dr.ESLAM MOSAAD
dr.ESLAM MOSAAD
X-ray
X-rays were first discovered in
1895 by Wilhelm Conrad Roentgen,
the professor of physics and
director of the physics institute at
the University of Wurzburg in
Bavaria.
Hence the term ROENTGEN
RAYS, often applied to mechanically
generated x-rays. He won a Noble
prize for his discovery of X-ray.
Roentgen called them X-rays
after the mathematical symbol X
for unknown.
History History History
dr.ESLAM MOSAAD
History History
History
Roentgen soon found that photographic
plates were sensitive to the newly discovered
rays.
He convinced his wife to participate in an
experiment.
Roentgen placed her hand on a cassette
loaded with a photographic plate. He then
aimed the activated cathode ray tube at her
hand for fifteen minutes.
When the image was developed, the bones
of her hand and the two rings she wore were
clearly visible.
X-ray of Bertha Roentgen's Hand
dr.ESLAM MOSAAD
Early x-ray machine. Arrow points to
“live” electrical wire.
History History History
dr.ESLAM MOSAAD
Specialized radiography.
• Panoramic radiography.
• Computed Tomography.
• Sialography.
• Ultrasonography.
• Magnetic resonance image.
• Nuclear medicine. (Radio nuclide imaging )
• Digital imaging.
• Arthrography.
• Electronic thermography.
• Endoscopy.
dr.ESLAM MOSAAD
Panoramic radiography
rotational radiography, or curved surface tomography
It is a radiographic technique for
producing a single image of the facial
structures that includes both maxillary and
mandibular arches and their supporting
structures.
dr.ESLAM MOSAAD
dr.ESLAM MOSAAD
As Tomographic principles, the x-ray
tube and film cassette rotate in opposite
directions around the patient’s head to
produce a specific curved image of the
maxilla and mandible on the film.
dr.ESLAM MOSAAD
dr.ESLAM MOSAAD
• In panoramic technique, during exposure,
the x-ray source moves in one direction
while the film moves in the opposite
direction
• The area of the object in the center of this
movement will appears in focus and very
sharp on the resultant radiograph as its
shadow.
• All other structures will appears blurred or
out of focus
dr.ESLAM MOSAAD
dr.ESLAM MOSAAD
Diagnostic imaging and techniques, help develop and
implement a cohesive and comprehensive treatment plan to the
implant patient.
Diagnostic Imaging objectives depend on a number of factors
including :
• The amount and type of information required
• The time period of the treatment rendered.
dr.ESLAM MOSAAD
Imaging modalities
• Depend on the patient clinical needs.
• The imaging modality should yield the necessary diagnostic
information versus the least radiologic risk.
• Examinations that are known to produce this result are not
necessarily those that cost the least.
• Basically the dentist should use the modality that provides the
standard of proper care .
dr.ESLAM MOSAAD
Imaging modalities can be described as
1-Analogue
-2 dimensional systems
-use x-ray films or intensifying
screens
dr.ESLAM MOSAAD
2-Digital
• Two dimensions : described by an image matrix that has an
individual picture elements called (pixels)(width X height)
• Three dimensions: described by an image matrix that has an
individual picture elements called(voxels) (width X height X
depththickness)
dr.ESLAM MOSAAD
The decision of when to image along with which
modality to use depends on the integration of the
previous factors and can be organized into three
phases:
dr.ESLAM MOSAAD
Phase one :
preprosthetic implant imaging
dr.ESLAM MOSAAD
Global objectives
• Develop and implement a treatment plan for
the patient that enables restoration of the
patient’s function and esthetics.
dr.ESLAM MOSAAD
Specific Objectives:
• identify disease.
• determine bone quality.
• determine bone quantity.
• Determine implant position.
• Determine implant orientation.
dr.ESLAM MOSAAD
Imaging modalities
1-analog imaging modalities.
• -periapical radiography.
• -panoramic radiography.
• -occlusal radiography.
• -cephalometric radoigraphy.
dr.ESLAM MOSAAD
2-three dimensional imaging modalities
-computed tomography
-magnetic resonance imaging
-interactive computed tomography.
dr.ESLAM MOSAAD
1-periapical radiographs
These are images of a limited region of the mandibular and
maxillary alveolus.
• Common technique used: long cone paralleling technique,to
eliminate and to limit the magnification distortion to less than
10%.
• Film used :commonly among our clinics is no.2 size dental film
which provides (25-mm X 40-mm)view of the jaws.
dr.ESLAM MOSAAD
In terms of objectives of
preprosthetic imaging
• Useful high –yield modality for ruling out local bone and dental
disease.
• Of value in identifying critical structures but of little use in
depicting the relationship between the proposed implant site
and those structures.
