Angulation
The alignment of the central x-ray beam in the horizontal and vertical planes
Horizontal angulation
The positioning of the PID in a horizontal, or side-to-side, plane
Bitewing tab
A heavy paperboard tab or loop fitted around an intraoral receptor and used to stabilize the receptor during exposure
Open contact
On a dental image, open contacts appear as a thin radiolucent line between adjacent tooth surfaces
Contact areas
The area where adjacent tooth surfaces contact each other
Overlapped contacts
On a dental image, the area where the contact area of one tooth is superimposed over the contact area of an adjacent tooth
Cone-cut
A clear, unexposed area on a dental image that occurs when the PID is not aligned and the x-ray beam is not centered over the receptor
Vertical angulation
The positioning of the PID in a vertical, or up and down, plane
Edentulous
Without teeth; an area where teeth are no longer present
Vertical bitewing
The bitewing receptor is placed in the mouth with the long portion of the receptor in a vertical direction
Elongation
A term used in imaging to describe the image of a tooth that appears longer than the actual tooth; the result of flat or insufficient vertical angulation
Foreshortening
A term describing the image of a tooth that appears shorter than the actual tooth; the result of steep or excessive vertical angulation
Positive angulation
The positioning of the PID above the occlusal plane that directs the central ray downward
Negative angulation
The positioning of the PID below the occlusal plane that directs the central ray upward
Receptor
Something that responds to a stimulus; a recording medium (examples: x-ray films, PSP plates or digital censors)
Bitewing technique
An intraoral imaging technique in which the interproximal surfaces of teeth are examined
Maxillary torus
A nodular mass of bone along the midline of the hard palate
Interproximal
Between two adjacent surfaces
Mandibular tori
A bony growth seen along the lingual aspect of the mandible
Crestal bone
Coronal portion of alveolar bone found between teeth; also known as the alveolar crest
Alveolar bone
Bone of the maxilla and mandible that supports and encases the roots of teeth; appears radiopaque
Phalangioma
Refers to the distal phalanx of the finger seen in the image
Herringbone pattern
The pattern seen on a dental radiograph when the film has been placed in the mouth backward and exposed (also known as tire-track pattern)
Overexposure
Results from excessive exposure time, kilovoltage, milliamperage, or a combination of these factors
Image appears dark or high in density
Too much exposure time is the most common cause overexposure
Underexposure
Results from too little exposure time, kilovoltage, milliamperage, or a combination of these factors
Image appears light or low in density
Too little exposure time is the most common cause of underexposure
Recognize the purpose of posterior, anterior and vertical bitewing radiographs.
� Posterior - mainly used to detect interproximal caries
� Anterior - used to view the entire tooth, including the apex and surrounding areas
� Vertical - mainly used to detect bone loss
Compare the rationales for using size 0, 1, 2 or 3 bitewing films.
� 0 - used for examination of posterior teeth in very small children (always horizontal)
� 1 - used for anterior images on adults or bitewings on children
� 2 - used for bitewings on adults
� 3 - long narrow film, sometimes used for bitewings on adults, b
What is the technique for placing a bitewing film?
1. Make sure your patient is sitting up straight with their occlusal plane parallel to the floor.
2. Receptor should be placed parallel to the teeth, making sure to cover both maxillary and mandibular evenly.
3. Patient should bite down slowly on the tab
Compare various methods for holding bitewing films in a client's mouth.
� Beam alignment device (XCP)
� Bitewing tab
Utilize correct vertical and horizontal PID angulations for bitewing exposures.
� Horizontal PID angulations: Central ray of x-ray beam directed through the contact area between teeth; +10 degrees
� Vertical PID angulations: +10 degrees
List the five basic rules for exposing bitewing radiographs.
1. Receptor placement. The bitewing receptor must be positioned to cover the prescribed area of teeth to be examined.
2. Receptor position. The bitewing receptor must be positioned parallel to the crowns of both maxillary and mandibular teeth and must be
Discuss the causes of and corrections for overlapping.
