Study On Clinical Anatomy Of The Great Auricular Nerve And The Transverse Nerve Of Neck

Objective In this study,Anatomical landmarks of the great auricular nerve (GAN)and the transverse nerve of neck(TN) were studied to provide a reliable surgical basis for treatment of neck dissection and parotidectomy.Meanwhile,we investigated the approach of protection in operation.Methods(1) In 38 patients,totally 47 hemi necks,who were undergone the treatment of neck dissection for the first time from Jul 2006 to Dec 2007,we mainly investigated the course of the GAN and the TN.Meanwhile,the correlations among the two nerves above and their surrounding structures were observed.We also studied the correlation among the GAN,the TN and the external jugular vein(Ⅴ) as well as the layers they advanced.(2) We described the observations collected from the dissection of 9 cadavers and 20 patients who undergone the parotidectomy from July 2006 to Dec 2007.We analyzed the anatomical relation between the GAN and the fascia parotidea masseteric. Simultaneously,the course,the layer and the branches of the GAN were also identified. All data analysis was performed with Statistical Package 11.5 for Social Sciences(SPSS 11.5).Results we found that the point where GAN emerges from sternomastoid muscle(point A) all located above the point where the accessory nerve(AN) exits the sternomastoid(point B),the distance between the two points is(1.00±0.34) cm.The GAN leaves the cervical plexus at the posterior border of the sternocleidomastoid muscle and courses anteriorly between the lateral surface of this muscle and the deep surface of platysma.It's(0.83±0.54) cm above the angle of mandible where GAN sents out its post aurem branches,auricular lobule branches and anterior auricular branches.It is(6.36±0.71) cm long from point A to point C where the GAN gives off branches.The distances from point A to the middle point of clavicle is(7.72±0.96) cm.Mostly,GAN and external jugular vein run in the same layer and nearly in parallel.Besides,the distance between them is(1.07±0.54) cm.The bole and the branches of GAN both stay on the superficial lamella of fascia parotidea(FP) which sents out pycnotic fibrous tissue to wrap up them.The point(point D) where the TN emerges from the posterior border of the sternocleidomastoid is below point A,then,the TN which is below the external jugular vein runs almost horizontally over the surface of the sternocleidomastoid to sector branches in the lateral neck and some of its branches are distributed in the proso necke after going across the anterior jugular vein.The point where the TN gives off branches is multivariate.There isn't significant difference between the data which was gotten from left and right neck(P＜0.05).Conclusions In our research,we found that GAN keeps a constant relationship with the anatomic structure including external jugular vein,AN and superficial lamella of FP. Besides,TN possesses a stable relation with external jugular vein,sternomastoid muscle and point A.With our objective findings,it is probably to avoid damage to GAN and TN so that their function can be preserved in neck dissection and parotidectomy.