[The shape of the ideal arcogrammetric dental arch]

On 48 arcograms of 24 cases with ideal occlusion polynomes of the form y = bo + b1x + b2x2 + b3x3 ... + b8x8 were established by the method of least squares. By means of a stepwise polynomal regression the coefficients up to the 8th degree were tested on significance. Finally polynomes of 4th degree were chosen to describe the anterior dental arch from 6 mesial to mesial 6 of the arcogram. Resulting error expressed as mean of the residuals of values observed--values calculated was 0.08 +/- approximately 0.6 mm (mean +/- 1 SD).