Various methods have been reported by which dentists determine the vertical dimension. It is crucialto know the vertical dimension for successful complete denture, although no ideal method is knownto predict the exact value. Acephalometric analysis is one method. The approximate vertical dimensionis determined functionally and morphologically with the aid of the cephalogram. The present authorhas tried to improve the prediction by means of multiple regression analysis.
In this study were included 100 subjects with natural teeth, 50 men and 50 women, ranging from 18 to 33 years of age, the mean age being 24. Lateral cephalometric roentgenograms were obtainedfrom the subjects in centric occlusion, and some specified points were located on each cephalogram.
According to the linear model, prediction formulae for the vertical dimension have been obtained.
For example: N to Me (vertical dimension)
=-139.01+19.248×(Sex)+0.221×(Co to Me)+0.373×(N to ANS)+0.304×(N to PNS)+0.406×(N to Z)+0.214×(Go to Me)+2.676×(Gonial Angle)
where Sex is 1 for male and 0 for female, the distances 10-1mm, the angle degree, and N: Nasion, Me: Menton, Co: Condylion, ANS: Anterior nasal spine, PNS: Posterior nasal spine, Z: Point ofinferior zygomatic bone ridge, Go: Gonion. This regression equation possesses the multiple regressioncoefficient of 0.86, or R2 of 0.747.