在正畸弹性牵引时,常需在病人口腔内测量牵引拉勾间距离、牙间隙等.采用市售圆规测量,特别是在后牙区测量,操作困难。笔者用医用注射针头自制两脚规,方便于口内测量距离。其制作简单,现介绍如下取16~#针头一只,磨去针头斜面,焊上(?)0.9mm In orthodontic elastic traction, it is often necessary to measure the distance between the traction hooks in the mouth of the patient, interdental spaces, etc. The use of commercially available compasses, especially in the posterior area, is difficult to operate. I use medical needle made two feet gauge, to facilitate the measurement of the mouth distance. The production is simple, are introduced as follows Take 16 ~ # a needle, grinding needle bevel, welding (?) 0.9mm