A geometrical method to classify face forms

Abstract

IntroductionFace form is a useful reference in numerous clinical prosthodontic procedures for nearly ten decades since the postulation of Leon Williams typal form theory. Hitherto, face forms has been studied by clinical and photographic assessment methods and classified it as square, tapering, square tapering and ovoid forms. The existing method of classifying face form is subjective as it is derived on visual perception and hence alternative methods have to be studied further. AimThe aim of the study was to analyze the existing classification of face form and to classify face forms based on geometrical method to eliminate the errors in classifying the face form by visual judgment. Methods200 subjects of age group 18 to 25 were investigated with the clinical method using face form indicator and photographic method. Reference points were marked on the face form indicator and the photographs to classify face form. A geometrical method was used to classify face form based on the angle of convergence in the photograph. Based on the angle of convergence between the widest part of the face to the lower, middle and the upper third of the face, face form was classified. This method of classification widens the existing classification of face form with three additional types of face forms. ResultsA Comparison was done between the face forms obtained by clinical and photographic methods. Face forms obtained by clinical and photographic method showed no significant differences (p > .05) between them. ConclusionA geometrical method on photograph can be an effective method to analyze the various face forms to overcome the errors in visual judgment in the commonly used clinical method with face form indicator.