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Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
Advanced radiographic aids in periodontics
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Advanced radiographic aids in periodontics

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advances in radiodiagnosis for periodontics.the latest advances

advances in radiodiagnosis for periodontics.the latest advances

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  • Doagnosis established by
  • Panoramic radiographs have no of draw backs that limits its use in periodontics
  • However, that is not the issue. The issue must be whether there is any additional therapeutic yield for many greater accuracy in representation of alveolar bone destruction revealed on periapical radiographs
  • Aquistion stage-correction for pixel,exposure normalization and offset adjustment
    Reconstruction stage-special reperesentation –sinogram,recostructed using filter back algorithm feldkamp algorithm
  • to confirm the location of the
    fixture at implant insertion. From 3 to 5 years and
    beyond, imaging is used to assess the bone-implant
    interface and marginal peri-implant bone height.
  • Transcript

    • 1. Advanced diagnostic aids in periodontology Radiographs & imaging
    • 2. Introduction A better understanding of the periodontal disease process challenged usefulness of traditional clinical and radiographic methods for diagnosis and prompted revision of outdated diagnostic aids.
    • 3. DIAGNOSIS The act or process of identifying or determining the nature and cause of a disease or an injury Evaluation of patient history Physical examination Laboratory investigations
    • 4. PRINCIPLES OF DIAGNOSIS Diagnostic test are assessed in terms of their sensitivity and specificity Specificity – is the ability of test to clearly differentiate one disease from other True negative Percentage of subjects with truly absent disease who have a negative test
    • 5. SENSITIVITY - the ability of a test to detect the disease whenever it is present Percentage of subjects with truly present disease who have positive test PREDICTIVE VALUE –Probablity that the test result agress with disease status Positive predictive value-Probablity of disease in a subject with positive test results Negative predictive value Probabllity of health in presence of negative test results
    • 6. RADIOGRAPHS
    • 7. It is the traditional method to asses the destruction of alveolar bone associated with periodontitis. CONVENTIONAL RADIOGRAPH CAN BE USED TO EVALUATE  Bone levels  Bone loss – even or angular patterns  Intra(infra) – bony defects  Root morphologies ⁄ topographies  Furcation radiolucencies  Endodontic lesions  Endodontic mishaps  Developmental anomalies  Root length and shape(s) remaining in bone
    • 8. RADIOGRAPHS INTRA ORAL IOPA,BITEWINGS &OCCLUSAL EXTRA ORAL OPGS CONVENTIONAL AND DIGITAL
    • 9. CONVENTIONAL RADIOGRAPHS INTRA ORAL RADIOGRAPHS
    • 10. Intra oral periapical radiographs Paralleling technique Also called as “right angle” or “long cone technique”. X-ray film is placed parallel to long axis of tooth and central ray of x-ray beam is directed at right angle to teeth & film. Preferable technique for periodontal use.
    • 11. Central ray is directed at right angles to a plane bisecting the angle between long axis of teeth & film. Bisecting angle technique Projection Maxilla Mandible Incisors +40 degrees -15 degrees Canine +45 degrees -20 degrees Premolar +30 degrees -10 degrees Molar +20 degrees 2-5 degrees
    • 12. Extraoral Periapical Radiograph (Newman And Friedman 2003) Limitations with intraoral periapical radiographic imaging: Advancing age Anatomical difficulties like large tongue, shallow palate, restricted mouth opening, Neurological difficulties, and size of radiographic sensor Chen et al in 2007 developed a sensor beam alignment aiming device for performing radiographs using this technique
    • 13. aiming device with placement of the sensor
    • 14. BITEWING RADIOGRAPHS Records the coronal part of upper & lower dentition along with periodontium. USES 1)To study height & contour of interdental alveolar bone. (2)To detect interproximal calculus. (3)To detect periodontal changes Horizontal bitewing radiographs  useful for proximal caries detection  limited use in periodontal treatment and treatment planning if bone loss is advanced
    • 15. Vertical bitewing radiographs film is placed with its long axis at 90º to the placement for horizontal bitewing radiography, can be helpful in evaluating periodontium POSITIONING DEVICES FOR BITEWING Hawe Paro-Bite Centering Device a positioning aid is advised to reduce the need for repeat radiographs and hence the unnecessary x-ray exposure is reduced
    • 16. Occlusal Radiographs – Intraoral occlusal radiographs enable viewing of a relatively large segment of dental arch. They are useful in patients who are unable to open mouth wide enough for periapical radiographs
    • 17. LIMITATIONS OF RADIOGRAPHS Conventional radiographs are specific but lack sensitivity  More than 30% of bone mass at alveolar crest must be lost to be recognized on radiographs  Radiographs provide a 2-dimensional view of a 3- dimensional situation,  provides only information about inter proximal bone level.  Radiographs do not demonstrate soft tissue - to - hard tissue relationship hence no information about depth of soft tissue pocket
    • 18. STANDARDIZATION OF RADIOGRAPHS • Constant film position – film holders, stents • Constant tube geometry - Positioning devices , Cephalostat • Using paralleling techniques • Using vertical bitewings • Using superimposed mm grid
    • 19. Extraoral radiographs Extraoral radiographs are taken when large areas of the skull or jaw must be examined or  when patients are unable to open their mouths for film placement. Useful for evaluating large areas of the skull and jaws but are not adequate for detection of subtle changes such as the early stages of dental caries or periodontal disease.
