[Rabbit facial nerve damager after Nd: YAG laser irradiation: an experimental study]

OBJECTIVE:To investigate the change effects of rabbit facial nerve after Nd:YAG laser irradiation.METHODS: According to therapeutic laser energy density,the facial nerves of 28 rabbits were irradiated by Nd:YAG laser with 5 different laser dosages.RESULTS: The facial nerves were functionally intact with mild degeneration histologically at three weeks postoperatively,when the energy density of Nd: YAG laserlaser lower than 70J/cm(2).In the group with energy density of 140J/cm(2),facial nerve density functionally impaired with moderate degeneration which rehabilitated within six weeks. While the laser power increaseed to more than 240J/cm(2),irreversible nerve damages happened.CONCLUSION: laser thermal effect is the main cause of nerve damage,there is a positive correlation between laser dosage and nerve impairment.