Neck Health and Finding the Right Loupes
Finding the right dental flip-up loupes or TTL (through-the-lens) loupes is paramount to maintaining good neck health, improving working posture and being comfortable. Loupe systems can vary widely in their ability to promote a neutral head position, which is having one’s ears positioned directly over the shoulders. In order to find the right flip-up loupes or TTL loupes, there are three essential criteria for selecting the right system. When these three criteria are present, a correct forward-head posture of 20 degrees or less can be effortlessly achieved.
The declination angle is the angle created by the eyes being downwardly-inclined to the work area. A good working declination angle is 20 degrees or less, and without the right dental loupes in place, the head may be positioned too far forward in order to see through the loupe’s telescope. Flip-up loupes generally allow for a steeper declination angle and help achieve a neutral head position when compared to TTL loupes. Therefore, finding the right flip-up loupes will reduce the need for leaning forward and promote good posture and neck health.
Frame Size and Loupes
Frames rest differently on different faces. Identical loupe systems may have a slightly different declination angle on different people because of papillary distance and the height of one’s nose bridge. With frame size, it is generally easier to achieve a proper declination angle if the frames can sit low on the cheek. This allows a lower placement of the loupe’s scope in relation to the pupil and aids in improved working posture.
Perhaps the one factor most common in poor neck health and improper working posture is working distance. Working distance is the distance between the eyes and the work area. Generally, the distance is too short, which encourages excessive hunching or neck flexion. Even a distance of two or three inches can significantly impact neck health and working comfort. Proper working distance factors into the working ranges of the scopes on flip-up loupes and TTL loupes.
Working distance can be properly measured by having a patient in a chair while simulating treatment. From the 12, 10 and 8 o’clock positions, measure the distance (or have someone measure) between the patient’s mouth and the provider’s eyes. These measurements are generally between 14 and 20 inches, depending on the height of the provider.
Also important when consider the working distance and applying that distance to the right pair of flip-up loupes or TTL loupes is the depth of field. Also known as the working range, this indicates how long an object will remain in focus as the operator moves closer or further away from the target. The magnification strength in loupe scopes affects the working range. In scopes with higher magnification, the working range is decreased. To compensate for the natural tendency to drift closer to a working area, it may be necessary to measure the working distance slightly longer than normal, which will give an operator a more flexible working range.
The Right Telescope
The three criteria above will factor into choosing the best flip-up or TTL loupe system. However, there are also general guidelines for selecting the right magnification strength for loupe telescopes. For general dentistry, a scope power of 2.5x up to 3x is preferred. Endodontists and periodontists often choose a magnification of 4x to 6x for surgical telescopes. As a reminder, magnification strengths factor into proper working ranges, and this is why a smaller magnification strength gives a general dentist a larger working range and makes working different areas of the mouth easier.
High magnification 4x, 5x, 6x Moderate magnification 2.5x, 3x
New loupe systems will need minor adjustments and an accommodation period. For a best practice, new dental or surgical loupes should only be worn for no more than two hours the first few days. Afterwards, gradually increase the wearing time over five to 10 days until it is comfortable to wear the flip-up or TTL loupes without neck strain. Any attempt to quicken the adjustment period could lead to headaches.
The Difference between TTL Loupes and Flip-Up Loupes
Knowing how the previous factors play into choosing the right loupe system can now help one choose between TTL loupes and flip-up loupes. There are several important differences between these two styles of dental and surgical loupes.
TTL (through-the-lens) loupes feature a telescope mounted directly onto an eyeglasses lens. They stay focused and adjusted. Their declination angle is preset and they are lighter weight than flip-up loupes. However, if the operator’s eyeglass prescription is changed, the TTL loupes must be returned to the manufacturer for adjustment.
Flip-up loupes are mounted in front of the eyeglasses lens on a hinge mechanism. This can offer a steeper declination angle, but the flip-up loupes can sometimes get knocked out of adjustment. They can be heavier than TTL loupes but, as their namesake implies, can be flipped up when not in use.
Neck health is important in the dental profession. Consider all these factors when choosing the best loupe system and fatigue and neck strain will be experiences of the past.