role of conventional radiography in implantology · discuss the importance of conventional...
TRANSCRIPT
Role of conventional
radiography in implantology
1. Identify the rule of periapical radiographs in preoperative
assessment.
2. Identify the rule of periapical radiographs in evaluation of bone
quality and density.
3. Explain how the cross-sectional occlusal radiograph can be valid
in evaluation of bucco-lingual width of the alveolus.
4. Discuss the importance of conventional tomography in
localization of vital structures (Maxillary sinus & Inferior dental
canal ... etc.)
5. Know the rule of other extra-oral plain radiographs
(e.g. Panoramic & Lateral cephalometric) as
preoperative assessment aids.
6. Know the rule of radiography in the presence of any
underlying disease or abnormalities.
7. Compare between 2D and 3D imaging techniques
8. Enumerate the Diagnostic Imaging Modalities in
Dental Implantology
Introduction
Radiography has an essential role in all phases of
treatment extending from pre-surgical diagnosis
and treatment planning, through surgical
placement and postoperative assessment of the
implant, into the prosthetic restoration and
long-term surveillance phase.
Purpose of radiography
• to decide appropriate implant treatment.
• know the location of vital anatomical structures.
• assessment of bone quantity
• to estimate appropriate number, length, width, location
and orientation of implants to be inserted.
• the possible need for additional treatment before
implant placement.
• to estimate the prognosis.
PRINCIPLES OF IMAGING FOR
DENTAL-IMPLANT ASSESSMENT
• Images should have appropriate diagnostic
quality and not contain artifacts that
compromise anatomic-structure assessments.
• Images should extend beyond the immediate
area of interest to include areas that could be
affected by implant placements.
The goal of radiographic
selection criteria is to identify
appropriate imaging modalities
that complement the goals at each
stage of implant therapy.
Imaging techniques used in
dental implantology
1. Intraoral
radiography
Periapical radiographs
It produce a high resolution planner image.
It may suffer from both distortion &
magnification which is limited
by using long cone paralleling
technique.
Its rule In the pre-prosthetic phase
• Useful for identification of local bone or dental
disease.
• Identifying critical structures, but of limited value
in depicting the spatial relationship between the
structures and proposed implant site.
• Used for single tooth implants.
Advantages:
• Availability.
• High resolution image.
• Optimum and reproducible geometry if
paralleling technique used.
• Low dose technique.
• Low cost.
Periapical radiograph of an implant
taken 4 months following socket
preservation showing complete bone fill
of the socket
Failing implant restoration. Arrows
show saucerized area of bone loss.
Periapical
Limitations:
• No bucco-lingual dimension.
• Limited reproducibility unless
stents and paralleling technique used.
• Limited value in determining bone
density or mineralization.
• Limited area imaged.
• Distortion and magnification.
Direct digital intraoral imaging
Its advantages include
• rapid viewing of images, their
storage, retrieval, and tramission
to remote sites
• Enhancement of images.
• Patient Education
• Decreased Radiation
• Elimination of Chemicals and Dark Rooms
limitations
• Significant Cost .
• Use of the rigid intraoral sensors for periapical (PA) images
can be very uncomfortable for patients, especially if they
have a shallow palate, narrow palate, tori, or an exaggerated
gag reflex.
• its use is dependent on the operator’s ability to manipulate
image density and contrast to measure the bone density at
specific sites and to use it further for treatment planning.
Occlusal radiographs
Occlusal radiographs are used for the
mandible/maxilla to obtain information
regarding bucco-lingual width and
contour.
Occlusal radiograph
Occlusal
Advantages:
indication of buccal-lingual dimension of mandible
determination of jaw size, jaw
curve at proposed implant site
readily accessible to clinician
low cost to patient.
Limitations:
• only reveals maximum buccal-lingual dimension
as it shows the widest width of bone (i.e. the
symphysis)
• two dimensional
• No role in maxillary implantology.
• The degree of mineralization of trabecular bone
can be not determined
2. Extra oral
techniques
Lateral cephalometric radiographs
Lateral cephalometric radiographs
They are oriented planer radiograph for the skull,
the skull is oriented using a cephalometer.
The geometry of cephalometric imaging devices
results in a 10% magnification of the image
with a 60 inch focal object and 6 inch object to
film distance.
Lateral cephalometric radiographs
Advantages
• evaluating the relation between maxilla and mandible
for dental implant.
• The soft tissue profile is apparent on and can be used
to evaluate profile alterations after prosthodontic
rehabilitation
Disadvantages
• They are not very useful when planning placement of
implants lateral to the mid-sagittal plan.
• not useful for demonstrating bone quality.
• there is a uniform magnification of about 10%
.&superimposition.
• Resolution is less when compared to intraoral
radiographs.
PANORAMA
Although the resolution and shape of
panoramic radiograph is less than that of an
intraoral film, panoramic projection provides a
broader visualization of the jaws and adjoining
anatomic structures.
PANORAMA
PANORAMA
Advantages:
-- excellent "screening" film for pre-surgical implant
planning
-- can be preformed with convenience, ease & speed.
-- gross anatomy of the jaws & any related pathologic
finding can be evaluated.
-- vertical height of the bone initially can be assessed.
Limitations:
-- little or no information about width or ridge inclination
-- magnification is not uniform especially in the horizontal
direction
-- poor resolution and presence of artifacts may limit
diagnostic accuracy
-- image distortion (technique sensitive to patient
positioning errors)
-- Does not demonestrate bone quality / mineralization.
PANORAMA
Conventional tomography
Cross-sectional tomographic X-ray
machines produce images of slices or layers
(focal plane) of the body by using the
movement of the X-ray beam and film
(connected by a fulcrum bar) during an
exposure to blur unwanted body parts.
Conventional tomography
different types of motion of the x-ray tube and
the film are employed: linear (the simplest),
circular, trispiral, elliptical and hypocycloidal.
The images generated by complex motion
tomography are generally sharper than those
generated by linear tomography.
Conventional tomography
Image of one of the selected tomographic slices
Advantages:
-- produces cross-sectional images of specific proposed
implant sites
-- assessment of bone height, width and inclination of ridge
-- assessment of bone quality
-- determination of anatomic spatial relationship
-- little or no superimposition
-- development of treatment planning software for certain
imaging systems
Limitations:
-- equipment cost
-- recommends availability of trained Oral Radiologist to
perform imaging and calculate bone dimensions
-- time consuming when multiple sites are indicated
-- transfer of radiographic information to clinical site may
necessitate imaging stent
-- variable definition of specific anatomic structures
dependent of imaging system and availability