A method for quickly arriving at a virtual pre-set-up of the orthodontic treatment plan for a single jaw of interest, either lower or upper, of a patient, comprising the steps of:
- a. obtaining a three-dimensional virtual model of the dentition of a patient;
- wherein said virtual model of the dentition comprises the upper jaw and upper teeth, the lower jaw and lower teeth, and virtual tooth roots for said upper teeth and said lower teeth;
- b. obtaining tooth-features derived from said upper teeth and said lower teeth;
- wherein said tooth-features comprise cusp tips, incisal edges, marginal ridges, central groove lines, buccal grooves, contact points;
- c. determining upper occlusal surface corresponding to said upper jaw;
- d. determining lower occlusal surface corresponding to said lower jaw;
- e. determining a horizontal plane from said upper occlusal surface and said lower occlusal surface;
- wherein said horizontal plane is calculated as a balance between said upper occlusal surface and said lower occlusal surface;
- f. identifying, as the case may be, either said upper jaw or said lower jaw as the single jaw of interest;
- g. defining a reference co-ordinate system;
- wherein said reference co-ordinate system comprises x, y and z axes;
- wherein said x-axis is the sagittal axis, said y-axis is the transversal axis, and said z-axis is the vertical axis;
- h. determining virtual tooth root resistance centers for said virtual tooth roots of the teeth of said single jaw of interest;
- i. finding an Alveolar Reference Curve using the sub-steps comprising:
- (1) projecting said virtual tooth root resistance centers onto said horizontal plane, thereby producing the projected centers;
- (2) fitting a planar convex curve to said projected centers whereby the sum of squares of the two-dimensional distances between the projected centers and the convex curve is minimized while maintaining the convexity of the convex curve;
- and
- (3) labeling the convex curve the Alveolar Reference Curve;
- j. determining controlled tipping filter from said Alveolar Reference Curve;
- wherein said controlled tipping filter is a record of said two-dimensional distances between said projected centers and said Alveolar Reference Curve;
- k. creating the arch form spline for said single jaw of interest by connecting with a smooth planar curve projections of buccal cusp tips of molar teeth and lateral edges of anterior teeth into said occlusal plane of said single jaw of interest;
- and
- l. performing alignment of the teeth of said single jaw of interest while restricting the tooth movement along said x, y and z axes of said reference co-ordinate system;
- and controlling the virtual tooth-root center movement with said controlled tipping filter;
- wherein said alignment is done with respect to said occlusal surface and with respect to said arch form spline of said treatment pre-set-up jaw;
- using the sub-steps comprising:
- (1). determining relative transversal position of the incisal contact points using the standardized offset value;
- (2). aligning on arch form spline using standardized fixed interproximal distances;
- (3). aligning on the occlusal surface using standardized offset values for the vertical position of the teeth;
- (4). performing mesiodistal shift of the lateral segments for the standardization of the desired molar class;
- and
- (5). adjusting possibly created interproximal gaps or intersections in the front by the equal distribution of all created gaps or intersections on the individual interproximal distances on the left and the right half of the jaw;
- and wherein all of the steps (a.-l.) are implemented with a computer.