Objectives: The principles of intraoral radiography are difficult for undergraduate students to understand. The existing training method using a model dedicated to intraoral radiography involves radiation exposure, which creates limitations for the implementation of this training method, such as the need for a specially designed room for radiation protection. We designed a shadowgraph training system to facilitate understanding of the principles of intraoral radiography without radiation exposure. The effectiveness of this system was examined.<br>Materials and methods: The shadowgraph system consisted of plastic model of teeth and an LED penlight. One of the reasons for developing this system was to keep the cost as low as possible. Fifth year students participated in this experiment during clinical training in oral radiology. The shadowgraph practice was tried at this first day. Thirty-nine students participating in this study were divided into 2 groups. One group used the shadowgraph training system before they began training in intraoral radiograph using the model (DXTTR) dedicated for intraoral radiography. The other group used the shadowgraph training system after training using DXTTR. Then a questionnaire survey was conducted. One oral radiology specialist evaluated the intraoral radiographs taken by students of DXTTR, and then the effectiveness of the shadowgraph practice was estimated.<br>Results and conclusions: Thirty-nine students participated in this experiment. On the questionnaire survey, the shadowgraph practice was given an excellent rating. On evaluation of the intraoral radiographs, the grade for horizontal angulations of X-ray in the group that underwent shadowgraph practice before DXTTR training was better than that in the group that received shadowgraph training after DXTTR training. The shadowgraph practice was thought to demonstrate the influence of the geometric layout during radiography on the image, and thus allowed students to begin DXTTR training with a superior understanding of the underlying practical concepts. Therefore, the shadowgraph method was considered an effective teaching method.