Prediction of the combined right and left canine and premolar widths in both arches of the mixed dentition.

Presently available methods used to predict the mesiodistal widths of unerupted canines and premolars in the mixed dentition provide an estimate for the widths of one canine and two premolars which must be either doubled for the prediction of the six tooth widths on both sides of the arch, or which must be computed separately for each side of the arch. The purpose of this study was to develop, with multiple regression analysis, equations which would predict the sum of the mesiodistal widths of the right and left canines and premolars in each arch. Measurements were taken from plaster casts and periapical radiographs of the upper arch of 92 subjects (46 females and 46 males), and of the lower arch of 83 subjects (41 females and 42 males). Prediction equations were developed for sexes combined and for each sex. All equations performed satisfactorily when tested on data taken from orthodontic patients (upper arches of 43 patients and lower arches of 53 patients). Prediction equations developed from the sexes combined are recommended for clinical use.