The Effect of Magnification Loupes on Posture During Instrumentation by Dental Hygienists

Purpose: The purpose of this study was to determine the effects of dental magnification loupes on posture during instrumentation. Methods: A convenience sample of twenty-seven righthanded dental hygienists with no history of injuries or disabilities of the head, neck, and trunk regions was enrolled. Baseline posture calibration was taken. Accelerometers were placed on four locations of the head and trunk (occipital pole of head, cervical vertebrae: C5, thoracic vertebrae: T5, lumbar vertebrae: L1) to measure changes in posture. Accelerations in three axes were recorded (anterior/posterior (AP), medial/lateral (ML), vertical (VT)). Mean accelerations of the three axes were used to compute average forward tilt (APangle) and sideways tilt (MLangle) of each sensor. For each axis, root mean square (rms) was also calculated to determine the magnitude of tremor fluctuations (i.e., APrms, MLrms and VTrms). Chair mounted typodonts with artificial calculus represented a simulated oral environment. Subjects were randomly assigned to wear loupes during the first or second half of the experiment and instructed to instrument all areas of the mouth with an ODU 11/12 explorer. An end user opinion survey was completed by participants. Results: Twenty seven participants (26 female and 1 male) completed the study. Results revealed no statistically significant differences between loupes and no loupes in the tilt angle of each sensor location in the AP or ML planes. In contrast, a statistically significant difference in mean fluctuations while wearing loupes (M=.215152, SD=.0741530) (rms) in AP at C5; t(24)=2.63, p=.015, compared to not wearing loupes (M=.261028, SD=.1379292) indicated posture fluctuations decreased while wearing loupes. APrms was only significant at C5; for ML and VT axes and sensor positions (head, C5, T5, L1) there were no statistically significant differences in mean fluctuations (rms) between wearing loupes and not. Overall, 74% of the participants strongly agreed that magnification loupes made exploring easier and 67% of participants strongly agreed that magnification loupes improved their posture. Conclusion: While participants perceived that magnification loupes enhanced their posture, the study provided little evidence that wearing loupes leads to changes in body orientation; only to reduced postural tremors at C5 in the AP axis