Abstract

A three-dimensional model of the teeth of a patient is prepared by taking molded impressions of the mandibular and maxillar teeth, placing separately the impressions on a support table define an X-Y plane and detecting the Z distance from a probe by directing a beam of laser light onto the impression and calculating from the pattern of reflected light a centre of the light falling on an area array. The scanning in the X-Y plane is effected continuously and is limited by datum points defining a dental arch. The impression is then tilted and the process repeated and information correlated to provide the three-dimensional model. A partial impression is then taken of both mandibular and maxillar teeth in comparison with datum points to provide information concerning the bite (occlusal) positions of the teeth. This information is then compared with the full impression to simulate using the three-dimensional models movement of the jaw from an open position to the bite (occlusal) position.