Objective:Bruxism is the term used for teeth grinding or jaw clenching. An electronic monitor of bruxism was developed to evaluate bruxism duration and frequency. Methods: Ten cases were selected in the Department of Prosthodontics of Jiangsu Stomatological Hospital to evaluate the monitor. A stabilization occlusal splint was fabricated for each of the 10 cases. The vertical dimension for each splint was 0.5 mm lower than mandibular postural position. Some sensors had been prearranged at each splint which could transfer the variation of the biting force into electronic signals. The data of sleeping duration, grinding duration and grinding frequency were recorded with this new type of bruxism monitor, which had been specifically invented to study bruxism. Results:The data from 10 bruxism cases were collected and the results were considered reliable. Subjects nocturnal duration parameters did not change significantly from night-to-night. Conclusion:The bruxism monitor can automatically measure and record bruxism data using an occlusal splint. This device is valuable for diagnosis and evaluation of bruxism.