Position statement of the American Academy of Oral and
Maxillofacial Radiology on selection criteria for the use of
radiology in dental implantology with emphasis on cone beam
Donald A. Tyndall, DDS, MSPH, PhD,aJeffery B. Price, DDS, MS,bSotirios Tetradis, DDS, PhD,c
Scott D. Ganz, DMD,dCharles Hildebolt, DDS, PhD,eand William C. Scarfe, BDS, MSf
A Position Paper Subcommittee of the American Academy of Oral and Maxillofacial Radiology (AAOMR) reviewed the
literature since the original position statement on selection criteria for radiology in dental implantology, published in
2000. All current planar modalities, including intraoral, panoramic, and cephalometric, as well as cone beam computed
tomography (CBCT) are discussed, along with radiation dosimetry and anatomy considerations. We provide research-
based, consensus-derived clinical guidance for practitioners on the appropriate use of specific imaging modalities in
dental implant treatment planning. Specifically, the AAOMR recommends that cross-sectional imaging be used for the
assessment of all dental implant sites and that CBCT is the imaging method of choice for gaining this information. This
document will be periodically revised to reflect new evidence. (Oral Surg Oral Med Oral Pathol Oral Radiol 2012;113:
In 2000, the American Academy of Oral and Maxillofa-
cial Radiology (AAOMR) published a position paper on
the role of imaging in dental-implant treatment planning.1
They state, “After reviewing the current literature, the
AAOMR recommends that some form of cross-sectional
imaging be used for implant cases and that conventional
cross-sectional tomography be the method of choice for
gaining this information for most patients receiving im-
plants.” Since then, the introduction and increased use of
maxillofacial cone beam computed tomography (CBCT)
has had an impact on the availability of digital, cross-
sectional imaging and expanded imaging clinical applica-
tions for dental-implant imaging.2-18
In 2008, the Executive Council (EC) of the AAOMR
published an executive opinion statement on the per-
formance and interpretation of CBCT in dentistry.19
The EC proposed guidelines and principles for CBCT
use in contemporary dental practice; these included
practitioner responsibilities, the requirement for docu-
mentation, and the need for radiation-dose and quality-
assurance optimization. If CBCT is used (as with any
radiographic imaging technology), the benefits to the
patient must outweigh the risks associated with expo-
sure to ionizing radiation.
The purpose of developing imaging selection criteria
for implant therapy is to identify the most appropriate
imaging technology for each stage of patient care.1The
development of selection criteria is based on review of
treatment-decision and outcome-assessment studies.
Although more than 10 years have passed since publi-
cation of the AAOMR position paper on dental im-
plants,1studies of the clinical efficacy of cross-sec-
tional imaging for implant planning decisions have
The purpose of this document is to summarize cur-
rent knowledge about maxillofacial imaging (with em-
phasis on CBCT) for dental, endosseous-implant ther-
apy and to provide up-to-date radiographic selection
criteria for dental implantology. The recommendations
presented are not prescriptive but rather advisory and
are intended to provide the dental profession with cur-
rent considered opinions on the appropriate imaging for
implant dentistry. The underlining goal is to maximize
diagnostic efficiency while minimizing patient radia-
CLINICAL CONSIDERATIONS IN SELECTION
CRITERIA FOR DENTAL IMPLANTOLOGY
The diagnostic phase of dental-implant therapy and, in
particular, the appropriate choice of radiographic ex-
aDiplomate, American Board of Oral and Maxillofacial Radiology,
University of North Carolina at Chapel Hill School of Dentistry,
Chapel Hill, NC.
bDiplomate, American Board of Oral and Maxillofacial Radiology,
Meharry Medical College School of Dentistry, Nashville, TN.
cDiplomate, American Board of Oral and Maxillofacial Radiology,
University of California in Los Angeles School of Dentistry, Los
dPrivate practice limited to Prosthodontics, Maxillofacial Prosthetics,
and Implant Dentistry, Fort Lee, NJ.
eMallinckrodt Institute of Radiology, Washington University in St.
Louis School of Medicine, St Louis, MO.
fDiplomate, American Board of Oral and Maxillofacial Radiology,
University of Louisville School of Dentistry, Louisville, KY.
© 2012 Elsevier Inc. All rights reserved.