• Limited value in determining quantity because the image is
magnified and does not depict the third dimension of bone
width.
dr.ESLAM MOSAAD
• Limited value bone density or mineralization(the lateral
cortical plates prevents accurate interpretation and
cannot differentiate the subtrabecular bone changes.
These films most often are used for single-
tooth implants in region of abundant bone
width.
dr.ESLAM MOSAAD
2-Occlusal radiographs
Common technique used :placing the film
intraorally parallel to the occlusal plane with
the central X-ray beam
1)oblique usually 45degrees for the maxillary
images ,this is why the images are inherently
distorted.
dr.ESLAM MOSAAD
2) perpendicular to the film for the mandibular image ,which is
usually less distorted than the maxillary image ,but the
mandibular alveolus generally flares anteriorly and
demonstrates lingual inclination in the posterior region,
producing an oblique and a distorted image .
• As a result occlusal radiographs rarely are indicated for
preprosthetic phases in implant patient.
dr.ESLAM MOSAAD
3-cephalometric radiographs.
• These films usually provide useful information for the 1-cortical
thickness , 2-height and 3-width of the alveolar ridge at the mid
line ,as well as the 4-skeletal relationship between the maxilla
and the mandible and 5-facial profile.
• Their use in implant patient is limited to structures at the mid
line , with minimal usefulness for other areas of the jaws.
dr.ESLAM MOSAAD
A cephalometric film.
dr.ESLAM MOSAAD
4-panoramic radiography.
Curved plane tomographic radiographic
technique used to depict the body of the
mandible , maxilla and the lower half of the
maxillary sinuses in a single images.
dr.ESLAM MOSAAD
Advantages of panoramic radiographs
• Opposing land marks are easily identified .
• The vertical height of bone initially can be assessed.
• Convenient ,easy and speed procedure that can be
carried in most dental offices.
• Gross anatomy of the jaws and related pathologic
findings can be evaluated.
• Popular and widely available technique in dentistry.
dr.ESLAM MOSAAD
disadvantages
• Does not demonstrate bone quality minerlaization.
• Misleading because of magnification and third
dimensional cross sectional view is abscent.
• Does not depict the spatial relation between the
structures and dimensional quantitation of the implant
site.
dr.ESLAM MOSAAD
dr.ESLAM MOSAAD
• Diagnostic templates that have 5-mm ball bearings or
wires are incorporated around the curvatureof the dental
arch and worn by the patient ,to enable the dentist to
evaluate the magnification in the radiograph.
dr.ESLAM MOSAAD
• Recently a modification of the panoramic x-ray machine
developed that has the ability of making cross sectional image
of the jaws.
• These devices use limited angle linear tomography
(zonography) and means of positioning the patient.
• Tomographic layer of 5mm.
• This technique enables correlation between spatial structures
and implant sites and quantification of the geometry of the
implant site.
dr.ESLAM MOSAAD
5-Tomgraphy
• This is a generic term formed from greek words tomo
(slice) and graphy (picture).
• It describes all forms of body sectoin radiography.
• It is a special X-ray technique that enables visualization
of a section of the patient anatomy by blurring regions
of the patient’s anatomy.
dr.ESLAM MOSAAD
• In conventional tomography the X-ray source and the
film are connected and rotate around a fixed
point(fulcrum)usually performing simple ( linear )or
complex (elliptic or hypocycloidal)tomographic
motions.
• Structures that are in the plane (focal area)of
rotation do not move in realtion to the tube and the
film and thus are depicted in the sharp focus .
• Structures outside the plane of rotation are blurred
progrssively depending on their distance from the
focal plane.
dr.ESLAM MOSAAD
Advantages :with proper patient seating
• Generates a true cross section of the alveolar ridge.
• Provide diagnostic information of the cortical
thikness , trabecular density , height and width of
the alveolus and location of vital anatomic
structures.
• Imaged structures are predictably magnified , so
measurments made of tomograms can be adjusted
to provide accurate angular and linear assesments.
dr.ESLAM MOSAAD
• Dose is limited as the area of the jaw imaged
is limited
• Useful during the placement of a single or
few implants.
dr.ESLAM MOSAAD
Disadvantages
• Equipment requires familiarity with the image
acquissaton.
• Image interpretation is some times
challenging . especially when the anatomy of
the jaws are altered because of traumatic
extractions , alveolar ridge resorption , and
other conditions.
dr.ESLAM MOSAAD
• The progressive blurring of structures outside the focal
plane does not allow sharply defined tomographic slices ,
the prominent opaque structures can cast ( ghost )
shadows and complicate the images.
• Generated images are created once a time ,so patient
has to be repositioned each time
dr.ESLAM MOSAAD
6-Computed tomography(CT)
• CT was invented by sir Hounsfield in1972.
• CT enabled differentiation and quantification of
soft and hard tissues.
