An applied science concerned with designing and arranging things people use so that the people can do work most efficiently and comfortably.

1. ERGONOMICS
IN DENTISTRY

2. NOW IT’S THE ERA OF
designing tools, equipments, work stations and tasks
to fit the work ….. NOT worker to the job.

3. What is Ergonomics?
 An applied science
concerned with
designing and
arranging things
people use so that
the people can do
work most
efficiently and
comfortably.
IN SHORT……
In Greek, “Ergo,” means
work and, “Nomos,”
means natural laws or
systems

4. WHY SHOULD DENTAL STUDENTS AND
DENTISTS CARE?
 Ergonomics might
positively impact dentists
throughout their
professional lifespan.
 More than 70 percent of
dental students reported
neck, shoulder and lower
back pain by their third year
of dental school
issue of January 2005

5.  Dentists and dental students often assume
awkward physical positions while providing
treatment ...

6. REASONS FOR EARLY RETIREMENT
AMONG DENTISTS
•MSD Musculoskeletal Disorder (29.5%)
•CVS Cardio Vascular Diseases (21.2%)
•NEUROTIC SYMPTOMS(16.5%)
•TUMORS(7.6%)
•DISEASE OF NERVOUS SYSTEM(6.1%)
Source: Burke et al., 1997

7. One term to get to know is
Musculoskeletal
Disorder(MSD).
Fortunately, good ergonomic practices can drastically reduce the
likelihood that an MSD will slow you down.

8. Musculoskeletal Disorders (MSDs)
 Include a group of conditions
that involve nerves, tendons,
muscles, and supporting
structures such as intervertebral
discs
Severity of Symptoms
Mild periodic Severe chronic &
debilitating conditions

9. MSD SYMPTOMS AMONG DENTISTS
0%
10%
20%
30%
40%
50%
60%
70%
80%
Neck Shoulder Upper
Back
Lower
Back
Elbows Wrists/
Hands
Knees
%
Reporting
Body Part
Males
Females
Source: Finsen et al., 1998

10. TYPES OF MSDS
 Neck and Shoulder
Disorders
Cervical Spondylosis
◦ Thoracic Outlet Syndrome
Rotator Cuff Tendinitis/Tears
Myofacial pain disorder

11.  Back Disorders
◦ Herniated Spinal Disc
◦ Lower Back Pain
◦ Sciatica

12. HAND AND WRIST DISORDERS
Carpal tunnel syndrome
Trigger fi nger Swelling
Ganglion cysts
non-cancerous, fl
uid-fi lled lumps
Tendonitis/Tenosynovi
tis Infl ammation or
thickening

13. MSDs
Signs Symptoms
 Decreased range
of motion
 Deformity
 Decreased grip
strength
 Loss of muscle
function
 Pain
 Numbness
 Tingling
 Burning
 Cramping
 Stiffness

14. USAF Dental Evaluation & Consultation Service
What Factors Contribute to MSDs?
 Forceful hand exertions
◦ Grasping small instruments for prolonged periods
◦ Forceful squeezing/release of instruments
 Repetitive movements—e.g., scaling, root
planing, polishing

15. What Factors Contribute to MSDs?
 Fixed or awkward postures
◦ Neck, back, shoulder posture
◦ Hand/wrist positions
◦ Standing/sitting
◦ Operatory organization
◦ Patient positioning

16. What Factors Contribute to MSDs?
 Prolonged use of vibrating hand tools—
dental handpieces, laboratory equipment

17. Contributing Factors for MSDs
 A risk factor is not always a
causation factor
 The level of risk depends on
◦ Amount
◦ duration
◦ Level of exposure

18. APPLYING ERGONOMICS
PRINCIPLE TO WORK
•Tools /
Instruments
•Work stations
• Work practices

19. USAF Dental Evaluation & Consultation
Service
Applying Ergonomics to Dentistry
TOOL/Instrument Design
 Goal: reduce force exertion;
maintain hand/wrist in neutral
position (no wrist bend)
Holding the
Wrist in a Non-
Neutral
Position
Tight Pinch Grip:
The distal index
finger joint is
straight
Work with wrist
in neutral
position, when
possible.
Use a more
relaxed grip,
when possible.
The distal: finger
joint is slightly fl
exed in arelaxed

20. Applying Ergonomics to Dentistry
Hand Instruments  When selecting
instruments, look for
◦ Hollow or resin handles
◦ Round,
textured/grooves, or
compressible handles
◦ Carbon-steel
construction
◦ Color-coding may make
instrument identification
easier

21. Applying Ergonomics to Dentistry
Dental Handpieces
 When selecting handpieces, look for
◦ Lightweight, balanced models
◦ Sufficient power
◦ Built-in light sources
◦ Angled vs. straight-shank
◦ Pliable, lightweight hoses (extra
length adds weight)
◦ Swivel mechanisms

22. Applying Ergonomics to Dentistry
Provide Sufficient Space
 Permanently place
equipment used in every
clinical procedure within
comfortable reach (within
20 inches of the front of the
body)
 Use mobile carts for less
commonly used equipment
◦ Allows convenient
positioning when
required

23. LIGHTING
GOAL: Produse even ,shadow-free,
color- corrected illumination
concentrated on operating field
•The overhead light
switch should be
readily accessible
•Hand mirrors can be
used to provide light
intra orally
•Use of fibreoptics
for hand pieces add
concentered lighting
to operating field

24. MAGNIFICATION
GOAL: improve neck posture,
provide clearer vision
•Working distace
•Depth of field
•Eye loupes single lens
multi lens
telescopic
loupes

25. Applying Ergonomics to Dentistry
Operator Chair
 Goal: promote mobility and patient access;
accommodate different body sizes
 Look for:
◦ Stability
◦ Lumbar support
◦ Hands-free seat height
adjustment
◦ Fully adjustable

26. PATIENT CHAIR
GOAL: Should promote patient
comfort, maximise patient
access
•Look for
stability
•Fully adjustable
head rest
•Hands free
operaion
•Support head
torso feet

27. Applying Ergonomics to Dentistry
Work Practices
 Goal: maintain neutral posture;
reduce force requirements
 Potential strategies
◦ Ensure instruments are
sharpened, well-maintained
◦ Use automatic handpieces
instead of manual instruments
wherever possible
◦ Use full-arm strokes rather than
wrist strokes

28. Applying Ergonomics to Dentistry
Reduce Physical Effort
 Improve neck posture and clear vision

29. GOAL : Avoid static or awkward postures
Eye 14 16 inches away from
patients oral cavity
Shoulder relaxed and not
elevated
Elbows elevated not more than 30 degrees.
Should adjust patient chair when accessing different quadrants
Sit tall ,legs seperatedAdjust the
height of your seat so that your feet
can be flat on the fl oor and your
knees are a little below the level of
your hips (your thighs are slanted
slightly
downward). Allow the thighs to be

30. PATIENTS
 Traditionally placed
in supineposition
back of dental chair
almost parallel to the
ground

31. Applying Ergonomics to Dentistry
Reduce Physical Effort
 Use reasonable operating forces and minimal
repetitions reduces overall physical effort required
by a task
 Minimize sustained effort
◦ Brief but frequent rest pauses can minimize
fatigue and enhance productivity
◦ Try to incorporate a variety of different activities to
shift musculoskeletal demands from one part of
the body to another

32. Goal: provide sufficient recovery time
to avoid muscular fatigue
Potential strategies
• Increase treatment time for
more difficult patients
• Alternate heavy and light
calculus patients within a
schedule
• Vary procedures within the
same appointment
• Shorten patient’s recall
interval
SHEDULING

33. Applying Ergonomics to Dentistry
Personal Protective Equipment
 Glasses
◦ Lightweight, clean, well-
fitted
◦ Magnifying lenses and
head lamps are
encouraged
 Clothing
◦ Fit loosely, lightweight,
pliable

34. Applying Ergonomics to Dentistry
Personal Protective Equipment
 Gloves
◦ Be of proper size,
lightweight, and pliable
◦ Should fit hands and
fingers snugly
◦ Should not fit tightly
across wrist/forearm

35.  And because even dental students have a life outside of dentistry,
everyday habits can add to the stress on your body and well-being.
avoid “Blackberry Thumb.”
heavy, plastic bag can concentrate stress in a
small area of your hand
Holding your phone between your
shoulder and ear
When using a computer
keyboard, use the padded wrist
rest
Ergonomics and Everyday
Life

36. STRATEGY METHOD/RATIONALE
Magnification Magnification loupes
Patient positioning Appropriate chair position, patient
head anguations
Operator positioning Use of clock positions, avoiding static
postures, seated dentistry
Assistant positioning Seated above operator eye level, hips
and thighs parallel with patients
shoulders,avoiding static postures
Equipment Designed and positioned to minimize
bending and reaching, using lumbar
support
Instruments Larger diameter handle, textured grip,
balanced weight
Maintain Good Health Exercise, meditation ,regular breaks
SUMMARY

37. RECOMMENDATIONS
Exercise and fitness is an important element of overall health
and prevention of musculoskeletal disorders. Research has
shown that

38. excercises
The un-twister
Legs in tripod position; bend
to left side.
Rest your left elbow on left
knee.
Stretch right arm overhead
and look towards the ceiling.
Hold for 2-4 breath cycles
Trunk rotation
Sit tall. Cross right leg over left leg.
Place left forearm on right thigh
and turn trunk to the right.
Hold for 2-4 breath cycles
The reversal
Support wrists on
hips and slowly lean
backward.
Do not overextend
the head.
Hold for 2-4 breath
cycles

39. CONCLUSION
 Ergonomics and You
 Two dental students may be
exposed to the same risks, at
the same degree of intensity,
and one will develop an MSD
and the other will not.
 We dont know why? But its
true…
 A poor ergonomic choice may
impact you today or even a few
years down the roads.
Risk factors for MSDs affect everyone differen

40. THANK YOU
 DR ROOPA
 DR SASI KUMAR