384 Journal of Dental Education ■ Volume 68, Number 3 Effect of Magnification Lenses on Student Operator Posture B.G. Branson, R.D.H., Ph.D.; K.K. Bray, R.D.H., M.S.; C. Gadbury-Amyot, R.D.H., Ed.D.; L.A. Holt, R.D.H., M.S.; N.T. Keselyak, R.D.H., M.A.; T.V. Mitchell, R.D.H., M.S.; K.B. Williams, R.D.H., Ph.D. Abstract: A distinct body of literature supports the association between clinical postures of the dental practitioner and work- related musculoskeletal disorders (WRMD). Several aids or devices have been tested to improve clinical posture in the interest of decreasing WRMD. The use of magnification lenses while performing dental procedures may increase the quality of work and decrease the likelihood of musculoskeletal problems. To date, only anecdotal and personal opinions had existed regarding the benefits of using magnification lenses, and no empirical evidence had authenticated the contention that use of magnification lenses exerts a positive change in operator posture. The objective of this study was to assess the effect magnification lenses had on the posture of dental hygiene students. Using a randomized crossover design, researchers videotaped nineteen senior dental hygiene students performing an intra-oral procedure with and without the use of magnification lenses. The tapes were then evaluated by a panel of five dental hygiene educators calibrated in the use of Branson’s Posture Assessment Instrument (PAI). Results of a paired t-test indicate that the posture of the students while wearing magnification lenses was more acceptable (p=.019) than when wearing traditional safety glasses. Results of this study indicate a quantifiable change in acceptability of posture for clinicians wearing magnification lenses and suggest that the use of such lenses in dental education may be warranted. Dr. Branson is Assistant Professor, Division of Dental Hygiene; Prof. Bray is Associate Professor, Division of Dental Hygiene; Dr. Gadbury-Amyot is Associate Professor and Chairperson, Division of Dental Hygiene; Prof. Holt is Assistant Professor, Division of Dental Hygiene; Prof. Keselyak is Assistant Professor, Division of Dental Hygiene; Prof. Mitchell is Assistant Professor, Division of Dental Hygiene; and Dr. Williams is Professor and Director of Clinical Research, School of Dentistry— all at the University of Missouri-Kansas City. Direct correspondence and requests for reprints to Dr. Bonnie Branson, Division of Dental Hygiene, School of Dentistry, University of Missouri-Kansas City, 650 East 25 th Street, Kansas City, MO 64108; 816-235-2053 phone; 816-235-2157 fax; bransonb@umkc.edu. Key words: magnification lenses, clinician posture, PAI, dental hygiene students, videotapes Submitted for publication 10/23/03; accepted 12/19/03 A distinct body of literature exists supporting the association between clinical postures of the dental practitioner and work-related musculoskeletal disorders. 1-17 Fixed working posi- tions and repetitive motions over extended periods of time are attributed to musculoskeletal disor- ders. 1,7,9,10,15,16 Assuming a more neutral and less stressful posture is reported to reduce the amount and severity of musculoskeletal disorders. 18-20 The litera- ture suggests that the use of magnification lenses while performing dental procedures may increase the quality of work and has the potential to decrease the likelihood of musculoskeletal problems, although in- dications of a physiological benefit are primarily based on anecdotal evidence. 21-28 Systematic observations of posture require that dental operator posture be clearly defined. Basic in- strumentation texts have sought to describe ideal posture for the clinician. 29,30 However, the literature reveals no description of the limits for posture out- side of the ideal ranges. Recently, Branson’s Pos- ture Assessment Instrument (PAI) was developed based on expert opinion of a panel of clinical dental hygienists, physical therapists, occupational thera- pists, and educators. This instrument provides a reli- able method to examine posture over a period of five minutes. 31 During a five-minute period, the evalua- tor examines ten components of the body’s posture and then, using established criteria, rates the posture in one of three categories; 1) acceptable, 2) compro- mised, 3) harmful. A weighted composite score is then computed such that the final score represents posture impact over the five-minute time frame. This instrument provides a means for measuring posture outside of ideal ranges. Two previous experimental studies have re- ported on dental students’ use of magnification lenses with respect to quality of work and satisfaction in lens use. 32,33 However, neither provided any evidence of magnification lenses making a difference in posture. Lekinius et al., using a crossover design study, reported that the performance of dental students in a preclini- cal fixed prosthodontics laboratory wearing magnifi- cation lenses was superior to those students not wear-