orofacial implant
DESCRIPTION
Radiology II Forth YearTRANSCRIPT
![Page 1: Orofacial implant](https://reader033.vdocuments.us/reader033/viewer/2022052321/55496b95b4c905525e8b4c60/html5/thumbnails/1.jpg)
Oro-facial implants
By Dr. Hassan M. Abouelkheir
BDS, MSC, PhD.
![Page 2: Orofacial implant](https://reader033.vdocuments.us/reader033/viewer/2022052321/55496b95b4c905525e8b4c60/html5/thumbnails/2.jpg)
Ideal image casting:• The ability to visualize implant site
buccolingually, mesio-distally & superio-inferiorly.
• The ability to allow reliable accurate measurements.
• The capacity to evaluate trabecular density & cortical thickness.
• The capacity to correlate the imaged site with clinical site.
• Reasonable access & cost to patient. • Low radiation dose.
![Page 3: Orofacial implant](https://reader033.vdocuments.us/reader033/viewer/2022052321/55496b95b4c905525e8b4c60/html5/thumbnails/3.jpg)
Intra-oral Radiography
• 1- Periapical Radiographs: • It Provide superior resolution
and sharpness. • Parallel technique is used to
decrease geometric errors. • They determine vertical
height, architecture and bone quality (bone density, amount of cortical & trabecular bone.
!
![Page 4: Orofacial implant](https://reader033.vdocuments.us/reader033/viewer/2022052321/55496b95b4c905525e8b4c60/html5/thumbnails/4.jpg)
Intra-oral Radiography (continue):
• Geometric & anatomical limitations:
• Foreshortening & elongation of radiographic alveolar height.
• Positioning of film may miss anatomical structures.
• Unable to provide any cross- sectional information.
![Page 5: Orofacial implant](https://reader033.vdocuments.us/reader033/viewer/2022052321/55496b95b4c905525e8b4c60/html5/thumbnails/5.jpg)
2- Occlusal radiographs: • Although it gives a clue about facio-
lingual dimension of mandibular alveolar ridge .
• It records the widest portion of the mandible which is below the alveolar ridge .
• It is not suitable for maxilary arch due to anatomical limitations.
Intra-oral Radiography (continue):
![Page 6: Orofacial implant](https://reader033.vdocuments.us/reader033/viewer/2022052321/55496b95b4c905525e8b4c60/html5/thumbnails/6.jpg)
Extra-oral radiographs:
• 1- Lateral & Lateral-oblique cephalometric radiography:
!• Lateral cephalometric: has 7% to 12% magnification
It gives the axial tooth inclination and dento - alveolar relationships as well as cross section at midline only due to over projection of the lateral areas of the jaw.
![Page 7: Orofacial implant](https://reader033.vdocuments.us/reader033/viewer/2022052321/55496b95b4c905525e8b4c60/html5/thumbnails/7.jpg)
Extra-oral radiographs (continue)
2-Oblique Lateral Cephalometric Radiographs (OLCR)
• One side of the body of the mandible positioned parallel to the film cassette.
• A cephalostat with earplugs and a nasion support was used to position the head with the porion-subnasal plane in a horizontal position. A light beam was used to position the mandibular lower border with an inclination of 20 degrees.
• Measurements from this image are not reliable.
![Page 8: Orofacial implant](https://reader033.vdocuments.us/reader033/viewer/2022052321/55496b95b4c905525e8b4c60/html5/thumbnails/8.jpg)
Extra-oral radiographs (continue):
!3- Panoramic radiography: • It is important for broad visualization
of the jaws and anatomical structures. • It is useful for preliminary estimations
of crestal alveolar bone and cortical boundaries of ID canal, max. s. & nasal fossa.
![Page 9: Orofacial implant](https://reader033.vdocuments.us/reader033/viewer/2022052321/55496b95b4c905525e8b4c60/html5/thumbnails/9.jpg)
Limitations of panoramic radiography:
1- angular measurements are accurate but horizontal ones are not.
2 - Magnification (size distortion) varies among films from different panoramic unites and also at different areas on the same film.
3- Foreshortening and elongation of vertical measurements.
4- Overestimation of vertical bone heights. 5- Magnification of horizontal image measurements
as a result focal trough area constructed on average population (0.70 to 2.2 times actual size) .