• The individual element of the CT is called a voxel ,
which has a value referred to in Hounsfield
units,that describes the denisty of the CT image
at each point .
• Each voxel contains 12bits of data and ranges
from -1000 (air) to +3000 (enamel /dental
materials)and 0 for water.
dr.ESLAM MOSAAD
• A thin fan-beam of X-rays rotates around the patient to
generate in one revolution a thin(0.5-1.00mm wide)axial slice
of the area of interest.
• Multiple overlapping axial slices are obtained by several
revolutions of the X-ray beam until the whole area of interest is
covered.
• The image detector is Gaseous or solid state ,producing
electronic signals that serve as input data for a dedicated
computer .
• The computer processes the data using back –projection fourier
algorithm techniques.
dr.ESLAM MOSAAD
dr.ESLAM MOSAAD
dr.ESLAM MOSAAD
dr.ESLAM MOSAAD
• A three dimensional digital map of the jaws are constructed,and
a specialized software can be used to generate approprite
views that can depict the dimensions of the jaws and the
location of the important anatomic structures.
• Typical dental views obtained from a CT scan include axial
,panoramic,and cross- sectionalviews of the jaws.
dr.ESLAM MOSAAD
dr.ESLAM MOSAAD
dr.ESLAM MOSAAD
Advantages
• True cross sections offer a precise and detailed evaluation of
the height and width of the alveolar ridge.
• The images can be adjusted and printed without magnification.
, facilitating measurments directly from the prints or films . with
standard rulers not magnified.
• Anatomic structures can be visualized and analyzed at all three
coordinate axes.
• Bone and soft tissue contrast and resolution are excellent for
the diagnostic task.
dr.ESLAM MOSAAD
Disadvantages
• requires specialized equipment.(expensive)
• High radiation dose compared to other modalities.
• Metallic restorations cause ring artifacts.
dr.ESLAM MOSAAD
Dentascan imaging
• Provides programmed reformation , organization , and
display of the imaging study.
• The radiologist determines the curvatures of the
maxillary or the mandibular arch and the computer is
programmed to determine referenced cross sectional and
tangentialpanoramic images of the alveolus along with
three dimensional images of the arch.
• The cross sectional and panoramic images are spaced
1mm apart and enable accurate pre prosthetic treatment
planning.
dr.ESLAM MOSAAD
Denta scan images of
reformated and
reorganized CT images
dr.ESLAM MOSAAD
Limitations
• May Not be true in size ,and require compensation for
magnification .usually a diagnostic template is required
to take full advantage of the technique.
• The diagnostic template usually contains lead balls of
known diameter ,to calculate the magnification.
dr.ESLAM MOSAAD
7-Cone beam computed
tomography
• CBCT scanners generates a cone shaped X-ray beam in contrast to the
fan shaped beam produced by CT scanners.
• Images are generated in 1- degree increments, at the end of a single
rotation 360 images are created.
• Computer then uses these images to create a 3-D map of the face.
• Multiplanar reconstructions of sections of variable thickness can be
reconstructed as the CT scan.
dr.ESLAM MOSAAD
• CBCT offers the same advantages and disadvantages of
CT, with only few differences.
The most important difference is that
• CBCT delivers a radiation dose which is similar to full
mouth x-ray, this is 50-100 times less the radiation dose
deliverefor CT.d
dr.ESLAM MOSAAD
Interactive computed tomography
• A technique that was developed to bridge the gap
in information transfer between the radiologist and
the practitioner.
• Dentist’s computer becomes a radiologic workstation
with tools to measure the length and the width of
the alveolus,measure bone quality,and change the
window and level of the grayscale of the study to
enhance the perception of the critical structures.
dr.ESLAM MOSAAD
• Electronic surgery(ES) can be performed by the dentist
and the radiologist .
• By selecting arbitrary –size cylinders that simulates root
form implants in the images .
• With appropriate diagnostic template ,ES can be
performed to develop the patient’s treatment plan
electronically in three dimensions.
dr.ESLAM MOSAAD
dr.ESLAM MOSAAD
Advantages
• Three dimensional treatment plan that is integrated with
the patient’s anatomy and can be visualized before
surgery.
• Enables the determination of bone quality adjacent to
the prospective implant sites.
Limitations
• Refinement and exact orientation (parallelism of the
electronic implants is difficult
dr.ESLAM MOSAAD
8-Magnetic resonance imaging
Technique :
• Imaging protons of the body using magnetic
field ,radio frequancies,and electromagnetic
detectors and computers .
dr.ESLAM MOSAAD
dr.ESLAM MOSAAD
dr.ESLAM MOSAAD
Usage :
• When complex tomography fails to differentiate inferior
alveolar canal in about 60 % of cases and CT fails to
differentiate the inferior alveolar canal in about 2% of
the cases.