    • 20. Conventional panoramic imaging/Pantamography
    • 21. LIMITATIONS OF OPG  Image distortion  Lingual structures would be projected higher than buccal surfaces  Use of screen film combination results in less details than intral oral images  Production of ghost images It can be used as a alternative for intra oral full mouth series when combined with bite wing radiographs
    • 22. Tugnait et al. 2000,2005  The periodontal structures of interest noted on periapical radiographs are also noted on panoramic radiographs.  The radiographic features of interest on a panoramic radiograph supplemented when necessary by a small number of intra-oral views, is sufficient for the management of periodontal diseases. Pepallasi EA et al 2000 Panoramic radiographs may not reveal alveolar bony defects as accurately as periapical radiographs. But question is whether there is any additional therapeutic yeild from greater accuracy from IOPAs
    • 23. Vazquez et al 2007  Determined the efficacy of panoramic radiographs in the preoperative planning of posterior mandibular implants  mental nerve parasthesia following implant placement in 1527 patients with 2584 implants with only OPGs as preoperative imaging technique  No permanent sensory disturbances of the inferior alveolar nerve  Only 2 cases 0.08 %reported paresthesia  Panoramic examination safe preoperative evaluation tool
    • 24. Digital radiography Digital radiography is a superior alternative for film based imaging Digital in digital radiography means numeric format of image content as well as its discreteness Images are numeric and discrete in two ways – • Spatial distribution of picture elements (pixels) and • In terms of different shades of gray of each of pixels • Collections of individual pixels organized in a matrix of rows and columns Digital image
    • 25. DIGITAL RADIOGRAPHY Direct Method  Uses a Charge Couple Device (CCD) or CMOS sensor linked with fiberoptic or other wires to computer system  CCD receptor is placed intraorally as traditional films , images appear on a computer screen which can be printed or stored Indirect Method  This method uses a phosphor luminescence plate, which is a flexible film like sensor placed intraorally & exposed to conventional x-ray tube.  A laser scanner reads the exposed plates & reveals digital image data.
    • 26. Direct Digital Imaging Components • X-ray source • an electronic sensor, • A digital interface card, • a computer with an analog to- digital converter (ADC), • a screen monitor, software, and a printer. Direct digital sensors- charge-coupled device (CCD) or complementary metal oxide semiconductor active pixel sensor (CMOS-APS). array of X-ray or light sensitive pixels on a pure silicon chip.
    • 27. Indirect imaging Photostimulable phosphor radiographic systems PSP is scanned with a helium-neon laser beam. The emitted light is captured and intensifi ed by a photomultiplier tube and then converted into digital data.
