Abstract: A measuring device for use in model surgery in connection with the surgical treatment of the teeth and jaws, commonly referred to as orthognathic surgery. The trial surgery is performed on a plaster dental model which has been correctly mounted on a dental articulator, and in which the Frankfort Horizontal plane or axis orbital plane is utilized. In addition, a model block to which the dental model is affixed is placed on a model platform provided with a caliper, such as an electronic digital caliper, precisely mounted relative to the base of the platform so that measurements of the dental models are made which are free from error due to positioning relative to the base line, as well as due to parallax.