To reach saddle area along callosum anterior border. ( 2) SKA: the medial margin of incision situate at the 1/ 3 inner junction of supraorbital arch ( foramen sive incisura supraorbitalis) and the lateral extend to the lateral border of eyebrow a little. SKA:皮肤切口内侧位于眶上缘内、中1/3交界处(眶上切迹),外侧延伸至眉外少许。