Background: Dentists are subject to staying in static or awkward postures for long periods due to their highly concentrated work.

Objectives: This study describes a real-time personalized biofeedback system developed for dental posture training with the use of vibrotactile biofeedback.

Methods: The real-time personalized biofeedback system was an integrated solution that comprised of two components: 1) a wearable device that contained an accelerometer sensor for measuring the tilt angle of the body (input) and provided real-time vibrotactile biofeedback (output); and 2) software for data capturing, processing, and personalized biofeedback generation. The implementation of real-time personalized vibrotactile feedback was computed using Hidden Markov Models (HMMs). For the test case, we calculated the probability and log-likelihood of the test movements under the Work related Musculoskeletal Disorders (WMSD) and non-WMSD HMMs. The vibrotactile biofeedback was provided to the user via a wearable device for a WMSD-predicted case. In the system evaluation, a randomized crossover trial was conducted to compare dental posture measure using tilt angles of the upper back and muscle activities of those dental students that received vibrotactile biofeedback from the system with the control group against the dental students who received no feedback.

Results: The participants who received feedback from the system had a lower tilt angle at 10^th, 50^th, and 90^th percentiles of Backx and Backy, as well as muscular load, which were statistically different (p < 0.05) from those who received no feedback from the system.

Conclusions: The results presented here demonstrate that a personalized biofeedback system for posture training in dental students is feasible and associated with quantitative improvements of the dental posture.