{ ergonomics }

Selecting dental loupes To improve your health … not make it worse!

In the last issue of the Focus, the editorial discussed the importance of ergonomics, and noted that we would begin featuring a series of ergonomics articles. In addition to loupes, we’ll cover patient positioning, are right angles “right” … and more.

to today’s sophisticated procedure scopes, visualization solutions recently have evolved at an unprecedented rate. Modern magnifi- cation aids are raising dentists’ productivity and the level of excellence and confidence in dental treatment.¹ However, the ergonomic advantages of magnification increasingly are being recognized as an important reason to invest in them. Students have been found to work in an ergonomically better posture when using magnification loupes compared to using regular safety glasses.²

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But what are the ergonomic implications of improved posture? Consider that working with a forward head posture of only 20 de- grees or more for 70 percent of the working time has been associated with neck pain.³ Most dentists and hygienists operate with a forward head posture of least 30 degrees for 85 percent of their time in the operatory.⁴ It should come as no surprise that the preva- lence of neck pain among dentists hovers around 70 percent.⁵,⁶

Properly designed loupes can reduce or eliminate neck pain by minimizing danger- ous forward head postures with a set focal range combined with adequate declination angle. However, it is important to note that poorly designed or adjusted loupes can actually cause neck pain and increase risk of injury. Well-designed loupes should enable a working posture of less than 20 degrees of forward head posture. Loupes are available in two basic styles: fixed mounts (through-the- lens) and front lens mount (flip-ups).

22 focus | JUL/AUG 2013 | ISSUE 4

isualizing the oral cavity has always posed a challenge in dentistry. From early fiberoptic lights mounted on handpieces

Through-the-lens loupes (TTLs) have the scope mounted directly into the carrier lens with a fixed declination angle. Because they are fixed, the loupes do not get knocked out of alignment. Compared to flip-up loupes, they offer a wider field of vision, because the scope is closer to the eyes. Prescription lenses can be included in the carrier lens of the fixed loupes to enable distance viewing, however if the prescription changes, the loupes will need to be modified by the loupes manufacturer.

Flip-up loupes have the scope mounted on a hinge mechanism in front of the carrier lens and can be flipped up for un-magnified view- ing. Most importantly, flip-ups generally have a much better declination angle than TTLs, which, in turn, promotes more neutral head posture. Because flip-up loupes are highly adjustable, they sometimes can be knocked out of alignment. In the past, many female dentists and hygienists have steered clear of flip-up loupes due to the heavier weight. With the new ultra-light weight flip-up models on the market today, weight is a no longer an issue.

ERGONOMIC CRITERIA FOR SELECTION

To ensure your loupes will benefit your health, it is essential to understand the three most important ergonomic factors: declina- tion angle, working distance and frame size/ shape.

Declination angle: From an ergonomic standpoint, a good declination angle is the most important factor in selecting loupes. This is the angle that your eyes are inclined downward toward the work area. (Fig. 1) This angle should be steep enough to help you

FIG. 2 A good declination angle is useless unless the scope sits low in relation to your pupil. A vertical slide feature (Surgitel shown) ensures that the scope can adjust low enough to obtain maximum declination angle. Photo ©2011 Posturedontics, LLC

attain a comfortable working position with minimal forward head posture (less than 20

FIG. 1: Loupes with a good declination angle (black lines) will allow the operator to work with minimal forward head posture. Photo ©2008 from “Practice Dentistry Pain-Free”