• MRI visualizes the fat in the trabecular bone and
differentiates the inferior alveolar canaland neuro
vascular bundle from adjacent trabecualr bone.
dr.ESLAM MOSAAD
Limitations
• Not useful in characterizing bone
mineralization or as a high-yield technique for
identifying bone or dental disease.
dr.ESLAM MOSAAD
Diagnostic templates
• Purpose :is to incorporate the patient proposed
treatment plan into the radiographic examination
• The pre prosthetic imaging procedure enables
evaluationof the proposed implant site at the ideal
position and orientation identified by radiographic
markers incorporated into the template.
dr.ESLAM MOSAAD
Several types for diagnostic templates to
be effective and more precise
1-clear acryl and radio opaque denture teeth.
2-acryl and the restoration sites is covered by barium
sulfate and filling a hole drilled through the occlusal
plane with guttta percha..
• N.B : do not use metal markers if CT or CBCT is going to
be carried.
dr.ESLAM MOSAAD
dr.ESLAM MOSAAD
Surgical templates:
dr.ESLAM MOSAAD
CAD-CAM STEREOTACTIC SURGICAL
TEMPLATES
• Depends on producing a three dimensional model of
the patient’s alveolar anatomy using a computer
aided manufacturing (CAD-CAM) and rapid proto
typing procedure.
• Derived from the model by aligning cylinders at the
implant sites which just accommodate pilot drill.
• Used to establish pilot drilling up to 10mm then the
template is removed and the osteotomies
Are completed.
dr.ESLAM MOSAAD
Phase two
surgical and interventional implant
imaging
• Involves imaging the patient during and
immediately after surgery.
Purpose:
• Evaluation of depth of implant placement.
• Position and orientation implant osteotomies.
• Evaluation of graft sites.
dr.ESLAM MOSAAD
• This is usually carried at the dentist’s office this is why it
is usually the periapical and the panoramic
radiography.
• Digital radiography software facilitated the process.
dr.ESLAM MOSAAD
Advantages of digital radiography for
the implant surgery.
• Fast
• Low radiation.
• Calibration.
• Magnification.
• Excellent quality.
• Measures depth,density, and neighbouring
structures.
• Patient stays in surgical setting
• Keeps aseptic setting
dr.ESLAM MOSAAD
Phase three
post prosthetic implant imaging
Purpose:
• Evaluate status and prognosis of the dental implants.
• Evaluate bone adjacent to the implant for changes in
mineralization or bone volume.
dr.ESLAM MOSAAD
Peripaical radiography:
Produces high resolution planer images of the
dental implant and the alveolar bone adjacent to
the implant.
dr.ESLAM MOSAAD
Bite-wing radiographs
Purpose :
• Evaluate crestal bone loss around the implants.
• In this image the superior third of the implant is the
region of interest.
• A vertical bitewing film is ideal once prosthesis is in
place.
• Quality periapical and bitewing radiographs should be
parallel to the implant body with the central ray of
source oriented perpendicular to the film enable
sequential radiographs for crestal and periimplant bone
loss.
dr.ESLAM MOSAAD
Temporal subtraction radiography:
• (SR) is a radiographic technique that enables two
radiographs made at different points of time and
of the same anatomical region to be subtracted
resulting in an image of the difference of the two
original radiographs.
• Needs to be standardized to account for changes
in exposure and processing between each
radiograph then they can be digitalized registered
and subtracted with a resulting subtraction
image.
dr.ESLAM MOSAAD
a. Immediately after tooth extraction
b. At 12 months after tooth
extraction
Blue region = ROC, Red region = ROI
Blue figures 1-6 = reference points
a. Immediately after tooth extraction b. At 12
months after tooth extraction
Blue region = ROC, Red region = ROI
Blue figures 1-6 = reference points
c. Resulting subtraction image
d. Resulting subtraction image
Blue area in ROI = Bone gain
Red area in ROI = Bone loss
dr.ESLAM MOSAAD
Advantages:
• More accurate than periapical in depicting the changes
in bone mineralization and bone volume.
Limitations :
• Difficulty to obtain a reproducible radiograph.
dr.ESLAM MOSAAD
Computed tomography
• Unlike the conventional imaging techniques the
resolution ,, spatial discrimination ,and three
dimensional imaging capabilities of CT enable
• precise evaluation of the position of the dental
implant relative to critical structures .
• failing implants characterized by trabecular and
crestal demineralization,resorption ofbone
implant interface,cortical plate fenestrations and
perforation of the inferior alveolar canal.
dr.ESLAM MOSAAD
conclusion
• Many radiographic projections are available for the
evaluation of implant placment. each with advantages and
disadvantages . the clinician must follow sequential steps
inpatient evaluation, and radiography is an essential
diagnostic tool for implant patient . selection of appropriate
radiographic modalities will provide the maximum diagnostic
information , help avoid unwanted complications and
maximizes treatment outcome while delivering as low as
reasonably achievable(ALARA) radiation dose to the patient.
dr.ESLAM MOSAAD
dr.ESLAM MOSAAD
dr.ESLAM MOSAAD

Radiology

  • 1.