2212-4403/$ - see front matter
Vol. 113 No. 6 June 2012
amination is important to the long-term success of a
dental implant. Over the past decade, there has been a
dramatic conceptual shift from a surgically driven to a
prosthetically driven approach to dental-implant ther-
apy.5,14,17,26,27It is no longer acceptable practice to
place implants in alveolar bone without a previously
developed plan for prosthetic restoration. To optimize
implant placement and to avoid surgical complications,
the clinician must have full knowledge of oral-bone
anatomy so that any osseous-topography, bone-volume
excesses/deficiencies can be corrected before implant
Several organizations, including the Faculty of Gen-
eral Dental Practice (UK),32Academy of General Den-
tistry,33and Academy of Osseointegration,26dichoto-
mize dental-implant placement difficulty as either
straightforward or complex based on specific, patient-
presenting characteristics. A straightforward case is one
for which the “desired tooth position is clear,” the
surgical procedure “involves minimal anatomical
risks,” and there is no need for “significant hard or soft
tissue grafting or modification of anatomical struc-
tures.” A complex case is one for which the tooth
position is “not easily identifiable” with a possible need
for “extensive hard and soft tissue grafting” of the
residual alveolar ridge. The International Team for Im-
plantology (ITI) recommends the SAC classification,
which has 3 levels of difficulty: straightforward (S),
advanced (A), and complex (C).27,34This system pro-
vides general and site-specific criteria of surgical and
prosthetic degrees of difficulty to define case types.
Presurgical assessment guidelines underscore the need
for accurate assessment of bone volume and location of
adjacent anatomical structures in relation to prostheti-
cally derived, dental-implant positioning.
Each location in the dental alveolus has unique mor-
phologic characteristics owing to edentulousness and
specific regional anatomic features that need to be
identified and assessed in the diagnostic and treatment-
planning phase of dental-implant therapy.
The maxillary anterior region (commonly referred to
as the esthetic zone) often presents both surgical and
prosthetic implant-assessment complexities.27,34Sub-
sequent to tooth loss, decrease in the height and/or
width of the alveolar process and the development of a
labial concavity often necessitate bone augmenta-
tion.5,16The morphology and dimension of the naso-
palatine (incisive canal)3,6-38and the location of the
floor of the nasal fossae may also compromise the
available bone volume.
The available residual alveolar ridge in the posterior,
maxillary molar region is limited superiorly by the floor
of the maxillary sinus. Assessment of the extent of this
structure, including the locations of septae, is important
in determining the bone volume available for implant
placement and the possible need for bone-supplemen-
tation procedures, such as sinus lift and bone augmen-
tation.39Of the various regions of the maxilla and
mandible, the maxillary posterior region has the lowest
bone density and the highest implant failure rate.40,41
Assessment of the anterior recess of the maxillary sinus
is also important if markedly angled implants are con-
sidered for implant-supported edentulous prostheses.
Although the anterior mandible is a relatively safe
location for implant placement, to avoid intraoperative
and postoperative hemorrhage, neurosensory loss, and
to increase the likelihood of osseointegration, the loca-
tions of osseous and intraosseous neurovascular struc-
tures must be identified before osteotomy and subse-
quent implant placement.16Osseous structures include
the lingual cortical plates,42,43and neurovascular struc-
tures include the lingual foramen,44the terminal branch
of the inferior alveolar canal, the mandibular incisive
canal, the anterior loop,45and the mental foramen of
the inferior alveolar canal.46,47
In the posterior mandible, there are several anatomic
structures that can compromise prosthetically driven,
dental-implant placement. The lingual concavity (sub-
mandibular gland fossa, submandibular fossa) below
the mylohyoid ridge and the inferior alveolar (mandib-
ular) canal have variations that can restrict implant
placement. The deficiencies of 2-dimensional imaging
techniques for accurate location of the inferior alveolar
canal are well documented.48-51
A number of radiographic examinations are used for
preoperative, dental-implant-site assessment. Clini-
cians commonly use 2 or more examinations. Each
examination has specific indications, advantages, and
disadvantages. A perfect imaging examination for den-
tal-implant treatment planning does not exist.
Plain film radiography. This term refers to projec-
tion images obtained with a stationary x-ray source and
area detector. Plain-film images represent the entire
volume through which the x-ray beam is transmitted
and is subject to differential magnification, geometrical
distortion, and anatomic superimposition.
