Best Practices in Intraoral Digital Radiography
Best Practices in Intraoral Digital Radiography
Best Practices in Intraoral Digital Radiography
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<strong>Best</strong> <strong>Practices</strong> <strong>in</strong> <strong>Intraoral</strong><br />
<strong>Digital</strong> <strong>Radiography</strong><br />
A Peer-Reviewed Publication<br />
Written by Gail F. Williamson, RDH, MS<br />
Abstract<br />
Detailed, accurate radiographs are a primary<br />
diagnostic tool as well as necessary for and dur<strong>in</strong>g<br />
some treatments. Increas<strong>in</strong>gly, digital radiographic<br />
imag<strong>in</strong>g is be<strong>in</strong>g used with two types of available<br />
receptors. Anatomical variations and patient<br />
comfort must be considered when tak<strong>in</strong>g <strong>in</strong>traoral<br />
radiographs. In addition, recogniz<strong>in</strong>g common<br />
sources of errors is important to ensure that the<br />
cl<strong>in</strong>ician avoids them and knows how to correct<br />
them when they occur. Techniques, as well as<br />
devices and accessories, can be used that will enable<br />
accurate image acquisition and improve patient<br />
comfort.<br />
Publication date: June 2011<br />
Expiration date: May 2014<br />
PennWell designates this activity for 3 Cont<strong>in</strong>u<strong>in</strong>g Educational Credits<br />
Supplement to PennWell Publications<br />
This course was written for dentists, dental hygienists and assistants, from novice to skilled.<br />
Educational Methods: This course is a self-<strong>in</strong>structional journal and web activity.<br />
Provider Disclosure: Pennwell does not have a leadership position or a commercial <strong>in</strong>terest <strong>in</strong> any<br />
products or services discussed or shared <strong>in</strong> this educational activity nor with the commercial supporter.<br />
No manufacturer or third party has had any <strong>in</strong>put <strong>in</strong>to the development of course content.<br />
Requirements for Successful Completion: To obta<strong>in</strong> 2 CE credits for this educational activity you must pay<br />
the required fee, review the material, complete the course evaluation and obta<strong>in</strong> a score of at least 70%.<br />
Learn<strong>in</strong>g Objectives:<br />
1. List and describe the types of digital receptors<br />
used for <strong>in</strong>traoral radiographic imag<strong>in</strong>g.<br />
2. List and describe the pr<strong>in</strong>ciples of parallel<strong>in</strong>g<br />
and bisect<strong>in</strong>g angle techniques for effective<br />
and accurate <strong>in</strong>traoral digital radiography.<br />
3. List and describe the adjustments <strong>in</strong> technique<br />
that may be necessary to accommodate<br />
anatomy, discomfort and placement difficulties.<br />
4. List and describe best practices for patient<br />
radiation safety and protection.<br />
Author Profiles<br />
Gail F. Williamson, RDH, BS, MS, is a professor of Dental<br />
Diagnostic Sciences <strong>in</strong> the Department of Oral Pathology, Medic<strong>in</strong>e<br />
and Radiology at Indiana University School of Dentistry <strong>in</strong><br />
Indianapolis, Indiana. She received an A.S. <strong>in</strong> Dental Hygiene,<br />
a B.S. <strong>in</strong> Allied Health, and a M.S. <strong>in</strong> Education, all from Indiana<br />
University. She serves as Director of Allied Dental Radiology<br />
and Course Director for Dental Assist<strong>in</strong>g and Dental Hygiene<br />
Radiology courses. A veteran teacher, Prof. Williamson has<br />
received numerous awards for teach<strong>in</strong>g excellence throughout<br />
her career. She is a published author and presents numerous<br />
cont<strong>in</strong>u<strong>in</strong>g education courses on Oral and Maxillofacial Radiology<br />
on the national level. In addition, she is actively <strong>in</strong>volved <strong>in</strong><br />
the American Academy of Oral and Maxillofacial Radiology and<br />
currently serves as a radiology expert on the American Dental<br />
Association’s Dental Hygiene National Board Test Construction<br />
Committee B.<br />
Author Disclosure<br />
The author of this course has no commercial ties with the<br />
sponsors or the providers of the unrestricted educational<br />
grant for this course.<br />
Go Green, Go Onl<strong>in</strong>e to take your course<br />
This course has been made possible through an unrestricted educational grant.<br />
CE Planner Disclosure: __________, CE Coord<strong>in</strong>ator does not have a leadership or commercial <strong>in</strong>terest<br />
with Orapharma, the commercial supporter, or with products or services discussed <strong>in</strong> this educational activity.<br />
Educational Disclaimer: Complet<strong>in</strong>g a s<strong>in</strong>gle cont<strong>in</strong>u<strong>in</strong>g education course does not provide enough <strong>in</strong>formation<br />
to result <strong>in</strong> the participant be<strong>in</strong>g an expert <strong>in</strong> the field related to the course topic. It is a comb<strong>in</strong>ation of many<br />
educational courses and cl<strong>in</strong>ical experience that allows the participant to develop skills and expertise.<br />
Registration: The cost of this CE course is $49.00 for 3 CE credits.<br />
Cancellation/Refund Policy: Any participant who is not 100% satisfied with this course can request a<br />
full refund by contact<strong>in</strong>g PennWell <strong>in</strong> writ<strong>in</strong>g.
Educational Objectives<br />
The overall goal of this article is to provide the reader with<br />
<strong>in</strong>formation on <strong>in</strong>traoral digital radiography. Upon completion<br />
of this course, the reader will be able to:<br />
1. List and describe the types of digital receptors used for<br />
<strong>in</strong>traoral radiographic imag<strong>in</strong>g.<br />
2. List and describe the pr<strong>in</strong>ciples of parallel<strong>in</strong>g and bisect<strong>in</strong>g<br />
angle techniques for effective and accurate <strong>in</strong>traoral digital<br />
radiography.<br />
3. List and describe the adjustments <strong>in</strong> technique that may<br />
be necessary to accommodate anatomy, discomfort and<br />
placement difficulties.<br />
4. List and describe best practices for patient radiation safety<br />
and protection.<br />
5. List and describe common errors that occur when tak<strong>in</strong>g<br />
<strong>in</strong>traoral digital radiographs and corrections that can be<br />
made when errors occur.<br />
Abstract<br />
Detailed, accurate radiographs are a primary diagnostic tool as<br />
well as necessary for and dur<strong>in</strong>g some treatments. Increas<strong>in</strong>gly,<br />
digital radiographic imag<strong>in</strong>g is be<strong>in</strong>g used with two types of<br />
available receptors. Anatomical variations and patient comfort<br />
must be considered when tak<strong>in</strong>g <strong>in</strong>traoral radiographs. In addition,<br />
recogniz<strong>in</strong>g common sources of errors is important to<br />
ensure that the cl<strong>in</strong>ician avoids them and knows how to correct<br />
them when they occur. Techniques, as well as devices and accessories,<br />
can be used that will enable accurate image acquisition<br />
and improve patient comfort.<br />
Introduction<br />
Dental radiographs are taken as primary diagnostic tools and<br />
for treatment purposes. As such, they must be as detailed and<br />
accurate as possible to meet cl<strong>in</strong>ical requirements. Increas<strong>in</strong>gly,<br />
digital radiography is becom<strong>in</strong>g the technology of<br />
choice and offers several advantages over film radiography.<br />
These <strong>in</strong>clude the ability to view images on the screen, computerized<br />
archiv<strong>in</strong>g of images, ability to enhance acquired<br />
images, reduced exposure to radiation, and rapid acquisition<br />
of images without the need for chemical process<strong>in</strong>g. In order<br />
