• INTRODUCTION

• DENTAL CHAIR AND PATIENT POSTIONS

• OPERATOR POSITIONS

• OPERATING STOOLS

• GENERAL CONSIDERATIONS

• HISTORY

• 1790 was a big year for dentistry, as this was also the year the first specialized dental chair was invented.

• It was made from a wooden Windsor Chair with a headrest attached.

Until a few decades ago , most

dental procedures were performed

with patient seated upright and

dentist standing next to patient

,this prolonged period caused

musculoskeletal disorders for

dentists.

The role of Ergonomics in dentistry

can avoid these occupational

hazards .

INTRODUCTION

Proper positioning of the patient and

operator, illumination and retraction for

optimal visibility are fundamental pre

requisites to proper dental treatment

Modern dental chairs are

designed to provide to

provide total body support in

any chair position.

The patient head is

supported by a head rest

cushion which elevates the

chin and thus reducing strain

on neck

Dental chair and patient position

For operative dental procedures , the patient may be seated in one of the following positions:

1. Almost supine

2. Reclined 45 degrees

In this position the chair is tilted so that the

patient is almost in a lying down posture

The patient’s head ,knees and feet are

approximately at the same level

The head should not be positioned below the

feet level as blood pressure increases

gradually

1. ALMOST SUPINE POSITION:

In this position the chair is reclined at 45 degrees

so that when the patient is seated, the mandibular

occlusal surfaces are almost at 45 degrees to the

floor

Once the treatment is over the chair is brought

back to upright position so that the patient can

leave the chair easily

2. RECLINED 45 DEGREE POSITION:

Forearm parallel to the floor

Thighs parallel to the floor

Hip angle of 90 degrees

Seat height positioned low enough

so that the heels of your feet touch

the floor

POSITONS OF THE OPERATOR

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

The main thing which we have to

consider are the Operator Position

Correct positioning of the operator is

very important to operator to have

good visibility and accessibility to

oral cavity.

Operator position:

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

FOR A RIGHT HANDED OPERATOR:

RIGHT FRONT POSITION:

This is convenient for examination and working on

the mandibular anterior teeth ,mandibular right

posterior teeth and maxillary anterior teeth

RIGHT POSITION :

The operator is directly to the right of the patients.

The position is convenient for operating on the facial surface of the maxillary & mandibular right posterior teeth & occlusal surface on mandibular right posterior teeth .

Pen grasp is used for this position.

RIGHT REAR POSITION:

From this position the dentist can have

good access to most areas of the mouth

using direct or indirect vision. The

dentist sits to the right and slightly

behind the patient and the left arm is

positioned around the patient’s head

In this position working on the lingual

surfaces of maxillary anterior teeth is

most convenient.

DIRECT REAR POSITION :

Here the dentist sits directly

behind the patient and looks down

over the patient’s head

This position is mainly used only

for working on lingual surfaces of

mandibular anterior teeth , lingual

surfaces of maxillary anterior teeth.

The design of the stool is important.

It should be sturdy and well balanced to

prevent tipping/gliding away from dental

chair

It should be well padded with cushion

edges and should be adjusted up and down

A well designed stool increases operator

comfort and reduces fatigue

Operator stools:

The operator should be well illuminated

either by natural or artificial light.

If the light is kept too close , it impairs the

physical movement of operator & also

increases patient discomfort due to heat

production.

If the light is kept far away, it reduces the

illumination.

As a rule for mandibular arch the light is

kept in a higher position & for maxillary

arch it is kept in a lower position.

LIGHTING;

The patient’s head should be rotated according to need of operator

without hesitation

During working maxillary occlusal surfaces should be perpendicular to

the floor and for mandibular occlusal surface should be 45 degrees

The operator should maintain space between the patient as while

reading a book

There should be reduced contact with that of patient

a) The operator should never rest his hand on patient’s face

b) The chest of patient should never be used as trays to keep instruments

The left hand should be kept free to retract using the mouth mirror

general considerations:

REFERENCES:

Sturdevent’s Art & Science of operative Dentistry. Clinical Operative dentistry- Ramya Raghu & Raghu Srinivasan Internet sources

PRESENTED BY :

J MITHUN KASHYAP

VARSHA MALVADKAR

YAMUNA

DEEBA SADAF

VASUDHA

VEENA

ZAHIRA