Dental Radiology Exam 2-Analysis of errors and artifacts

What is this projection of?

Premolars projection

Projection (technique) errors include:

Apical areas "cut off"

Horizontal Angulation

Vertical Angulation

Partial images -"Cone Cuts"

Plate Bending

Phalangioma

Double Exposure

Movement

Exposed Backwards

Plate Placed Incorrectly

Appliances & glasses

Thyroid collar

Exposure, scanning and handling errors include:

Scanning Errors

Underexposed

Overexposed

Moisture Contamination

Scratched or damaged plate

List the three basic film quality evaluation criteria and the factors that control them.

1. All rads must have acceptable image characteristics of detail, definition, density and contrast

2. All crowns and roots, including apices, are fully depicted together with inter proximal alveolar crests, tooth contact areas, and surrounding apical bone regions

3. Images of all teeth and other structures are shown in proper relative size and contour with minimal distortion and without overlapping images, where anatomically possible

Bitewing radiograph evaluation criteria

1. No overlapping of interproximal contacts

2. Crowns centered

3. Crest of the alveolar bone should be visible

4. The occlusal plane should be horizontal

5. Buccal and lingual cusps shouldn't be separated excessively

State the three groups wherein the majority of errors are produced

1. Technique errors

2. Exposure and processing errors

3. Film-handling errors

Absence of apical structures

Appearance-Apices "cut off"

Cause-plate too close to the teeth

Correction-Make certain the incisal-occlusal surfaces of the teeth touch the bite-block. Position plate in the middle of the oral cavity when working in the maxillary arch

The X-ray beam must travel ____ the embrasures of the teeth.

Through

Apices "cut off"-maxillary teeth

Usually caused by the plate being placed too close to the teeth in the paralleling technique

Technique for taking images on patients with shallow palates

Increase vertical angulation slightly

Use bisecting angle technique

Apices "cut off"-mandibular teeth

Usually caused by the plate not being pushed into the lingual vestibule, or positioned on top of the tongue

Dropped plate corner

Appearance-Occlusal plane appears tipped/tilted

Cause-Plate was not parallel to the incisal-occlusal surfaces of teeth

Correction-Make sure incisal-occlusal surfaces of teeth touch the bite-block (cotton roll under biteblock, not on the side of teeth to be radiographed)

Incorrect horizontal angulation

Appearance-Overlapped contacts or roots

Cause-Plane of plate not parallel to long axis of teeth. Central ray was not directed through inter proximal spaces.

Correction-Position plate parallel to the teeth. Direct x-ray beam through interproximal regions

Incorrect vertical angulation-foreshortened images

Appearance-Short teeth with blunted roots

Cause-Excessive vertical angulation

Correction-Align BID with Rinn instrument bar

Incorrect vertical angulation-elongated images

Appearance-Long, distorted teeth

Cause-Insufficient vertical angulation

Correction-Use adequate vertical angulation

BID alignment problems cone-cuts

Appearance-A clear area appears on the plate

Cause-BID was not properly aligned with the periapical plate holder or, incorrect setting of the RINN instrument

Correction-Make certain the x-ray beam is centered over the plate

Rotation error

Can cause cone cut

Improper alignment of the BID*

Overlapping inter proximal contact ares*

This is a Rotation error, because just by rotating the BID toward the center of the plate, it can be avoided

Translation error

A cone-cut can also result from a Translation error, when the BID is directed to the plate with the correct angulation*, but too far mesially or distally.

Therefore, radiation failed to hit the X ray plate in its entirety.

*Open inter proximal contacts

Film/plate bending

Appearance-Images appear stretched and distorted

Cause-The plate was bent excessively

Correction-Check plate placement before exposure

Film/plate creasing

Appearance-A thin radiolucent line appears on the plate

Cause-The plate was creased

Correction-Do not bend or crease the plate

Phalangioma

Appearance-The patient's finger appears on the plate

Cause-The patient's finger was positioned in front of the plate

Correction-Make certain the patient's finger is placed behind the plate (if necessary)

Double exposure

Appearance-A double image appears on the plate

Cause-The plate was exposed twice in the patient's mouth

Correction-Always separate exposed and unexposed plates

Movement

Appearance-Blurred images appear on the plate

Cause-The patient moved during exposure of the plate

Correction-Instruct the patient to remain still while the plate is being exposed

Reversed plate (exposed backwards)

Appearance-Light images with a lighter circle appear on the radiograph

Cause-The plate was placed backwards in the mouth and then exposed

Correction-Always place the front side of the plate adjacent to the teeth

How do you prevent positioning errors?

Avoid faulty plate placement -center the plate over the area to be radiographed

Distal surface of the canine on radiographs

Not routinely seen on the canine projection due to overlap of the lingual cusp of the first premolar

Underexposed or overexposed rads are affected by

kVp, mAs, source to plate distance

Backwards plate is caused by:

•Improper placement of wrapped plate in the mouth

•Improper wrapping of the plate in dispensary

It is your responsibility to verify that the plate has been correctly wrapped

X rays must hit the plate on the blue side

You should avoid taking radiographs that lack

Diagnostic quality

Retakes cause

Expose patients to unnecessary radiation

Waste time

Faulty radiographs interfere with interpretation

Wrong insertion of the plate in the scanner window

Scanning error caused by

Remove appliances

What is this error?

Remove glasses

What is his error?

Thyroid collar

What is this error?

Underexposed

What is this error?

Overexposed

What is this error?

Moisture contamination

What is this error?

Moisture contamination

What is this error?

Damaged plate

What is this error?

Damaged plate

What is this error?

Wrong film direction, backwards, positive angulation, wrong film size, no open contacts

What is this error?

Double exposed, damage to plate

What is this error?

Moisture contamination

What is this error?

Elongated, vertical angulation, film holder (metal bar)

What is this error?

Damage, elongation, can't see apices

What is this error?

Water damage

What is this error?

Artifact

What is this error?

Rinn instrument bar, vertical angulation

What is this error?

Damage

What is this error?

Moisture contamination

What is this error?

Backwards film

What is this error?

Patient is not biting down

What is this error?

Positive vertical angulation

What is this error?

Positive vertical angulation

What is this error?

Lip piercing

What is this error?

Film fall, drop corner

What is this error?

Double image

What is this error?

Horizontal angulation, no apices show, vertical angulation

What is this error?

Cone cut, rotation

What is this error?