Abstract

The dental arches for humans change their shape from a parabola to an ellipse at canine. This was shown by the change in the value of discriminant B2 #x2212; 4AC in the general second degree equation. In the present study the change for the dental arch shape has been alternatively suggested through the change in the value of eccentricity e, which is 1 for parabola and less than 1 for ellipse. The range of values between 0 and 1 for e can then be possibly assigned to different races or ethnic groups, through corresponding data values.