An Intraoral Non-Occlusal MEMS Sensor for Bruxism Detection

Bruxism is a masticatory muscle activity that can involve involuntary clenching or grinding of teeth. As bruxing occurs subconsciously, patients are often unaware of it until injury or damage has occurred. Here, a novel method of intraoral detection of bruxism is proposed. A pressure sensor was used to detect the deformation of the masseter muscle as it approaches the upper molars during bruxism. Bruxism episodes detected using the masseter pressure sensor were compared with simultaneous recording of masseter muscle electromyogram (EMG) activity in eight subjects (5 male and 3 female, age 39.8+/−13.1). Each subject carried out a series of bruxism and non-bruxism simulated activities while wearing the masseter pressure device and recording masseter surface EMG. A linear discriminant analysis model was developed to classify recorded pressure data as bruxism or non-bruxism events and the model was tested using cross-validation. The accuracy of the sensor and machine-learning model was compared to that of the established method of detecting bruxism using masseter EMG. The masseter pressure and masseter EMG methods for detecting bruxism returned similar results with accuracy values of 82.2% and 82.8% respectively. Detecting bruxism through masseter pressure changes using a novel intra-oral device in combination with a machine-learning algorithm yields similar accuracy to established methods using masseter EMG. The masseter pressure approach has minimal impact on bite, it is less obtrusive than surface EMG, as it is discretely enclosed in the user’s mouth, and offers potential as a platform for long-term home monitoring of bruxism.