Periapical intraoral radiography provides images of
limited dentoalveolar regions. These images have ex-
cellent spatial and contrast resolution with minimal
distortions. Images taken using film-holding devices
allow regional visualizations of vertical and anteropos-
terior bounds of residual alveolar ridges and identifica-
ORAL AND MAXILLOFACIAL RADIOLOGY
Tyndall et al.
tions of adjacent anatomical structures. The technique
is the most widely available, inexpensive, and most
common initial dental radiographic examination for
implant-site assessment. The technique, however, is
highly operator dependent and requires a moderate
level of patient compliance to provide images with
minimal geometrical distortions. Because reproducible
imaging geometry is difficult to obtain in areas of
extended edentulousness, images of these areas have
relatively low reliabilities and accuracies. Vertical ac-
curacy can be improved by using a radiographic marker
of known dimension to calibrate image measure-
ments.52The greatest limitation of this strategy is the
lack of cross-sectional information to access bone vol-
Because occlusal radiography provides information
on the general shape of the residual dental arch and
maximum bucco-lingual dimension of the alveolar
ridge, occlusal radiography has been proposed as a
supplement to periapical radiography for implant as-
sessments. Occlusal radiography, however, provides no
information in addition to that provided by dental study
models, and its use is, therefore, not justified for im-
The entire maxillofacial area is contained within a
lateral cephalometric radiograph, which includes 2-di-
mensional representations of the anteroposterior and
vertical relationships of the maxillary and mandibular
dental arches. Because of fixed, image-projection ge-
ometry, midline structures have constant magnifica-
tions, and this allows assessments of interarch, dentoal-
veolar positions and angulations. Edentulous spaces in
the midline are represented as cross-sectional images
that can be calibrated to provide accurate measurement
of bucco-lingual as well as vertical bone dimensions of
the anterior residual alveolar ridge. Equipment for lat-
eral cephalometric radiography is readily available, and
cephalometric images are relatively easy to obtain and
of low cost. The use of these images is limited, how-
ever, in that they provide uniformly magnified images
of midline structures only.53Although oblique, lateral
cephalograms are used to image anterolateral seg-
ments,54the alveolar process is often obscured by the
superimposition of teeth adjacent to the edentulous
Rotational panoramic radiography. This is the most
commonly used extraoral imaging modality in implant
are placed within a focal trough (a volumetric curved
columnar space), and a narrow x-ray beam moves in
synchrony and in opposite directions with an x-ray recep-
tor. The result is a projection image of the jaws. Pan-
oramic radiographs provide information on the inferior
alveolar canals and maxillary sinuses and may show
pathologic conditions not demonstrated on complete, in-
is commonly available, is relatively low cost, provides
information on both dental arches, and is useful in the
initial diagnostic phase of implant planning. By calculat-
ing the ratio between image dimensions and known di-
mensions of radiopaque markers on a radiographic stent,
estimates of the available vertical distances between the
alveolar crest and anatomic structures can be estimated at
specific positions in a panoramic image. Many factors,
however, limit the accuracy and reliability of this calcu-
lation. These include (1) patient-positioning errors, (2)
inherent distortions related to equipment differences, (3)
discrepancies between the shape of the dental arch and
focal trough, and (4) beam angulation.55Only 17% of
measurements from the crest of the residual alveolar ridge
to the inferior alveolar canal have errors of ?1 mm.50A
major limitation of panoramic radiography is that bucco-
lingual assessments cannot be made. Because of its inher-
ent limitations, panoramic radiography is considered un-
suitable as a single imaging source for dental-implant site
Cross-sectional imaging techniques. Cross-sectional
imaging techniques produce in-focus, thin-section im-
ages. Cross-sectional images can be produced with
conventional tomography, panoramic-based scanogra-
phy and tomography, CBCT, and computed tomogra-
phy (CT). (In this position paper, the term “computed
tomography” and the abbreviation “CT” represent scan-
ners that use multirow, detector arrays. CT scanners are
most commonly used in medical radiology departments
and hospitals.) Tomographic images can also be ob-
tained with magnetic resonance (MR) imaging. Tomo-
graphic techniques produce multiple, contiguous image
sections (slices) with minimal distortions, and uniform
thicknesses and magnifications. In addition, images can
be reconstructed such that they are perpendicular to
each other. The main advantage of these images for
implant dentistry is that they minimize or eliminate
anatomic superimposition. Image sections perpendicu-
lar to the long axis of the region (object) of interest
