A pilot study of hand and arm musculoskeletal disorders in dental hygiene students.

PURPOSE This study was designed to determine the relationship between musculoskeletal disorder symptoms and vibration in dental hygiene students as a pilot for a larger scale study. METHODS A custom-designed questionnaire was distributed to three intact student groups: those accepted for admission, those at the end of the first year, and graduating students at the end of the second year. Data were analyzed using tabular and multivariate analysis. Students increased their use of ultrasonic instruments from 0.2 to 2.8 to 7.3 hours per week over the three years. Dental hygiene students with symptoms of numbness in the upper extremities used ultrasonic scalers a mean of 8.2 hours per week compared to 2.8 hours of use by students with no upper extremity numbness. These students also used manual instruments 10.1 hours and 4.8 hours per week, respectively. RESULTS Logistic regression revealed a significant association between hours of use of ultrasonics and upper extremity numbness/tingling, with an odds ratio of 1.10 for each increased hour of use (95% CI 1.01-1.19; chi-square = 4.9). A similar result was found for manual instrument use. CONCLUSION Results indicate that musculoskeletal disorder symptoms may increase with the use of ultrasonic and/or manual instruments.