Facial digital images to identify the vertical dimension of occlusion through a mathematical formula

Abstract

To restore some stomatognathic system functions, such as the deglutition, the phonation, the mastication, and the facial aspect, is extremely important to maintain the maxillomandibular relation. When the restoration of facial dimension is needed, the methods available to identify the correct facial dimension rely on subjective factors. According to the data, there are no consensus about standard procedure to identify the vertical dimension, and for that reason, some authors frequently associate methods to guarantee the reliability of results. In the present study, the Vertical Dimension of Occlusion (VDO) and the Vertical Dimension of Rest Position (VDR) were measured and compared to the distance between the lateral canthus of the eye and the commissurae. Standardized digital images of 50 dentate Brazilian subjects were used to measure the facial distances, through an image-processing program (HL Image97++, Western Vision Software, L. C.). The test of Pearson’s Correlation was calculated to determine the relationship between the distances. A significant correlation was found between the VDO and the VDR, and after linear regression analysis, a specific formula was developed to calculate VDO from VDR, with 87% of chance to occur. Key words: removable prosthesis, vertical dimension, maxillomandibular relation, facial analysis.