Transcript Slide 1

IN THE NAME OF GOD
Diagnostic Imaging and
Techniques
PRESENTED BY:DR.HASAN KHANI
SUPERVISED BY: DR. MANSOUR RISMANCHIAN
AND DR.SAIED NOSOUHIAN
DENTAL OF IMPLANTOLOGY
DENTAL IMPLANTS RESEARCH CENTER
ISFAHAN UNIVERSITY OF MEDIACAL SCIENCE
DIAGNOSTIC IMAGING AND
TECHNIQUES
The objectives of diagnostic imaging depend on a number of
factors, including the amount and type of information
required and the time period of the treatment rendered.
Phase one is termed preprosthetetic implant imaging
• Identify disease
• Determine bone quality
• Determine bone quantity
• Determine implant position
• Determine implant orientation
Phase two is termed surgical implant imaging evaluate the surgery sites
during and immediately after surgery, assist in the optimal position and orientation of
dental implants, evaluate the healing and integration phase of implant surgery,
and ensure that abutment position and prosthesis fabrication are correct.
Phase three is termed postprosthetic implant imaging.
This phase commences just after the prosthesis
placement and continues as long as the implants remain in the jaws.
The objectives of this phase of imaging are to evaluate the long-term maintenance of
implant rigid fixation and function, including the crestal bone levels around each implant,
and to evaluate the implant complex.
IMAGING
MODALITIES

The imaging modality is used that yields the necessary diagnostic information
related to the patient's clinical needs and results in the least radiologic risk.

