Chapter 19: Bite-Wing Technique
Size of the Receptor
*A* Horizontal and *B* Vertical bitewing readiographs bitwing radiographs are ideal at imageing the interproximal areas of the teeth to show caries and alveolar bone crests. Note the increased coverage of the alveolar bone imaged on the vertical bitewing radiograph
Fundamentals of Bite-wing (BWX)
*Bite-wing radiographs (BWX or BW)* "bite-down" image the crowns and alveolar bone of both the maxillary and mandibular teeth on a single radiograph *Bite-wing radiographs are probably *the most frequently performed intraoral dental radiographic technique.*
Image receptor Holding Device
*Bitewing image receptor* holder with metal positioning arm and plastic external aiming ring
Posterior BWX Image receptor Size
*Comparison of size #2 and size #3 image* A. *Size #2* has a shorter horizontal dimension, taller vertical dimension B.*Size #3* has a longer horizontal dimension, shorter vertical dimension
BWX Vertical Angulation-->*improper vertical angulation:*
*Excessive Vertical Angulation* (greater than +10 degree) - Results in more maxillary teeth being imaged *Inadequate Vertical Angulation* (less than +10 degree) -Results in more mandibular teeth are imaged.
Fundamentals of Bite-wing
*Ideal for examining dental caries* on the proximal surfaces of the teeth -Where adjacent teeth contact each other in the arch -It reveals careis in the very early stages
MesioDistal Error DistoMesio Error
*MesoalDistal* = More overlapping in the distal *DIstoMesial* = More overlapping in the mesial *Fix by moving PID towards the error 10-15 degrees*
Fundamentals of Bite-wing
*To evaluate periodontal bone levels* of supporting teeth= *VBW>HBW* *Severe periodontal bone loss reveal better in vertical bite-wing (VBW) *Vertical and horizontal molar bitewings *must reveal the terminal distal portion of the teeth*
Image Receptor Holding Device
*Two Stick-on bitetabs* lengthen the holder for use in the anterior region
Posterior BW Image receptor Size
- #0- Child with primary dentition- 2HBW - #1-Child with primary or mixed-2HBW - #2- Child with mixed dentition-2HBW - #2-Adolescent with permanent- 2-4 HBW - #2-Adult-4HBW *#2-Adult with periodontal disease - 4 VBW* *#3- Adolescent - 2 HBW* - #3- Adult - 2 HBW
Size of Image receptor = Anterior BWX Image Receptor Size
- #1 image receptor 3 or 5 vertical BW Adult for caries or periodontal diseases - #2 Image receptor 3 or 4 vertical BW
Size 1 Receptor
- 3 or 5 vertical BW -Adult for caries or periodontal disease
Describe the 2 ways to stabilize the receptor in the bite-wing technique
Beam alignment device or a bite wing tab
Interproximal
Between 2 adjacent surfaces
Film exposed to light appears
Black
Alveolar bone
Bone that supports and encases the roots of the teeth
Mandibular tori
Bony growths along the lingual aspect of the mandible
BWX Prescription
1. Part of a series= 2-8 BWX 2. In conjunction with a full mouth series of periapical radiograph= 4 BW 3. With a panoramic radiograph 4. Often part of recare appointments.
5 Basic rules to follow when using the bite-wing technique
1. Receptor placement 2. Receptor position 3. Vertical angulation 4. Horizontal angulation 5. Receptor exposure
Describe why a +10 degree vertical angulation is used with the bite-wing technique and a bite tab.
