ergonomic applications to dental practice

INSTITUTE FOR ENVIRONMENT, SAFETY AND OCCUPATIONAL HEALTH RISK ANALYSIS

Ergonomic Applications to Ergonomic Applications to Dental PracticeDental Practice

Ir. Sudiyono Kromodihardjo MSc. PhD


OverviewOverview

What is Ergonomics? What are the Consequences of Poor

Ergonomics? What Policies/Standards Address

Ergonomics? How can Ergonomic Principles Be

Applied to Dental Practice?


JobCharacteristics

HumanCapabilities

What is Ergonomics?What is Ergonomics?

ERGONOMICS is a way to work smarter--not harder by designing tools, equipment, work stations and tasks to fit the job to the worker--NOT the worker to the job


Ergonomics

• Relationship between humans, the tasks they perform, and the environment in which tasks are performed.

• Equipment-centered Ergonomics: Human Adaptation to Requirements of Equipment.

• Human-centered Ergonomics: Equipment is adapted to Requirements of Humans.


Humans Do DentistryNot Equipment

Priority: Human Factors and the Way We Work


Ergonomic Design GoalsErgonomic Design Goals Improve job process by eliminating unnecessary

tasks, steps & effort Reduce potential for overexertion injury Minimize mental / physical fatigue potential Leverage workers’ skills / knowledge of their

jobs to re-design work to increase their satisfaction, comfort, morale and fulfillment


Consequences of Poor DesignConsequences of Poor Design Discomfort Chronic Pain Accidents Injuries

Fatigue Increased Errors Work-Related Musculoskeletal

Disorders (WMSDs) Low back pain Tendonitis Epicondylitis Bursitis Carpal tunnel syndrome


U.S. Navy Ergo-Injuries

Source: OSHSYS RAW DATA FY 89 to FY 97

Non Ergonomic Related Cases Declined

Compensation Cases FY89 - FY97

-

4,000

8,000

12,000

16,000

20,000

24,000

FY89 FY90 FY91 FY92 FY93 FY94 FY95 FY96 FY97

Num

ber

of C

ases

Ergonomic Related Cases Non Ergonomic Related Cases

Ergonomic - Carpal Tunnel Syndrome, Chrondromalacia, Back Strain, Multiple Strain


WMSDs in DentistryWMSDs in Dentistry

?

?

??

?

?

??

??

? ?

? ?


75%Studies have shown

of dentists & hygienists suffer from musculoskeletal disordersthat affect occupational health

& the quality of practice life


WMSDs in DentistryWMSDs in DentistryReasons for Early Retirement Among DentistsReasons for Early Retirement Among Dentists

Musculoskeletal Disorders (29.5%) Cardiovascular Disease (21.2%) Neurotic Symptoms (16.5%) Tumors (7.6%) Diseases of the Nervous System (6.1%)

Source: Burke et al., 1997


WMSD Symptoms Among WMSD Symptoms Among DentistsDentists

0%10%20%30%40%50%60%70%80%

Body Part

% R

ep

ort

ing

Males

Females

Source: Finsen et al., 1998


WMSD Symptoms Among WMSD Symptoms Among Dental HygienistsDental Hygienists

01020304050607080

*DiagnosedCTS

*Hand-wristpain

*Shoulderpain

*Neck pain Low Backpain

% R

epor

ting

Dental Hygienists Dental Assistants

Source: Liss et al., 1995* indicates difference is significant


ImagineDental practice

without the compromise of your health, the quality of care you provide,

& the quality of practice life you deserve.


ImagineDental practice

free from back, neck & shoulder pain that afflict so many clinicians every workday.


ImagineReaching your peak performance potential

while you work comfortably,with energy & enthusiasm left over

at the end of the day.


What Factors Contribute to WMSDs?What Factors Contribute to WMSDs?

Repetitive motions (e.g., scaling, polishing)



Static neck, back, and shoulder postures



Grasping small instruments for prolonged periods



Prolonged use of vibrating hand tools


Applying Ergonomics Principles Applying Ergonomics Principles to Dental Workto Dental Work

Tools/InstrumentsTools/Instruments

WorkstationsWorkstations

Work PracticesWork Practices


Ergonomics in DentistryErgonomics in DentistryTool/Instrument DesignTool/Instrument Design

Considerations: Overall shape/size Handle shape/size Weight Balance Maneuverability Ease of operation Ease of maintenance

Goals: Reduce force exertion;Maintain hand/wrist in neutral posture


Ergonomics in DentistryErgonomics in DentistryHand InstrumentsHand Instruments

Look for: Hollow or resin

handles Round, knurled or

compressible handles Carbon steel

construction (for instruments with sharp edges)


Ergonomics in DentistryErgonomics in DentistryAutomatic HandpiecesAutomatic Handpieces

