Historically, the focus of most dental chair manufacturers has been on patient comfort—cushy chairs with wide armrests—with little regard for operator accessibility. Rising awareness of work-related pain among dentists has forced many manufacturers to shift their focus over the past decade and consider ergonomic features.
The resultant multitude of ‘ergonomic’ patient chair design concepts in the marketplace can make purchasing chairs a confusing and frustrating endeavor.
When considering patient chair ergonomics, desirable features should facilitate neutral posture of the spine, shoulder, elbow, and wrist, maintain proper body mechanics, and limit excessive reaching of the operator. The most common problem I observe is operators experiencing difficulty gaining close proximity to the oral cavity while maintaining neutral posture. If the patient chair does not allow close operator positioning, the dentist is forced to either reach excessively forward with the entire arm or bend the trunk forward. Both place the operator at risk for injury.
From an ergonomic perspective, I feel the two most important ergonomic features in Portable Dental Patient Chair selection are a small, thin headrest and a narrow upper backrest.
Small, thin headrests allow more legroom and closer accessibility. The Eco 19 Patient Dental Chair headrest is ultra-thin, and the magnetic headrest allows great flexibility in patient positioning, including sidebending of the patient’s head for viewing difficult surfaces. Double articulating headrests, when angled up into the patient’s occiput, can greatly aid in viewing the upper arch, as well as relaxing the patient’s neck musculature. Avoid large knobs behind headrests as these can limit accessibility by hitting the operator’s knees or the edge of the operator chair.
Since movement around the patient’s head is imperative to the operator’s health, a narrow upper backrest is important. There are many patient chairs on the market now that have thin upper backrests, but are still quite wide through the shoulder area. This inhibits close positioning, especially in the 9-10 o’clock positions. (A narrow upper backrest will also allow closer positioning of the assistant.) The chair baseplate should also be small, so it does not obstruct the operator’s chair in the 9 o’clock position.
The patient chair should adjust low enough to allow the dentist to operate in a neutral seated posture. Some patient chairs do not adjust low enough for shorter operators, which forces them to either sit on the front edge of their chair or elevate their arms. The chair should also adjust high enough so the dentist has the option to comfortably stand for extractions, exams, or impression-making without bending forward.
Sling-style armrests, as featured on the J/V-Generation® Chair, help the operator to work in the 9-10 o’clock positions without knee obstruction.
A biomechanical consideration for lighting is the orientation of the handle. The light handle should be oriented vertically, as this is the safest position for the shoulder when reaching. Handpiece tubing pull-back should be minimal to none, so the operator can easily maintain a working position without hand strain.
A chairbase swivel feature enables the chair to rotate in the operatory. This is an important feature if the space between the patient headrest and counter is minimal.
Patient chair length is a frequently overlooked consideration when purchasing a new chair. Many operatories are small and cannot accommodate certain chair models. Strive for a minimum of 22” between the top of the patient chair headrest (when fully reclined) and the counter, so you can easily move into the 12 o’clock position.
The choice of proper ergonomic equipment is critical, and can either improve or worsen a dentist’s comfort and level of musculoskeletal health. The preceding guidelines should aid dentists in their selection of appropriate patient chair seating for the dental clinic.