to produce high-quality diagnostic images, a careful technique<br />
is required that considers best practices and patient<br />
comfort. Accurate technique, effective patient management,<br />
and proper exposure are required to optimize the <strong>in</strong>formation<br />
that can be obta<strong>in</strong>ed from radiographs and, therefore,<br />
their value.<br />
Typically, radiographic exam<strong>in</strong>ations are used to evaluate<br />
oral disease states such as periodontal disease, caries,<br />
and periapical pathology. While for periodontal disease and<br />
periapical pathology the radiographic projection of choice is<br />
usually a periapical or series of periapical images that record<br />
the entire tooth and support<strong>in</strong>g bone and is of value <strong>in</strong> diagnos<strong>in</strong>g<br />
bony and root pathoses, bitew<strong>in</strong>g radiographs are<br />
the radiograph of choice for the detection and monitor<strong>in</strong>g of<br />
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dental caries <strong>in</strong> the posterior teeth and can also better detect<br />
alveolar bone levels <strong>in</strong> these sextants. Vertical bitew<strong>in</strong>gs (size<br />
1) may also be used to take images of the anterior teeth to<br />
assess alveolar bone levels. The patient’s medical and dental<br />
history, cl<strong>in</strong>ical signs and symptoms of disease, risk factors,<br />
age and dentition, and new or recall patient status must also<br />
be considered when determ<strong>in</strong><strong>in</strong>g which radiographs are required.<br />
Recommendations are available for the appropriate<br />
patient-specific selection of radiographs (The Selection of<br />
Patients for Dental Radiographic Exam<strong>in</strong>ations, Revised<br />
2004). 1 The overall objective of <strong>in</strong>traoral radiography is to<br />
m<strong>in</strong>imize exposure to radiation while maximiz<strong>in</strong>g the diagnostic<br />
and <strong>in</strong>terpretative value of the radiographs. The focus<br />
of this article is on the use of digital radiography, which <strong>in</strong> the<br />
last two decades has steadily <strong>in</strong>creased.<br />
I. <strong>Digital</strong> Receptors<br />
<strong>Digital</strong> receptors are available <strong>in</strong> two formats: 1) photostimulable<br />
phosphor plate (PSP) receptors; or 2) rigid wired<br />
or wireless charge-coupled devices (CCD), complementary<br />
metal oxide semi-conductors (CMOS) or complementarymetal-oxide<br />
semiconductor active pixel sensor (CMOS-APS)<br />
receptors. These rigid digital receptors are often referred to as<br />
sensors and the term is used <strong>in</strong>terchangeably. Both systems<br />
are computer-based technologies that require specific hardware<br />
and software components for operation.<br />
<strong>Digital</strong> receptors are faster than film, which reduces the<br />
amount of radiation needed to produce a diagnostic image and<br />
elim<strong>in</strong>ate chemical process<strong>in</strong>g errors, darkroom ma<strong>in</strong>tenance,<br />
and chemical waste disposal. They are available <strong>in</strong> sizes comparable<br />
to film, most typically sizes 0, 1, and 2. Both types of<br />
digital receptors are reusable. Therefore, it is important for<br />
the cl<strong>in</strong>ician to consult the manufacturer’s <strong>in</strong>structions for<br />
proper preparation and coverage of the receptor, as well as<br />
for effective barrier removal techniques. Care must be taken<br />
to avoid direct saliva contact with the receptor and prevent<br />
cross-contam<strong>in</strong>ation. Dis<strong>in</strong>fection can be accomplished with<br />
ADA- or EPA-approved products and typical dis<strong>in</strong>fection<br />
techniques followed by coverage with an effective barrier. For<br />
rigid receptors, the Centers for Disease Control and Prevention<br />
recommends us<strong>in</strong>g a double barrier, with both an <strong>in</strong>ternal<br />
and external barrier. 2<br />
Phosphor plate receptors are more flexible and th<strong>in</strong>ner<br />
than rigid digital receptors but have the same dimensions<br />
as film. Plate receptors are used much like film but must be<br />
handled carefully, scanned to digitize the image, and erased<br />
before reuse. Rough handl<strong>in</strong>g may produce plate scars, result<br />
<strong>in</strong> image artifacts, and necessitate plate replacement, mak<strong>in</strong>g<br />
them less user friendly <strong>in</strong> these <strong>in</strong>stances. 3 These problems <strong>in</strong><br />
turn may result <strong>in</strong> retakes, thereby <strong>in</strong>creas<strong>in</strong>g patients’ radiation<br />
exposure. Recent improvements <strong>in</strong> plate technology have<br />
been directed toward mak<strong>in</strong>g plates more scratch resistant to<br />
improve longevity, and permitt<strong>in</strong>g immediate erasure after<br />
scann<strong>in</strong>g to save time.<br />
November 2011<br />
Figure 1. <strong>Digital</strong> receptors<br />
November 2011<br />
Phosphor plate receptors<br />
Rigid digital receptors<br />
Rigid digital receptors are more difficult to use <strong>in</strong>itially than<br />
phosphor plate receptors, and may result <strong>in</strong> more problems<br />
for both periapical and bitew<strong>in</strong>g radiographic images when<br />
compared to film. Common issues associated with rigid digital<br />
receptors <strong>in</strong>clude: 1. placement errors, especially <strong>in</strong> premolar<br />
and molar areas; 2. vertical angulation errors <strong>in</strong> the anterior<br />
regions, result<strong>in</strong>g <strong>in</strong> <strong>in</strong>cisal edge cutoffs; 3. horizontal overlapp<strong>in</strong>g;<br />
4. cone-cutt<strong>in</strong>g; 5. difficulties with bitew<strong>in</strong>g placement,<br />
especially premolar views and vertical bitew<strong>in</strong>gs; and 6. discomfort.<br />
4-7 To avoid these problems, attention to the details of<br />
placement <strong>in</strong> terms of precise location, horizontal and vertical<br />
parallelism of the receptor to the structures, and accurate alignment<br />
of the x-ray beam are critical. To avoid cutt<strong>in</strong>g off <strong>in</strong>cisal<br />
edges, a cotton roll can be placed on the biteblock to facilitate<br />
placement and allow the crowns to be fully recorded. In addition,<br />
rigid receptors should be placed closer to the midl<strong>in</strong>e to<br />
reduce discomfort and to achieve a parallel rather than angular<br />
placement. It is particularly important to employ this approach<br />
when a patient has a shallow palate or floor of mouth, both to<br />
avoid discomfort and distortion of the image. Typically, rigid<br />
sensors have a slightly smaller surface area for record<strong>in</strong>g the<br />
image than film does, and this must be taken <strong>in</strong>to consideration<br />
dur<strong>in</strong>g receptor placement. To overcome placement difficulties<br />
on premolar and molar periapicals or premolar bitew<strong>in</strong>gs,<br />
two alternative approaches can be employed. 1. To capture the<br />
distal surface of can<strong>in</strong>es, it may be easier to take an additional<br />
anterior periapical on each arch to capture the can<strong>in</strong>e-premolar<br />
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contact. 2. To achieve a more anterior position of a premolar<br />
periapical or bitew<strong>in</strong>g or a more posterior placement of a molar<br />
periapical, a horizontal offset technique can be utilized. This<br />
approach alters the horizontal placement of the receptor toward<br />
the area of <strong>in</strong>terest while direct<strong>in</strong>g the x-rays through the<br />
contacts of the teeth. This is best accomplished visually, with<br />
the r<strong>in</strong>g guide removed from the <strong>in</strong>strument.<br />
Figure 2. Offset bitew<strong>in</strong>g placement<br />
Many manufacturers have designed rounded edges and reduced<br />