Cause: the central ray was not directed through the interproximal spaces
Correction: direct the central ray through the proximal contacts of the teeth. The use of XCP and BAI alignment devices minimize errors in horizontal angulation.
Discuss the causes of and corrections for cone-cutting WITH a beam alignment device.
Cause: the PID was not properly aligned with the beam alignment device, and the x-ray beam did not expose the entire receptor.
Correction: position the PID carefully. Make certain that the PID and the aiming ring device are flush and aligned.
Discuss the causes of and corrections for cone-cutting WITHOUT a beam alignment device.
Cause: the PID was not directed at the center of the receptor, and the x-ray beam did not expose the entire receptor.
Correction: position the PID carefully. Make certain the x-ray beam is centered over the receptor and that the entire receptor is covered
Discuss the causes of and corrections for a sloped occlusal plane.
Cause: the edge of the receptor was not placed parallel to the occlusal surfaces of the teeth. A corner of the receptor may slip or drop if the patient isn't firmly closed on the tab or bite-block.
Correction: make certain that the edge of the receptor is
Discuss the causes of and corrections for foreshortened images vertical angulation errors.
Cause: the vertical angulation was excessive (too steep). Makes the teeth look shorter than they actually are.
Correction: do not use a steep vertical angulation with the bisecting technique. The use of a beam alignment device minimizes errors in vertical
Discuss the causes of and corrections for elongated images vertical angulation errors.
Causes: the vertical angulation was insufficient (too flat). Makes the teeth look longer than they actually are.
Correction: do not use a flat vertical angulation with the bisecting technique. The use of a beam alignment device minimizes errors in vertica
Discuss the causes of and corrections for incorrect pre-molar bitewing receptor errors.
Cause: the bitewing receptor was placed too far back in the mouth; the anterior edge of the receptor was not placed to include the mandibular canine.
Correction: make certain the anterior edge of the bitewing receptor is positioned at the midline of the m
Discuss the causes of and corrections for incorrect molar bitewing receptor errors.
Cause: the bitewing receptor was placed too far forward in the mouth; the anterior edge of the receptor was not placed to include the mandibular second premolar.
Correction: make certain the anterior edge of the bitewing receptor is positioned at the midl
Explain modifications in technique for patients with mandibular and/or maxillary tori, and the edentulous areas.
Mandibular tori - The receptor must be placed between the tongue and the tori (not on the tori) and then exposed.
Large tori - the receptor gets pushed away from the teeth causing the patient to bite on the very end of the tab making it difficult to achie
Explain how incorrect receptor placement effects bitewing radiographs.
A non-diagnostic periapical image may result from:
� Incorrect placement of premolar bitewings - as a result the distal of the canines are not visible on the image
� Incorrect placement of molar bitewings - the third molar regions are not visible on the i
Explain how incorrect receptor angulation effects bitewing radiographs.
� Incorrect horizontal angulation - causes overlapping on the images
� Incorrect vertical angulation - causes the images to appear distorted
Explain how incorrect PID placement effects bitewing radiographs.
When the PID is misaligned and the x-ray beam is not centered over the receptor, a partial image known as a cone-cut, results.
� With a round PID it appears as a curved clear (unexposed) area on the image.
� With a rectangle PID it is seen as a linear cle
Explain how bending effects bitewing radiographs.
The image appears stretched and distorted
Explain how creasing effects bitewing radiographs.
A thin radiolucent line is seen on the image
Discuss the results of misuse of the number scale.
Could cause elongation or foreshortening
Mr. Brown comes into the clinic and you determine that he needs a series of bitewing images. After the exam, you notice that he has a large maxillary torus and bilateral mandibular tori. What will you do to alter the technique? What other tactics would be
Position the receptor between the tori and the tongue. Use an XCP kit instead of a tab because tabs don't fit very well around tori and aren't very stable.