By ANNE NUGENT GUIGNON, RDH
My love affair with magnification loupes started 17 years ago. They just made sense clinically and my postural improvements were astonishing. Loupes allow me to provide better clinical care with less strain on my body, and my brain is amazed with how magnification makes even the minutest details easier to see.
In addition to appreciating the clinical benefits, my inner geek always wants to know how things work. Customized equipment doesn’t jump off a shelf; it comes from meticulous assembly based on precision measurements. Through the years, I’ve had several opportunities to visit a factory where loupes are made, which was time well spent, but I’ve always wanted to learn how to take the measurements necessary to create custom magnification.
During a recent lull in the ADHA annual session exhibit hall in Phoenix, I had an opportunity to learn how to measure the working distance, interpupillary distance, and where the oculars should be placed in a frame’s carrier lens. It’s been a long time since I’ve tackled a new task that requires digital dexterity. It looks easy in the hands of someone who routinely takes measurements, but I got a severe case of fumbling fingers trying to read the millimeter markings on a small ruler laid against a frame. At the end of 30 minutes, my young coach, Devon, declared that I had passed Basic Measurements 101. Whew!
Even though I passed the basic test, my instincts suggested there was more to creating a perfect pair of magnification loupes than taking a few measurements. Several of my friends who have been in the loupes business for years shed light on the art and science of the process, the intricacies of what it takes to create the perfect product for each person. Just as we assess our patients before we ever look in their mouths, those that fit us for loupes study the details of our facial features before we ever sit down to get measured.
When I got my first pair of loupes, there were only a few basic types of frames, and they all had big carrier lenses. Very few hygienists wore loupes and the frames were masculine in appearance. The biggest decision revolved around whether to get a Buddy Holly style or a silver or gold-tone titanium frame. These kinds of frames still exist. While the design is not incredibly stylish, larger carrier lenses offer optimal eye protection, have adjustable nose pads and temples, and can accommodate the steepest declination angles as well as the weight of heavier, high-powered telescopes.
Designer and sport frames are all the rage today. Head shape as well as individual facial geometry determines which frame will work the best. A frame with a deep profile, which is the width of the frame from top to bottom, provides better eye protection for those with a slender face. For the sake of comfort, clinicians with a wide face or chubby cheeks need to be fitted with a low profile lens.
Clinicians with large, prominent eyes are easier to fit than those with deep-set eyes, since there is less distance from the front of the eye to the ocular. The size and shape of the nose play a role in frame selection. The higher the bridge of the nose, the more difficult it is to get a deep declination angle. Adjustable nose pads are critical for a proper fit, especially for those with a flat or wide bridge.
Most frames are made with one of three materials — lightweight titanium, carbon composite, or plastic. Even though aluminum is lightweight and flexible, it does not have the strength to support the weight of the oculars, and stainless steel is too heavy, so these types of frames are rarely used in magnification systems. Carbon composite and titanium offer the strength and flexibility that make it easier to custom fit a frame to one’s face, a feature particularly important since most faces are not symmetrical. Most people have one ear that is higher than the other. Being able to adjust a temple can take a pair of loupes from mediocrity to being an indispensible tool.
Custom through-the-lens (TTL) are designed with the oculars placed in the lower third of the carrier lens, creating an unobstructed view through the top one-third of the carrier lens. In fabricating a TTL system, the carrier lens must be large enough to accommodate weight and declination angle of the oculars. While not as popular, flip-up styles allow a deeper declination angle because the telescopes are attached to an independent support system mounted in front of the carrier lens.
In recent years, a lot of attention has been given to the declination angle, the ability to have a comfortable view through the oculars while maintaining an erect head posture. Some suggest the steeper the angle the better, but significant eyestrain will occur if the angle is too deep. This is further complicated by the fact that we do not sit still in the clinical setting. We move around a patient to make minor adjustments in head position even when wearing loupes.
Seating posture also has an effect on the measurements. Dental professionals use an upright seating position with a forward tilt while working on patients. We tend to move toward the operating field rather than leaning back during instrumentation. Saddle seating uses a sit/stand position, a form of declined seating. Saddles allow clinicians to sit up higher and use a more erect core posture, thus increasing the working distance over traditional seating, which calls for having the thighs parallel to the floor. Saddle seating also moves the actual workspace closer to the clinician’s body, requiring a deeper declination angle.
Improved upper body and neck posture is one of the benefits of using properly fitted loupes; however, this won’t happen if your working distance is measured while you’re sitting in a slumped position. For those who have had poor posture for years, it takes a conscious effort and commitment to overcome years of muscle memory. Just like other forms of body training, it is possible to learn to sit up straight. It may take a week or two, but the benefits will become obvious as your body adjusts to healthier positioning.
Don’t despair if the loupes in the exhibit hall don’t fit your measurements. Demonstration loupes are fabricated to fit average facial geometry. Customization is what you want, and it is the result of exacting measurements that take into account your facial features and seating posture, creating your ultimate personal comfort zone. RDH
Anne Nugent Guignon, RDH, MPH, provides popular programs, including topics on biofilms, power driven scaling, ergonomics, hypersensitivity, and remineralization. Recipient of the 2004 Mentor of the Year Award and the 2009 ADHA Irene Newman Award, Anne has practiced clinical dental hygiene in Houston since 1971.
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