thickness to enhance comfort and ease of placement.<br />
Maximiz<strong>in</strong>g the diagnostic value of radiographs starts with<br />
correct receptor position, ensur<strong>in</strong>g that the x-ray beam is<br />
centered and aligned at the correct vertical and horizontal<br />
angulations and is exposed at the correct time.<br />
II. Technique Overview<br />
<strong>Intraoral</strong> radiographic images must be positioned accurately,<br />
which can be achieved us<strong>in</strong>g an appropriate technique for<br />
the desired radiographic projection and anatomical situation.<br />
Devices used to accomplish this <strong>in</strong>clude receptor <strong>in</strong>struments<br />
with r<strong>in</strong>g guides, standard bite blocks, cotton rolls, and bitew<strong>in</strong>g<br />
tabs. The techniques that can be used are the parallel<strong>in</strong>g,<br />
bitew<strong>in</strong>g, and bisect<strong>in</strong>g angle techniques.<br />
Parallel<strong>in</strong>g Technique<br />
The parallel<strong>in</strong>g technique is used for both periapical and<br />
bitew<strong>in</strong>g radiographs and is the most accurate technique for<br />
tak<strong>in</strong>g these projections. The digital receptor should be placed<br />
vertically and horizontally parallel with the teeth that are be-<br />
81
<strong>in</strong>g radiographed. The x-ray beam should be directed at right<br />
angles to the teeth and receptor.<br />
82<br />
Figure 3. Parallel<strong>in</strong>g technique<br />
In the case of periapical radiographs, the digital receptor should<br />
be placed parallel to the full length of the crown and root of the<br />
teeth be<strong>in</strong>g imaged. To achieve the best placement and patient<br />
comfort, the digital receptor should be placed closer to the<br />
midl<strong>in</strong>e rather than close to the teeth. It is helpful to use a cotton<br />
roll underneath the biteblock to reduce the need for heavy<br />
bit<strong>in</strong>g forces that often result <strong>in</strong> patient discomfort. Technique<br />
guidel<strong>in</strong>es call for precise location and <strong>in</strong>clusion of specific<br />
structures on each projection.<br />
Figure 4. Radiograph sensor holder (Uni-grip 360® w/ Uni-Grip AR)<br />
Bitew<strong>in</strong>g Technique<br />
Regardless of approach, <strong>in</strong>strument, or tab, bitew<strong>in</strong>gs are based<br />
on the parallel<strong>in</strong>g technique. The digital receptor should be<br />
placed vertically and horizontally parallel to the crowns of the<br />
teeth. For patients who gag easily or for children, tab bitew<strong>in</strong>gs<br />
are less cumbersome and more comfortable for the patient.<br />
Bitew<strong>in</strong>g tabs hold the digital receptors <strong>in</strong> position <strong>in</strong>traorally<br />
but provide no external alignment guide for PID (Position<br />
Indicat<strong>in</strong>g Device, or x-ray cone) position<strong>in</strong>g and beam direction.<br />
Careful placement and beam alignment will produce good<br />
results. The vertical angulation is typically set at +5°, with the<br />
beam centered to the tab or the center of the receptor. The tab<br />
should be aligned with the teeth contacts, which will <strong>in</strong>dicate<br />
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the correct horizontal angulation to use to enter the contacts.<br />
Central ray entry po<strong>in</strong>ts will help with x-ray beam center<strong>in</strong>g, as<br />
will us<strong>in</strong>g the l<strong>in</strong>es on the PID that <strong>in</strong>dicate the direction of the<br />
x-rays exit<strong>in</strong>g the collimator.<br />
Figure 5. Bitew<strong>in</strong>gs tabs<br />
Bisect<strong>in</strong>g Angle Technique<br />
The bisect<strong>in</strong>g angle technique is an alternate approach for<br />
periapical radiography. With this technique, the receptor is<br />
placed diagonal to the long axis plane of the teeth. The beam<br />
is then directed at a right angle to a plane that is midway<br />
between (bisects or divides) the receptor and the teeth. This<br />
method produces less optimal images because the receptor<br />
and teeth are not <strong>in</strong> the same vertical plane. However, it is<br />
a useful method when ideal receptor placement cannot be<br />
achieved due to anatomic obstacles or placement difficulties.<br />
This technique is more operator-sensitive. If the angle is not<br />
correctly divided, elongation or foreshorten<strong>in</strong>g will occur. A<br />
variety of holders can be used for accurate position<strong>in</strong>g of the<br />
receptor <strong>in</strong> different locations <strong>in</strong> the mouth.<br />
Figure 6. Bisect<strong>in</strong>g technique<br />
One approach the cl<strong>in</strong>ician can use is to align the PID parallel<br />
to the receptor or external r<strong>in</strong>g guide <strong>in</strong>itially and then<br />
November 2011<br />
reduce the vertical angle by approximately 10°, which will<br />
approach the bisect<strong>in</strong>g plane (Table 1). Also, start<strong>in</strong>g angles<br />
can be used that will get the operator close to the bisect<strong>in</strong>g<br />
plane <strong>in</strong> each area of the mouth when non-r<strong>in</strong>ged <strong>in</strong>struments<br />
or devices are used. These angles can be aligned us<strong>in</strong>g<br />
the angle meter on the side of the x-ray head. Application<br />
of the bisect<strong>in</strong>g angle technique has become more common<br />
<strong>in</strong> digital radiography with rigid digital receptors. Often it is<br />
difficult to achieve true parallelism with the tooth structure;<br />
as a result, crowns and apices are frequently cut off due to<br />
overangulation. Reduc<strong>in</strong>g the vertical angulation compensates<br />
for the lack of parallelism to the structures.<br />
Table 1. Bisect<strong>in</strong>g angle <strong>in</strong>strumentation angulations<br />
Arch Molar Premolar Can<strong>in</strong>e Incisor<br />
Maxilla +15° to<br />
+25°<br />
Mandible +5° to<br />
-5°<br />
Figure 7. Central ray entry po<strong>in</strong>ts<br />
Pupil of eye<br />
Ala of nose<br />
Tip of nose<br />
Nares of nose<br />
Commissure<br />
of lips<br />
Mentum<br />
November 2011<br />
+25° to<br />
+35°<br />
-10° to<br />
-15°<br />
+40° to<br />
+50°<br />
-10° to<br />
-15°<br />
+40° to<br />
+50°<br />
-10° to<br />
-15°<br />
Outer canthus<br />
Tragus of ear<br />
<strong>Digital</strong> Receptor Instruments<br />
Receptor <strong>in</strong>struments with x-ray beam r<strong>in</strong>g guides improve<br />
the accuracy of the PID alignment to ensure correct beam<br />
angulation and center<strong>in</strong>g. Receptor <strong>in</strong>struments comb<strong>in</strong>e a<br />
receptor holder with an arm that has an attached r<strong>in</strong>g <strong>in</strong>dicat<strong>in</strong>g<br />
the position for the PID. This helps the operator avoid<br />
cone cut errors by specifically direct<strong>in</strong>g the x-ray beam toward<br />
the center of the receptor. Regardless of the <strong>in</strong>strument<br />
used, the placement of the receptor relative to the teeth must<br />
be correct. Instruments are available for parallel<strong>in</strong>g, bisect<strong>in</strong>g,<br />
and bitew<strong>in</strong>g techniques, as well as for endodontic imag<strong>in</strong>g<br />
where endodontic files may impede proper position<strong>in</strong>g of<br />
the receptor beh<strong>in</strong>d the tooth.<br />
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Figure 8. Receptor <strong>in</strong>struments<br />
III. Technique Adaptations<br />
Technique adaptations may be required due to anatomical<br />
considerations or to avoid patient discomfort. These anatomical<br />
considerations <strong>in</strong>clude shallow palates, narrow arches, the<br />
presence of tori, and loss of alveolar bone (edentulous ridges).<br />
Adaptations may also be required <strong>in</strong> the presence of endodontic<br />
