[Positions of the implanted stimulating electrodes for artificial facial nerve for inducing contraction of the orbicularis oris muscle in rabbit with peripheral facial paralysis].

Objective: To explore the optimal positions of the implanted stimulating eletrodes for artificial facial nerve (AFN) for inducing contraction of the orbicularis oris muscle (OOM) in rabbit with peripheral facial paralysis. Methods: According to the four microelectrodes of the AFN stimulating side, four modes of the implanted positions were divided. In line with different modes, the electrodes were implanted into the affected OOM of the rabbits with unilateral peripheral facial paralysis. AFN output electric stimulation to induce contraction of the affected OOM with uniform stimulating frequency and pulse length in vitro. Then compared the stimulus threshold amplitude and the peak amplitude separately among different modes by SAS 9.3 version statistical software. Results: The differences of the stimulus threshold amplitude and the peak amplitude had no statistically significant separately between the first mode and the second mode (P>0.05), but there were statistically significant differences between the third mode and the fourth mode (P<0.05). Both kinds of the amplitudes were approximated between the first mode and the second mode respectively, and higher than those in the third mode or the fourth mode. Furthermore, both kinds of the amplitudes in the fourth mode were higher than those in the third mode. Conclusions: The microelectrodes of the AFN stimulating lateral are implanted into the upper lip with a public microelectrode and an output microelectrode, into the lower lip with an output microelectrode, and into the way, which is located to the angle 40° to 45° about the line joining between the midpoint of the ipsilateral auricle root and the corner of the mouth with an output microelectrode. This is the third positional mode which requires lowest effective stimulus current intensity. Thus the mode is suitable as the optimal placement programme.目的： 利用人工面神经(artificial facial nerve，AFN)诱发单侧失神经支配的兔口轮匝肌(orbicularis oris muscle)收缩，探讨AFN诱发闭口时刺激侧电极的最适植入位置。 方法： 根据AFN刺激侧4路微电极的植入位置分为4种模式，按不同模式将微电极植入于单侧周围性面神经麻痹兔的患侧口轮匝肌，经AFN体外输出统一刺激频率和脉宽的电刺激，诱发患侧口轮匝肌收缩，采用SAS 9.3统计软件比较各电极植入模式阈刺激和峰刺激的电流强度。 结果： 第1种与第2种模式的阈刺激电流强度及峰刺激电流强度的差异均无统计学意义(P值均>0.05)；第3种与第4种模式的阈刺激电流强度及峰刺激电流强度的差异均有统计学意义(P值均<0.05)。第1种、第2种模式的阈刺激电流强度及峰刺激电流强度相接近，且均高于第3种与第4种模式；第4种模式的阈刺激电流强度、峰刺激电流强度均分别高于第3种模式。 结论： 当AFN刺激侧微电极在上唇植入公用1路、输出1路，在下唇植入输出1路，在与口角至同侧耳廓根部中点的连线成40°～45°夹角方向植入输出1路，即第3种植入模式时所需的有效刺激电流强度最低，适合作为优选植入方案。.