(e.g., the mandibular arch) are referred to as cross-
sectional trans-axial images. Cross-sectional images
provide optimal accuracy for visualizing the bony ar-
chitecture of the jaws.28,59-62
Unimodal machines capable of conventional tomog-
raphy for the assessment of implant sites gained
increasing popularity throughout the 1980s and
1990s.63In conventional tomography, the x-ray
Volume 113, Number 6
Tyndall et al. 819
source and the receptor move in synchrony and in
opposite directions to each other about a fixed ful-
crum, and this results in the blurring of structures
outside the image plane, which is at the level of the
fulcrum. For implant dentistry, this provides uni-
formly magnified images in 2 dimensions usually
sagittal and coronal (cross-sectional). A limitation of
this technique is that it produces images of limited
regions (a few teeth) of a single dental arch. Only
objects within the specific region of interest are in
focus. Usually stents with radiopaque markers are
needed to confirm positions of imaged sites. Because
of blurring outside the region in focus, it is often
difficult to identify structures and interpret the im-
ages.64-66Increasing complex, synchronized, poly-
directional movement patterns (e.g., circular, elliptic,
hypocycloidal and tri-spiral) increase image clarity
but also increase patient dose. These limitations re-
duce the usefulness of this technique for implant
dentistry, particularly for the assessment of multiple
Some panoramic units use x-ray beam motions and area
receptors to produce planar or curved (scanogram) to-
mographic images. Units vary markedly in the ana-
tomic localization methods used, the number and thick-
ness of tomographic slices, and the resultant image
magnifications. Images are often extremely wide com-
pared with the area under study, may not cover the
region of interest sufficiently, and suffer from blur,
making interpretation of images difficult.67Although
this technique can be helpful in preliminary evaluations
of specific implant sites, the technique is time-consum-
ing and multiple inter- or intra-arch implant site assess-
ments require multiple exposures.
Data acquisition in CT has evolved over the past 4
decades with 4 generations of CT scanners. The most
advanced systems use fan-beam radiation and multiple
detector arrays. Usually, one source of fan-beam radi-
ation is used. The user makes selections to define the
spatial resolution, field of view (FOV), and image
sharpness. As the object being scanned is translated
through the CT scanner, the object attenuates the x-ray
beam, and the attenuated x-ray beam data are collected
by detector arrays. From the volume of data that is
collected, mathematical formulas are used to recon-
struct volumetric and/or multiplanar images. The mul-
tiplanar reconstructions can have various image thick-
nesses (several mm to tenths of mm) and be in any
image plane (sagittal, coronal, axial, or any plane in
between). Images are undistorted, calibrated for dimen-
sional accuracy, and have high soft tissue and hard
tissue contrast resolution.68With the use of phantoms
and appropriate calibrations, small changes in ra-
diodensities can be detected.69Dual-source, dual-en-
ergy CT has been developed for use in angiography and
for making more accurate measurements of hard and
soft tissues. New techniques are being introduced for
exposure reductions with the use of CT. CT is relatively
expensive and usually available in hospitals and med-
ical imaging centers only.
Cone beam computed tomography
CBCT differs from CT in that it uses a single x-ray
source that produces a cone beam of radiation (rather
than a fan beam, as with CT). There is no accepted
definition of when a fan beam (which is assumed to be
planar) becomes a cone beam.70CBCT uses a single,
relatively inexpensive, flat-panel or image intensifier
radiation detector. CBCT imaging is performed using a
rotating platform to which the x-ray source and detector
are fixed. The x-ray source and detector rotate around
the object being scanned and multiple, sequential, pla-
nar projection images are acquired in an arc of 180° or
greater and are mathematically reconstructed into a
volumetric dataset.71Only one rotational sequence is
necessary to acquire enough data for volumetric image
construction because the entire FOV is irradiated si-
multaneously. The first CBCT unit with specific max-
illofacial application (the NewTom DVT 9000; QR srl,
Verona, Italy) became commercially available in Eu-
rope in 1999. The adoption of this technology in den-
tistry has expanded exponentially since then owing to
numerous technical improvements and commercial
market forces. Many CBCT devices are now multi-
modal, providing panoramic and cephalometric imag-
ing. Most have a low footprint suitable for dental office
placement, are technically as easy to operate as pan-
oramic units, allow collimation of the beam to the
region of interest to reduce patient radiation exposures,
and produce submillimeter resolution images of high
quality. Although CBCT images have high spatial res-
olution, the data from which images are created con-
tains considerable noise caused by scattered radiation.