files when radiographs are taken dur<strong>in</strong>g treatment. Select<strong>in</strong>g<br />
the bisect<strong>in</strong>g angle technique <strong>in</strong>stead of the parallel<strong>in</strong>g technique<br />
is useful <strong>in</strong> the case of shallow palates; careful placement<br />
of receptors or the use of special receptor <strong>in</strong>struments (endodontic<br />
imag<strong>in</strong>g) are necessary to accommodate all the listed<br />
anatomical variations (Table 2).<br />
Table 2. Anatomical Variations<br />
Shallow Palates • Use bisect<strong>in</strong>g technique <strong>in</strong>stead of<br />
parallel<strong>in</strong>g technique<br />
• Move receptor more toward the<br />
midl<strong>in</strong>e<br />
Presence of tori • Ensure maxillary tori are between<br />
the teeth and receptor<br />
• Place receptor beh<strong>in</strong>d mandibular<br />
tori<br />
Narrow arches • Place receptor as far l<strong>in</strong>gual as<br />
possible<br />
• Use size 1 receptors <strong>in</strong> anterior or<br />
occlusal technique<br />
Edentulous<br />
situations<br />
• Place receptor more toward the<br />
midl<strong>in</strong>e/tongue<br />
• Use cotton rolls on the bite block to<br />
replace miss<strong>in</strong>g teeth<br />
Endo • Place receptor more l<strong>in</strong>gual to avoid<br />
endodontic files<br />
• Use special endodontic receptor<br />
<strong>in</strong>struments<br />
83
84<br />
IV. Receptor Placement (Parallel<strong>in</strong>g) V. Patient Comfort<br />
Ensur<strong>in</strong>g that patients are as comfortable as possible while<br />
Projection<br />
Or View<br />
Molar<br />
periapical<br />
Premolar<br />
periapical<br />
Can<strong>in</strong>e<br />
periapical<br />
Lateral<br />
<strong>in</strong>cisor<br />
periapical<br />
Central<br />
<strong>in</strong>cisor<br />
periapical<br />
Can<strong>in</strong>e-<br />
lateral<br />
periapical<br />
Molar<br />
bite-w<strong>in</strong>g<br />
Premolar<br />
bite-w<strong>in</strong>g<br />
Molar<br />
periapical<br />
Premolar<br />
periapical<br />
Can<strong>in</strong>e-<br />
lateral<br />
periapical<br />
Central<br />
<strong>in</strong>cisor<br />
periapical<br />
Receptor Placement<br />
Place the receptor toward the midl<strong>in</strong>e<br />
and the biteblock under the 2 nd molar<br />
crown, and align the mesial edge of<br />
the biteblock between the 1 st and 2 nd<br />
molar contact po<strong>in</strong>t<br />
Place the receptor toward the midl<strong>in</strong>e<br />
and the biteblock under the 2 nd premolar<br />
crown, and align the mesial edge of<br />
the biteblock between the 1 st and 2 nd<br />
premolar contact po<strong>in</strong>t<br />
Place the receptor l<strong>in</strong>gual to the<br />
can<strong>in</strong>e, with the biteblock centered<br />
with the cusp tip<br />
Place the receptor l<strong>in</strong>gual to the<br />
lateral <strong>in</strong>cisor and the biteblock under<br />
the lateral <strong>in</strong>cisor crown<br />
Place the receptor l<strong>in</strong>gual to the central<br />
<strong>in</strong>cisors, and center the biteblock<br />
with the central <strong>in</strong>cisor contact po<strong>in</strong>t<br />
Place the receptor l<strong>in</strong>gual to the can<strong>in</strong>e<br />
and lateral; center the biteblock<br />
with the lateral-can<strong>in</strong>e<br />
contact po<strong>in</strong>t<br />
Align the mesial edge of the tab between<br />
the 1st and 2nd molar contact<br />
on the mandible<br />
Align the mesial edge of the biteblock<br />
between the 1st and 2nd premolar<br />
contact on the mandible<br />
Place the receptor toward the tongue,<br />
place the biteblock on the 2 nd molar<br />
crown, and align the mesial edge of<br />
the biteblock between the 1 st and 2 nd<br />
molar contact po<strong>in</strong>t<br />
Place the receptor toward the<br />
tongue, place the biteblock on the 2 nd<br />
premolar, and align the mesial edge of<br />
the biteblock between the 1 st and 2 nd<br />
premolar contact po<strong>in</strong>t<br />
Place the receptor l<strong>in</strong>gual to the<br />
can<strong>in</strong>e and lateral with biteblock<br />
centered with the contact po<strong>in</strong>t<br />
Place the receptor l<strong>in</strong>gual to the central<br />
<strong>in</strong>cisors, and center the biteblock<br />
with the central <strong>in</strong>cisor contact po<strong>in</strong>t<br />
Teeth<br />
Recorded<br />
1 st , 2 nd , 3 rd molar<br />
teeth crowns and<br />
apices<br />
Distal of the<br />
can<strong>in</strong>e, 1 st and<br />
2 nd premolar, 1 st<br />
molar crowns and<br />
apices<br />
Mesial and apex<br />
of the can<strong>in</strong>e<br />
Mesial, distal, and<br />
apex of the lateral<br />
<strong>in</strong>cisor<br />
Mesial, distal,<br />
and apices of the<br />
central <strong>in</strong>cisors<br />
Mesial and apex<br />
of the can<strong>in</strong>e,<br />
mesial, distal, and<br />
apex of the lateral<br />
<strong>in</strong>cisor<br />
Maxillary and<br />
mandibular<br />
molar crowns <strong>in</strong><br />
occlusion<br />
Distal of the maxillary<br />
and mandibular<br />
can<strong>in</strong>e,<br />
premolar and 1st<br />
molar crowns <strong>in</strong><br />
occlusion<br />
1 st , 2 nd , 3 rd molar<br />
teeth crowns and<br />
apices<br />
Distal of the<br />
can<strong>in</strong>e, 1 st and 2 nd<br />
premolar, 1 st molar<br />
teeth crowns<br />
and apices<br />
Distal of the<br />
lateral and mesial<br />
of the can<strong>in</strong>e<br />
and apices<br />
Mesial and distal<br />
of the central <strong>in</strong>cisors<br />
and mesial<br />
of the lateral <strong>in</strong>cisors<br />
and apices<br />
Central Ray Entry Po<strong>in</strong>t<br />
MAXILLARY PERIAPICALS<br />
Po<strong>in</strong>t down from the outer<br />
canthus (corner)<br />
of the eye to midcheek area<br />
Po<strong>in</strong>t down from the pupil of<br />
the eye to<br />
mid-cheek area<br />
Ala (corner) of the nose<br />
Nares (nostril) of the nose<br />
Tip of the nose<br />
OPTION<br />
Ala (corner) of the nose<br />
BITE-WINGS<br />
Po<strong>in</strong>t down from the outer<br />
corner of the eye<br />
to the occusal plane<br />
Po<strong>in</strong>t down from the pupil of<br />
the eye to the<br />
occusal plane<br />
MANDIBULAR PERIAPICALS<br />
Po<strong>in</strong>t down from the outer<br />
canthus (corner)<br />
of the eye to the midmandible<br />
area<br />
Po<strong>in</strong>t down from the pupil of<br />
the eye to<br />
mid-mandible area<br />
Po<strong>in</strong>t down from the ala<br />
(corner) of the nose<br />
to the ch<strong>in</strong> corner<br />
Po<strong>in</strong>t down from the tip of<br />
the nose to the<br />
ch<strong>in</strong> center<br />
www.rdhmag.com<br />
Receptor<br />
Orientation<br />
Horizontal<br />
placement;<br />
dot toward crown<br />
Horizontal<br />
placement;<br />
dot toward crown<br />
Vertical<br />
placement;<br />
dot toward crown<br />
Vertical<br />
placement;<br />
dot toward crown<br />
Vertical<br />
placement; dot<br />
toward crown<br />
Vertical<br />
placement;<br />
dot toward crown<br />
Horizontal or<br />
vertical placement;<br />
dot toward<br />
mandible<br />
Horizontal or<br />
vertical placement;<br />
dot toward<br />
mandible<br />
Horizontal<br />
placement;<br />
dot toward crown<br />
Horizontal<br />
placement;<br />
dot toward crown<br />
Vertical<br />
placement; dot<br />
toward crown<br />
Vertical<br />
placement; dot<br />
toward crown<br />
Receptor<br />
Size<br />
Size 2<br />
Size 2<br />
Size 1<br />
Size 1<br />
Size 1 or 2<br />
Size 2<br />
Size 2<br />
Size 2<br />
Size 2<br />
Size 2<br />
Size 1 or 2<br />
Size 1 or 2<br />
Image<br />
November 2011<br />
tak<strong>in</strong>g radiographs not only helps patients but also results <strong>in</strong><br />
a greater likelihood of successful imag<strong>in</strong>g and reduced risk<br />
of retakes associated with patients mov<strong>in</strong>g or alter<strong>in</strong>g the<br />
position of a digital receptor while the radiograph is be<strong>in</strong>g<br />
taken. Gagg<strong>in</strong>g and discomfort associated with the edges of<br />
