Marginal mandibular nerve injury during neck dissection of level IIa, and the influence of different types of dissection: diathermy versus cold knife.

Introduction: Post-operative injury of the marginal mandibular branch of the facial nerve is consider a complication in neck dissection and can be related to different factors including traction, devascularisation or the conduction block due to diathermy.
Material and Methods: Prospective, crossover study including patients treated bilateral selective neck dissection of level IIa during a 12 months-period, was performed to evaluate the efficacy of the Hayes-Martin manoeuvre to prevent nerve injury during the use of cold or monopolar diathermy dissection.
Results: 20 patients met the inclusion criteria (40 neck dissections). Just one case of a right temporal MMN weakness in the post-operative period was observed (1/40 = 2,5%). There were no cases of permanent marginal mandibular nerve weakness using the Hayes-Martin manoeuvre Conclusion: The Hayes-Martin manoeuvre is a safe way to preserve MMN during neck dissection of level IIa, regardless of the type of dissection.