Residency · Residency · Oral Maxillofacial Surgery
Submandibular Gland Excision
Introduction
Submandibular gland excision (submandibulectomy) is one of the most commonly performed salivary gland procedures in OMFS. Indications include chronic sialadenitis, recurrent sialolithiasis refractory to conservative management, and neoplasms. The procedure requires meticulous surgical technique due to the intimate relationship of the gland with the marginal mandibular nerve, lingual nerve, and hypoglossal nerve.
Indications
Indications include chronic submandibular sialadenitis with recurrent infections unresponsive to antibiotics and conservative measures, sialolithiasis with intraglandular stones or large hilar stones not amenable to sialendoscopy or transoral retrieval, neoplasms (both benign and malignant), Sjogren syndrome with refractory symptoms and gland dysfunction (rare), plunging ranula arising from the sublingual gland that may necessitate combined sublingual and submandibular gland excision, and IgG4-related sclerosing sialadenitis (Kuttner tumor) when the diagnosis is uncertain or symptoms are refractory.
Surgical Anatomy Review
Submandibular Triangle
The submandibular triangle is bounded by the anterior and posterior bellies of the digastric muscle and the inferior border of the mandible. The gland fills this triangle, with its superficial portion lying superficial to the mylohyoid muscle. The deep lobe wraps around the posterior free edge of the mylohyoid into the floor of mouth.
Critical Neural Structures
The marginal mandibular branch of the facial nerve (CN VII) courses superficial to the facial artery and vein, deep to the platysma, within or just deep to the investing layer of deep cervical fascia. It lies at or below the inferior border of the mandible in 80% of patients (up to 1-2 cm below). Injury causes ipsilateral lower lip weakness with inability to depress the lower lip. The lingual nerve courses in the floor of mouth deep to the mylohyoid, crossing Wharton's duct twice (lateral to medial then medial to lateral from posterior to anterior). It must be identified and preserved during duct ligation and deep lobe dissection, as injury causes ipsilateral tongue numbness and taste loss of the anterior two-thirds. The hypoglossal nerve (CN XII) lies deep to the submandibular gland on the surface of the hyoglossus muscle, coursing between the mylohyoid and hyoglossus. Injury causes ipsilateral tongue deviation toward the injured side and atrophy.
Vascular Structures
The facial artery courses deep to the posterior belly of the digastric, loops through or deep to the gland, and exits over the mandibular border. The facial vein courses superficial to the gland. Both vessels are typically ligated during the procedure.
Preoperative Workup
CT with contrast or ultrasound assesses gland pathology, stone location, and excludes neoplasm extension. FNA is obtained for suspected neoplasms to distinguish benign from malignant before surgery. Medical history addresses anticoagulation status, prior neck surgery, and radiation history. The consent discussion covers risks of marginal mandibular nerve, lingual nerve, and hypoglossal nerve injury, as well as scar, hematoma, and infection.
Surgical Technique
Patient Positioning
The patient is positioned supine with the neck extended and head turned to the contralateral side. A shoulder roll optimizes neck extension. Nasotracheal or contralateral oral intubation keeps the field clear.
Incision
A curvilinear incision is placed approximately 2 cm below the inferior border of the mandible in a natural skin crease to protect the marginal mandibular nerve. The length is approximately 4 to 5 cm, centered over the gland. Extension posteriorly beyond the angle of the mandible is avoided to prevent injury to the great auricular nerve.
Dissection
The incision is carried through skin, subcutaneous tissue, and platysma. The marginal mandibular nerve is identified and protected using the Hayes-Martin maneuver, in which the facial vein is ligated at the inferior border of the mandible and retracted superiorly with the nerve. The investing fascia is incised along the inferior border of the gland, and the superficial lobe is dissected free. The facial artery is identified and ligated at the posterior and superior poles of the gland. The facial vein is ligated (already elevated with the Hayes-Martin maneuver).
Deep Lobe Dissection
The mylohyoid is retracted anteriorly to expose the deep lobe. The lingual nerve is identified crossing Wharton's duct, preserved, and the duct is ligated and divided. The hypoglossal nerve is identified on the hyoglossus and the gland is carefully dissected off this structure. The gland is delivered with its deep lobe from the wound. The submental artery is identified and ligated if encountered.
