# Augmented Reality-Assisted Surgical Exposure of an Impacted Tooth: A Pilot Study
###### Abstract  
Three-dimensional radiological evaluation through cone beam computer tomography is essential in diagnosing and establishing proper surgical management in impacted teeth. Through Augmented Reality (AR), clinicians have the opportunity to use three-dimensional computer-generated radiologic information to visualise the patient and simultaneously the superimposition of his internal structures. Here, we describe a digital workflow to assist the oral surgeon in pre-orthodontic exposure of a vestibular impacted canine using AR. The AR hardware consists of a camera and a traditional stand-up monitor. The registration and tracking are video-based and marker-free, with an automatic pose estimation obtained through VisLab 20.10.1 AR software algorithm's object recognition and tracking approach. A 3D model is created by combining the anterior teeth taken from the intraoral scan with the same teeth plus the included tooth taken from the CBCT segmentation. The 3D file is uploaded into the AR software. Model tracking is straightforward to set up without prior registration of targets or surroundings. The AR information is used successfully to define the surgical access to perform flap and osteotomy. The accuracy of model tracking matching was calculated constantly by the software. During the tracking, the process recorded an inlier ratio of 0.39.0.48. Further studies and clinical trials will evaluate the value of this novel technology in the management of impacted teeth. augmented reality; guided surgery; real-time tracking; digital dentistry; object recognition; object tracking; CBCT +
Footnote †: journal: Medical  
of a tooth's accurate position relative to other teeth and the identification of associated complications that arise from the orthodontic movement of the tooth, such as root resorption of adjacent teeth. Treatment for tooth disimpaction requires teamwork, especially in regard to the role of the orthodontist and the oral surgeon. The therapeutic approach generally involves surgical exposure of impacted teeth, which is performed by preparing a flap and removing the cortical bone around the crown of the teeth [7]. This procedure provides optimal conditions for the orthodontist. Surgical exposure allows the orthodontist to bond the impacted tooth in the correct position depending on the intended direction to apply the proper traction forces for alignment. Several parameters should be considered when planning surgical exposure of an impacted tooth. Flap design and the correct position of the osteotomy site are key points for successful treatment. Oral surgeons should be as precise and non-invasive as possible to minimise post-operative patient stress; only enough bone should be removed [8; 9]. New software is being used to assist the clinician in precisely identifying the impacted teeth position pre- and intra-operatively. Digital medicine is very focused on developing protocols to help the surgeon to visualise internal structures in the human body acquired from digital CBCT directly on the patient [10]. The modern technology that allows this to be carried out is Augmented Reality (AR), which aims to enrich the perception of reality through digital processing. Software for AR uses algorithms to recognise shapes and objects. Clinicians upload digital diagnostic imaging into the software and superimpose it into a real-time video frame from a camera to view the patient and his internal structures [11]. AR software is in constant development and will reveal the full potential of oral treatment in the near future. The operation of the software in AR uses two processes. The technical process of recognising a target in an image or a single video frame is called \"object detection\". Object detection only works if the target image is visible on the input. If the target object is hidden by any interference, it will not be able to detect it. Following the structures after object detection is known as \"object tracking\". Video tracking, if processed in a video frame, is the task of tracking a moving object in a video.