  • 2.
    dr.ESLAM MOSAAD X-ray X-rays werefirst discovered in 1895 by Wilhelm Conrad Roentgen, the professor of physics and director of the physics institute at the University of Wurzburg in Bavaria. Hence the term ROENTGEN RAYS, often applied to mechanically generated x-rays. He won a Noble prize for his discovery of X-ray. Roentgen called them X-rays after the mathematical symbol X for unknown. History History History
  • 3.
    dr.ESLAM MOSAAD History History History Roentgensoon found that photographic plates were sensitive to the newly discovered rays. He convinced his wife to participate in an experiment. Roentgen placed her hand on a cassette loaded with a photographic plate. He then aimed the activated cathode ray tube at her hand for fifteen minutes. When the image was developed, the bones of her hand and the two rings she wore were clearly visible. X-ray of Bertha Roentgen's Hand
  • 4.
    dr.ESLAM MOSAAD Early x-raymachine. Arrow points to “live” electrical wire. History History History
  • 5.
    dr.ESLAM MOSAAD Specialized radiography. •Panoramic radiography. • Computed Tomography. • Sialography. • Ultrasonography. • Magnetic resonance image. • Nuclear medicine. (Radio nuclide imaging ) • Digital imaging. • Arthrography. • Electronic thermography. • Endoscopy.
  • 6.
    dr.ESLAM MOSAAD Panoramic radiography rotationalradiography, or curved surface tomography It is a radiographic technique for producing a single image of the facial structures that includes both maxillary and mandibular arches and their supporting structures.
  • 7.
  • 8.
    dr.ESLAM MOSAAD As Tomographicprinciples, the x-ray tube and film cassette rotate in opposite directions around the patient’s head to produce a specific curved image of the maxilla and mandible on the film.
  • 9.
  • 10.
    dr.ESLAM MOSAAD • Inpanoramic technique, during exposure, the x-ray source moves in one direction while the film moves in the opposite direction • The area of the object in the center of this movement will appears in focus and very sharp on the resultant radiograph as its shadow. • All other structures will appears blurred or out of focus
  • 11.
  • 12.
  • 13.
    Diagnostic imaging andtechniques, help develop and implement a cohesive and comprehensive treatment plan to the implant patient. Diagnostic Imaging objectives depend on a number of factors including : • The amount and type of information required • The time period of the treatment rendered. dr.ESLAM MOSAAD
  • 14.
    Imaging modalities • Dependon the patient clinical needs. • The imaging modality should yield the necessary diagnostic information versus the least radiologic risk. • Examinations that are known to produce this result are not necessarily those that cost the least. • Basically the dentist should use the modality that provides the standard of proper care . dr.ESLAM MOSAAD
  • 15.
    Imaging modalities canbe described as 1-Analogue -2 dimensional systems -use x-ray films or intensifying screens dr.ESLAM MOSAAD
  • 16.
    2-Digital • Two dimensions: described by an image matrix that has an individual picture elements called (pixels)(width X height) • Three dimensions: described by an image matrix that has an individual picture elements called(voxels) (width X height X depththickness) dr.ESLAM MOSAAD
  • 17.
    The decision ofwhen to image along with which modality to use depends on the integration of the previous factors and can be organized into three phases: dr.ESLAM MOSAAD
  • 18.
    Phase one : preprostheticimplant imaging dr.ESLAM MOSAAD
  • 19.
    Global objectives • Developand implement a treatment plan for the patient that enables restoration of the patient’s function and esthetics. dr.ESLAM MOSAAD
  • 20.
    Specific Objectives: • identifydisease. • determine bone quality. • determine bone quantity. • Determine implant position. • Determine implant orientation. dr.ESLAM MOSAAD
  • 21.
    Imaging modalities 1-analog imagingmodalities. • -periapical radiography. • -panoramic radiography. • -occlusal radiography. • -cephalometric radoigraphy. dr.ESLAM MOSAAD
  • 22.
    2-three dimensional imagingmodalities -computed tomography -magnetic resonance imaging -interactive computed tomography. dr.ESLAM MOSAAD
  • 23.
    1-periapical radiographs These areimages of a limited region of the mandibular and maxillary alveolus. • Common technique used: long cone paralleling technique,to eliminate and to limit the magnification distortion to less than 10%. • Film used :commonly among our clinics is no.2 size dental film which provides (25-mm X 40-mm)view of the jaws. dr.ESLAM MOSAAD
  • 24.
