Palpation is important medical diagnostic technic to make correct diagnosis of symptomatic state. It requires a lot of palpation experience under leadership of an experienced medical doctor. Hence, a palpation training system with virtual model of an affected part is useful to get better at the skill. However, there is no practical training for maxillofacial palpation in the dental education curriculum in Japan. So, it is necessary for dental students that the virtual training system is developed, which can to practice maxillofacial palpation. Then, a trial palpation training system for maxillofacial disorder is developed by using virtual reality model and haptic interface. The system is consisted of a PC and the haptic device - PHANToM Omni. A virtual affected part model is constructed from multi-CT images through commercial software. In particular, the dynamic responding virtual model and real-time analysis method through simplified mesh free method are improved. Consequently, we succeed in operation at the real-time by the palpation training system.

Intraoral radiography is one of the effective diagnosis method for dental clinic, which is used to examine dental caries and gum disease. A patient needs to have a small film inserted in their mouth. The position and orientation of the film are properly adjusted by the dentist. An indicator cone which directs X-ray is set up outside the patient's mouth. The intraoral radiograph provide a dental perspective projection image of the patient's teeth, thus the individual differences of patients make it more difficult to take an appropriate radiograph regardless of the experience of dentist. Recently, the skills of intraoral radiography of Japanese dental students and intern doctors are declining. A conventional education method for intraoral radiography currently conducted does not provide enough time to master intraoral radiographic technique for the dental students, because much time to develop the roentgenogram is necessary. This paper describes the development of a training system for intraoral radiography. The system is composed of a notebook computer, two PHANToM Omni devices, and a dental arch model, where the PHANToM Omni devices are used to measure the position and orientation of a indicator cone and film of the system. We applied the computer graphics technique to draw an intraoral radiograph on the computer display, thus the system enables trainees to practice the intraoral radiography without a X-ray machine, lots of film sheets, and time for the development of roentgenogram. In this paper, we present the system structure, a simulation method for generating an intraoral radiography, and simulation results

Intraoral radiography is one of the most important techniques for dentists, which is commonly used to diagnose dental caries and gum disease. An intraoral radiograph shows a perspective projection image of the teeth of patient, so that the roentgenogram is affected by the positional relationship between film, teeth, and indicator cone which directs X-ray radiation toward the film. In order to administer intraoral radiography for a patient, he/she has to have a small X-ray film inserted in their oral cavity. The position and orientation of the film are properly adjusted by the dentist or radiologic technician. And then, the indicator cone is positioned outside the patient's mouth, and its orientation is determined depending on the teeth and film. Recently, it has been reported that the skill of intraoral radiography of dental students and interns are declining in Japan. The background of this issue is that the conventional training method needs to use an actual X-ray machine and lots of film, and much time to develop the roentgenogram. We assumed that these training inefficiencies would be improved by using virtual reality technique. In this paper, we propose a training simulator for intraoral radiography based on virtual reality, where the trainees quickly obtain a graphical image of intraoral radiograph on a computer display after the setting of film and indicator cone is finished. This paper presents a simulation algorithm for generating a graphical image of intraoral radiograph, and discusses about optimum design of an indicator cone positioning device for the simulator. Simulation results show that the proposed simulation algorithm provides realistic observations of intraoral radiograph