To compensate for the slight bend of the upper portion of the receptor and the slight tilt of maxillary teeth
Explain the modifications in the bite-wing technique that are used for patients with edentulous spaces or bony growths
-A cotton roll must be placed in the area of missing tooth to support the bitewing tab or film holder. Failure to support the bitewing with an edentulous patient can result in a tipped occlusal plane on the radiograph -Receptor must be placed between the tori and the tongue. With large tori the receptor is pushed away from the teeth
Molar bitewing exposures
-Diagrams show the relationship of the image receptor and holder, teeth, and PID -Vertical angulation is directed perpendicular to the image receptor at approx. +10 degrees with the PID tilted downward. CR is directed at the center of the image receptor at a spot on the occlusal plane between the max and mand teeth. - Patient showing position of the image receptor holder and 12 in circular PID - Horizontal molar bitewing radiograph -Vertical molar bitewing radiograph, in the posterior region the image receptor may be positioned with the long dimension horizontal or vertical
Central Incisors bitewing exposure
-Diagrams show the relationship of the image receptor and holder, teeth, and PID -Vertical angulation is directed perpendicular to the image receptor at approximately +10 degrees with the PID tilted downwards. Central Ray is directed at the center of the image receptor at a spot on the incisal plane between the maxillary and mandibular teeth. -Patient showing position of image receptor holder and 12 in circular PID -Central incisor bitewing radiograph. In the anterior region, the image receptor is positioned with the long dimension vertical
Limitation of Bite-wing
-Do not image the entire tooth. Therefore will not reveal apical condition or lesions -*Early incipient caries are often concealed* by the wide buccal-lingual diameters of these teeth.
Image Receptor Holding Device
-Instruct the patient to close so that the teeth *occlude normally*. Failure to hold the tab firmly may lead to a drift lingual and distally and increase the possibility that the tongue will move the image receptor out of the correct position
Incorrect Vertical Angulation
-Results in a distorted image -If a negative vertical angulation is used, the occlusal surfaces of maxillary teeth are evident, and the apical regions of mandibular teeth are seen - A bite-wing image exposed with an excessive negative vertical angulation is non diagnostic.
BWX Vertical Angulation
-Slightly angled positively from the occlusal plane for bitewings - *+10 degrees for adults* - *+5 degrees for children*
Correct Horizontal Angulation
-The central ray is directed perpendicular to the curvature of the arch and through the contact areas of teeth -As a result the contact areas on an exposed image appear "opened" and can be examined for evidence of caries
Incorrect Horizontal Angulation
-results in overlapped or "unopened" contact areas -An image with overlapped interproximal contact areas cannot be used to examine the interproximal areas of teeth for evidence of caries.
Bite-wing Techniques
1. *BWX Horizontal Angulation* 2. *BWX Vertical Angulation*
Types of Bite-wings
1. *Horizontal Bite-wing* (HBWX or HBW 2. *Vertical Bite-wing* (VBWX or VBW)
BWX Horizontal Angulation
1. Use with bite tabs or bite loops 2. Use with image receptor holder, horizontal bitewing XCP, to accurately direct *the central ray perpendicularly to the embrasures.* 3. *The image receptor must be parallel to the 2 predetermined teeth of interest to open the contact* 4. *Mesiodistal projection* 5. *Distomesial projection* 6. The Canine will often have significant overlap of the distal contact Correction=Position the primary beam directly at the center of the canine, *then shift the PID no more than 10 degrees directed coming from the distal* (this will open up the area posterior to the image)
Guidelines for Bite-Wing Receptor Placement (Box 19-1)
1. When using film, the white side of the film always faces the tooth. The identification dot on the film has no significance in bite-wing film placement. 2. In posterior bite-wings series, receptors are placed horizontally or vertically. 3. When positioning the receptor, always center the receptor over the area to be examined (as defined in the prescribed placements) 4. When positioning the receptor, ask the patient to "slowly bite" on the bite-wing tab or on the bite-block of the beam alignment device.
Discuss the exposure sequence for a CMRS that includes both periapical and bite-wing exposures
1. expose all anterior pariapical films first. 2. follow it posterior piratical 3. finish with bite-wing exposure.( last because they are easy to tolerate)
State the basic rules of the bite-wing technique
1.receptor placed to cover the area of tooth to be examined 2.bite wing receptor positioned parallel to crowns 3.vertical angulation-beam must be directed at +10 degree 4.horizontal angulation- central ray of X-ray be must be directed though contact area b/w teeth 5. X-ray beam must be centered on the receptor
Which of the following about receptor placement is correct? a Anterior bite-wings may be placed horizontally. b Anterior bite-wings may be placed vertically. c Posterior bite-wings may be placed horizontally. d Posterior bite-wings may be placed vertically. 1) a, b, and c 2) b, c, and d 3) b and c 4) a and d
2) b, c, and d
Bite-wing technique
Also known as the interproximal technique is a method used to examine the interproximal surfaces of teeth.
