Implementation of Augmented Reality in Dental Surgery Using HoloLens 2: An In Vitro Study and Accuracy Assessment

Abstract

Computer-guided dynamic navigation systems have elevated dental implant surgery into a more patient-friendly and efficient procedure. However, commercially available systems use displays as an output for guidance. This implies that surgeons have to take their eyes off the surgery site frequently in order to accurately adjust surgical instruments. The solution for such an issue is to use augmented reality (AR) head-mounted devices to showcase all necessary guiding instructions without any distractions. In this work, the implementation of augmented reality in dental surgery using the HoloLens 2 AR headset for the assessment of accuracy is described. The experiments were performed in vitro with two implementation steps, evaluating calibration and perspective of the virtual dental model alignment accuracies using a newly created marker. The calibration results showed overall accuracy and precision surpassing the 1 mm threshold in distance-related measurements. Dependency on the side on which the marker was observed and the movement of the user’s head were considered to be the most influential factors regarding the perspective of the virtual dental model alignment accuracy estimate.

A Novel Registration Method for a Mixed Reality Navigation System Based on a Laser Crosshair Simulator: A Technical Note

“…While offering advantages like superimposing virtual anatomical structures onto the surgical area, the latter comes with high costs and requires substantial hardware components. However, concerns about the accuracy and reliability of MRN were frequently raised on the other hand [9,10,30,37,39,[41][42][43]49,50].…”

“…Landmark-based registration uses uniquely identifiable natural or artificial landmarks for paired-point matching. These markers can be pasted or anchored on the patient's scalp or custom pointers which function in a similar way to the tracking pointer utilized in conventional navigation systems [9,10,44,49,53]. It is quicker to implement than manual alignment [9,38].…”

“…Beyond the fully manual registration methods reported in early MRN prototypes [7,8,32,48], several other registration methods similar to those in commercial navigation systems have proven technically feasible. These include point matching of anatomical landmarks, cranial fixations, affixed skin markers [9,10,35,36,44,[49][50][51][52][53], and surface matching [33,[54][55][56][57][58][59]. Nevertheless, due to marker shifts or skin shifts during imaging relative to patient positioning in the OR, coupled with users' errors while acquiring points on the surface or from the markers with physical tools, the reported MRN registration methods are almost entirely user-dependent [46,55,56].…”

“…Calipers or commercial navigation probes are typically used to directly read the error in the former way [32,33,35,36,[50][51][52]56,58]. It is worth mentioning that a recent study reported a more precise and efficient measurement by cleverly utilizing customized probes within the MRN system [49]. Nonetheless, the accessibility of the measurement tools could lead to an underestimation of TRE, as virtual targets may be located beneath the patient or phantom.…”