2Diagnostic 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
4Phase one is termed preprosthetetic implant imaging The objectives of diagnostic imaging depend on a number of factors, including the amount and type of informationrequired 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 orientationPhase two is termed surgical implant imaging evaluate the surgery sitesduring 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 prosthesisplacement 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.
5IMAGING MODALITIESThe 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-benefitTypes of Imaging ModalitiesPeriapical radiography (analog)Panoramic radiography (analog)Occlusal radiography (analog)Cephalometric radiography (analog)Tomographic radiographyComputed tomography (three-dimensional)Magnetic resonance imaging (three-dimensional)Interactive computed tomography (three-dimensional)
6PREPROSTH ETIC IMAGING Subdivided into planar two-dimensional, quasi— three-dimensional, and three-dimensional imaging modalities.ALARA : as low as reasonably achievable95% just panoramic , <15% conventional CT
7Periapical 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
8For 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 dimensionAdvantagesLow radiation doseMinimal magnification with proper alignment and positioningHigh resolutionInexpensiveLimitationsDistortion and magnificationMinimal site evaluationDifficulty in film placementTechnique sensitiveLack of cross-sectional imagingIndicationsEvaluation of small edentulous spacesAlignment and orientation during surgeryRecall/maintenance evaluation
10DIGITAL RADIOGRAPHYA 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
11Occlusal RadiographyOcclusal radiographs are planar radiographs produced by placing the filmintraorally parallel to the occlusal plane with the central x-ray beamperpendicular to the film for the mandibular image and oblique (usually 45degrees) to the film for the maxillary image.The mandibular occlusal radiograph shows the widest widthof 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 projectionAs a result, occlusal radiographs rarely are indicated for diagnostic preprosthetic phases in implant dentistryAdvantages: Evaluation for pathologyLimitations: Does not reveal true buccolingual width in mandible, Difficulty in positioningIndications: None
12Cephalometric 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
13Lateral Cephalometric Images AdvantagesHeight/width in anterior regionLow magnificationSkeletal relationshipCrown-implant ratio (anterior)Tooth position in prosthesisEvaluation of the quantity of bone in anterior region prior to symphysis graftingLimitationsAvailabilityImage information limited to midlineReduced resolution and sharpnessTechnique sensitiveIndicationsUsed in combination with other radiographic techniques for anterior implantsSymphysis bone graft evaluation
14Panoramic 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
15Zonography: The tomographic layer is approximately 5 mm. Objects in front of and behind the focal trough are blurred, magnified,reduced in size, or distorted to the extent of being unrecognizablewhen 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.AdvantagesEasy identification of opposing landmarksInitial assessment of vertical height of boneConvenience, ease, and speed in performance in most dental officesEvaluation of gross anatomy of the jaws and any related pathologic findings'LimitationsDistortions inherent in the panoramic systemErrors in patient positioningDoes not demonstrate bone qualityMisleading quantitate because of magnification and no third dimension
17TomographyTomography 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.
19Computed TomographyCT 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 bodyHounsfield 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 imagingAdvantages: Negligible magnification, Relatively high-contrast image, Various views, Three-dimensional bone models, Interactive treatment planning, Cross-referencingLimitations: Cost, Technique sensitiveIndicationsInteractive treatment planningDetermination of bone densityVital structure locationSubperiosteal implant fabricationDetermination of pathologyPreplanning for bone augmentation
20Quality Density Hounsfield unit Tissue Characterization Tissue Hounsfield unitAirWaterMuscleFibrous tissueCartilageTrabecular boneCortical boneDentinEnamel
21Interactive Computed Tomography ICT is a technique that was developed to bridge the gap ininformation transfer between the radiologist and the practitioner. Thistechnique enables the radiologist to transfer the imaging study to thepractitioner as a computer file and enables the practitioner to view and interact with the imaging study on a personal computerAn 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 imagesDiagnostic template
22Cone Beam Volumetric Tomography new type of CT specific for dental applicationsThe 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 dosesx-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 exposuremagnification being almost 0% with no superimposition or overlapping of images and minimal distortion
24Magnetic 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 CTMRI 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
25Magnetic Resonance Imaging AdvantagesNo radiationVital structures are easily seen (inferior alveolar canal, maxillary sinus)LimitationsCostTechnique sensitiveNo reformatting softwareAvailabilityNon signal for cortical boneUsesEvaluation of vital structures when computed tomography is not conclusiveEvaluation of infection (osteomyelitis)
26RADIOGRAPHIC IMAGING OF VITAL STRUCTURES IN ORAL IMPLANTOLOGY Mental Foramen and Mandibular Canal50% of periapical radiographs, the mental foramen is not visible. the mental foramen is absent in approximately 12% of panoramicthe most accurate means of identification is with conventional and computerized tomographytilting 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 radiographsMandibular Lingual Concavities2.4% prevalence of concavities with average depths of 6 mm (±2.6mm). Within these concavities or submandibular gland fossa, branches of the facial artery may be present.Mandibular Ramusvery popular donor site for autogenous onlay bone grafting.Standard radiographs for preassessment include panoramicMandibular SymphysisThe mandibular symphysis area is a very critical anatomical area for oralimplantology. Lateral cephalometric and conventional CT, may be usedMaxillary SinusCT
27INTRAOPERATIVE IMAGING Advantages of Digital Radiography for Implant SurgeryFastLow radiationCalibrationMagnificationExcellent qualityMeasures depth, density, and neighboring structuresPatient stays in surgical settingKeeps aseptic setting
28Immediate 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 filmsAbutment and Prosthetic Component ImagingRadiographs should be taken to verify secure adaptation. When positioning is difficult for periapical radiographs, bitewing or panoramic radiographs may be usedPostprosthetic Imaginga 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 radiographsRecall and Maintenance ImagingFor 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
29Evaluation of Alveolar Bone Changes Radiographically, lack or loss of integration is usually indicatedas a radiolucent line around the implant."Mach band effect"Mach band effect is significantly reduced with digital imageprocessing.Periapical RadiographsFilmholding devicesIf the threads are not clearly seen in the radiographs,modification of the beam angle needs tobe made. If diffusethreads are present on the right side of the implant. then thebeam angle was positioned too much in the superiordirection. If the thread are diffuse on the left side, then thebeam angle was from an inferior angulationBitewing Radiograph.