Complications of Submandibular Gland Excision

Anatomical Considerations and Mechanism

The marginal mandibular branch of the facial nerve, which innervates the muscles controlling the lower lip, is vulnerable to injury during submandibular gland surgery, leading to decreased oral competence and subsequent drooling from the corner of the mouth 1
Injury to the marginal mandibular nerve during submandibular gland surgery results in weakness of the lower lip, causing decreased oral competence and subsequent drooling from the corner of the mouth 2

Marginal mandibular nerve injury results in weakness or paralysis of the lower lip on the affected side, causing inability to maintain oral seal and leading to drooling specifically from the corner of the mouth 2
The lingual nerve provides sensory innervation to the anterior two-thirds of the tongue and floor of mouth, and injury causes numbness and taste disturbance, not drooling 3
The ansa cervicalis innervates the infrahyoid muscles, and injury would affect neck movement and swallowing but not cause drooling 1
The hypoglossal nerve innervates the intrinsic and extrinsic muscles of the tongue, and injury causes tongue weakness, deviation toward the affected side, and potential speech/swallowing difficulties 3

Drooling from marginal mandibular nerve injury may be temporary or permanent depending on the nature of nerve damage, and management includes physical therapy, facial exercises, and surgical options such as nerve grafting or dynamic muscle transfers 2