    In terms ofobjectives of preprosthetic imaging • Useful high –yield modality for ruling out local bone and dental disease. • Of value in identifying critical structures but of little use in depicting the relationship between the proposed implant site and those structures. • Limited value in determining quantity because the image is magnified and does not depict the third dimension of bone width. dr.ESLAM MOSAAD
  • 25.
    • Limited valuebone density or mineralization(the lateral cortical plates prevents accurate interpretation and cannot differentiate the subtrabecular bone changes. These films most often are used for single- tooth implants in region of abundant bone width. dr.ESLAM MOSAAD
  • 26.
    2-Occlusal radiographs Common techniqueused :placing the film intraorally parallel to the occlusal plane with the central X-ray beam 1)oblique usually 45degrees for the maxillary images ,this is why the images are inherently distorted. dr.ESLAM MOSAAD
  • 27.
    2) perpendicular tothe film for the mandibular image ,which is usually less distorted than the maxillary image ,but the mandibular alveolus generally flares anteriorly and demonstrates lingual inclination in the posterior region, producing an oblique and a distorted image . • As a result occlusal radiographs rarely are indicated for preprosthetic phases in implant patient. dr.ESLAM MOSAAD
  • 28.
    3-cephalometric radiographs. • Thesefilms usually provide useful information for the 1-cortical thickness , 2-height and 3-width of the alveolar ridge at the mid line ,as well as the 4-skeletal relationship between the maxilla and the mandible and 5-facial profile. • Their use in implant patient is limited to structures at the mid line , with minimal usefulness for other areas of the jaws. dr.ESLAM MOSAAD
  • 29.
  • 30.
    4-panoramic radiography. Curved planetomographic radiographic technique used to depict the body of the mandible , maxilla and the lower half of the maxillary sinuses in a single images. dr.ESLAM MOSAAD
  • 31.
    Advantages of panoramicradiographs • Opposing land marks are easily identified . • The vertical height of bone initially can be assessed. • Convenient ,easy and speed procedure that can be carried in most dental offices. • Gross anatomy of the jaws and related pathologic findings can be evaluated. • Popular and widely available technique in dentistry. dr.ESLAM MOSAAD
  • 32.
    disadvantages • Does notdemonstrate bone quality minerlaization. • Misleading because of magnification and third dimensional cross sectional view is abscent. • Does not depict the spatial relation between the structures and dimensional quantitation of the implant site. dr.ESLAM MOSAAD
  • 33.
  • 34.
    • Diagnostic templatesthat have 5-mm ball bearings or wires are incorporated around the curvatureof the dental arch and worn by the patient ,to enable the dentist to evaluate the magnification in the radiograph. dr.ESLAM MOSAAD
  • 35.
    • Recently amodification of the panoramic x-ray machine developed that has the ability of making cross sectional image of the jaws. • These devices use limited angle linear tomography (zonography) and means of positioning the patient. • Tomographic layer of 5mm. • This technique enables correlation between spatial structures and implant sites and quantification of the geometry of the implant site. dr.ESLAM MOSAAD
  • 36.
    5-Tomgraphy • This isa generic term formed from greek words tomo (slice) and graphy (picture). • It describes all forms of body sectoin radiography. • It is a special X-ray technique that enables visualization of a section of the patient anatomy by blurring regions of the patient’s anatomy. dr.ESLAM MOSAAD
  • 37.
    • In conventionaltomography the X-ray source and the film are connected and rotate around a fixed point(fulcrum)usually performing simple ( linear )or complex (elliptic or hypocycloidal)tomographic motions. • Structures that are in the plane (focal area)of rotation do not move in realtion to the tube and the film and thus are depicted in the sharp focus . • Structures outside the plane of rotation are blurred progrssively depending on their distance from the focal plane. dr.ESLAM MOSAAD
  • 38.
    Advantages :with properpatient seating • Generates a true cross section of the alveolar ridge. • Provide diagnostic information of the cortical thikness , trabecular density , height and width of the alveolus and location of vital anatomic structures. • Imaged structures are predictably magnified , so measurments made of tomograms can be adjusted to provide accurate angular and linear assesments. dr.ESLAM MOSAAD
  • 39.
    • Dose islimited as the area of the jaw imaged is limited • Useful during the placement of a single or few implants. dr.ESLAM MOSAAD
  • 40.
    Disadvantages • Equipment requiresfamiliarity with the image acquissaton. • Image interpretation is some times challenging . especially when the anatomy of the jaws are altered because of traumatic extractions , alveolar ridge resorption , and other conditions. dr.ESLAM MOSAAD
  • 41.
    • The progressiveblurring of structures outside the focal plane does not allow sharply defined tomographic slices , the prominent opaque structures can cast ( ghost ) shadows and complicate the images. • Generated images are created once a time ,so patient has to be repositioned each time dr.ESLAM MOSAAD
  • 42.
