A computer-implemented method comprising: rendering a digital representation of at least a portion of a tooth within a three-dimensional environment; receiving a desired mesio-distal position for an orthodontic appliance associated with the tooth; and executing software to automatically adjust the position of the orthodontic appliance based on the desired mesio-distal position on the tooth within the 3D environment relative to a coordinate system associated with the orthodontic appliance, said automatically adjusting comprising: eliminating a set of points that define a lingual surface of the tooth within the 3D environment; determining a current distal-most point and a current mesial-most point of the tooth from a remaining set of the points within the 3D environment relative to the coordinate system associated with the orthodontic appliance, the remaining set of points being obtained by eliminating the set of points that define the lingual surface from the digital representation; determining a current distal-most plane that intersects the current distal-most point and a current mesial-most plane that intersects the current mesial-most point; and adjusting the mesio-distal position of the orthodontic appliance based on the determined current distal-most plane and current mesial-most plane. rendering a digital representation of at least a portion of a tooth within a three-dimensional environment; receiving a desired mesio-distal position for an orthodontic appliance associated with the tooth; and executing software to automatically adjust the position of the orthodontic appliance based on the desired mesio-distal position on the tooth within the 3D environment relative to a coordinate system associated with the orthodontic appliance, said automatically adjusting comprising: eliminating a set of points that define a lingual surface of the tooth within the 3D environment; determining a current distal-most point and a current mesial-most point of the tooth from a remaining set of the points within the 3D environment relative to the coordinate system associated with the orthodontic appliance, the remaining set of points being obtained by eliminating the set of points that define the lingual surface from the digital representation; determining a current distal-most plane that intersects the current distal-most point and a current mesial-most plane that intersects the current mesial-most point; and adjusting the mesio-distal position of the orthodontic appliance based on the determined current distal-most plane and current mesial-most plane. eliminating a set of points that define a lingual surface of the tooth within the 3D environment; determining a current distal-most point and a current mesial-most point of the tooth from a remaining set of the points within the 3D environment relative to the coordinate system associated with the orthodontic appliance, the remaining set of points being obtained by eliminating the set of points that define the lingual surface from the digital representation; determining a current distal-most plane that intersects the current distal-most point and a current mesial-most plane that intersects the current mesial-most point; and adjusting the mesio-distal position of the orthodontic appliance based on the determined current distal-most plane and current mesial-most plane. <EOS>