Cost-benefit

Types of Imaging Modalities
Periapical radiography (analog)
Panoramic radiography (analog)
Occlusal radiography (analog)
Cephalometric radiography (analog)
Tomographic radiography
Computed tomography (three-dimensional)
Magnetic resonance imaging (three-dimensional)
Interactive computed tomography (three-dimensional)
PREPROSTH ETIC IMAGING
Subdivided into planar two-dimensional, quasi—
three-dimensional, and three-dimensional
imaging modalities.
ALARA : as low as reasonably achievable
95% just panoramic , <15% conventional CT
Periapical Radiography
Periapical radiography provides a high-resolution planar image of a limited
region of the jaws.' No. 2 size dental film provides a 25 x 40-mm view of the jaw
with each image.
The long cone paralleling technique eliminates distortion and limits magnification
to less than 10%.
The opposing landmark of available bone in implant dentistry is beyond lingual
muscle attachments in the mandible or beyond the palatal vault
in the maxilla.
(1) a useful high-yield modality for ruling out local bone or dental disease;
(2) of limited value in determining quantity because the image is magnified, may be
distorted, and does not depict the third dimension of bone width;
(3) of limited value in determining bone density or mineralization (the lateral
cortical plates prevent accurate interpretation and cannot differentiate subtle
trabecular bone changes); and
(4) of value in identifying critical structures but of little use in depicting the
For example, a ball bearing radiographic measurement of 8 mm
relates to a 60% magnification. Therefore the image below the
ball bearing may represent a 60% magnification of dimension
Advantages
Low radiation dose
Minimal magnification with proper alignment and positioning
High resolution
Inexpensive
Limitations
Distortion and magnification
Minimal site evaluation
Difficulty in film placement
Technique sensitive
Lack of cross-sectional imaging
Indications
Evaluation of small edentulous spaces
Alignment and orientation during surgery
Recall/maintenance evaluation
DIGITAL RADIOGRAPHY
DIGITAL RADIOGRAPHY
A disadvantage of digital radiography is the size and
thickness of the sensor and the position of the
connecting cord. These features make the
positioning of the sensor more difficult in some sites
such as those adjacent to tori or a tapered arch form
in the region of the canines
Occlusal Radiography
Occlusal radiographs are planar radiographs produced by placing the film
intraorally parallel to the occlusal plane with the central x-ray beam
perpendicular to the film for the mandibular image and oblique (usually 45
degrees) to the film for the maxillary image.
The mandibular occlusal radiograph shows the widest width
of bone (i.e., the symphysis)
The spatial relationship between critical structures, such as the mandibular canal and the
mental foramen, and the proposed implant site is lost with this projection
As a result, occlusal radiographs rarely are indicated for diagnostic preprosthetic phases in
implant dentistry
•Advantages: Evaluation for pathology
•Limitations: Does not reveal true buccolingual width in mandible, Difficulty in positioning
•Indications: None
Cephalometric Radiography
The geometry of cephalometric imaging devices results in a 10% magnification of the
image
A lateral cephalometric radiograph is produced with the patient's midsagittal plane
oriented parallel to the image receptor
Unlike panoramic or periapical images, the cross-sectional view of the alveolus
demonstrates the spatial relationship between occlusion and
esthetics with the length, width, angulation, and geometry of the alveolus and is more
accurat for bone quantity determinations
The width of bone in the symphysis region and the relationship between the
buccal cortex and the roots of the anterior teeth also may be determined
before harvesting this bone for ridge augmentation.
cephalometric radiographs are a useful tool for the development of an implant
treatment plan, especially for the completely edentulous patient
This technique is not useful for demonstrating bone quality
Lateral Cephalometric Images
 Advantages
Height/width in anterior region
Low magnification
Skeletal relationship
Crown-implant ratio (anterior)
Tooth position in prosthesis
Evaluation of the quantity of bone in anterior region prior to symphysis grafting
 Limitations
Availability
Image information limited to midline
Reduced resolution and sharpness
Technique sensitive
 Indications
Used in combination with other radiographic techniques for anterior implants
Symphysis bone graft evaluation
Panoramic Radiography
This technique used to depict the body of the mandible, maxilla, and the
lower one half of the maxillary sinuses in a single image. This modality is
probably the most used diagnostic modality in implant dentistry.
For quantitative preprosthetic implant imaging, panoramic radiography is not
the most diagnostic
The x-ray source exposes the jaws from a negative angulation and produces a
relatively constant vertical magnification of approximately 10%. The horizontal
magnification is approximately 20%
Structures of the jaws become magnified more as the object-film distance
increases and the object x-ray source distance decreases.
The posterior maxillary regions are generally the least distorted regions of a
panoramic radiograph
Diagnostic templates that have 5-mm ball bearings or wires incorporated around the
curvature of the dental arch and worn by the patient during the panoramic x-ray
examination enable the dentist to determine the amounts of magnification in the
radiograph
mandibular foramen cannot be identified 30% of the time on the x-ray film and when
visible may not be identified correctly.The maxillary anterior edentulous region is
generally oblique to the film and is often the most difficult area of a panoramic
radiograph to evaluate
Objects in front of and behind the focal trough are blurred, magnified,
reduced in size, or distorted to the extent of being unrecognizable
when the canal runs lingual within the body, the position displayed on the film is
more crestal compared with a nerve that is positioned more buccal,
Zonography: The tomographic layer is approximately 5 mm.
 Advantages
Easy identification of opposing landmarks
Initial assessment of vertical height of bone
Convenience, ease, and speed in performance in most dental offices
Evaluation of gross anatomy of the jaws and any related pathologic findings'
 Limitations
Distortions inherent in the panoramic system
Errors in patient positioning
Does not demonstrate bone quality
Misleading quantitate because of magnification and no third dimension
Tomography
Tomography is a generic term formed from the Greek words
tomo (slice) and graph (picture)
Body section radiography is a special x-ray technique that enables visualization
of a section of the patient's anatomy by blurring regions of the patient's
anatomy above and below the section of interest.
The diagnostic quality of the resulting tomographic image is determined by the
type of tomographic motion, the section thickness, and the degree of
magnification. The type of tomographic motion is probably the most
important factor in tomographic quality.
Magnification varies from 10% to 30%, with higher magnification generally
producing higher-quality images
Ideally, tomographic sections spaced every 1 or 2 mm enable evaluation of the
implant site
Complex tomography is not particularly useful in determining bone quality or
identifying dental and bone disease.
Conventional Tomography
 Advantages
Cross-sectional views
Constant magnification
 Limitations
Availability
Cost
Multiple images needed
Technique sensitive
Blurred images
High radiation dose
 Indications
Single-site evaluation
Vital structures evaluation
Computed Tomography

CT enables differentiation and quantification of soft and hard tissues.

CT produces axial images of a patient's anatomy. images are produced perpendicular to the long axis of the body

Hounsfield units, that describes the density of the CT image at that point. Is quantitative and meaningful in identifying and
differentiating structures and tissues.

CT enables identification of disease, determination of bone quantity, determination of bone quality, identification of critical
structures at the proposed regions, and determination of the position and orientation of the dental implants. Thus CT is
capable of determining all five of the radiologic objectives of preprosthetic implant imaging

Advantages: Negligible magnification, Relatively high-contrast image, Various views, Three-dimensional bone models,
Interactive treatment planning, Cross-referencing

Limitations: Cost, Technique sensitive

Indications
Interactive treatment planning
Determination of bone density
Vital structure location
Subperiosteal implant fabrication
Determination of pathology
Preplanning for bone augmentation
Quality
D1
D2
D3
D4
D5