    6-Computed tomography(CT) • CTwas invented by sir Hounsfield in1972. • CT enabled differentiation and quantification of soft and hard tissues. • The individual element of the CT is called a voxel , which has a value referred to in Hounsfield units,that describes the denisty of the CT image at each point . • Each voxel contains 12bits of data and ranges from -1000 (air) to +3000 (enamel /dental materials)and 0 for water. dr.ESLAM MOSAAD
  • 43.
    • A thinfan-beam of X-rays rotates around the patient to generate in one revolution a thin(0.5-1.00mm wide)axial slice of the area of interest. • Multiple overlapping axial slices are obtained by several revolutions of the X-ray beam until the whole area of interest is covered. • The image detector is Gaseous or solid state ,producing electronic signals that serve as input data for a dedicated computer . • The computer processes the data using back –projection fourier algorithm techniques. dr.ESLAM MOSAAD
  • 44.
  • 45.
  • 46.
  • 47.
    • A threedimensional digital map of the jaws are constructed,and a specialized software can be used to generate approprite views that can depict the dimensions of the jaws and the location of the important anatomic structures. • Typical dental views obtained from a CT scan include axial ,panoramic,and cross- sectionalviews of the jaws. dr.ESLAM MOSAAD
  • 48.
  • 49.
  • 50.
    Advantages • True crosssections offer a precise and detailed evaluation of the height and width of the alveolar ridge. • The images can be adjusted and printed without magnification. , facilitating measurments directly from the prints or films . with standard rulers not magnified. • Anatomic structures can be visualized and analyzed at all three coordinate axes. • Bone and soft tissue contrast and resolution are excellent for the diagnostic task. dr.ESLAM MOSAAD
  • 51.
    Disadvantages • requires specializedequipment.(expensive) • High radiation dose compared to other modalities. • Metallic restorations cause ring artifacts. dr.ESLAM MOSAAD
  • 52.
    Dentascan imaging • Providesprogrammed reformation , organization , and display of the imaging study. • The radiologist determines the curvatures of the maxillary or the mandibular arch and the computer is programmed to determine referenced cross sectional and tangentialpanoramic images of the alveolus along with three dimensional images of the arch. • The cross sectional and panoramic images are spaced 1mm apart and enable accurate pre prosthetic treatment planning. dr.ESLAM MOSAAD
  • 53.
    Denta scan imagesof reformated and reorganized CT images dr.ESLAM MOSAAD
  • 54.
    Limitations • May Notbe true in size ,and require compensation for magnification .usually a diagnostic template is required to take full advantage of the technique. • The diagnostic template usually contains lead balls of known diameter ,to calculate the magnification. dr.ESLAM MOSAAD
  • 55.
    7-Cone beam computed tomography •CBCT scanners generates a cone shaped X-ray beam in contrast to the fan shaped beam produced by CT scanners. • Images are generated in 1- degree increments, at the end of a single rotation 360 images are created. • Computer then uses these images to create a 3-D map of the face. • Multiplanar reconstructions of sections of variable thickness can be reconstructed as the CT scan. dr.ESLAM MOSAAD
  • 56.
    • CBCT offersthe same advantages and disadvantages of CT, with only few differences. The most important difference is that • CBCT delivers a radiation dose which is similar to full mouth x-ray, this is 50-100 times less the radiation dose deliverefor CT.d dr.ESLAM MOSAAD
  • 57.
    Interactive computed tomography •A technique that was developed to bridge the gap in information transfer between the radiologist and the practitioner. • Dentist’s computer becomes a radiologic workstation with tools to measure the length and the width of the alveolus,measure bone quality,and change the window and level of the grayscale of the study to enhance the perception of the critical structures. dr.ESLAM MOSAAD
  • 58.
    • Electronic surgery(ES)can be performed by the dentist and the radiologist . • By selecting arbitrary –size cylinders that simulates root form implants in the images . • With appropriate diagnostic template ,ES can be performed to develop the patient’s treatment plan electronically in three dimensions. dr.ESLAM MOSAAD
  • 59.
  • 60.
    Advantages • Three dimensionaltreatment plan that is integrated with the patient’s anatomy and can be visualized before surgery. • Enables the determination of bone quality adjacent to the prospective implant sites. Limitations • Refinement and exact orientation (parallelism of the electronic implants is difficult dr.ESLAM MOSAAD
  • 61.
    8-Magnetic resonance imaging Technique: • Imaging protons of the body using magnetic field ,radio frequancies,and electromagnetic detectors and computers . dr.ESLAM MOSAAD
  • 62.
  • 63.
  • 64.
    Usage : • Whencomplex tomography fails to differentiate inferior alveolar canal in about 60 % of cases and CT fails to differentiate the inferior alveolar canal in about 2% of the cases. • MRI visualizes the fat in the trabecular bone and differentiates the inferior alveolar canaland neuro vascular bundle from adjacent trabecualr bone. dr.ESLAM MOSAAD
  • 65.
