These acupoints should be inserted slowly 0.3-0.8 cun, avoiding the carotid artery.
Renying (ST 9)--It is needled slowly and perpendicularly 0.2-0.5 cun in depth, avoiding the common carotid artery. Cares should be taken to avoid deep insertion, or lateral insertion, or strong manipulations.
Lianquan (CV 23)
It is needled obliquely 0.3-0.5 cun towards the root of the tongue.