receptors are key considerations.<br />
Gagg<strong>in</strong>g patients can be challeng<strong>in</strong>g and require patience<br />
and reassurance from the cl<strong>in</strong>ician. It is important to be organized,<br />
preset the exposure time, pre-align the PID, and<br />
be ready to act quickly. The most common area to elicit the<br />
gag reflex is the maxillary molar periapical view. Placement<br />
of the receptor toward the midl<strong>in</strong>e and away from the soft<br />
palate will reduce the tendency for gagg<strong>in</strong>g. A variety of<br />
strategies will help manage the gagg<strong>in</strong>g patient: breath<strong>in</strong>g<br />
through the nose, salt on the tongue, distraction techniques<br />
(lift<strong>in</strong>g one leg <strong>in</strong> the air, bend<strong>in</strong>g the toes toward the body,<br />
humm<strong>in</strong>g), use of topical anesthetics, and tissue cushions on<br />
the receptor.<br />
Similar approaches can be useful when the patient experiences<br />
discomfort from the receptor. The use of topical<br />
anesthetic agents and receptor cushions improve comfort.<br />
Rigid digital receptors can cause more discomfort than<br />
other receptors; plac<strong>in</strong>g these closer to the midl<strong>in</strong>e can<br />
reduce patient discomfort. This is especially important<br />
<strong>in</strong> patients with a shallow palate or shallow floor of the<br />
mouth, because the edge of the receptor is more likely to<br />
dig <strong>in</strong> as there is less space for position<strong>in</strong>g and placement<br />
of the receptor, and tori necessitate plac<strong>in</strong>g the receptor<br />
beh<strong>in</strong>d them. Us<strong>in</strong>g lightweight bite blocks and receptor<br />
arms/r<strong>in</strong>gs also improves patient comfort. Another option<br />
is to use a receptor holder without the accompany<strong>in</strong>g arm<br />
and r<strong>in</strong>g, allow<strong>in</strong>g for position<strong>in</strong>g of the sensor that optimizes<br />
patient comfort without compromis<strong>in</strong>g accuracy;<br />
this requires knowledge of the bisect<strong>in</strong>g angle technique<br />
and is useful when position<strong>in</strong>g must accommodate anatomical<br />
variations as described above.<br />
In bitew<strong>in</strong>g radiography, tabs can be used and are usually<br />
less uncomfortable for the patient, although the edges of a<br />
rigid receptor may still be a potential source of discomfort.<br />
While regular bitew<strong>in</strong>g tabs are more comfortable, they are<br />
less reliable than the use of a hold<strong>in</strong>g device because they<br />
may allow movement or displacement of the sensor. Bitew<strong>in</strong>g<br />
tabs with extended straps that wrap around the sensor<br />
solve this problem and keep the tab positioned exactly <strong>in</strong> the<br />
center of the sensor and the barrier cover without compromis<strong>in</strong>g<br />
patient comfort. Self-adhesive foam covers can be<br />
used over the receptor for both bitew<strong>in</strong>gs and periapicals<br />
to smooth the edges and provide cushion<strong>in</strong>g aga<strong>in</strong>st the<br />
patient’s oral mucosa.<br />
November 2011<br />
www.rdhmag.com<br />
Figure 9. Cover-Cozee Universal Adhesive Comfort Tab<br />
Another option is the use of foam covers that fit over all<br />
edges of the receptor and have soft, pliable edges. When adhesive<br />
holders are used, keep<strong>in</strong>g the sensor firmly with<strong>in</strong> the<br />
sensor barrier is critical and can be achieved by us<strong>in</strong>g a th<strong>in</strong><br />
foam layer designed for this purpose that precisely fits over the<br />
sensor barrier. S<strong>in</strong>ce this is constructed of soft foam, it also aids<br />
patient comfort.<br />
Figure 10. Soft silicone covers<br />
In addition, <strong>in</strong>struct<strong>in</strong>g the patient to “lightly” or “gently”<br />
bite just hard enough to keep the sensor <strong>in</strong> place and stable also<br />
aids comfort and serves to ma<strong>in</strong>ta<strong>in</strong> proper position<strong>in</strong>g and<br />
alignment.<br />
Regardless of techniques accommodat<strong>in</strong>g patient comfort<br />
and anatomy, accuracy of position<strong>in</strong>g must be ma<strong>in</strong>ta<strong>in</strong>ed to<br />
avoid errors and retakes that expose patients to unnecessary radiation<br />
and potential discomfort. Poor position<strong>in</strong>g is a common<br />
source of errors <strong>in</strong> radiography.<br />
VI. Patient Protection<br />
Patients tend to be more cooperative and receptive to radiographic<br />
procedures when radiation protection is provided.<br />
Patient protection <strong>in</strong>cludes the use of lead collars and lead<br />
aprons dur<strong>in</strong>g radiographic imag<strong>in</strong>g procedures. Lead collars<br />
are designed to protect the thyroid. These collars have been<br />
found to substantially reduce radiation to the thyroid dur<strong>in</strong>g<br />
dental radiographic exam<strong>in</strong>ations. 8 There are vary<strong>in</strong>g perspectives<br />
on the necessity of lead aprons and thyroid collar shields.<br />
Selection criteria guidel<strong>in</strong>es recommend that all precautions<br />
should be taken and patient shield<strong>in</strong>g be provided whenever<br />
possible, particularly for children, women of childbear<strong>in</strong>g age,<br />
and pregnant women. 1 The National Council on Radiation Protection<br />
(NCRP) Report 145, Radiation Protection <strong>in</strong> Dentistry,<br />
states that if all the safety measures outl<strong>in</strong>ed <strong>in</strong> the report are<br />
85
igorously followed, a lead apron is not required. 9 However, the<br />
radiation safety measures <strong>in</strong>clude rectangular collimation of the<br />
x-ray beam, use of fast image receptors, application of selection<br />
criteria, and a variety of other standards that all must be <strong>in</strong><br />
place <strong>in</strong> order to elim<strong>in</strong>ate the use of the lead apron. In addition,<br />
NCRP Report 145 states that thyroid collars shall be provided<br />
for children and should be provided for adults except when they<br />
<strong>in</strong>terfere with exam<strong>in</strong>ation, as <strong>in</strong> the case of panoramic imag<strong>in</strong>g.<br />
9 Therefore, best practices <strong>in</strong>clude the use of lead aprons and<br />
thyroid collars and other safety measures that help the cl<strong>in</strong>ician<br />
comply with the ALARA (As Low As Reasonably Achievable)<br />
pr<strong>in</strong>ciple and keep the patient’s exposure to a m<strong>in</strong>imum.<br />
Also, the cl<strong>in</strong>ician must remember that the lead conta<strong>in</strong>ed<br />
<strong>in</strong> lead aprons and collars is th<strong>in</strong> and malleable, and if the apron<br />
or collar is folded or improperly stored, the lead can be bent<br />
and damaged such that it compromises protection. Collars and<br />
aprons should be hung up to avoid damage. As an alternative to<br />
leaded aprons, lightweight options are available that <strong>in</strong>corporate<br />
materials that effectively absorb the scatter radiation but are not<br />
as heavy or unga<strong>in</strong>ly to use, and may be more comfortable for<br />
patients. 10<br />
86<br />
Figure 11. Protective apron with collar<br />
VII. Common Errors<br />
When the pr<strong>in</strong>ciples of radiographic technique are not applied,<br />
technical errors will occur. Errors need to be identified,<br />
understood, and corrected so that they do not cont<strong>in</strong>ue<br />
to occur. The most typical technique errors occur <strong>in</strong> placement,<br />
vertical angulation, horizontal angulation, x-ray beam<br />
center<strong>in</strong>g, and exposure.<br />
Placement errors occur when the cl<strong>in</strong>ician fails to properly<br />
place the receptor to record the correct teeth, or cuts off the<br />
