Validation of a new three-dimensional imaging system using comparative craniofacial anthropometry

Abstract

BackgroundThe aim of this study is to validate a new three-dimensional craniofacial stereophotogrammetry imaging system (3dMDface) through comparison with manual facial surface anthropometry. The null hypothesis was that there is no difference between craniofacial measurements using anthropometry vs. the 3dMDface system.MethodsFacial images using the new 3dMDface system were taken from six randomly selected subjects, sitting in natural head position, on six separate occasions each 1 week apart, repeated twice at each sitting. Exclusion criteria were excess facial hair, facial piercings and undergoing current dentofacial treatment. 3dMDvultus software allowed facial landmarks to be marked and measurements recorded. The same measurements were taken using manual anthropometry, using soluble eyeliner to pinpoint landmarks, and sliding and spreading callipers and measuring tape to measure distances. The setting for the investigation was a dental teaching hospital and regional (secondary and tertiary care) cleft centre. The main outcome measure was comparison of the craniofacial measurements using the two aforementioned techniques.ResultsThe results showed good agreement between craniofacial measurements using the 3dMDface system compared with manual anthropometry. For all measurements, except chin height and labial fissure width, there was a greater variability with the manual method compared to 3D assessment. Overall, there was a significantly greater variability in manual compared with 3D assessments (p < 0.02).ConclusionsThe 3dMDface system is validated for craniofacial measurements.

Accuracy and reliability of 2-dimensional photography versus 3-dimensional soft tissue imaging

“…To achieve this, SPG has been highly recommended based on its precision and high-quality output. 1,4,19,25 De Menezes et al reported that SPG was reliable and reproducible for most the linear distances, in accordance with the findings of the present study. 26 Dindaroglu et al compared 2D imaging and stereo- photogrammetry with direct anthropometry and found that the highest mean difference was lower for 3D imaging than for 2D imaging based on comparisons with direct measurements, which also aligns with our findings.…”

“…Weinberg et al also found that LS showed very high precision and good agreement with direct anthropometry. 2,19 Zogheib et al compared 2D imaging and laser scanning to direct measurements and found that linear measurements with LS were closer to the clinical standard than measurements made with 2D imaging, while in the present study, SPG had significantly less error than both 2D and LS. 24 The images captured with LS showed distortions around the eye region, and the measurements had higher variability than those obtained using SPG, even though it was lower than the variability of 2D imaging.…”

“…This variability in LS accuracy could have resulted from motion artefacts owing to patient movement, facial expressions, or eye distortion caused by the blinking reflex. 19 For soft tissue evaluation, it is crucial to have a realistic and complete representation of the face. To achieve this, SPG has been highly recommended based on its precision and high-quality output.…”

“…[14][15][16] However, only a few studies have compared 3D imaging systems to each other and to direct anthropology or 2D imaging systems. 3,[17][18][19] To our knowledge, quantitative and qualitative comparisons of SPG, LS, and 2D images with direct anthropometry as a gold standard have not yet been reported in the literature. Therefore, the aim of this study was to conduct a comparative evaluation of the objective and subjective reliability and accuracy of 3D imaging modalities versus standard 2D facial photography.…”

Sources of variation in the 3dMDface and Vectra H1 3D facial imaging systems

“…Image capture. The 3dMDface (3dMD, Atlanta, GA) and Vectra H1 (Canfield, Parsippany, NJ) are two currently available systems for 3D imaging, with the 3dMDface being very common and extensively tested [22][23][24]26,[33][34][35] . The 3dMDface is a stationary rig composed of either 2 or 3 cameras positioned at angles that provide overlapping views of the face from different angles.…”