Use of digital photographs in prosthodontic reconstruction of vertical dimension

Aim: Many methods have been described to determine the occlusal vertical dimension in edentulous patients, but none of them is completely reliable. The aim of this study was to examine the possibility of reconstrucing the occlusal vertical dimension by using a digital photography.
Methods: Digital photographs (obtained from a 1.5 m distance with a digital camera elevated to the height of the Frankfort plane) (frontal and profile) were obtained from 55 dentate subjects clenching in maximum intercuspidation (ICP). Sn-Gn (subnasale-gnation) and N-Sn (nasion-subnasale) distances were measured in the subjects and in their photographs. The Sn-Gn distance of each subject was also calculated by using the following formula: N-Sn (subject) x Sn-Gn (photograph) / N-Sn (photograph). Sn-Gn distance was calculated from both the frontal and profile photographs. A statistical analysis was performed (Kolmogorov-Smirnov test, descriptive statistical methods and Student t test for dependent samples) (p<0.05).
Results: There were no significant differences between the Sn-Gn distance measured in a subject and the same distance calculated from a digital photograph (from both, the profile and frontal photographs) (p>0.05).
Conclusions: The occlusal vertical dimension could be reconstructed from a digital photographs by using the formula: N-Sn (measured on a subject) x Sn-Gn (measured on the photograph) / N-Sn (measured on a photograph). Therefore, the general practitioner should obtain and keep stored such photographs in a computer together with other dental records of an individual.