    Limitations • Not usefulin characterizing bone mineralization or as a high-yield technique for identifying bone or dental disease. dr.ESLAM MOSAAD
  • 66.
    Diagnostic templates • Purpose:is to incorporate the patient proposed treatment plan into the radiographic examination • The pre prosthetic imaging procedure enables evaluationof the proposed implant site at the ideal position and orientation identified by radiographic markers incorporated into the template. dr.ESLAM MOSAAD
  • 67.
    Several types fordiagnostic templates to be effective and more precise 1-clear acryl and radio opaque denture teeth. 2-acryl and the restoration sites is covered by barium sulfate and filling a hole drilled through the occlusal plane with guttta percha.. • N.B : do not use metal markers if CT or CBCT is going to be carried. dr.ESLAM MOSAAD
  • 68.
  • 69.
  • 70.
    CAD-CAM STEREOTACTIC SURGICAL TEMPLATES •Depends on producing a three dimensional model of the patient’s alveolar anatomy using a computer aided manufacturing (CAD-CAM) and rapid proto typing procedure. • Derived from the model by aligning cylinders at the implant sites which just accommodate pilot drill. • Used to establish pilot drilling up to 10mm then the template is removed and the osteotomies Are completed. dr.ESLAM MOSAAD
  • 71.
    Phase two surgical andinterventional implant imaging • Involves imaging the patient during and immediately after surgery. Purpose: • Evaluation of depth of implant placement. • Position and orientation implant osteotomies. • Evaluation of graft sites. dr.ESLAM MOSAAD
  • 72.
    • This isusually carried at the dentist’s office this is why it is usually the periapical and the panoramic radiography. • Digital radiography software facilitated the process. dr.ESLAM MOSAAD
  • 73.
    Advantages of digitalradiography for the implant surgery. • Fast • Low radiation. • Calibration. • Magnification. • Excellent quality. • Measures depth,density, and neighbouring structures. • Patient stays in surgical setting • Keeps aseptic setting dr.ESLAM MOSAAD
  • 74.
    Phase three post prostheticimplant imaging Purpose: • Evaluate status and prognosis of the dental implants. • Evaluate bone adjacent to the implant for changes in mineralization or bone volume. dr.ESLAM MOSAAD
  • 75.
    Peripaical radiography: Produces highresolution planer images of the dental implant and the alveolar bone adjacent to the implant. dr.ESLAM MOSAAD
  • 76.
    Bite-wing radiographs Purpose : •Evaluate crestal bone loss around the implants. • In this image the superior third of the implant is the region of interest. • A vertical bitewing film is ideal once prosthesis is in place. • Quality periapical and bitewing radiographs should be parallel to the implant body with the central ray of source oriented perpendicular to the film enable sequential radiographs for crestal and periimplant bone loss. dr.ESLAM MOSAAD
  • 77.
    Temporal subtraction radiography: •(SR) is a radiographic technique that enables two radiographs made at different points of time and of the same anatomical region to be subtracted resulting in an image of the difference of the two original radiographs. • Needs to be standardized to account for changes in exposure and processing between each radiograph then they can be digitalized registered and subtracted with a resulting subtraction image. dr.ESLAM MOSAAD
  • 78.
    a. Immediately aftertooth extraction b. At 12 months after tooth extraction Blue region = ROC, Red region = ROI Blue figures 1-6 = reference points a. Immediately after tooth extraction b. At 12 months after tooth extraction Blue region = ROC, Red region = ROI Blue figures 1-6 = reference points c. Resulting subtraction image d. Resulting subtraction image Blue area in ROI = Bone gain Red area in ROI = Bone loss dr.ESLAM MOSAAD
  • 79.
    Advantages: • More accuratethan periapical in depicting the changes in bone mineralization and bone volume. Limitations : • Difficulty to obtain a reproducible radiograph. dr.ESLAM MOSAAD
  • 80.
    Computed tomography • Unlikethe conventional imaging techniques the resolution ,, spatial discrimination ,and three dimensional imaging capabilities of CT enable • precise evaluation of the position of the dental implant relative to critical structures . • failing implants characterized by trabecular and crestal demineralization,resorption ofbone implant interface,cortical plate fenestrations and perforation of the inferior alveolar canal. dr.ESLAM MOSAAD
  • 81.
    conclusion • Many radiographicprojections are available for the evaluation of implant placment. each with advantages and disadvantages . the clinician must follow sequential steps inpatient evaluation, and radiography is an essential diagnostic tool for implant patient . selection of appropriate radiographic modalities will provide the maximum diagnostic information , help avoid unwanted complications and maximizes treatment outcome while delivering as low as reasonably achievable(ALARA) radiation dose to the patient. dr.ESLAM MOSAAD
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