Comparison of Three-Dimensional Surface Imaging Systems Using Landmark Analysis

Abstract

Numerous 3d imaging systems are now available commercially for the capture of facial shape data via landmarking or surface shape comparisons but it is not known whether these systems produce data of comparable quality. This study investigates the error associated with landmark coordinate data collected on facial surface images taken using three 3d imaging systems: the 3dMDface system (3dMD, Atlanta, GA), the Planmeca ProFace system (Planmeca, Roselle, IL), and the Vectra H1 handheld system (Canfield Scientific, Parsippany, NJ). This was a retrospective study involving 3d imaging data that used geometric morphometric analysis to assess overall shape differences as well as landmark-specific differences among the systems. Ten individuals evaluated at the NIDCR dental clinic on various protocols were imaged on all 3 systems. The subject pool consisted of syndromic and unaffected subjects, as disease status was irrelevant to the question of reproducibility and variability. Variation in landmark placement across systems was assessed by ANOVA, covariance matrix, and summary statistics. No overall shape or size differences were found among the systems. However, there was some landmark-specific variation and the 3dMD and Vectra systems were generally more similar to each other than either was to the Planmeca system. The data acquired by these 3 systems are comparable, although landmarks on the eyes and ears are noisy and most different among systems.