Patent ID: 7695278

Claim:
A method of digitally finding one or more ridge points on the occlusal surface of a virtual three-dimensional model of a tooth using a workstation, comprising the steps of: (a) obtaining a virtual three-dimensional model of a tooth from scanned images of said tooth; wherein said virtual three-dimensional model of said tooth has a mesial direction, a distal direction, a buccal direction, a lingual direction, an occlusal direction, and a gingival direction; wherein said virtual three-dimensional model of said tooth further has an occlusal surface and a bottom, wherein said bottom is opposite said occlusal surface; (b) defining a tooth axes system (TAS) for said virtual three-dimensional model of said tooth; wherein said TAS comprises an origin, an x-axis in the mesial and distal directions, a y-axis in the buccal and lingual directions and a z-axis in the occlusal and gingival directions; (c) defining a plane containing said z-axis from said TAS, said plane intersecting the entire surface of said virtual three-dimensional model of said tooth, thereby showing a curve formed along the surface of said three-dimensional model of said virtual three-dimensional model of said tooth; and (d) tracing said curve from the bottom of said virtual three-dimensional model of said tooth (i) starting on one side of said curve with a moving tangent until said tangent becomes horizontal thereby finding a ridge point on the surface at the location where said tangent touches said curve; and (ii) then starting on the other side of said curve with a moving tangent until said tangent becomes horizontal thereby finding a ridge point on the surface at the location where said tangent touches said curve.