![Page 10: Orofacial implant](https://reader033.vdocuments.us/reader033/viewer/2022052321/55496b95b4c905525e8b4c60/html5/thumbnails/10.jpg)
4- conventional tomography:
• This technique produces a cross –sectional , flat-plane image layer that is perpendicular to the x-ray beam.
• The complex (multidirectional) tube motion of current conventional tomographic units minimizes image superimposition & provide fixed uniform image magnification for accurate measurements.
![Page 11: Orofacial implant](https://reader033.vdocuments.us/reader033/viewer/2022052321/55496b95b4c905525e8b4c60/html5/thumbnails/11.jpg)
• Radiographic stents are used to determine the width and height of pre-planned implants after correction with magnification factor as in case of using scanora integrated imaging system.
• Two or three cross-sectional tomographic slices are required to preplan each intended implant site.
![Page 12: Orofacial implant](https://reader033.vdocuments.us/reader033/viewer/2022052321/55496b95b4c905525e8b4c60/html5/thumbnails/12.jpg)
5- Reformatted computed Tomography:
It is indicated for : 1- Edentulous pts. 2- Multiple implants. 3- Augmentation procedures. 30 axial images are required per jaw
(1-2mm). These sequential axis images can be
manipulated by process called multiplannar reformatting (MPR) to produce multiple two dimensional images in various planes.
![Page 13: Orofacial implant](https://reader033.vdocuments.us/reader033/viewer/2022052321/55496b95b4c905525e8b4c60/html5/thumbnails/13.jpg)
Reformatted computed Tomography (cont.)• The CT analysis comes from 3 basic
image types: • Axial images. • Reformatted cross-sectional
images. • Panoramic like images. • The computer places a series of
sequential dots on selected scan then connect them to construct a customized arch .
• Then it places a series of lines at constant intervals (1-2mm) on axial image to indicate the position at which each cross sectional slice will be reconstructed.
![Page 14: Orofacial implant](https://reader033.vdocuments.us/reader033/viewer/2022052321/55496b95b4c905525e8b4c60/html5/thumbnails/14.jpg)
Reformatted computed Tomography (cont.)• These reformatted images
provide the clinician with two-dimensional diagnostic information in all three dimensions.
• It gives information on; 1- amount of cortical bone and
residual bone. 2- location of vital structures. 3- contour of soft tissues. 4- 3D reformations for
augmentation as in maxillary sinus lifting.
![Page 15: Orofacial implant](https://reader033.vdocuments.us/reader033/viewer/2022052321/55496b95b4c905525e8b4c60/html5/thumbnails/15.jpg)
Pre-operative planning:• Diagnostic image can give 3D information
about quality and quantity of alveolar bone. Quality: • 1- the thicker the cortical bone the best
withstand for functional load. • 2- A greater number of internal trabeculae
per unit area is advantageous.
![Page 16: Orofacial implant](https://reader033.vdocuments.us/reader033/viewer/2022052321/55496b95b4c905525e8b4c60/html5/thumbnails/16.jpg)
Pre-operative planning (cont.):Quantity: 1- Height . 2- Width of alveolar
bone. 3- Morphology of ridge. Cross –sectional image
to determine facio-lingual width and height , along with inclination of bone contour.
![Page 17: Orofacial implant](https://reader033.vdocuments.us/reader033/viewer/2022052321/55496b95b4c905525e8b4c60/html5/thumbnails/17.jpg)
Pre-operative planning (cont.): • Pre-planning
measurements in different technique shows variable magnification factor (MF).
• Radiographic image / MF to correct measurements.
• (Pan, Periapical).
![Page 18: Orofacial implant](https://reader033.vdocuments.us/reader033/viewer/2022052321/55496b95b4c905525e8b4c60/html5/thumbnails/18.jpg)
Pre-operative planning (cont.):• If MF is constant a
plastic overlay with 1mm grids or diagrams of available implant sizes can be used directly on image.
• Specialized reformatted CT implant programs can perform image without magnification. It can be printed life size.
![Page 19: Orofacial implant](https://reader033.vdocuments.us/reader033/viewer/2022052321/55496b95b4c905525e8b4c60/html5/thumbnails/19.jpg)
Imaging stent
• Pre-surgical imaging can be enhanced by radiographic stent to locate the position of pre-surgical site for end osseous implant.
• The intended implant sites are identified by radiopaque spheres or rods (metal, composite resin or Gutta percha).
