Mandible movements reconstruction based on six-freedom displacement measurement

Objective:In order to record the movements of mandible and to display occlude movements in 3-D graphics, a six-freedom displacement measurement method was designed. Methods:Two beams of laser with angle and two superposed screens were adopted. The laser sources were attached on chin and a CCD video camera was used for taking pictures. Two laser sources formed four light spots on the two screens, and the spots moved when chin moved. According to the positions of the light spots on the screens, the positions and the attitudes of chin could be calculated. Results:Combining with the 3-D scanning data of plaster casts, the occlude movements could be rebuilt in 3-D graphics. The method showed the characteristics of simple, real time, and no errors accumulation. Conclusion:Six-freedom displacement measurement method can be used in dentistry for recording the movements of mandible.