As drills increase in diameter, the patient experiences pain.  Since the bone density is high, it is hard to place 5x10 mm implant to the lowest space (Fig.2 *, ~ 60 Ncm).  骨坏死常发生于牙槽嵴顶，那里骨质可能更硬，而即种不接触牙槽嵴顶，所以骨坏死减少。近中植入离神经远，植体与骨接触面积大。

Slow Gentle Osteotomy Last Next Xin Wei, DDS, PhD, MS 1st edition 07/30/2019, last revision 04/25/2021