Evaluation of virtual handles for dental implant manipulation in virtual reality implant planning procedure

Purpose: Many surgical complications can be prevented by careful operation planning and preoperative evaluation of the anatomical features. Virtual dental implant planning in three-dimensional stereoscopic virtual reality environment has advantages over three-dimensional projections on two-dimensional screens. In the virtual environment, the anatomical areas of the body can be assessed and interacted with in six degrees-of-freedom. Our aim was to make a preliminary evaluation of how professional users perceive the use of the virtual environment on their field. Methods: We prepared a novel implementation of a virtual dental implant planning system and conducted a small-scale user study with four dentomaxillofacial radiologists to evaluate the usability of direct and indirect interaction in a planning task. Results: We found that all four participants ranked direct interaction, planning the implant placement without handles, to be better than the indirect condition where the implant model had handles. Conclusion: The radiologists valued the three-dimensional environment for three-dimensional object manipulation even if usability issues of the handles affected the feel of use and the evaluation results. Direct interaction was seen as easy, accurate, and natural.