Marginal Mandibular Nerve Dysfunction after Submandibular Surgeries

Abstract

Introduction: Marginal mandibular nerve (MMN) is a branch of facial nerve. It is vulnerable to iatrogenic injuries during surgeries involving submandibular region. This leads to significant post-operative morbidity. Injuries to this nerve can distort the expression of the smile as well as other facial expressions. Objectives: The aim of the study is to determine the incidence of MMN dysfunction in the submandibular surgeries and to determine the factors affecting post-operative MMN dysfunction. Methodology: This was a longitudinal study conducted in the department of general surgery, in a tertiary care hospital for a period of 1 year in 48 patients undergoing submandibular surgeries. The study subjects were followed up intra-operatively, post-operative day 1 and 2 weeks after surgery for any post-operative MMN dysfunction. The incidence was correlated with different variables using statistical tests. Results: Out of 48 subjects, six had post-operative MMN dysfunction, forming 12%. Considering the age, majority of the patients with MMN dysfunction were aged above 60 years. Majority of surgeries in which post-operative MMN dysfunction developed were performed using electrocauteries, and the duration of surgery was 1–2 h. Systemic diseases such as diabetes mellitus also contributed. Conclusion: The incidence of MMN dysfunction is 12% in the submandibular surgeries with contributory factors being advanced age, diabetes mellitus, prolonged surgeries with excessive traction and use of energy devices such as electrocautery.