Closure
Meticulous hemostasis is achieved and the wound irrigated. A small closed suction drain (Jackson-Pratt or Penrose) is placed. The platysma is closed with absorbable sutures, and the skin is closed with subcuticular sutures for optimal cosmesis. The drain is removed when output is less than 10 to 15 mL per 24 hours, typically on postoperative day 1 to 2.
Postoperative Care
Drain output is monitored and the drain removed when minimal. A soft diet is maintained for 3 to 5 days and advanced as tolerated. The incision is kept clean and dry, with suture removal at 5 to 7 days. Nerve assessment tests marginal mandibular nerve function (smile, show teeth), tongue sensation, and tongue movement. Antibiotics are not routinely required unless active infection was present.
Complications
| Complication | Temporary Rate | Permanent Rate | Management |
|---|---|---|---|
| Marginal mandibular nerve injury | 5-10% | 1-3% | Observation; most recover in 3-6 months |
| Lingual nerve injury | 2-5% | <1% | Observation; microsurgical repair if persistent |
| Hypoglossal nerve injury | Rare | Rare | Careful dissection on hyoglossus; observation |
| Hematoma/seroma | 2-5% | N/A | Drain placement; evacuation if expanding |
| Wound infection | Uncommon | N/A | Antibiotics; drainage if abscess |
| Salivary fistula/sialocele | Uncommon | N/A | Usually self-limiting; aspiration if persistent |
| Hypertrophic scarring | Variable | N/A | Skin crease incision; steroid injection |
Marginal mandibular nerve injury is the most concerning complication, with temporary neuropraxia in 5 to 10% and permanent injury in 1 to 3%. Lingual nerve injury occurs as temporary paresthesia in 2 to 5% with permanent injury in less than 1%. Hypoglossal nerve injury is rare with careful technique and causes tongue deviation and dysarthria. Hematoma or seroma is managed by the drain and may require evacuation if expanding. Wound infection or abscess is uncommon. Salivary fistula or sialocele from residual salivary tissue or duct remnant is usually self-limiting. Hypertrophic scarring is possible, though placement in a skin crease minimizes visibility. Recurrence may occur if excision for chronic sialadenitis is incomplete.
Special Considerations
Malignant Tumors
Submandibular gland tumors are malignant in 40 to 50% of cases. Excision must include adequate margins, and neck dissection may be required for nodal disease. Perineural invasion (especially from adenoid cystic carcinoma) may require sacrifice of the lingual or hypoglossal nerve. Adjuvant radiation therapy is indicated for high-grade malignancies, positive margins, or nodal metastasis.
Plunging Ranula
Plunging ranula requires excision of the sublingual gland (the source of the pseudocyst), not just the submandibular gland. A combined transoral sublingual gland excision with or without a cervical approach is used. Simple marsupialization has high recurrence rates.
Clinical Pearls
The Hayes-Martin maneuver (ligating the facial vein and retracting it superiorly) is the key technique for protecting the marginal mandibular nerve. The lingual nerve crosses Wharton's duct twice, so the nerve must always be identified before ligating the duct. The incision should be placed at least 2 cm below the inferior border of the mandible in a skin crease for nerve protection and cosmesis. Submandibular gland tumors are malignant in nearly half of cases, so FNA should always be obtained before excision and the patient counseled accordingly. Closed suction drainage reduces hematoma risk and should be removed within 24 to 48 hours.
References
- Megwalu UC, Shin JY. "Outcomes of Submandibular Gland Excision." Laryngoscope. 2021;131(1):E189-E195.
- Preuss SF, et al. "Submandibular Gland Excision: 15 Years of Experience." Journal of Oral and Maxillofacial Surgery. 2007;65(5):953-957.
- Carlson ER. "Submandibular Gland Resection." In: Fonseca RJ, ed. Oral and Maxillofacial Surgery. 3rd ed. Elsevier; 2018.
- De Silva MN, et al. "A Study of the Marginal Mandibular Branch of the Facial Nerve." British Journal of Oral and Maxillofacial Surgery. 2004;42(4):274-278.