[POSTER] Augmented Reality for User-Friendly Intra-Oral Scanning

Abstract

Digital impressions of teeth, obtained through intra-oral scanning, allow for more efficient and cost effective treatments of many dental indications. Current state-of-the-art intra-oral impression acquisition systems make use of a separate monitor to show the scanning progress, forcing the dentist to divert attention away from the scanner and the patient. In this paper, we present an augmented reality based solution to this problem. During the scanning process, an optical see-through head-mounted display is used to show an online overlay of the dynamic dental model onto the patient's teeth. The dentist can then fully focus on the patient and the scanner, while still being able to keep track of the current state of the model. This type of novel application, which fundamentally changes the humancomputer interaction of intra-oral scanning systems, requires a fast and accurate registration of a dynamically growing model onto a glossy, partially occluded surface at a very small scale. To meet this demand, we propose application tailored algorithms for indirect high accuracy online 3D teeth tracking and optical see-through head-mounted display calibration. Experimental results indicate that our system does have a potential to noticeably facilitate intraoral scanning in the future.

An Online Calibration Method for Microsoft HoloLens

“…Image-guided Surgical Navigation Systems (IGSs) based on augmented reality (AR) have been applied in laparoscopic surgery, neurosurgery, dentistry, orthopedics and other clinical surgeries in recent years [2]- [9]. According to display technologies, augmented reality [9] can be classified into the following forms: projection onto patient [6]- [8], [10], [11], static video display [3]- [5], [13], [15], [16], video seethrough (VST) HMDs [2], [17] and optical see-through (OST) HMDs [12], [14], [17], [18]. Although visual models can be projected onto patients [6], the discrepancy between the surgeon's point of view and that of the projector limits the AR accuracy [9].…”

“…endoscopic video [3]. This will divide the surgeon's attention between a separate monitor on one side, and the patient and the endoscope on the other [18]. Head-mounted displays (HMDs) are preferred methods for AR techniques.…”

“…This significantly improves the convenience over the shooting-gallery method and bore-sight method that require the user to remain still during calibration. There are several HMD calibration methods based on SPAAM [18], [22], [23]. However, human-computer interaction is needed in SPAAM [1], which will have an impact on the accuracy of the calibration and is a major obstacle for the practical usage of OST-HMDs.…”

Augmented Reality Implementations in Stomatology

“…The use of advanced 3D scanners, as presented in Figure 2a, and wireless communication links allows the construction of more accurate digital models (see Figure 2b) that are based on stereolithography (STL) data. The use of AR for user-friendly intra-oral scanning [19] allows detailed analysis of dental objects, restoration of tooth cavities and tooth alignment in the computational environment, and then enables the return from the digital to real world again. This approach is often used for surgical navigation and for the study of dental arch models during the orthodontic treatment.…”

Endodontic guided treatment using augmented reality on a head‐mounted display system

“…Useful information, measurements and assistive overlays can be provided to the clinician on a see-through display. In a recent work [15], Thoma et al proposed an HMD-based AR application for intra-oral scanning, in which an OST-HMD is used to show an online overlay of the dynamic dental model onto the patient's teeth.…”