The
oral cavity opening size adjusting device comprises a fixing frame and a measuring
assembly, rotating seats are rotationally clamped to the two ends of the fixing frame correspondingly, through holes are formed in the rotating seats, a sliding rod and a
threaded rod are slidably clamped in the two through holes correspondingly, and fixing blocks are fixedly connected to the bottom ends of the sliding rod and the
threaded rod through longitudinal rods correspondingly; the measuring
assembly comprises a guide rail connected between the two fixing blocks, a moving seat is slidably clamped on the outer side of the guide rail, and a pair of pneumatic rods are rotatably connected to one side, close to the guide rail, of the moving seat; the external shape of teeth of a patient can be measured by the measuring
assembly and synchronized to the soft strip clamped in the shaping clamp, then the
occlusion block is arranged in the extension direction of the soft strip and clamped to teeth of the lower jaw of the patient, and finally, the
occlusion block is pulled through the fixing block so as to be matched with the fixing frame to open the
oral cavity of the patient for auxiliary fixing.