Because formulas do not exist to correct for this scat-
tered radiation, soft tissue contrast in CBCT images is
inferior to that in CT images and CBCT images are not
appropriate for detecting small changes in radiodensi-
Both CT and CBCT volumetric datasets can be ex-
ported in DICOM (Digital Imaging and Communications
in Medicine) format and imported into third-party soft-
ware that is specifically designed for implant planning.
With such software, various 3-dimensional and cross-
sectional images can be created. It is also possible to
ORAL AND MAXILLOFACIAL RADIOLOGY
Tyndall et al.
create virtual image-displays; simulated, implant place-
ments7,15,72; and to use the software for computer-guided
surgery.6,8-10,60-62,73Both CT and CBCT are used to per-
form multidimensional, presurgical assessments of anat-
omy, thereby reducing the possibilities of incorrect im-
plant placements, which can result in untoward sequelae,
such as perforations of cortical borders and invasions of
adjacent structures.11,12,28-31,37,38,44,74-76In comparison
with conventional dental imaging, volumetric, data sets
provide additional information that can be used for more
sophisticated analyses and expanded, treatment-planning
options that result in higher likelihoods for achieving
satisfactory prosthetic results. For use in implant dentistry,
a major advantage of CBCT compared with CT is that
CBCT equipment is usually far less expensive than CT
equipment. Another advantage is that CBCT software for
use in planning implants is usually much easier to use and
far more useful than is software available with CT. The
primary disadvantages of both CT and CBCT are their
relative higher effective radiation exposures77and addi-
tional costs compared with plain, panoramic and some
other cross-sectional radiographic methods.
Magnetic resonance imaging
With MR imaging (which does not use ionizing radia-
tion), cross-sectional images (suitable for dental-im-
plant treatment planning) can be created78-80The lim-
itations of these images for dental-implant imaging are
the increased imaging scan times, dentists’ unfamiliar-
ity with MR images, and higher costs. For dental-
implant imaging, MR images are of research and edu-
cational interest only.
RADIATION DOSE CONSIDERATIONS
Understanding the radiation dose imparted to the pa-
tient is an important patient safety issue. Appropriate
selection criteria must be used with the minimum radi-
ation exposures that result in images of acceptable
diagnostic qualities.19,81This concept is known as
ALARA (as low as reasonably achievable). Radiat-
ion effective doses are available (E2007)82for various
maxillofacial imaging modalities, including CT and
CBCT.3,77,83-90Although CBCT usually results in
lower doses than CT, both result in substantially higher
doses to patients than do other dental-implant imaging
methods. With both CT and CBCT, there is wide vari-
ability in doses among different systems and among
different imaging protocols (slice thickness, FOV,
mAs, kVp, scan time). It is recommended that appro-
priate selection criteria be used along with imaging
protocols that use the minimal doses that ensure accept-
able diagnostic qualities.
PRINCIPLES OF IMAGING FOR
The basic principles of radiology apply to imaging for im-
plant evaluations. Images should have appropriate diag-
nostic quality and not contain artifacts that compromise
anatomic-structure assessments. Images should extend be-
yond the immediate area of interest to include areas that
could be affected by implant placements. Practitioners
should have appropriate training in operating radiographic
equipment and competence in interpreting images from
the modality used. This training and competence should
be maintained through continuing dental education
courses. Such training should include a thorough review
of normal maxillofacial anatomy, common anatomic vari-
ants, and imaging signs of diseases and abnormalities.
This is particularly important for CT and CBCT19imag-
ing because of the complexity of structures within the
The goal of radiographic selection criteria is to identify
appropriate imaging modalities that complement the goals
at each stage of implant therapy. The use of specific
imaging is based on professional judgment (i.e., the clini-
cian’s professional opinion as to whether or not informa-
tion from the clinical examination is inadequate and im-
aging is needed to formulate a diagnosis and a treatment
plan, and/or for use at surgery). Professional judgment
varies depending on the skill, competence, knowledge,
and experience of the clinician. Specific considerations
must include clinical and anatomic complexity, potential
ing selection criteria recommendations provide literature-
based, consensus-derived, clinical guidance for practitio-
ners on the appropriate imaging (with particular relevance
to CBCT) at each phase of dental-implant therapy.
