Ergonomics for Dentists- Ergodontics

Not many people look forward to visiting the dentist. And personally speaking, my vote lies with the majority.

Now my sweet tooth left me no option but to visit the dentist. As I lay down in the much dreaded patient's chair, I needed a distraction. Desperately! I tried to make myself comfortable in the chair but the posture I was in just aggravated my anxiety. :(

The procedure started, since my vocal chords were rendered useless, I was asked to signal with my hand if I had any pain. I signaled! But my dentist couldn't see my signal. Reason? he was bent over looking into my mouth!

That's when it struck me! The awkward posture the dentist was assuming for performing the task at hand. And I noticed how long he maintained that posture, without a break. His neck & upper back were bent & rotated for maximum view into the oral cavity. I also noticed how long he held his hands & fingers in the same position. The dentist sat back only after the procedure was completed.

This is when I started reading up about the role of ergonomics in dentistry & came up with quite a few ways dentists can avoid occupational hazards which they frequently face, especially musculo-skeletal disorders (MSDs) of the neck, back & hands.

Now the Commonest Posture adopted by the dentist is-

If right- handed, a right- forward leaning position i.e. right side bending (30 degrees), and twisting to the left (15 degrees) of the head, neck & trunk.
The combination of maintaining the above said posture for prolonged periods of time, minimal breaks & excessive patient load, dentists in India are extremely prone to MSDs.

What can be done to help this community of medical professionals?

A LOT!!

The main Aim is to maintain their spine in as neutral a position as possible. This can be achieved by adopting healthy work practices, using ergonomic equipment & instruments correctly & maintaining an active physical lifestyle.

The Golden Rule: ADJUST YOUR CHAIR FIRST!!

POSTURAL AWARENESS TECHNIQUES

Buttocks should fit snugly against the backrest. The edge of the seat should not press against the back of the knees.

Place feet flat on the floor and adjust the seat height till thighs gently slope downward while the feet remain flat on floor.

Two kinds of chairs can be used:

• If the tilt feature is available in the seat, angle it slightly forward up to 15 degrees to  increase the low back curve. This will place your hips slightly higher than your knees, which allows for closer positioning to the patient.
• Chairs without the tilt feature can be fitted with an ergonomic wedge-shaped cushion. If this cushion is not comfortable, you can instead attach the lumbar cushion to the backrest.
• Using a saddle-style operator stool also promotes the natural low back curve. This type of stool allows you to be closer to the patient when the patient chairs have thick backs and headrests.

Use of magnification Loupes- Reduce Strain on Neck & Upper Back:
Visualizing the oral cavity has always posed a challenge in dentistry.

The Use of Loupes Improves Posture:

1.Working with forward head posture of greater than 20 degrees for 70% of working time causes neck pain. Most dentists operate with a 300 Forward head for 85% of their working time. The prevalence of neck pain in dentists is around 70%!

2.The declination angle of the loupes should allow you to maintain less than 20 degrees of neck flexion.

3.Magnification of 2x will allow you to see the working field detail that is approximately identical to that you would see when hunching over the patient without scopes. Magnification greater than 2x provides enhanced visual detail but a smaller field of vision.

Important to Note: Improper adjustment/ selection of these magnification aids can worsen existing pain/ increase risk of injury.

Let the loupes do the work, not your back/ neck!

Lighting and Vision:

Lighting:

Prolonged visual strain leads to overall exhaustion.

Inadequate lighting also leads to contorted postures to view shadowed areas of the mouth.

Modifications:

1.Position the light parallel to your line of sight. For this the light has to be behind the your head.

2.Hand mirrors can be used to provide light intra- orally.

3.Fibre optics for hand pieces provide concentrated lighting to the operating field.

Vision:

Dental routine requires the use of normal-speed and high-speed drills.

Modifications:

Wear protective glasses which have hard plastic lenses and are designed like goggles or glasses with edges fitting against the skin. These offer complete security from sprays, droplets and solid bodies.

POSITIONING TECHNIQUES

Avoid static postures:

As seen earlier, spending long periods in one position increases your susceptibility to injury. So avoid holding one position for long.

Alternate between Standing and Sitting:

 

1.Standing uses different muscle groups than sitting. Alternating between the two positions lets one group of muscles rest, while the workload is shifted to another group of muscles.

2.If standing for a long period of time, rest one foot on a small stool or step, alternating feet; also alternate doing this with standing on both feet.

3.This is an effective tool in preventing injuries.

Reposition the feet:

Slight changes in foot position shifts the workload from one group of low back muscles to another, allowing the overworked tissues to recover.

Avoid twisting:
Individuals vary in size, shape, training, and experience.

• Operatory design plays an important part in how often you perform twisting movements during the workday.
• Ensure equipment and work areas allow flexibility.
• Move the position of the patient, rather than bending and twisting your body.
• Position instruments within easy reach. Keep the items used most frequently within a distance of about 20 inches (50 cm).
• Retrieve items with the closest hand, especially with rear delivery systems, to avoid twisting or reaching across the body.
• Use mobile carts for less commonly used equipment

Shoulder- Elbow Position:

Position the patient so that your

1.Shoulders are relaxed

2.Keep elbows and arms close to the body

3.Elbows are lower than your shoulders, at about 900 or less flexion

4.Keep your wrists at the same with or lower than your elbows

If your chair has armrests, adjust them to support your elbows so that the shoulders are relaxed. This decreases neck and shoulder fatigue.

When possible, use chair arms to support your upper arm or forearm when doing fine, precision work with your hands.

Wrist Position: 

 WRONG- The wrist is bent (flexed) while the fingers are being used.

RIGHT- Hold the wrist straight or in a slight extension.

Finger Position:

Tight Pinch Grip- The distal index finger joint is straight or hyperextended in a tight grip.

Use a more relaxed grip- The distal finger joint is slightly flexed in a relaxed grip.

Finger Rests:

Use a finger rest to stabilize your hand while operating.

Finger rest should be in the same arch & as close to the working area as possible.

Various types of finger rests:

 
 Finger rests also reduce muscle stress and prevent injury due to muscle fatigue.

PERIODIC BREAKS

• Take ‘Micro breaks’ in between patients for performing stretches.
• Frequently pausing can minimize fatigue and the risk of MSDs.
• Schedule patients so that you alternate between long, difficult cases and short, easier cases.

The most common reason for premature retirement from the dental profession is due to musculoskeletal disorders (particularly in the neck). Using the above mentioned ergonomic tips, dentists can increase their working efficiency.


As computers & smartphones/tablets also play an integral part in the ergonomics for dentists.