Comparison of axonal densities of posterior auricular branch and zygomatic branch of facial nerve in unilateral dynamic facial reanimation: A cadaveric study

Facial paralysis adversely affects the functional, aesthetic, psychological and social integrity of the patient and decreases the quality of life. Because of this important issue, treatment techniques vary and the success of microsurgical procedures is increasing with technological development. Despite these satisfactory results, facial reanimation surgery is still a challenging area for surgeons. One of the most frequently discussed issues in the literature is the lack of spontaneous and voluntary smile when the masseter is used as the donor nerve, and in contradiction the inability to provide motor force in the cross-facial nerve graft (CFNG)-based reanimations. At this point, in our study, it was aimed to examine the posterior auricular nerve (PAN), an alternative donor motor nerve, which will provide additional motor force to the zygomatic nerve in CFNG-based procedures. Microscopic examination of PAN and zygomatic nerve specimens were performed on the bilateral facial halves of 14 fresh frozen cadavers and the anatomical course of PAN was recorded. As a result of our study, it was concluded that PAN can be used as a donor motor nerve because of its easily accessible and stable anatomic course, it does not cause a significant side effect in case of sacrifice, and it provides spontaneous smile and motor support. Thus, the problem of motor weakness, which is the main problem in nerve graft cases where the facial nerve is used as a donor, can be solved. However, in the near future, this should be demonstrated by different clinical studies and results should be compared by using alternative methods. Key Words: Axonal Density, facial nerve, facial paralysis, posterior auricular nerve, zygomatic nerve.