[Mixed dentition space analysis in a eastern Sicilian population]

The purposes of this study are: 1) predicting the sum of mesio-distal crown diameters of unerupted canines, first and second premolars, using the sum of mesio-distal diameters of lower permanent incisors, in a sample of Eastern Sicily population; 2) estimating the differences between our predictions and the ones developed by Tanaka & Johnston, by Moyers and by Ballard & Wylie.

We selected 150 plaster casts of permanent dentition of patients - 82 females and 68 males - examined at the School of Orthodontics of the University of Catania. The width of canines, first and second premolars and lower incisors were taken by means of a bow-compass and a sliding digital caliper on the selected plaster casts.

We calculated the following linear regression equations, with statistical method, to predict the sum of mesio-distal dimensions of canines, first and second premolars (Y) using the width of the lower incisors (X): Yfs = 11.40 + 0.42X for females in the upper arch; Yfi = 11.34 + 0.41X for females in the lower arch; Yms = 12.84 + 0.39X for males in the upper arch and Ymi =11.38 + 0.44X for males in the lower arch.

The results in our sample indicate that the sum of mesio-distal crown diameters of canines, first and second premolars is smaller in females than in males; besides those results suggest that the North-American authors' predictions overestimate the mesio-distal dimension of canines, first and second premolars in both sexes.