An essential surgical tool to accurately and consistently measure patients' vertical dimension of occlusion (VDO).
 
Using the two straight arms of the gauge (A), measure the distance between the center of the eye and where the top lip meets the bottom lip; lock the measurement by tightening the screw. Next, use the other side of the gauge with the curved chin bar by placing the gauge between the bottom of the nose and the chin (B).
 
As an example, the size measured in picture A is 7.2cm, which is equivalent to the size of picture B. In the case of patients with edentulous, the difference in length between A and B determines the thickness of the block arch and tooth size.