侧腭杆离开龈缘的距离至少是A. 1 ?2mmB. 2?4mmC. 4?6 mmD. 6 ?8mmE

侧腭杆离开龈缘的距离至少是

A. 1 ?2mm

B. 2?4mm

C. 4?6 mm

D. 6 ?8mm

E. 8~10mm