The rise of virtual reality and haptic technologies has created exciting new applications in medical training and education. In a dental simulation, haptic technology can create the illusion of substances (teeth, gingiva, bone, etc.) by providing interaction forces within a simulated virtual world of the mouth. In this article, a haptic periodontal training simulation system, named Haptodont, is developed and evaluated for simulating periodontal probing. Thirty-two faculty members from New York University College of Dentistry were recruited and divided into three groups to evaluate three fundamental functionalities: Group 1 evaluated bi-manual 3 Degrees of Freedome (DoF) haptic interaction, Group 2 evaluated bi-manual 3 DoF haptic interaction with a finger support mechanism, and Group 3 evaluated bi-manual 3 DoF haptic interaction with finger support mechanism and vibrotactile feedback. The probe and mirror interactions were simulated with the Geomagic Touch haptic device whereas the finger support was implemented using the Novint Falcon device. The three groups conducted two probing tasks: healthy gingiva scenario with no pockets (2- to 3-mm depth) and periodontitis scenario with deep pockets (4- to 8-mm depth). Results demonstrated that experts performed comparably to clinical settings in terms of probing depth error (within 0.3 to 0.6 mm) and probing forces (less than 0.5 N). Furthermore, the finger support mechanism significantly improved the probing accuracy for periodontitis condition in the lingual region. The argument that probing the lingual region is more difficult than the buccal region is supported by quantitative evidence (significantly higher probing depth error and probing force). Further research is planned to improve the usability of the finger support, integrate the Haptodont system into the pre-clinical curriculum, and evaluate the Haptodont system with dental students as a learning tool.
Framework for haptic interaction with virtual avatars