1. Initial examination
Maxillofacial imaging interfaces with patient history,
clinical examination, definitive diagnosis, treatment
planning, and implant therapy. The purpose of the
initial radiographic examination is to assess the overall
status of the remaining dentition, to identify and char-
acterize the location and nature of the edentulous re-
gions, and to detect regional anatomic abnormalities
and pathologies. Any of these may have important
ramifications in the overall timing and sequencing of
treatment phases, such as implant loading protocols and
postprosthetic occlusal protection.
Recommendation 1. Panoramic radiography should
be used as the imaging modality of choice in the initial
evaluation of the dental implant patient.
Recommendation 2. Use intraoral periapical radiog-
raphy to supplement the preliminary information from
Volume 113, Number 6
Tyndall et al. 821
Recommendation 3. Do not use cross-sectional im-
aging, including CBCT, as an initial diagnostic imaging
2. Preoperative site specific imaging
Imaging for presurgical, dental-implant planning must
provide information supportive of the following goals.
1. Establish the morphologic characteristics of the
residual alveolar ridge (RAR). The morphology of
the RAR includes considerations of bone volume
and quality. Vertical bone height, horizontal width,
and edentulous saddle length determine the amount
of bone volume available for implant fixture place-
ment. This information is necessary to match the
available bone dimensions with the number and
physical dimensions of the implant(s). Moderate
deficiencies in horizontal and vertical bone may be
corrected by augmentation procedures at the time of
the osteotomies and fixture placements, whereas se-
vere deficiencies require prior surgical procedures,
such as ridge augmentations. Similarly excessive or
irregular vertical alveolar bone may require prepro-
sthetic or simultaneous alveoloplasty.
It is generally agreed that the success of dental-implant
placement depends on oral bone quality. Currently,
however, there is no agreed on definition for the term
“bone quality” and no agreed on method for assessing
bone quality. Bone quality is considered good when
there is enough cortical and trabecular (cancellous)
bone to hold the implant securely (which is required for
osseointegration) and is considered poor when there is
inadequate oral bone to hold the implant securely.
Based on the abundance of published articles on assess-
ments of osteoporosis risks, there is little doubt that
oral-radiographic procedures are useful in assessing
bone quality; however, few studies have been devoted
to assessing oral-bone quality for implant placements.
The most commonly used classification system for as-
sessing oral-bone quality for implant placement was
introduced in 1985 and uses 4 radiographic oral-bone
classes that are based on visual assessments of the
amounts of the cortical and trabecular bone.91The use
of dental-radiographic trabecular features for the as-
sessment of implant sites has received little research
attention other than visual assessments of dense and
sparse trabeculation on radiographic images.92Al-
though several radiographic methods for assessing al-
veolar-bone quality have been suggested, no method
has been tested in large clinical trials and no method
can be recommended at this time. Better assessments of
bone quality may influence surgical technique, implant
selection (i.e., length, diameter, and type) and the load-
ing protocol. Research in this area is needed.
2. Determine the orientation of the RAR. The orien-
tation and residual topography of the alveolar-basal
bone complex must be assessed to determine
whether or not there are variations that could com-
promise the alignment of the implant fixture with the
planned prosthetic restoration. This is particularly
important in the mandible (e.g., submandibular
gland fossa) and anterior maxilla (e.g., labial cortical
3. Identify local anatomic or pathologic conditions
restricting implant placement. There are many
internal anatomic features that are not easily identi-
fied or localized by clinical examination or conven-
tional radiographic imaging that can compromise
and limit implant fixture placement or risk involve-
ment of adjacent structures. In the maxilla, these
include the incisor region (nasopalatine fossa and
canal, nasal fossa), the canine region (canine fossa,
nasal fossa), and the premolar/molar region (floor of
the maxillary sinus). In the mandible, these include
the incisor region (lingual foramen), canine/premo-
lar region (mental foramen), and molar region (sub-
mandibular gland fossa, inferior alveolar [mandibu-
lar] canal containing the neurovascular bundle).
4. Match imaging findings to the prosthetic plan.
Successful implant treatment planning involves both
surgical and prosthetic considerations. Radiographic
images are not only used for prosthetic planning, but
are also used to construct templates to guide surgical
procedures and implant placements. The use of
guided surgery for implant placement is increasing
because of a number of clinical advantages, includ-
ing increased practitioner confidence and reduced
operating time. Guided surgery requires imaging
capable of providing DICOM data (either CT or
CBCT). These data are imported into software pro-
grams where interactive surgical and prosthetic tools
can provide complex implant “simulations” within a
Most studies indicate that data from panoramic and
intraoral radiography alone are inadequate to accom-
plish these goals (particularly no. 4) and provide insuf-
ficient information to determine treatment difficulty.
