Validation of three-dimensional facial imaging captured with smartphone-based photogrammetry application in comparison to stereophotogrammetry system

Photographic Parameters in Three-Dimensional Facial Image Acquisition. A Scoping Review

“…All authors who described the tooth position in this study agree with using the maximum intercuspation (MIC) position as the reference tooth position for acquiring the 3D image 12,15,27,29,31 . However, the tooth position in resting conditions is the mandibular postural position, with teeth not in contact with each other.…”

“…Riml et al (2011) 42 showed the influence of some expressions on the measurements made on the facial photographs, observing some differences depending on the facial expression. In this study, some authors agree that the facial expression should be neutral and relaxed, with the lips gently closed 10,12,14,16,19,21,22,27,29,31–33,38 . However, no study refers to those individuals with forced lip closure, lip separation at rest, and lip incompetence.…”

“…Despite the considerable quantity of image acquisition systems presently employed for 3D photography, research use for this type of imaging is limited to a handful of devices, of which 2 are the most extensively utilized. First, we found that the most used system was the 3dMD, 10, 12–24 which consists of 2 groups of 3 cameras, each located at 45 degrees to the right and left side target, and was used by 52% of the authors, followed by the Vectra M3, 25–32 which consists of a device composed of 3 groups of 2 cameras each and was used by 28% of the authors. In contrast, some other systems were used by some authors.…”

“…In contrast, Cascos et al (2023) 36 standardized the ambient light at 1000 luxm 2 to have similar conditions in each image acquisition. Finally, Andrews et al (2023) 12 were the only ones that completely eliminated any light source (natural or artificial), keeping the environment 100% dark. Finally, most of the authors who used equipment with built-in lighting did not use any extra light or standardize the environmental lighting conditions.…”

“…This is because 3D systems are large and require a fixed position. In contrast, most of the authors used chairs with high backs to improve back support, reducing variations due to mobility or changes in body posture 12–16,18,19,25,27–33,36,37,41 …”