Torus, tori
A bony growth in the oral cavity
Beam alignment device
A device used to position an intraoral receptor in the mouth and maintain the receptor in position during the radiographic procedure.
Bite-wing tab
A heavy paperboard tab or loop that is fitted around an intraoral receptor and is used to stabilize the receptor during the procedure.
What does the term bite-wing refer to?
A particular radiograph used to view interproximal surfaces of teeth
Angulation
A term used to describe the alignment of the central ray of the x-ray beam in both horizontal and vertical planes
Avoid molar overlap when using a holder with external aiming device
A. Note the recommended premolar bite-wing placement positions the image receptor slightly diagonal with the front edge of the image receptor farther from the lingual of the teeth than the back part B. Because the proximal surfaces of the molar teeth are in a mesiodistal relationship to the sagittal plane, it is recommended that the image receptor be positioned perpendicularly to the embrasures, resulting in a diagonal placement similar to the premolar position.
Horizontal overlap error
A. When the PID is directed obliquely from the mesial *(mesiodistal projection* of the x-ray beam), the overlapping will be more severe in the distal or posterior region of the image B. When the horizontal angulation is directed obliquely from the distal (*Distomesial projection* of the x-ray beam), the overlapping will be more severe in the mesial or anterior region of the image
Unexposed receptor appears
Clear
Crestal bone
Coronal portion of alveolar bone found between teeth; also known as the alveolar crest
An overexposed image appears
Dark
Exposure sequence
Definite order for receptor placements and exposure, must be followed.
What condition is detected by the primary use of bite-wing images?
Detection of caries, examines crestal bone levels, and examines the interproximal areas of teeth
Too little vertical angulation results in images that are
Elongated
Errors that can occur with the bisecting technique
Elongation, overlapped contacts, cone cut, phalangioma (An error on a dental radiograph that results form the patient's finger being placed in front of the film)
Too much vertical angulation results in images that are...
Foreshortened
What type of angulation is determined by the side-to-side movement of the PID?
Horizontal Angulation
When does a cone cute result
If the beam is not centered over the film
Interproximal examination
Intraoral examination used to inspect the crowns of both maxillary and mandibular teeth on a single image.
An underexposed image appears
Light
Reversed film appears
Light
Size 3 Receptor
Longer and narrower than the standard size 2 and is used only for bite-wing exposures. -One receptor is exposed on each side of the arch to examine all the premolar and molar contact areas. -Placed with the long portion of the receptor in a horizontal direction -Not recommended, overlapped contacts often results because of the difference in the curvature of the arch between the premolar and molar areas.
Opened contacts
On a dental image, opened contacts appear as thin readiolucent lines between adjacent tooth surfaces
Overlapped contacts or closed contacts
On a dental image, the area where the contact area of one tooth is superimposed over the contact area of an adjacent tooth,
Incorrect horizontal angulation results in images that are...
Overlapped
Errors that can occur with the bitewing technique
Overlapped contacts and cone cut
When the central ray of the x-ray is not directed through the contact areas of teeth, what is seen on the resulting image.
Overlapping contacts
How is the patient's head positioned before exposing a bite-wing receptor?
Patients head must be positioned such that the maxillary arch is parallel to the floor and the mid-line is perpendicular to the floor
State the basic principles of the bite-wing technique
Receptor is placed in mouth parallel to the crowns, receptor is stabilized when patient bites down, central ray is directed through contacts of teeth by angulation of +10 degrees
Vertical angulation
Refers to the positioning of the PID in a vertical, or up-and-down, plane
Horizontal angulation
Refers to the positioning of the central ray in a horizontal, or side-to-side, plane
What size receptor is recommended for use with the bite-wing technique in the pediatric patient with primary dentition?
Size 0
What size receptor is recommended for use with the bite-wing technique in the adult patient?
Size 2
What size receptor is used to include all of the posterior teeth in one bite-wing exposure?
Size 3
edentulous
Space in an area where teeth are no longer present.