crowns or apices of teeth.<br />
Vertical angulation errors distort the length of the structures<br />
and result <strong>in</strong> either foreshorten<strong>in</strong>g or elongation. Foreshorten<strong>in</strong>g<br />
requires a decrease <strong>in</strong> the vertical angle for correction;<br />
elongation requires an <strong>in</strong>crease <strong>in</strong> the vertical angle. Vertical<br />
angulation errors are more common with the bisect<strong>in</strong>g angle<br />
technique than with the parallel<strong>in</strong>g technique. However, vertical<br />
angulation errors, especially elongation, can occur with the<br />
parallel<strong>in</strong>g technique when the patient bites too forcefully and<br />
torques or flexes the receptor out of the correct vertical position.<br />
www.rdhmag.com<br />
To correct, ensure light bit<strong>in</strong>g pressure with the use of a cotton<br />
roll under the biteblock, and use l<strong>in</strong>gual placement away<br />
from the teeth with receptor, teeth, and PID all parallel to<br />
each other.<br />
Horizontal angulation errors result <strong>in</strong> overlapp<strong>in</strong>g of<br />
proximal surfaces and limit caries and bone loss evaluations.<br />
To correct, the horizontal angle must be directed through the<br />
proximal surfaces of the teeth. It is helpful to align the lateral<br />
sides of the biteblock parallel with the teeth contacts to better<br />
guide the x-rays through the proximal contacts of the teeth.<br />
Overlapp<strong>in</strong>g occurs more commonly with tab bitew<strong>in</strong>gs.<br />
However, overlapp<strong>in</strong>g can occur with bitew<strong>in</strong>g <strong>in</strong>struments if<br />
the receptor is not placed parallel to the horizontal plane of the<br />
teeth.<br />
Cone cut errors are caused by not center<strong>in</strong>g the x-ray beam<br />
over the receptor. Lack of center<strong>in</strong>g produces partial exposure<br />
of the receptor with a “cut” where x-rays did not <strong>in</strong>teract with<br />
the receptor. Receptor <strong>in</strong>struments with beam guides facilitate<br />
beam center<strong>in</strong>g over the receptor when properly assembled.<br />
Exposure errors result <strong>in</strong> light or dark images due to improper<br />
exposure time or lack of consideration of patient size and the<br />
thickness of structures. Underexposures cannot be corrected<br />
with software enhancements, but overexposures can usually be<br />
adjusted to moderate image density.<br />
Figure 12. Common errors<br />
Placement Foreshorten<strong>in</strong>g<br />
Elongation Overlapp<strong>in</strong>g<br />
Cone Cut Underexposure<br />
November 2011<br />
Table 3: Correction Of Common Errors<br />
Error Description Correction<br />
Placement Improper area<br />
recorded, crowns or<br />
apices cut off<br />
Foreshorten<strong>in</strong>g Image shortened<br />
and smaller than<br />
the actual object<br />
length<br />
Elongation Image stretched<br />
and longer than actual<br />
object length<br />
Overlapp<strong>in</strong>g Proximal surfaces<br />
of the teeth are<br />
closed<br />
Cone Cutt<strong>in</strong>g White zone where<br />
x-rays did not<br />
strike the receptor<br />
Underexposure Light or low density<br />
image<br />
November 2011<br />
Place receptor accord<strong>in</strong>g<br />
to placement<br />
guidel<strong>in</strong>es to cover<br />
structures<br />
Decrease the vertical<br />
angulation of the<br />
x-ray beam<br />
Increase the vertical<br />
angulation of the PID<br />
Direct the x-rays between<br />
the contacts<br />
of the teeth<br />
Center the x-ray<br />
beam over the<br />
image receptor<br />
Increase exposure<br />
factors; check for<br />
large patient size<br />
VIII. Summary<br />
Dental radiographs are valuable diagnostic tools and expose<br />
the patient to m<strong>in</strong>imal amounts of radiation. Nonetheless,<br />
dental professionals must ensure that patients are protected<br />
from the harmful effects of cumulative exposure to radiation.<br />
Patients can be protected through the use of lead collars<br />
and aprons and by ensur<strong>in</strong>g that only necessary radiographs<br />
are taken and that radiation exposure is kept low. Patient<br />
comfort can be improved by plac<strong>in</strong>g digital receptors <strong>in</strong> a<br />
position that allows for accurate radiographs as well as us<strong>in</strong>g<br />
devices and accessories that improve patient comfort. One of<br />
the critical factors <strong>in</strong> m<strong>in</strong>imiz<strong>in</strong>g the number of radiographs<br />
is to ensure that retakes are not required due to improper<br />
technique or patient management. Receptor <strong>in</strong>struments are<br />
valuable tools that guide the x-ray beam and thereby assist<br />
<strong>in</strong> the accuracy of dental radiographic images.<br />
Selected References<br />
1. American Dental Association and U.S. Department of<br />
Health and Human Services. The Selection of Patients<br />
for Dental Radiographic Exam<strong>in</strong>ation, Revised 2004.<br />
2. Centers for Disease Control and Prevention. Guide¬l<strong>in</strong>es<br />
for <strong>in</strong>fection control <strong>in</strong> dental health-care sett<strong>in</strong>gs 2003.<br />
MMWR 2003;52(RR-17):1-68.<br />
3. Bedard A, Davis TD, Angelopoulos, C. Storage<br />
phosphor plates: How durable are they as a digital dental<br />
radiographic system? J Contemp Dent Pract 2004;5:057-<br />
069.<br />
www.rdhmag.com<br />
4. Matzen LH, Christensen J, Wenzel A. Patient discomfort<br />
and retakes <strong>in</strong> periapical exam<strong>in</strong>ation of mandibular<br />
third molars us<strong>in</strong>g digital receptors. Oral Surg Oral Med<br />
Oral Pathol Oral Radiol Endod 2009;107:566-572.<br />
5. Versteeg CH, et al. An evaluation of periapical radiography<br />
with a charge-coupled device. Dentomaxillofac Radiol<br />
1998;27:97-101.<br />
6. Sommers TM, Mauriello SM, Ludlow JB, Plat<strong>in</strong> E,<br />
Tyndall DA. Pre-cl<strong>in</strong>ical performance compar<strong>in</strong>g film<br />
and CCD-based systems. J Dent Hyg 2002;76:26-33.<br />
7. Bahrami G, Hagstrom C, Wenzel A. Bitew<strong>in</strong>g<br />
exam<strong>in</strong>ation with four digital receptors. Dentomaxillofac<br />
Radiol 2003;32:317-321.<br />
8. Sikorski PA, Taylor KW. The effectiveness of the thyroid<br />
shield <strong>in</strong> dental radiology. Oral Surg.1984;58:225-236.<br />
9. National Council on Radiation Protection and<br />
Measurements. Radiation Protection <strong>in</strong> Dentistry. NCRP<br />
Report No. 145. Bethesda, MD. NCRP 2003, Revised<br />
2004;14-27.<br />
10. Williamson GF. <strong>Intraoral</strong> <strong>Radiography</strong>: Position<strong>in</strong>g and<br />
Radiation Protection. Academy of Dental Therapeutics<br />
and Stomatology, Chesterland, OH, 2007.<br />
Author Profile<br />
Gail F. Williamson, RDH, BS, MS, is a professor of Dental<br />
Diagnostic Sciences <strong>in</strong> the Department of Oral Pathology,<br />
Medic<strong>in</strong>e and Radiology at Indiana University School<br />
of Dentistry <strong>in</strong> Indianapolis, Indiana. She received an A.S.<br />
<strong>in</strong> Dental Hygiene, a B.S. <strong>in</strong> Allied Health, and a M.S. <strong>in</strong><br />
Education, all from Indiana University. She serves as Director<br />
of Allied Dental Radiology and Course Director for<br />
Dental Assist<strong>in</strong>g and Dental Hygiene Radiology courses.<br />
A veteran teacher, Prof. Williamson has received numerous<br />
awards for teach<strong>in</strong>g excellence throughout her career. She<br />
is a published author and presents numerous cont<strong>in</strong>u<strong>in</strong>g<br />
education courses on Oral and Maxillofacial Radiology on<br />
the national level. In addition, she is actively <strong>in</strong>volved <strong>in</strong> the<br />
American Academy of Oral and Maxillofacial Radiology<br />
and currently serves as a radiology expert on the American<br />
