Comparative Study on the Anatomy of Extracranial Facial Nerve of Rats and Rabbits

Objective:To investigate the conformation,courser and the facial nerve branches of rats and rabbits and to provide the data for the experimental research on the repair of facial nerve defect.Methods:The facial nerve and branches were measured and dissected,then observed in light microscope after modified trichrome staining.Results:The facial nerve trunk of the two models come out from stylomastoid foramen,then go forward along the surface of jugomaxillary muscle,divided into temporal branch,zygomatic branch,buccal branch,marginal mandibular branch and cervical branch,then end to the facial muscle respectively.In rats,the five branches all come from the trunk while in rabbits,temporal and zygomatic branch are from the temporal facial trunk,and there are several furcations in buccal branch of the rabbit.There are 2 or 3 bundles in one branch in rat's facial nerve,while about 9 bundles in rabbits.Conclusion:Buccal and marginal mandibular branch of the facial nerve are suitable for the experiment of injury and regeneration model.Rat is suitable for pathological and histological study of the facial nerve for its fewer branch furcation,while the rabbit model is more fit for functional examination.