![Page 20: Orofacial implant](https://reader033.vdocuments.us/reader033/viewer/2022052321/55496b95b4c905525e8b4c60/html5/thumbnails/20.jpg)
Interactive Diagnostic software: several interactive
software packages (e.g. Sim-plant ) allow presurgical simulation of implant orientation and placement.
![Page 21: Orofacial implant](https://reader033.vdocuments.us/reader033/viewer/2022052321/55496b95b4c905525e8b4c60/html5/thumbnails/21.jpg)
Interactive Diagnostic software:• There are 3 basic views available
on the Sim/Plant™ screen: • The Panoramic view is similar to
a normal two dimensional panoramic view.
• The axial view offers a perspective from a coronal/apical direction.
• There is a cross sectional view that allows a mesial /distal cross sectional perspective of the arch.
![Page 22: Orofacial implant](https://reader033.vdocuments.us/reader033/viewer/2022052321/55496b95b4c905525e8b4c60/html5/thumbnails/22.jpg)
Selecting diagnostic imaging for pre-operative planning:
1- panoramic view. 2- intraoral periapical films for particular
region of interest. 3- CT if entire maxilla or/and mandible is
required. 4- conventional tomography for few selected
regions.
![Page 23: Orofacial implant](https://reader033.vdocuments.us/reader033/viewer/2022052321/55496b95b4c905525e8b4c60/html5/thumbnails/23.jpg)
Intra-operative & postoperative assessments:1- panoramic view. 2- intraoral radiographs. • Intra- operative films may be required for
confirmation of correct implant placement or to locate a lost implant.
• Inspection includes; 1- alveolar bone height around implant. 2- the appearance of bone around and
adjacent to implant.
![Page 24: Orofacial implant](https://reader033.vdocuments.us/reader033/viewer/2022052321/55496b95b4c905525e8b4c60/html5/thumbnails/24.jpg)
Intra-operative & postoperative assessments• Angulations of x-ray beam
must be within 9 degrees of long axis of the fixture to see the sharp image of threads of fixuture .
• Otherwise angular deviation of 13 degrees or more result in complete overlap to the threads.
![Page 25: Orofacial implant](https://reader033.vdocuments.us/reader033/viewer/2022052321/55496b95b4c905525e8b4c60/html5/thumbnails/25.jpg)
Intra-operative & postoperative assessments• Longitudinal assessment of
implant by serial standardized periapical films using XCP- film holder with rubber base impression material to measure;
1- Mesial & Distal bone height from standard landmark at the collar of implant.
2- or interthread measurements compared to bone levels on serial radiographs.
![Page 26: Orofacial implant](https://reader033.vdocuments.us/reader033/viewer/2022052321/55496b95b4c905525e8b4c60/html5/thumbnails/26.jpg)
Intra-operative & postoperative assessments
• There is initial circumscribed resorptive osseous changes around cervical area of fixture during 1st 6 months after surgery.
• It was estimated that there was marginal bone loss 1.2mm in the 1st year then 0.1mm in succeeding years.
![Page 27: Orofacial implant](https://reader033.vdocuments.us/reader033/viewer/2022052321/55496b95b4c905525e8b4c60/html5/thumbnails/27.jpg)
Intra-operative & postoperative assessments
• If any resorptive changes are present , they evidenced by apical migration of the alveolar bone or indistinct osseous margins.
• Density can be measured in intraoral digital radiographs to measure bone resorption .
![Page 28: Orofacial implant](https://reader033.vdocuments.us/reader033/viewer/2022052321/55496b95b4c905525e8b4c60/html5/thumbnails/28.jpg)
Intra-operative & postoperative assessments
• Digital subtraction radiography requires image geometry reproduction between radiographic examinations.
• The success of implant can be evaluated by normal bone surrounding and up to the surface of the implant .
• No clinical mobility.
![Page 29: Orofacial implant](https://reader033.vdocuments.us/reader033/viewer/2022052321/55496b95b4c905525e8b4c60/html5/thumbnails/29.jpg)
Radiographic signs of failing endosseous implants:
• Thin radiolucent area surrounding the entire implant.
• Crestal bone loss around the coronal portion of the implant.
• Apical migration of alveolar bone on one side of the implant.
• Widening of PDL space of nearest natural Tooth (abutment).
• Fracture of implant fixture.
![Page 30: Orofacial implant](https://reader033.vdocuments.us/reader033/viewer/2022052321/55496b95b4c905525e8b4c60/html5/thumbnails/30.jpg)