CP1 W1 Mod 1, 2, 8, 9, 3

What are the 4 ergonomic hazards for dental hygienists?

1. Awkward Positions

2. Static postures

3. Force/forceful exertion

4. Repetitive Movements

Injury to the musculoskeletal system can cause…

• Loss of strength

• Impairment of motor control

• Tingling

• Numbness

• Pain

Definition and Cause(s): Thoracic Outlet Syndrome

Compression of the brachial nerve plexus causing painful disorders of the fingers, hand and/or wrist

Cause:

• Tilting the head forward

• Hunching the shoulders forward

• Continuously reaching overhead

Definition and Cause(s): Rotator Cuff Tendinitis

Inflammation of the muscle tendons in the shoulder region causing pain in the shoulder

Cause:

• Holding elbow above waist level

• Holding upper arm away from the body

Definition and Cause(s): Pronator Syndrome

Compression of the median nerve by the pronator muscle causing pain in the wrist and hand.

Cause:

• Holding the lower arm away from the torso of the body

Definition and Cause(s): Extensor Wad Strain

Injury to the extensor muscle causing pain to the fingers

Cause:

• Extending the fingers independently of each other

Definition and Cause(s): Carpal Tunnel Syndrome

Compression of the median nerve in the wrist causing pain in the wrist and hand.

Cause:

• Repeatedly bending the hand up, down, or from side to side at the wrist

• Pinch-gripping an instrument without resting the muscles

Definition and Cause(s): Ulnar Nerve Entrapament

Compression of the ulnar nerve at the wrist causing pain to the lower arm and wrist.

Cause:

• Repeatedly bending the hand up, down, or from side to side at thwr ist

• Holding the little finger a full span away from the hand

Definition and Cause(s): Tenosynovitis

Inflammation of the tendons on the side of the wrist and the base of the thumb causing pain

Cause:

• Hand twisting

• Forceful gripping

• Bending the hand back or to the side

Definition and Cause(s): Tendinitis

Inflammation of the tendons of the wrist causing pain.

Cause:

• Repeatedly extending the hand up or down at the wrist

What is the ideal neutral neck position? What should we avoid to maintian it?

Head tilt of 0-15 deg
Avoid:

• head tilting too far forward or to one side

What is the ideal neutral back position? What should we avoid?

Leaning foward slightly from the waist or hips of 0-20 deg

Avoid:

• Curved back

What is the ideal neutral upper arm position? What should we avoid?

Elbows at waist level held slightly away from the body up to 20deg

Avoid:

• Elbows held above waist level

What should you avoid for neutral hand position?

Avoid palms parallel to the floor

What are the 3 healthy curves of the spine?

1. Cervical (inward curve)

2. Lumbar (inward curve)

3. Thoracic (slight outward curve)

What is the light position for the maxillary/mandibular arch?

Max = position will vary from over oral cavity or over the neck

Mand = position light directly over the oral cavity

*always position light arms length away

What is the 4 steps to establish Easy Neutral Position?

1. Sit alongside pt

2. Arm at your side

3. Arm crossed across your waist

4. Lower pt chair until pt’s mouth is below the point of your elbow

What is coaxial illumination?

Spectacle mounted light that is parallel to the clinicians line of vision

What are the 4 things for the ideal handle design of DH tools?

1. Large handle diameter

2. Light weight (hollow handle)

3. Handle tapers near shank

4. Raised texturing on the handle

Why is instrument balance important?

Ensures that finger pressure applied against handle is transferred to the working end

What is the difference between simple shank and complex shank?

Simple (aka straight shank):

• Bent in one plane

• Primarily used on anterior teeth

Complex (aka angled or curved shank):

• Bent in 2 or more plantes

• Primarily used on posterior teeth

Shank diameter determines what?

Strength that can be applied to remove heavy, medium, or small deposits.

Thicker shanks are more ridgid and used to remove heavy deposits

What is the advantage of flexible shanks?

Flexible shanks can transmit vibrations from the working end as it runs over irregular tooth surfaces. It is important for detecting deposits beneath the gingival margin

Draw an instrument shank and label the working end, terminal shank, and functional shank

working end = tip

terminal shank/lower shank= portion nearest to the working end

functional shank = portion of the shank that allows working end to be adapted to the tooth surface

What shank length would be best suited for SUPRAgingival?

SHORT functional shank length

What shank length is best suited for SUBgingival use?

LONG functional shank length

Instruments with extended lower shanks are used for?

Reaching the middle and apical-third of root surface.

What is the difference between a paired and un-paired working end?

Unpaired = dissimilar working ends

Paired = mirror image working ends

What are the 5 parts of the working end?

1. Face

2. Back

3. Lateral surfaces

4. Cutting edges

5. Toe or tip

The _____ is formed where face and lateral surfaces on instruments meet. (hint: working end)

Cutting edge

What is the signifcance of the cross-section of a working end?

It determines whether the tool can be used subgingivally.

Semi-circle = ok

Triangle = not ok

What are the 2 classifications of Periodontal Instruments?

1. Assessment Instruments

2. Calculus removal instruments (Debridement)

Use: Periodontal Probe

Evaluate health of periodontal tissue

Use: Explorer

Locate calculus deposits, tooth irregularities and defective restoration margins

Use: Sickle scalers

Used to remove SUPRAgingival calculus

*pointed tip, triangular xs

Use: Curets

Used to remove calculus both supra/sub gingivally

*semi-circular xs, round toe

Use: Periodontal file

Used to crush large calculus deposits

How should you be positioned for Standing work?

1. Shoulders relaxed

2. Elbow of dominant hand at waist level

3. Torso in neutral position

Why is proper glove fit important?

1. To avoid muscle strain (too tight = unnecessary tension)

2. Tactile sensitivity is enhanced with THIN gloves and good fit at the finger tip area

3. Nitrile glove provide more grip friction than latex = better grasp

What does proper glove fit look like ?

• Loose fitting across palm and wrist area

• Index finger of other hand should be able to slip under wrist area of gloved hand.

• Gloves should not be overly tight

Define Proprioception

A persons ability to sense their body and its position and movement through 3D space. (ex. you know where to touch your nose even though your eyes are closed)