X: {TAIL ~ axial distance} from the origin at the tooth surface at {HEAD ~ the center} of the tooth thickness, 
X : { TAIL ~ axial distance } from the origin at the tooth surface at { HEAD ~ the center } of the tooth thickness ,
OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH