patient and operator positions and their pros and cons

2. 2
 Ergonomics
 Importance Of Posture
 Ergonomics For Dentists
 Musculoskeletal Disorders
 Classification
 Signs
 Symptoms
 Risk Factors
 Prevention
 Ergonomics For Dental Students
 Body Strengthening Excercises
 Future Of Ergonomic Dentistry
 Conclusion
 References

3. 3

5. Proper positioning of the patient and operator, illumination and retraction
for optimal visibility are fundamental pre requisites to proper dental
treatment

6. • 1790 was a big year for dentistry, as this was the year the
first specialized dental chair was invented.
• It was made by Josiah Flagg, an American dentist from a
wooden Windsor Chair with a headrest attached.
•Before this, dental patients sat in a wooden chair without any
head rest at all.
HISTORY

9. Modern dental chairs offer an ever-increasing list of benefits for
patients and dental professionals.
They are built out of aluminium, steel, and heavy plastic, and most
offer smooth electric or hydraulic height and tilt adjustments.
These models also usually have a bevy of electrical ports to
accommodate drills and other medical equipment.
This keeps all electrical cords in one convenient place and lowers
the danger of tripping; it also allows the dentist to control the tools
with a series of foot pedals attached to the base of the chair.

10. FACTORS TO BE KEPT IN MIND REGARDING DENTAL CHAIR:
It should be able to provide comfort to the patient
It should be able to provide total body support
 Headrest of chair should be attached for supporting patient's chin and reducing
strain on chin muscles
 It should be able to provide maximum working area to the operator
 It should be placed at the convenient location with adjustable control switches
 Foot switches are preferred to improve infection control
10

11. For restorative dental procedures, the most preferred operating
positions are:
1. Upright position
2. Almost supine
3. Reclined 45 degree
The most common patient positions for operative dentistry are almost
supine or reclined 45 degrees. The choice of patient position varies with the
operator, the type of procedure, and the area of the mouth involved in the
operation.
CHAIR POSITIONS
11

12. UPRIGHT POSITION
This is the initial position of chair from which further adjustments are made
12

13. ALMOST SUPINE
• In this, chair position is such that head, knees and feet are approx. at same level
• Patient’s head should not be lower than feet except in case of syncopal attack
• The head should not be positioned below the feet level as blood pressure increases gradually
13

14. RECLINED 45 DEGREES
• In this position , chair is reclined at 45 degree
• Mandibular occlusal surface are almost 45 degree to the floor
14

15. PATIENT POSITIONS
• Patient should be seated so that all his body parts are well supported.
• The patient's head should always be supported by adjustable / articulated
headrest.
• Preferably the patient's head should be in line with his back
• The chair height should be kept low, backrest should be upright and armrest
should be adjustable while making the patient to seat in the dental chair.
• Now, the chair can be adjusted to place the patient in reclining position.
• Patient position can vary with operator, type of procedure and area of the oral
cavity.
15

16. OPERATING POSITIONS
• Once the patient has been comfortably positioned,
the dentist and the assistant should sit themselves
in the proper positions for treatment.
• Usually sitting position is preferred in modern
dentistry to relieve stress on operator's leg and
support the operator's back.
• The level of teeth being treated should be placed
at same level as the level of operator's elbow.
16

17. • For better understanding, sitting positions of
operator are related to a clock.
• In this clock concept, an imaginary circle is drawn
over the dental chair, keeping the patient's head at
the center of the circle.
• Then the numbering to circle is given similar to a
clock with the top of the circle at 12 o'clock.
7
17

18. 18
ACCORDINGLY THE OPERATOR'S POSITIONS
Right Handed Operator
1. Right front or 7’o clock position
2. Right or 9’o clock position
3. Right rear or 11’o clock position
4. Direct rear or 12’oclock position
Left Handed
1. 5 o'clock
2. 3 o'clock
3. 1 o'clock .

20.  When working from clock positions 9-12:00,
feet spread apart so that your legs and the
chair base form a tripod which creates a stable
position
 Avoid positioning your legs behind the
patient’s chair
 Back of the operator should be always straight
 Head erect and should not be bent of drooping

22. RIGHT FRONT POSITION (7 O'CLOCK)
1. It helps in examination of the patient
2. Working areas include:
a) Mandibular anterior
b) Mandibular posterior teeth (right side)
c) Maxillary anterior teeth
3. To increase the ease and visibility, the
patient's head may be turned towards the
operator.
22

23. 23
Torso Position : Sit facing the patient with your hip in line with the
patient’s upper arm.
Leg Position : Your thighs should rest against the side of the patient
chair.
Arm Position: To reach the patient’s mouth, hold your arms slightly away
from your sides. Hold your lower right arm over the patient’s chest.
Line of Vision: Your line of vision is straight ahead, into the patient’s
mouth.
Hand Position: Rest the side of your left hand in the area of the patient’s
right cheekbone and upper lip. Rest the fingertips of your right hand on
the anterior teeth in the patient’s maxillary left quadrant.
NOTE: Do not rest your arm on the
patient’s head or chest.
NOTE: It is difficult to maintain neutral arm
position when seated in the 8 o’clock
position. For this reason, use of this position
should be limited.

24. RIGHT POSITION (9 O'CLOCK)
1. In this position, dentist sits exactly right to the patient
2. Working areas include:
a) Facial surfaces of maxillary right posterior teeth
b) Facial surfaces of mandibular right posterior teeth
c) Occlusal surfaces of mandibular right posterior teeth.
24

25. 25
Torso Position. Sit facing the side of the patient’s head. The midline
of your torso is even with the patient’s mouth.
Leg Position. Your legs may be in either of two acceptable positions: (1)
straddling the patient chair or (2) underneath the headrest of the patient chair.
Neutral position is best achieved by straddling the chair; however, you should
use the alternative position if you find straddling uncomfortable.
Arm Position. To reach the patient’s mouth, hold the lower half of your right arm
in approximate alignment with the patient’s shoulder. Hold your left hand and
wrist over the region of the patient’s right eye.
Hand Position. Rest your left hand in the area of the patient’s right cheekbone.
Rest the fingertips of your right hand on the premolar teeth of the mandibular
right posterior sextant.
Line of Vision. Your line of vision is straight down into the patient’s mouth.

26. RIGHT REAR POSITION (11 O'CLOCK)
• Dentist sits behind and slightly to the right of the patient
and the left arm is positioned around patient's head
• This is preferred position for most of dental procedures
• Most areas of mouth are accessible from this position either
using direct or indirect vision
• Working areas include:
a) Palatal and incisal (occlusal) surfaces of maxillary teeth
b) Mandibular teeth (direct vision).
26

27. 27
Torso Position. Sit at the top right corner of the headrest; the
midline of your torso is even with the temple region of the patient’s
head.
Leg Position. Your legs should straddle the corner of the headrest.
Arm Position. To reach the patient’s mouth, hold your right hand
directly across the corner of the patient’s mouth. Hold your left
hand and wrist above the patient’s nose and forehead.
Hand Position. Rest your left hand in the area of the patient’s left
cheekbone. Rest the fingertips of your right hand on the premolar
teeth of the mandibular left posterior sextant.
Line of Vision. Your line of vision is straight down into the mouth.

29. 29

30. 30

31. 31

32. 32

33. 1. While doing work in maxillary arch, maxillary occlusal surfaces should be
perpendicular to the floor.
2. In mandibular arch, mandibular occlusal surface should be oriented 45° to the floor.
3. Patient's head can be rotated backward or forward or from side to side for operators
ease and visibility while doing work.
4. Maintain proper working distance during dental procedure. This will lead to an
increase in the cooperation and confidence among the patient.
5. Operator should not rest forearms on the patient's shoulders and hands on the face
of the patient.
CONSIDERATIONS WHILE OPERATOR POSITIONING
33

34. 6. Dentist should not use patient's chest as a instrument trolley.
7. The operator should leave left hand free during most of dental
procedures for retraction using mouth mirrors or fingers of left hand.
8. Operator should keep changing position if procedure is of long
duration to decrease the muscle strain and fatigue.
34

35. For successful instrumentation, it is important to proceed in a step-by-step
manner. A useful saying to help remember the step-by-step approach is
“me, my patient, my light, my non-dominant hand, my dominant hand.”
SEQUENCE FOR OPERATOR POSITIONING
35

36. SEQUENCE FOR ESTABLISHING POSITION
1 ME
Assume the clock position for the treatment area
2 MY PATIENT
Establish patient chair and head position
3 MY EQUIPMENT
Adjust the unit light. Pause and self-check the clinician, patient, and equipment position
4 MY NONDOMINANT HAND
Place the fingertips of my non-dominant hand as shown in the illustration for the clock position
5 MY DOMINANT HAND
Place the fingertips of my dominant hand as shown in the illustration for the clock position
36

40. Some Improper Postures That Dentists Take:
 Working with the neck in flexion and tilted
to one side.
 Shoulders elevated.
 Side bending to left or right.
 Excessive twisting

46. ERGONOMICS FOR DENTISTS

57. A risk factor is not always a causative factor
Amount
Duration
Level of
exposure

63. ERGONOMICALLY FAVOURABLE POSITION

65. HAND INSTRUMENTS

81. THE "FIVE TIMES" HAND AND WRIST EXERCISES
Exercise 1
Make a tight fist, hold for five second and
release, relaxing hand and fingers.
Repeat five times

82. Exercise 2
Stretch your fingers wide.
Hold for 5 seconds, and then return hand to relaxed position.
Repeat five times.

83. Exercise 3
Hold arms out in front at shoulder height ,with
palms of hands facing downwards.
Rotate your hands 5 times clockwise and 5
times anti-clockwise.

84. Exercise 4
Hold your arms out to the side of you at 90 degrees to your trunk at shoulder height
Flap your hands up and down 5 times from the wrist.
Tips
Support arms when working
Remember to support forearms as this
produces a reduction in muscle
contraction in erector spinae and
trapezius muscles and helps to prevent
fatigue.
Do this by resting arms on sides of dental
chair

85. 2) TWO NECK EXERCISES
Neck and backstretches for use whilst working in a dental surgery chair or at a
computer or writing at a desk.
 Horizontal Turns
 Chin Tucks
Exercise 1) Horizontal turns
Keeping the chin up and in the horizontal plane turn head from side to side, 90 degrees
in each direction, keeping cervical spine straight.
Make smooth gliding movements.

86. Exercise 2) Chin tucks
Keeping the head level ( keep looking straight ahead )
Tuck in chin and then lengthen back of neck

87. 3) TWO STRETCHES TO TRY WHILE SITTING IN THE DENTAL CHAIR
Shoulder Lifts
Backward Arching
Exercise 1) Shoulder lifts
Raise shoulders towards your ears and then lower and
relax shoulders.
Breath in deeply whilst raising shoulders, breathe out on
relaxing shoulders.

88. Exercise 2) Backward Arching
Stretch backward over the edge of the backrest.
Remember to stretch the neck at the same time
Hold arms at 45 degrees to the trunk; stretch arms at the
same time.
Hold three seconds and return to the vertical position and
repeat.

89. 4) END OF CLINICAL SESSION STRETCHES FOR THE LOWER BACK
1) Pelvic rocking
2) At the end of a working session
3) Whilst walking out through the door
Exercise 1) Pelvic rocking
Rock pelvis forward and backward whilst sitting in the
chair. Practice initially sitting on your hands to feel the
upward and then forward and downward movements of
your hipbones. Once you have mastered this movement
place your hands on your hips

90. Exercise 2) At the end of a working session
Stand up with feet slightly apart.
Place hands on either side of the lower spine, gently
push hips forward, and then lean the body backwards
from the hips.
Return to vertical position, relax and repeat five times.

91. Exercise 3)whilst walking out through the door
Stand in the doorway.
Feet slightly apart.
Raise arms upwards and place hands on each side
of the lintel of the doorway.
Supporting your weight with your hands and arms,
press body forward from the pelvis. Relax and
repeat.