ABSTRACT Three-dimensional (3D) virtual patients constructed from facial and intraoral scans often lack orientation information. The natural head position (NHP) is a standardized, reproducible posture re--ed for facial scanning. The present technique describes a workflow for registering the true horizontal plane in a desktop facial scanner using a 3D printed calibration device. The device calibrates the scanner and orients the facial scan with the patient in NHP, after which the NHP orientation is transferred to the virtual patient. Testing on a dental mannequin head demonstrated that this technique provides high repeatability and accuracy.
Ling et al. (Mon,) studied this question.