Submandibular Gland – Sialadinitis and Tumors

SIALADENITIS

·         Inflammation of the submandibular gland

·         Acute, Chronic, or Acute on chronic

·         Causes

o   Acute submandibular sialadenitis

§  viral

·         mumps

§  bacterial

·         commoner

·         occurs secondary to obstruction

·         usually becomes chronically inflamed and requires excision

o   Chronic submandibular sialadenitis

·         Obstruction within the gland

o   due to sialothiasis, trauma, overextend flange of lower denture impinging on lingual papilla and causing inflammation and finally leading to stricture formation

o   80% of salivary gland stones occur in the submandibular gland due to high viscosity, antigravity drainage, and longer duct

o   80% of stones are radio-opaque

o   stones are usually at the opening of the duct

o   partial obstruction occur when the stone lies with in the hilum of the gland or within the duct in the floor

·         History

o   Acute painful swelling below the jaw

o   lump increases in size and become painful during meals

o   swelling resolves spontaneously over 1–2 hours after the meal is completed (usually seen in complete obstruction)

o   pain in between

o   abnormal taste – due to pus

·         Examination

o   firm

o   tender on bimanual palpation

o   stone may be felt in the floor of the mouth

o   intra-oral examination - pus (chronic and non-specific bacterial infection) draining from the sublingual papilla (either side of the frenulum linguae)

·         Investigations

o   intra-oral X-ray

·         Management

o   For infection –

§  Amoxycillin 500 mg 8 hourly

§  Metronidazole 400 mg 8 hourly

o   For pain - paracetamol 1 g 8 hourly

o   remove the stone

§  If it is in the duct in the floor of the mouth anterior to the point at which the duct crosses the lingual nerve (second molar region)

§  Under local anaesthesia

§  Through a longitudinal incision

§  do not suture, left the duct open

§  stricture will form if sutured

§  If proximal to the lingual nerve – simultaneous submandibular gland excision and stone removal and ligation of the duct under direct vision

SUBMANDIBULAR SIALADENECTOMY

·         Indications

o   Sialadenitis

o   Salivary gland tumors

o   < 6 cm incision is made 3-4 cm below the lower border of the mandible to avoid marginal mandibular branch of facial nerve

Inflammatory conditions – intracapsular dissection

o   Tumors – extracapsular dissection

o   The superficial lobe of the submandibular gland is 1^st mobilized by retracting superiorly with Allis’s forceps.

o   Platysma muscle is sutured with continuous reabsorbable sutures

o   Skin is sutured with subcuticular non-reabsorbable sutues whoch are removed on the 7^th  post-op day

o   At the end a vacuum suction drain is inserted and kept for 24 hours

·         Complications

o   Haematoma

o   Wound infection

o   Damage to

§  Marginal mandibular branch of the facial nerve

§  Lingual nerve

§  Hypoglossal nerve

§  Nerve to the mylohyoid muscle producing submental skin anaesthesia

TUMORS

·         Salivary gland tumors

Location	Frequency	Malignant
Parotid	Common	10-20%
Submandibular	Uncommon	50%
Sublingual	Very Rare	85%
Upper aero-digestive	Rare	90%

Submandibular Gland Tumors

·         Uncommon

·         Slow growing

·         Painless

·         50% are benign

·         Clinical Features

o   Rapid enlargement of the swelling

o   induration and/or ulceration of the overlying skin

o   Facial nerve weakness

o   Cervical lymph node enlargement

·         Investigation

o   CT

o   MRI

o   Fine needle aspiration biopsy – 18G needle

o   Open surgical biopsy is contraindicated because that can seed the tumor to surrounding tissues.

·         Surgical excision

o   small intra-glandular tumor – intracapsular submandibular gland excision

o   Large tumor – suprahyoid neck dissection preserving marginal mandibular branch of facial nerve, lingual nerve and hypoglossal nerve

o   overt malignancy – modified neck dissection or radical neck dissection, which also removes lingual and hypoglossal nerves

References:

Bailey and Love’s Short Practice of Surgery 25^th edition