery back through the submental artery.

Flap Design

• Designed as an ellipse in the submental midline, with the superior incision ~1 cm below the inferior margin of the mandible (to hide the scar beneath the mandibular arch projection).
• Dimensions can reach up to 7 cm wide × 18 cm long.
• A pinch test is performed to assess submental skin redundancy and determine the maximum paddle width that permits primary closure of the donor site.

Surgical Technique

1. Dissection is usually initiated on the contralateral side to the planned pedicle.
2. Skin and subcutaneous tissue are incised to the level of the investing fascia of the digastric muscle, with the plane of dissection at the level of the mylohyoid in the submental triangle.
3. The ipsilateral anterior belly of digastric is divided distally and proximally to preserve the blood supply, and dissection proceeds in a retrograde fashion to the facial artery and vein.
4. The mylohyoid and ipsilateral anterior belly of digastric can be partially incorporated with the overlying platysma to protect the perforating branches.
5. The flap can be identified by dissecting the facial artery proximally, or by identifying the submental artery overlying the mylohyoid and dissecting retrograde.
6. Transposition: The flap is tunnelled under the mandible and through the submandibular and submental space for oral reconstruction, or rotated/transposed onto the face for soft tissue coverage.

Submental island flap for reconstruction of lateral pharynx with soft palate and tongue base involvement. (A) Flap harvest in setting of neck dissection - note available pedicle length. (B) Flap inset prior to closure of cheek flap. - Cummings Otolaryngology

Indications / Applications

Advantages

• Thin, pliable tissue paddle - ideal for intraoral mucosal reconstruction
• Reliable and well-described blood supply
• Accessible during oropharyngeal resections (no need for a second surgical team)
• Donor site closes primarily with a concealed scar
• Minimal donor site morbidity
• Shorter operative time compared to free flap reconstruction
• Can be performed with or without concurrent neck dissection

Disadvantages and Complications

• Venous congestion: The main concern, particularly with reverse-flow design or when tunnelled through the submandibular space (valves in the facial vein can obstruct retrograde venous drainage).
• Oncologic concern: When harvested during a selective neck dissection, there is a theoretical risk of translocating nodal tissue (level I lymph nodes) along with the flap pedicle into the oral cavity defect. This is the most frequently cited limitation for use after cancer resection, though its clinical significance remains debated.
• Wound dehiscence / hypertrophic scarring at the donor site, especially when closed under tension.
• Limited parallel access: Difficult for two surgical teams to work simultaneously, unlike free flap harvest.
• Requires preservation of submental vessels during neck dissection - if neck dissection is performed carelessly, the flap may be devascularized.

Comparison with Other Regional Flaps

• Cummings Otolaryngology Head and Neck Surgery (Regional Flaps, Ch. 98)
• Scott-Brown's Otorhinolaryngology Head & Neck Surgery (Submental island flaps, Ch. 92)
• Schwartz's Principles of Surgery, 11th Ed. (Regional Flaps, Ch. 18)