Dental Association’s Dental Hygiene National Board Test<br />
Construction Committee B.<br />
Disclaimer<br />
The author of this course has no commercial ties with the sponsors<br />
or the providers of the unrestricted educational grant for<br />
this course.<br />
Reader Feedback<br />
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1. Dental radiographs are taken ________<br />
a. for treatment purposes<br />
b. as primary diagnostic tools<br />
c. as def<strong>in</strong>itive tools<br />
d. a and b<br />
2. _________ is an advantage of digital<br />
radiography over film radiography.<br />
a. Computerized archiv<strong>in</strong>g of images<br />
b. The ability to enhance acquired images<br />
c. Rapid acquisition of images without the need for<br />
chemical process<strong>in</strong>g<br />
d. all of the above<br />
3. For periapical pathology, the radiographic<br />
projection of choice is usually _________.<br />
a. a series of bitew<strong>in</strong>g images<br />
b. a series of periapical images<br />
c. a series of periapical and bitew<strong>in</strong>g images<br />
d. none of the above<br />
4. <strong>Digital</strong> receptors are available <strong>in</strong><br />
________.<br />
a. rigid wired or wireless charge-coupled devices<br />
b. photostimulable phosphor plate (PSP) receptors<br />
c. complementary metal oxide semi-conductors or<br />
complementary-metal-oxide semiconductor active<br />
pixel sensor receptors<br />
d. all of the above<br />
5. For rigid receptors, the Centers for Disease<br />
Control and Prevention recommends<br />
_________.<br />
a. us<strong>in</strong>g a s<strong>in</strong>gle barrier, with an external barrier<br />
b. us<strong>in</strong>g a s<strong>in</strong>gle barrier, with an <strong>in</strong>ternal barrier<br />
c. us<strong>in</strong>g a double barrier, with both an <strong>in</strong>ternal and<br />
external barrier<br />
d. us<strong>in</strong>g a s<strong>in</strong>gle barrier, with both an <strong>in</strong>ternal and<br />
external barrier<br />
6. Phosphor plate receptors _________.<br />
a. are more flexible than rigid receptors<br />
b. are th<strong>in</strong>ner than rigid receptors<br />
c. have the same dimensions as film<br />
d. all of the above<br />
7. To capture the distal surface of can<strong>in</strong>es,<br />
it may be easier to take an additional anterior<br />
periapicals on each arch to capture<br />
the _________.<br />
a. can<strong>in</strong>e-lateral <strong>in</strong>cisor contact<br />
b. premolar-premolar contact<br />
c. can<strong>in</strong>e-premolar contact<br />
d. all of the above<br />
8. The parallel<strong>in</strong>g technique is used for<br />
_________ radiographs.<br />
a. periapical<br />
b. bitew<strong>in</strong>g<br />
c. panoramic<br />
d. a and b<br />
9. For the parallel<strong>in</strong>g technique, the x-ray<br />
beam should be directed _________ to the<br />
teeth and receptor.<br />
a. perpendicular<br />
b. at an acute angle<br />
c. at right angles<br />
d. at an obtuse angle<br />
10. For patients who gag easily or for<br />
children, tab bitew<strong>in</strong>gs are _________ for<br />
the patient.<br />
a. less convenient<br />
b. less cumbersome<br />
c. more comfortable<br />
d. b and c<br />
11. Central ray entry po<strong>in</strong>ts will help with<br />
_________.<br />
a. position<strong>in</strong>g of the sensor plate<br />
b. x-ray beam reduction<br />
c. x-ray beam lateralization<br />
d. x-ray beam center<strong>in</strong>g<br />
Questions<br />
12. The bisect<strong>in</strong>g angle technique is an<br />
alternate approach for _________.<br />
a. bitew<strong>in</strong>g radiography<br />
b. periapical radiography<br />
c. occlusal radiography<br />
d. all of the above<br />
13. Application of the bisect<strong>in</strong>g angle<br />
technique has become more common <strong>in</strong><br />
digital radiography with _________.<br />
a. rigid digital receptors<br />
b. flexible digital receptors<br />
c. flexible x-ray film<br />
d. none of the above<br />
14. When us<strong>in</strong>g the bisect<strong>in</strong>g angle<br />
technique, for a maxillary molar the<br />
angulation should be _________.<br />
a. +15° to +25°<br />
b. -15° to - 25°<br />
c. +25° to +35°<br />
d. -25° to -35°<br />
15. When us<strong>in</strong>g the bisect<strong>in</strong>g angle<br />
technique, for a mandibular can<strong>in</strong>e the<br />
angulation should be _________.<br />
a. +10° to +15°<br />
b. +15° to +25°<br />
c. -10° to -15°<br />
d. -15° to -25°<br />
16. For a periapical radiograph of the maxillary<br />
can<strong>in</strong>e, the central ray entry po<strong>in</strong>t<br />
should be the ________.<br />
a. corner of the mouth<br />
b. ala of the nose<br />
c. tip of the nose<br />
d. none of the above<br />
17. For a mandibular central <strong>in</strong>cisor periapical<br />
radiograph, a ________ should be used<br />
for the receptor orientation.<br />
a. horizontal placement<br />
b. vertical placement<br />
c. diagonal placement<br />
d. any of the above<br />
18. For a molar bitew<strong>in</strong>g radiograph, a<br />
________ should be used for the receptor<br />
orientation.<br />
a. horizontal placement<br />
b. vertical placement<br />
c. diagonal placement<br />
d. horizontal or vertical placement<br />
19 Technique adaptations may be required<br />
________.<br />
a. due to anatomical considerations<br />
b. <strong>in</strong> the presence of endodontic files<br />
c. to avoid patient discomfort<br />
d. all of the above<br />
20. If a patient has a shallow palate, the cl<strong>in</strong>ician<br />
can ________.<br />
a. use the bisect<strong>in</strong>g technique <strong>in</strong>stead of the parallel<strong>in</strong>g<br />
technique and move the receptor more towards<br />
the midl<strong>in</strong>e<br />
b. use the parallel<strong>in</strong>g technique <strong>in</strong>stead of the bisect<strong>in</strong>g<br />
technique and move the receptor farther from<br />
the midl<strong>in</strong>e<br />
c. use the parallel<strong>in</strong>g technique <strong>in</strong>stead of the bisect<strong>in</strong>g<br />
technique and move the receptor more towards<br />
the midl<strong>in</strong>e<br />
d. use the bisect<strong>in</strong>g technique <strong>in</strong>stead of parallel<strong>in</strong>g<br />
technique and move the receptor farther from the<br />
midl<strong>in</strong>e<br />
21. With gagg<strong>in</strong>g patients it is important to<br />
_________.<br />
a. be organized<br />
b. preset the exposure time and pre-align the PID<br />
c. be ready to act quickly<br />
d. all of the above<br />
www.rdhmag.com<br />
22. The most common area to elicit the gag<br />
reflex is the ________ view.<br />
a. maxillary molar periapical<br />
b. mandibular molar periapical<br />
c. maxillary <strong>in</strong>cisor periapical<br />
d. mandibular <strong>in</strong>cisor periapical<br />
23. The use of _________ can improve<br />
patient comfort.<br />
a. receptor cushions<br />
b. topical anesthetic agents<br />
c. lightweight bite blocks<br />
d. all of the above<br />
24. Self-adhesive foam covers can be used<br />
_________.<br />
a. over the receptor for bitew<strong>in</strong>gs<br />
b. over the receptor for periapicals<br />
c. to smooth the edges and provide cushion<strong>in</strong>g<br />
d. all of the above<br />
25 When adhesive tabs are used, keep<strong>in</strong>g the<br />
sensor firmly with<strong>in</strong> the sensor barrier can<br />
be achieved by us<strong>in</strong>g _________.<br />
a. a th<strong>in</strong> foam layer<br />
b. a thick foam layer<br />
c. a th<strong>in</strong> polystyrene layer<br />
d. a thick polystyrene layer<br />
26. Lead collars _________.<br />
a. are designed to protect the thyroid<br />
b. substantially reduce radiation to the thyroid<br />
c. is a best practice together with the use of lead<br />
aprons<br />
d. all of the above<br />
27.In radiography, ALARA stands for<br />
_________.<br />
a. As Level As Reasonably Achievable<br />
b. As Low As Reasonably Acceptable<br />
c. As Low As Reasonably Achievable<br />
d. none of the above<br />