Density Hounsfield unit
1250
850-1250
350-850
150-350
<150
Tissue Characterization
Air
Water
Muscle
Fibrous tissue
Cartilage
Trabecular bone
Cortical bone
Dentin
Enamel
Tissue Hounsfield unit
-1000
0
35-70
60-90
80-1 30
150-900
900-1800
1600-2400
2500-3000
Interactive Computed
Tomography
•ICT is a technique that was developed to bridge the gap in
information transfer between the radiologist and the practitioner. This
technique enables the radiologist to transfer the imaging study to the
practitioner as a computer file and enables the practitioner to view and
interact with the imaging study on a personal computer
•An important feature of ICT is that the dentist and radiologist can
perform electronic surgery by selecting and placing arbitrary-size
cylinders that simulate root-form implants in the images
•Diagnostic template
Cone Beam Volumetric Tomography
 new type of CT specific for dental applications
 The average absorbed radiation dose from a CBVT scanner (newTom
3G) is approximately 12.0 mSv (micro sieverts). This dose is
equivalent to five D-speed dental x-rays or 25% of the radiation from
a typical panoramic radiograph. medical scanner acquire images
that use radiation doses of 40 to 60 times that of CBVT doses
 x-ray tube on these scanners rotates 360 degrees and will capture
images of the maxilla and mandible in36 seconds, in which only 5.6
seconds is needed for exposure
 magnification being almost 0% with no superimposition or
overlapping of images and minimal distortion
Magnetic Resonance Imaging

Magnetic resonance imaging is a CT imaging technique that uses a
combination of magnetic fields that generate images of tissues in the
body without the use of ionizing radiation.
 Metal restorations will not produce scattering and thus will appear as
black images. Therefore MRI has been shown to be less prone to
artifacts from dental restorations, prostheses, and dental implants than
CT
 MRI is used in implant imaging as a secondary imaging technique when
primary imaging techniques such as complex tomography, CT, or ICT
fail.

MRI visualizes the fat in trabecular bone and differentiates the inferior
alveolar canal and neurovascular bundle from the adjacent trabecular
bone.

MRI is not useful in characterizing bone mineralization or as a high-yield
technique for identifying bone or dental disease
Magnetic Resonance Imaging
 Advantages
No radiation
Vital structures are easily seen (inferior alveolar canal, maxillary sinus)
 Limitations
Cost
Technique sensitive
No reformatting software
Availability
Non signal for cortical bone
 Uses
Evaluation of vital structures when computed tomography is not conclusive
Evaluation of infection (osteomyelitis)
RADIOGRAPHIC IMAGING OF VITAL
STRUCTURES IN ORAL IMPLANTOLOGY
 Mental Foramen and Mandibular Canal
50% of periapical radiographs, the mental foramen is not visible. the
mental foramen is absent in approximately 12% of panoramic
the most accurate means of identification is with conventional and
computerized tomography
tilting the patient's head approximately 5 degrees downward in reference
to the Frankfort horizontal plane allows these anatomical structures to
be seen in 91% of radiographs

Mandibular Lingual Concavities
2.4% prevalence of concavities with average depths of 6 mm (±2.6
mm). Within these concavities or submandibular gland fossa, branches
of the facial artery may be present.

Mandibular Ramus
very popular donor site for autogenous onlay bone grafting.
Standard radiographs for preassessment include panoramic

Mandibular Symphysis
mandibular symphysis area is a very critical anatomical area for oral
implantology.Lateral cephalometric and conventional CT, may be used

The
INTRAOPERATIVE IMAGING
• Advantages of Digital Radiography for Implant Surgery
Fast
Low radiation
Calibration
Magnification
Excellent quality
Measures depth, density, and neighboring structures
Patient stays in surgical setting
Keeps aseptic setting
 Immediate Postsurgical Imaging
A plain film radiograph (periapical or panoramic) should be taken
postsurgically so that a baseline image may be used to evaluate against
future films
 Abutment and Prosthetic Component Imaging
Radiographs should be taken to verify secure adaptation. When
positioning is difficult for periapical radiographs, bitewing or panoramic
radiographs may be used

Postprosthetic Imaging
a panoramic radiograph is the most ideal imaging technique for multiple
implants If single implants or if more detailed information concerning an
implant viewed on a Panorex is needed, periapical radiographs

Recall and Maintenance Imaging
For the evaluation of implant success, immobility and radiographic
evidence of bone adjacent to the implant . Follow-up or recall
radiographs should be taken after 1 year of functional loading and yearly
for the first 3 years
Evaluation of Alveolar Bone Changes
Radiographically, lack or loss of integration is usually indicated
as a radiolucent line around the implant.
"Mach band effect"
Mach band effect is significantly reduced with digital image
processing.
Periapical Radiographs
Filmholding devices
If the threads are not clearly seen in the radiographs,
modification of the beam angle needs tobe made. If diffuse
threads are present on the right side of the implant. then the
beam angle was positioned too much in the superior
direction. If the thread are diffuse on the left side, then the
beam angle was from an inferior angulation
Bitewing Radiograph
.
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Thanks