Rest vertical dimension is the lower face height measured from chin point to nasospinale, with the mandible in rest position.

直距离的概念可颌位于姿势位时这两个标志点之的距离，主要与肌功能有关。

The length of the face determined by the distance of separation of jaws. The reference mark are nasospinale and chin point .The distance of these two marks is VD.

临床上，面直距离的参考标志点一般用鼻点和颏点，这两点分别位于口裂的上、方。