The marginal mandibular nerve may be injured during surgery in the neck region, especially during excision of the submandibular salivary gland or during neck dissections due to lack of accurate knowledge of variations in the course, branches and relations. An injury to this nerve during a surgical procedure can distort the expression of the smile as well as other facial expressions.
The marginal mandibular nerve might be harmed during neck surgery, particularly when removing the submandibular salivary gland or performing neck dissections due to insufficient understanding of its path, branches, and connections. Damaging this nerve during a surgical procedure can alter the appearance of smiling as well as other facial expressions.