As dental professionals, we frequently attend continuing education courses. Many of these courses focus on the risk factors of patients. But what about the risk factors we experience? How many of us took into account the pain, injuries, and changes our body would experience from leaning over patients all day?
The problem dental professionals face is that we are in static, awkward, prolonged, and repetitive positions. The body needs to have the joints and muscles moved regularly. When we sit in the same position for too long, there is increased spinal-disc pressure, decreased joint lubrication, and decreased blood and nutrient flow to muscles and spinal discs. These changes contribute to soft-tissue damage, which over the years can result in a musculoskeletal disorder such as a herniated spinal disc, trapezius myalgia, neck tension syndrome, rotator cuff impingement, or carpal tunnel syndrome.1
When sitting unsupported in a provider chair, the lumbar part of the spine flattens. The bony infrastructure can provide little support to the spine, which is now hanging on the muscle ligaments and connective tissue at the back of the spine and causing tension in these structures. Ischemia or restricted blood supply to this area can occur and lead to low back strain or a disk herniation.
Forward head posture is another common problem among hygienists (see figure 1). In this posture the vertebrae can no longer support the weight of the head, which can lead to neck tension syndrome.2 This can cause headaches and chronic pain in the neck and shoulders, which can radiate into the arms.
The tools available to dental professionals today have progressed past the mask and gloves. We now have three tools to help prevent pain and curvature of the spine: the operator chair, magnification (telescopic lenses, scopes, or loupes), and illumination (light source) (see figure 2). When these tools are used together they increase the value of our role as dental detective, reduce fatigue, eliminate pain, and help us work more proficiently and effectively.
■ The operator chair - First, sit with a good ergonomic posture. One of the biggest factors contributing to back and neck pain is positioning the patient too high. It is important to sit close to the patient to obtain good head posture. The operator stool should be adjusted so the hip of the operator is slightly higher than the knee. You can also tilt the chair about 10 to 15 degrees if that feature is available. Tilting the chair helps maintain a low back curve and reduce low back disc pressure. This type of tilt causes an elevation in the shoulders and abduction, or movement of the arms away from the central axis of the body. A tilted seat will help the clinician be positioned closer to the patient by opening the hip angle (see figure 3).3
A good chair has a “waterfall” curve - a soft-sloped edge that will not cut off circulation in the back of the thigh. With this type of chair you should be able to raise the seat so that your hips are higher than your knees. This opens the hip and knee areas for better blood flow.
A saddle-style stool allows for closest positioning to the patient by positioning the provider between standing and sitting. This promotes the spine’s natural curves. It may be desirable to have one of each type of stool in the operatory to alternate working postures and prevent overworking of the same muscles.3 Always ask to test operator chairs or stools before purchasing (see figure 4).
A good chair should also have armrests. The simple weight of the arms hanging unsupported at one’s sides may increase and prolong pain. Armrests reduce this strain by providing an operating fulcrum at the elbow, which also promotes instrument stability.
Some characteristics of an ideal chair are:
• The ability to tilt the seat pan
• The ability to raise the hips higher than the knees. You will need a waterfall type of seat (a sloping front) so that the chair doesn’t cut into the back of the legs and cut off circulation.
• Armrests to eliminate strain and promote instrument stability
Figure 4
A checklist of important things when purchasing a chair are:
♦ Height of stool. Be sure the hips are higher than the knees.
♦ Slope
♦ Padding
♦ Arm support
♦ No preformed seat pan. When the seat pan is preformed it is not specific to how you should sit in the chair.
■ Magnification - Magnification (telescopic lenses, scopes, or loupes) has been available to clinicians for over two decades. It is very important for clinicians to wear due to the static postures we endure for long periods of time. There are many other reasons clinicians should wear magnification (see figure 5).
Magnification is becoming the standard of care in dentistry. A recent dental publication stated that 86 percent of dentists use some form of magnification, and many offices now provide it for the dental assistant. It can be an extremely helpful tool when assistants are fabricating or placing temporary crowns, etc. Lab technicians who fabricate crowns, dentures, and partial dentures also wear magnification.
When choosing the magnification best for you, consider the quality of the lens. A better quality lens allows better depth of field, more light to enter into the scope, and a sharper image. The quality of the optics is also key. The field of view should be sharp from edge to edge, and the best optics will let more light into the viewing area. More light equates to better depth of field.
It is important to have a sharp image rather than a large, “fuzzy” image. Here is a comparison: the television you viewed in 1990 versus a high definition television of today. The television available 15 years ago wasn’t as sharp as what we can see today. Think of a 2 mega pixel photograph on an 8 x 10 picture versus a 6 mega pixel photograph on an 8 x 10 picture. The 6 mega pixel picture will give a sharper, more detailed image. Most hygienists view the mouth by quadrants, and magnification is a perfect tool to enhance your view of the mouth and improve your dental detective skills.
Many companies now make a featherweight frame with a 2.5 magnification lens that is adequate for most hygiene procedures. The featherweight frame is often preferred because of the light weight and comfort on the nose. Through-the-lens (TTL) magnification doesn’t have to be heavy, and flip-up scopes have also become much lighter.
The declination angle of the lens - the angle at which the eyes are declined toward the work - is an important ergonomic aspect of magnification. This angle should support the clinician’s desired ergonomic position,4 and it is one of the most important factors when choosing the configuration of a lens.
■ Illumination - This is the third element available to dental professionals. Illumination provides a coaxial light, which is valuable because it follows your line of sight. Nothing can get in the way when you wear this type of light, not the assistant’s hand, an evacuation device, or the instruments. Most people who use illumination say it is as important as magnification. The size of the light source is very important. Consider counter space because this is worth a million dollars in the hygiene room! Also, how hard is this tool to clean? If there are lots of knobs and gadgets, and things to plug and unplug, it can be difficult and time consuming to care for. If the light optics is adaptable to your eyewear or headband, it is closer to being truly coaxial. If the light mounted onto your loupes or scopes is too heavy, a headband system with either a rigid or terry cloth headband may be helpful.
Also, light measurement should be considered. A fiber optic light should provide between a 4400 to 5500 “foot candle” of power as measured by a light meter at 16 inches. A light with a battery pack should register between 2200 to 3000 “foot candle.” Be aware of the light output and battery life of the battery pack. Look for an LED battery light that holds a charge for six or more hours with sufficient output. Make sure your lighting system adapts to your magnification system. Only a few manufacturers make their systems adaptable to all scopes.
Times have changed. Technology has advanced and so have the tools that decrease risk for dental professionals.
Think about the office budget. It is important that it include tools to prevent pain in the work place. Think of these things as insurance for a career without pain, and include them in the budget the same as disability insurance or money into savings. By combining magnification and illumination with a chair that eliminates static and prolonged postures, you win both physically and emotionally. Think of these three tools as the triangle of good patient care and good health for the provider. RDH
Author’s acknowledgement: The author sincerely thanks Bethany Valachi, MS, PT, CEAS, co-founder of Posturedontics, for her expertise in the field of ergonomics.
Figure 5
Reasons to wear magnification:
♦ Provides visual acuity
♦ Proper ergonomics for musculoskeletal disorders
♦ Examination (periodontal screening exam, oral cancer screening exam, caries detection, identify defective restorations, etc.)
♦ Viewing X-rays
♦ Allows clinician to more accurately identify supragingival deposits
♦ Reduction of eye strain
♦ OSHA approved
♦ The “standard of care”
♦ Puts you on the leading edge!