Contact areas
The area of a tooth that touches an adjacent tooth; the area where adjacent tooth surfaces contact each other
Horizontal Bite-wing -HBW, HBWX
The bite-wing receptor is placed in the mouth with the long portion of the receptor in a horizontal direction
Vertical Bite-wing -VBW, VBWX
The bite-wing receptor is placed in the mouth with the long portion of the receptor in a vertical direction
BWX Vertical Angulation-->*Bitewing placement*
The bitewing image receptor placement, slightly angled to take advantage of the height of the midline of the palate when the patient occludes, is such that the coronal potion of both the maxillary and the mandibular teeth will be recorded on the image. -The close relationship between the teeth and the image receptor and the ideal angle of the x-ray beam allow bitewings to accurately image caries and alveolar bone crests
Postitive vertical angulation
The positioning of the position-indicating device (PID) above the occlusal plane that directs the central ray downward
Negative vertical angulation
The positioning of the position-indicating device (PID) below the occlusal plane that directs the central ray upward
Image receptor placement error-->*Tilted image*
The slanted occlusal plane results from a failure to place the image receptor far enough lingually to avoid being *pushed down by the palate when the patient occludes onto the bitetab*
Receptor placement
The specific area where the receptor must be positioned before exposure, is dictated by the teeth and surrounding structures that must be include on the resulting bite-wing image.
Caries
Tooth decay
Bite-wing Receptor
Type of receptor used in interproximal examination. -has a "wing", or tab, and the patient "bites" on the wing to stabilize the receptor
Size 2 Receptor
Used to examine the posterior teeth in adults may be placed horizontally or vertically. -For most bite-wing exposures this receptor is placed with the long portion of the receptor in a horizontal direction. -When a vertical posterior bite-wing exposure is indicated, this size is placed with the long portion of the receptor in a vertical direction. -Recommended in the adult patient
Size 0 Receptor
Used to examine the posterior teeth of children with primary dentitions. -This receptor is always placed with the long portion of the receptor in a horizontal (sideways) direction
What type of angulation is determined by the up-and-down movement of the position-indicating device (PID)
Vertical Angulation
Correct Vertical Angulation
When a bite-wing tab is used, a vertical angulation of +10 degrees is recommended for the bite-wing image. -The +10 degree vertical angulation is used to compensate for the slight bend of the upper portion of the receptor and the slight tilt of maxillary teeth.
Vertical Angulation
When a bite-wing tab is used, the central ray of the x-ray beam must be directed at +10 degrees
Horizontal Angulation
When a bite-wing tab is used, the central ray of the x-ray beam must be directed through the contact areas between the teeth.
Distomesial projection
When horizontal angulation is directed *obliquely from the distal, overlapping will be more severe in the anterior region* of the image
Mesiodistal projection
When horizontal angulation is directed *obliquely from the mesial, overlapping will be more severe in the posterior region* of the imgae
When does a cone-cut result?
When the PID is misaligned and the x-ray beam is not centered over the film. There should not be any portion of the receptor visible
Positive Vertical Angulation
When the PID is positioned above the occlusal plane and the central ray is directed downward.
Negative Vertical Angulation
When the PID is positioned below the occlusal plane and the central ray is directed upward.
Which of the following describes the relationship of the receptor to maxillary and mandibular teeth in the bite-wing technique? a The receptor and teeth are parallel to each other. b The receptor and teeth are at right angles to each other. c The receptor and teeth are perpendicular to each other. d The receptor and teeth intersect each other.
a The receptor and teeth are parallel to each other.
Which of the following describes the primary use of the bite-wing radiograph image? a examination of the apical areas of teeth b examination of the apical and interproximal areas of teeth c examination of the interproximal areas of teeth d examination of the pulp chambers of teeth
b examination of the apical and interproximal areas of teeth
Which of the following is the correct vertical angulation used with the bite-wing technique and the bite tab? a. −10 degrees b −20 degrees c +10 degrees d +15 degrees
c +10 degrees
Which of the following about the exposure sequence for a CMRS that includes periapical and bite-wing exposures is incorrect? a anterior periapicals are always exposed first. b posterior periapicals are exposed after anterior periapicals. c bite-wings are exposed last. d none of the above.
d none of the above. ORDER: Anterior periapicals Posterior periapicals Bite wings
Discuss patient and equipment preparations necessary before using the bite-wing technique
explain the radiographic procedures to patient adjust chair so patient is upright and level of chair is comfortable working height Adjust headrest to support and position patient's head place lead apron on and remove all objects from patients mouth set the exposure factors, open sterile package containing beam devices and assemble it over a covered work area