BACKGROUND: Facial nerve defect seriously impacts the mental and physical health of patients as well as their quality of life. Pediceled neck muscle transplant and autologous nerve transplant have been used in clinical to repair facial nerve defect and restore the facial muscle function. However,there are disadvantages and limits of above methods which have restricted their wide application of them. It is a research hotspot for looking for a new material to repair facial nerve defect.OBJECTIVE: To investigate the effects of autologous degenerative skeletal muscle to repair facial nerve defect and provide theoretic basis for further improving the functions of facial nerve.DESIGN: Randomized controlled study based on animals.SETTING: Anatomy department and neurological department in a medical college.MATERIALS: The experiment was completed in the Neuro-histochemical Teaching Section of Xianning Medical College from April to September 2002. Twenty-two Japanese big ear rabbits were randomly divided into 3 groups: 8 in group A to conduct autologous degenerative skeletal muscle transplant, 8 in group B to conduct autologous nerve transplant and 6 in group C as normal control.METHODS: Animal model was built by make 8 mm defect of zygomatic branch of left facial nerve in 22 rabbits. Electrophysiological examination and morphologic observation were conducted to the zygomatic branch of facial nerve and the muscle it controlled to rabbits after 20 weeks.MAIN OUTCOME MEASURES: Electrophysiological examination results and morphologic observation of each group.RESULTS: Electrophysiological examination: Neural stem action potential (NAP), compound facial muscles action potential(cMAP) and nerve conduction velocity(NCV) were compared between groups. There was no difference between group A and B( P ＞ 0.05) while significant difference existed between group A and C, B and C ( P ＜ 0.05) . Morphological image analysis:number of nerve fibers was 2 559 ± 1 683 in group A, 2 658 ± 1 295 in group B and 3 253 ± 1 564 in group C. Diameter of nerve fiber was(4. 01 ± 0. 88) μm,(4. 26 ±0.77) μm, (4.98 ± 0. 72) μm for the three groups, respectively.Average density of regenerated nerve fiber: was(220 ±30) /0. 013 89 mm2,(233 ±32) /0. 0138 9 mm2, (315 ±27)/0. 013 89 mm2, respectively. When comparing the above parameters between groups, there was no difference between group A and B( P ＞ 0. 05), while there was significant difference between group A and C, B and C ( P ＜ 0.05).CONCLUSION: Autologous degenerative skeletal muscle can effectively induce and stimulate the regeneration of nerve and repair the facial nerve defect with the equivalent effects of autologous nerve transplant.