OBJECTIVE The purpose of this study is to address the high prevalence and costs of musculoskeletal disorders in dental hygienists and dental hygiene students by assessing the combined role of biomechanical and psychosocial risk factors. The paper explores new methods for measuring the effects of psychosocial risk factors (job stress) in hygienists. METHODS In a sample of practicing dental hygienists and dental hygiene students in Connecticut, the study assessed biomechanical exposures, psychosocial exposures, and symptom status by survey. Study participants were examined by physicians, providing measures of symptom and disease status. Two methods of bio-monitoring the potential effects of stress on the sympathetic nervous system were used: vibrotactile perception thresholds and nerve conduction velocity. RESULTS Biomechanical and psychosocial exposures have independent and additive associations with the wide variety of outcomes, often of similar magnitude. Biomechanical exposures tend to be associated with negative outcomes in identifiable body areas, whereas job stress had fewer identifiable associations with outcomes by body area. CONCLUSIONS The results of this study indicate that, in addition to identifying and controlling biomechanical risk factors, dental schools, dental practices, and dental hygienists themselves should pay attention to the identification and control of psychosocial risk factors in the workplace.