28. Vertical angulation errors _________.<br />
a. distort the length of the structures<br />
b. result <strong>in</strong> either foreshorten<strong>in</strong>g or elongation<br />
c. are more common <strong>in</strong> bisect<strong>in</strong>g angle technique than<br />
with parallel<strong>in</strong>g technique<br />
d. all of the above<br />
29. Horizontal angulation errors result <strong>in</strong><br />
and _________.<br />
a. overlapp<strong>in</strong>g of proximal surfaces<br />
b. limit caries evaluations<br />
c. limit bone loss evaluations<br />
d. all of the above<br />
30. Cone cutt<strong>in</strong>g can be corrected by<br />
_______.<br />
a. <strong>in</strong>creas<strong>in</strong>g the vertical angulation of the PID<br />
b. center<strong>in</strong>g the x-ray beam over the image receptor<br />
c. decreas<strong>in</strong>g the vertical angulation of the x-ray beam<br />
d. direct<strong>in</strong>g the x-rays between the contacts of the<br />
teeth RRNOV11RDH<br />
November 2011<br />
November 2011<br />
ANSWER SHEET<br />
Title<br />
Name: Title: Specialty:<br />
Address: E-mail:<br />
City: State: ZIP: Country:<br />
Telephone: Home ( ) Office ( ) Lic. Renewal Date:<br />
Requirements for successful completion of the course and to obta<strong>in</strong> dental cont<strong>in</strong>u<strong>in</strong>g education credits: 1) Read the entire course. 2) Complete all<br />
<strong>in</strong>formation above. 3) Complete answer sheets <strong>in</strong> either pen or pencil. 4) Mark only one answer for each question. 5) A score of 70% on this test will earn<br />
you 2 CE credits. 6) Complete the Course Evaluation below. 7) Make check payable to PennWell Corp. For Questions Call 216.398.7822<br />
1. Place objective 1 here.<br />
2. Place objective 2 here.<br />
3. Place objective 3 here.<br />
4 Place objective 4 here.<br />
Educational Objectives<br />
Course Evaluation<br />
1. Were the <strong>in</strong>dividual course objectives met? Objective #1: Yes No No Objective Yes #3:<br />
Objective #2: Yes No Objective #4: Yes No<br />
Please evaluate this course by respond<strong>in</strong>g to the follow<strong>in</strong>g statements, us<strong>in</strong>g a scale of Excellent = 5 to Poor = 0.<br />
2. To what extent were the course objectives accomplished overall? 5 4 3 2 1 0<br />
3. Please rate your personal mastery of the course objectives. 5 4 3 2 1 0<br />
4. How would you rate the objectives and educational methods? 5 4 3 2 1 0<br />
5. How do you rate the author’s grasp of the topic? 5 4 3 2 1 0<br />
6. Please rate the <strong>in</strong>structor’s effectiveness. 5 4 3 2 1 0<br />
7. Was the overall adm<strong>in</strong>istration of the course effective? 5 4 3 2 1 0<br />
8. Please rate the usefulness and cl<strong>in</strong>ical applicability of this course. 5 4 3 2 1 0<br />
9. Please rate the usefulness of the supplemental webliography. 5 4 3 2 1 0<br />
10. Do you feel that the references were adequate? Yes oN<br />
11. Would you participate <strong>in</strong> a similar program on a different topic? Yes oN<br />
12. If any of the cont<strong>in</strong>u<strong>in</strong>g education questions were unclear or ambiguous, please list them.<br />
___________________________________________________________________<br />
13. Was there any subject matter you found confus<strong>in</strong>g? Please describe.<br />
___________________________________________________________________<br />
___________________________________________________________________<br />
14. How long did it take you to complete this course?<br />
___________________________________________________________________<br />
___________________________________________________________________<br />
15. What additional cont<strong>in</strong>u<strong>in</strong>g dental education topics would you like to see?<br />
___________________________________________________________________<br />
___________________________________________________________________<br />
COURSE EVALUATION and PARTICIPANT FEEDBACK<br />
We encourage participant feedback perta<strong>in</strong><strong>in</strong>g to all courses. Please be sure to complete the survey <strong>in</strong>cluded with the course.<br />
Please e-mail all questions to: michellef@pennwell.com.<br />
INSTRUCTIONS<br />
All questions should have only one answer. Grad<strong>in</strong>g of this exam<strong>in</strong>ation is done manually. Participants will receive<br />
confirmation of pass<strong>in</strong>g by receipt of a verification form. Verification of Participation forms will be mailed with<strong>in</strong> two<br />
weeks after tak<strong>in</strong>g an exam<strong>in</strong>ation.<br />
PLEASE PHOTOCOPY ANSWER SHEET FOR ADDITIONAL PARTICIPANTS.<br />
PROVIDER INFORMATION<br />
Pennwell is an ADA CERP Recognized Provider. ADA CEROP is a service of the American Dental association to assist dental<br />
professionals <strong>in</strong> identify<strong>in</strong>g quality providers of cont<strong>in</strong>u<strong>in</strong>g dental education. ADA CERP does not approve or endorse<br />
<strong>in</strong>dividual courses or <strong>in</strong>structors, not does it imply acceptance of credit hours by boards of dentistry.<br />
Concerns or compla<strong>in</strong>ts about a CE Provider may be directed to the provider or to ADA CERP ar www.ada.org/cotocerp/<br />
COURSE CREDITS/COST<br />
All participants scor<strong>in</strong>g at least 70% on the exam<strong>in</strong>ation will receive a verification form verify<strong>in</strong>g 2 CE credits. The formal<br />
cont<strong>in</strong>u<strong>in</strong>g education program of this sponsor is accepted by the AGD for Fellowship/Mastership credit. Please contact<br />
PennWell for current term of acceptance. Participants are urged to contact their state dental boards for cont<strong>in</strong>u<strong>in</strong>g<br />
education requirements. PennWell is a California Provider. The California Provider number is 4527. The cost for courses<br />
ranges from $29.00 to $110.00.<br />
www.rdhmag.com<br />
If not tak<strong>in</strong>g onl<strong>in</strong>e, mail completed answer sheet to<br />
Academy of Dental Therapeutics and Stomatology,<br />
A Division of PennWell Corp.<br />
P.O. Box 116, Chesterland, OH 44026<br />
or fax to: (440) 845-3447<br />
For iMMEDiATE results,<br />
go to www.<strong>in</strong>eedce.com to take tests onl<strong>in</strong>e.<br />
Answer sheets can be faxed with credit card payment to<br />
(440) 845-3447, (216) 398-7922, or (216) 255-6619.<br />
Payment of $49.00 is enclosed.<br />
(Checks and credit cards are accepted.)<br />
If pay<strong>in</strong>g by credit card, please complete the<br />
follow<strong>in</strong>g: MC Visa AmEx Discover<br />
Acct. Number: ______________________________<br />
Exp. Date: _____________________<br />
Charges on your statement will show up as PennWell<br />
AGD Code XXX<br />
RECORD KEEPING<br />
PennWell ma<strong>in</strong>ta<strong>in</strong>s records of your successful completion of any exam for a m<strong>in</strong>imum of six years. Please contact our<br />
offices for a copy of your cont<strong>in</strong>u<strong>in</strong>g education credits report. This report, which will list all credits earned to date, will<br />
be generated and mailed to you with<strong>in</strong> five bus<strong>in</strong>ess days of receipt.<br />
Complet<strong>in</strong>g a s<strong>in</strong>gle cont<strong>in</strong>u<strong>in</strong>g education course does not provide enough <strong>in</strong>formation to give the participant the<br />
feel<strong>in</strong>g that s/he is an expert <strong>in</strong> the field related to the course topic. It is a comb<strong>in</strong>ation of many educational courses and<br />
cl<strong>in</strong>ical experience that allows the participant to develop skills and expertise.<br />
CANCELLATION/REFUND POLICY<br />
Any participant who is not 100% satisfied with this course can request a full refund by contact<strong>in</strong>g PennWell <strong>in</strong> writ<strong>in</strong>g.<br />
© 2011 by the Academy of Dental Therapeutics and Stomatology, a division of PennWell<br />
89