Look for: Lightweight, balanced models (cordless preferred) Sufficient power Built-in light sources Angled vs. straight-shank Pliable, lightweight hoses Swivel mechanisms Easy activation Easy maintenance


Ergonomics in DentistryErgonomics in DentistrySyringes and DispensersSyringes and Dispensers

Look for: Adequate lumen

size Ease in cleaning Knurled handles

(no finger cut-outs) Easy activation and

placement


Ergonomics in DentistryErgonomics in DentistryMagnification SystemsMagnification Systems

Consider: Working distance Depth of field Declination angle Convergence angle Magnification factor Lighting needs

Goal: Improve neck posture; Provide clearer vision


Ergonomics in DentistryErgonomics in DentistryWorkstation LayoutWorkstation Layout

Ensure: Instruments, materials, medications, etc. are accessible while seated Hoses are positioned away from the body Set-up can be adapted for different operators


Ergonomics in Dentistry Ergonomics in Dentistry Operator ChairOperator Chair

Look for: Stability (5 legged base w/casters) Lumbar support Hands-free seat height adjustment Adjustable foot rests Adjustable, wrap-around body support Seamless upholstery

Goal: Promote mobility and patient access;accommodate different body sizes


Ergonomics in Dentistry Ergonomics in Dentistry Patient ChairPatient Chair

Look for: Stability Pivoting or drop-down arm rests (for patient ingress/egress) Supplemental wrist/forearm support (for operator) Articulating head rests Hands-free operation

Goal: Promote patient comfort; maximize patient access

INSTITUTE FOR ENVIRONMENT, SAFETY AND OCCUPATIONAL HEALTH RISK ANALYSISErgonomics in Dentistry Ergonomics in Dentistry Posture/PositioningPosture/Positioning

Goal: Avoid static and/or awkward postures

Potential Strategies: Position patient so that operator’s elbows are

elevated no more than 30 degrees.

Adjust patient chair when accessing different quadrants

Alternate between standing and sitting


Ergonomics in Dentistry Ergonomics in Dentistry Work PracticesWork Practices

Goal: Maintain neutral posture, reduce force requirements

Potential Strategies: Ensure tools are sharpened, well-maintained Use automatic handpieces instead of manual

instruments where possible Use full-arm strokes rather than wrist strokes


Ergonomics in Dentistry Ergonomics in Dentistry SchedulingScheduling

Potential Strategies: Increase treatment time for more difficult

patients Alternate heavy and light calculus patients

within a flexible scheduling system Vary procedures within the same appointment Shorten patient’s recall interval

Goal: Provide sufficient recovery time for staff to avoid chronic muscular fatigue


Ergonomics in Dentistry Ergonomics in Dentistry Prosthetics LabsProsthetics Labs

Naval Station Rota Spain Clinic Case Study: Lab techs mentioned chronic back, shoulder & neck discomfort / pain during periodic Industrial Hygiene survey from working at non-adjustable bench in obviously stressful static postures -- with no forearm support nor bench edge padding



Naval Station Rota Spain Clinic Case Study -- Post intervention improvements offered by Kavo ergonomic lab benches : Lab techs affirm GREATLY increased comfort / decrease in back, shoulder & neck discomfort / pain.

KAVO dental prosthesis lab benches offer ample forearm supports and workpiece support centering prosthesis directly below technician which optimizes spinal / neck / head vertical alignment



Naval Station Rota Spain Clinic Case Study: Lab technicians now work in optimized ergonomic posture. In addition to forearm supports and central workpiece support (locally-ventilated for air contaminant removal !) , the table also has much improved overhead lighting, a magnifying lens and a drill speed control operated by the tech’s right knee


ERGONOMICS SUMMARY

• Good ergonomic design of tools, processes and furniture DOES improve personnel comfort, health, morale, productivity and readiness.

• Individual effort as part of a workshop team is the greatest means of identifying / improving workplace ergonomic issues.

• It’s critical to seek prompt medical aid for symptoms of ergonomic stress / CTDs


• Self-derivation of a natural and comfortable posture for comprehensive patient care

• Positioning of patients to maintain posture and optimize visual and physical control of intra-oral procedures

• Operatory light positioning to provide adequate illumination from one location with minimal adjustment

• Correctly positioning the dental assistant for efficiency and effectiveness in support of patient care

• Positioning all equipment and instrument items in the operatory proximal to the practitioner and the assistant to reduce unnecessary exertion and fatigue

Learn to Prevent or Reduce Occupational Ailments

By the following…


• Using instrument grips that ensure stabilization and control of performance

• Maximizing the potential of the mirror when direct vision compromises posture

• Selection of magnifying loupes that do not induce musculoskeletal pain

• Selection of equipment designed to optimize a comfortable working environment

• Using 5 movements for control of optimal posture in a 10-step decision process that assures performance without compromise of self, patient, or task

Learn to Prevent or Reduce Occupational Ailments continued

ergonomic applications to dental practice

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