Recommendation 4. The radiographic examination
of any potential implant site should include cross-
sectional imaging orthogonal to the site of interest.
This reaffirms the previously stated position of the
Conventional tomography provides cross-sectional
information but is technique sensitive and the images
are more difficult to interpret than CBCT. CBCT usu-
ally results in lower patient exposures to ionizing radi-
ation than does CT.
ORAL AND MAXILLOFACIAL RADIOLOGY
Tyndall et al.
Recommendation 5. CBCT should be considered as
the imaging modality of choice for preoperative cross-
sectional imaging of potential implant sites.
As with any type of imaging, a patient should be
exposed to the least amount of ionizing radiation that is
needed to produce CBCT images of acceptable diag-
nostic quality. This is achieved by careful selection of
exposure parameters and FOV. Although the FOV
should be limited to the area of interest, the FOV may
extend beyond the implant site to include the maxillary
sinus or opposing dental arch. CT may be considered
when CBCT is unavailable; however, dose-sparing pro-
tocols must be used.
The use of CBCT before bone grafting helps define
both the donor and recipient sites, allows for improved
planning for surgical procedures, and reduces patient
morbidities. CBCT is best for the evaluation of volu-
metric and topographic changes of the restored residual
Recommendation 6. CBCT should be considered
when clinical conditions indicate a need for augmenta-
tion procedures or site development before placement
of dental implants: (1) sinus augmentation, (2) block or
particulate bone grafting, (3) ramus or symphysis graft-
ing, (4) assessment of impacted teeth in the field of
interest, and (5) evaluation of prior traumatic injury.
Recommendation 7. CBCT imaging should be con-
sidered if bone reconstruction and augmentation proce-
dures (e.g., ridge preservation or bone grafting) have
been performed to treat bone volume deficiencies be-
fore implant placement.
3. Postoperative imaging
The purpose of postoperative imaging after dental-
implant placement is to confirm the location of the
fixture at implant insertion. From 3 to 5 years and
beyond, imaging is used to assess the bone-implant
interface and marginal peri-implant bone height. Tita-
nium implant fixtures inherently produce artifacts such
as beam-hardening and streak artifacts obscuring subtle
changes in marginal and peri-implant bone. In addition,
the resolution of CBCT images for the detection of
these findings is inferior to intraoral radiography.
Recommendation 8. In the absence of clinical signs
or symptoms, use intraoral periapical radiography for
the postoperative assessment of implants. Panoramic
radiographs may be indicated for more extensive im-
plant therapy cases.
Recommendation 9. Use cross-sectional imaging
(particularly CBCT) immediately postoperatively only
if the patient presents with implant mobility or altered
sensation, especially if the fixture is in the posterior
Recommendation 10. Do not use CBCT imaging for
periodic review of clinically asymptomatic implants.
Finally, implant failure, owing to either biological or
mechanical causes, requires a complete assessment to
characterize the existing defect, plan for surgical re-
moval and corrective procedures, such as ridge preser-
vation or bone augmentation, and identify the effect of
surgery or the defect on adjacent structures.
Recommendation 11. Cross-sectional imaging, op-
timally CBCT, should be considered if implant retrieval
Initial imaging assessment is best achieved with pan-
oramic radiography and may be supplemented with
periapical radiography. For the preoperative diagnostic
phase, the AAOMR reaffirms that cross-sectional im-
aging be used for implant site assessment. Furthermore,
the AAOMR recommends CBCT imaging as the cur-
rent method of choice for cross-sectional imaging in
that it provides the greatest diagnostic yield at an ac-
ceptable radiation dose risk. The decision to perform a
CBCT examination must be clinically justified and
based on professional judgment (that is, the judgment
of the clinician is that the use of CBCT will potentially
provide information needed for prosthetic treatment
planning, implant selection, and/or surgical placement).
The CBCT imaging protocol should include the small-
est FOV necessary and available and optimize exposure
parameters. For periodic, postoperative implant moni-
toring, periapical and, in some cases, panoramic images
provide adequate imaging. Finally, all CBCT volumes,
regardless of clinical application, should be systemati-
cally evaluated for signs of abnormalities. This can be
performed by the referring dentist or specialist (such as
an oral and maxillofacial radiologist) competent in the
interpretation of CBCT.
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