    • 28. ADVANTAGES  image can be instantly viewed by patient & dentist. Reduction in radiation received by patient by as much 50% to 80%  Images can be altered to achieve task specific image characteristics for eg. density & contrast can be lowered for evaluation of marginal bone and increased for evaluation of implant components.  enables the dental team to conduct remote consultations. Computerized images can be stored, manipulated & corrected for under & overexposure
    • 29. DISADVANTAGES  Familarity with digital nature of images and understanding of principles of image manipulation is required  Lack of infection control.  Patient discomfort during placement.  As image can be easily manipulated, it can be misused in legal proceedings  Grossly overexposed or underexposed images cannot be corrected
    • 30. Radiovisiography (RVG) Duret F et al (1988) Based on use of CCD Radio – X-ray generator connected to sensor Visio – storage of incoming signals during exposure and convertion to gray levels Graphy – digital mass storage unit – connected to various video printout devices latest version Trophy has released a wireless version of their RVG intraoral sensor named the RVG 6500.
    • 31. Mechanism of image display Radiographic digital detector Conventional radiographic source used to expose sensor Detector converts X-rays to visible image Image display on monitor
    • 32. Mouyen F et al (1989): The RVG system when compared with conventional uses considerably reduced levels of radiation to produce an image immediately after exposure.. Adosh L in 1997 in a comparative study for marginal bone between RVG and after surgical exploration presented that Majority showed difference of less than 0.5 mm between two techniques
    • 33.  The radiographic measurements overestimated interproximal bone loss as compared to the intrasurgical measurements: A.R. Talaiepour et al in 2005  evaluated the accuracy of RadioVisioGraphy (RVG) in the linear measurement of interproximal bone loss in intrabony defects.  Comparison between RVG measures and intrasurgical estimates were performed in 56 teeth with intrabony defects
    • 34. Diagnostic efficacy of digital imaging with regard to periodontal lesions Nair et al. 2000 investigated the accuracy of alveolar crestal bone detection utilizing Ektaspeed Plus film, Sidexis direct digital images, and brightness-enhanced digital images. No significant differences were found Wallace et al 2004 Demonstrated that E film displayed the highest sensitivity and specificity followed by PSP and CCD images when observers were able to adjust digital image contrast and brightness enhancements.
    • 35. Specialized techniques Introduction of digital radiography applications with meaningful in dentistry diagnostic utility Early detection Quantitative assessment 3 D imaging
    • 36. Digital subtraction radiography Zeidses des Plantes (1935) : 1st demonstrated use of subtraction imaging  Depends up on conversion of serial radiographs into digital images.  The serially obtained digital images are superimposed & image intensities of corresponding pixels are subtracted If change has occurred The brighter area represents gain Darker area represents loss
    • 37. This technique facilitates both qualitative & quantitative visualization of even minor density changes in bone by removing the unchanged anatomic structures from image Base line after one year bone gain
    • 38. Ortmann (1994)- 5% of bone loss can be detected. Diagnostic subtraction radiography (DSR) can be used for enhanced detection of crestal or periapical bone density changes and to evaluate caries progression
    • 39. STANDARDIZATION  Baseline projection geometry and image density should be reproduced  bite blocks must be made and attached to the film holders and the film holder must be reproducibly aligned to the x-ray beam collimating device
    • 40. Several image processing techniques are also developed to reduce the error in DSR  Semiautomated registration Byrd V et al 1998  Automated registration algoritham .Ettinger et al samarabandhu et al 1994  Computer corrected of distorted projections webber1984
    • 41. Overall contrast is improved Trabecular marrow spaces are visualized Enhancement of low and high density images no objective description High standardization of x rays No reduction in exposure ADVANTAGES DISADVANTAGES
    • 42. COMPUTER ASISTED DENSITROMETRIC IMAGE ANALYSIS SYSTEM Introduced by Urs Brägger et al 1988  A video camera mesaures the light transmitted through the a radiograph  Signal are converted to grey scale images  Camera is interfaced with computer and image processor for storage and mathematic manipulation of image  Offers an objective method for studying alveolar bone changes quantitatively  High degree of sensitivity ,accuracy and reproducablity
    • 43. Urs Brägger et al in 1988  CADIA was more sensitive than subtraction radiography  CADIA was capable of assessing differences in remodeling activity over 4–6 weeks after periodontal surgery  Objective method to quantify alveolar bone density Deas et al 1991 on monitoring the relationship of CALs and CADIA, found that prevelance of progressive lesions as detected by radiograph is higher than previous accepted data CADIA is still used in research purposes for detecting quantitatively the alveolar bone density
    • 44. Computer-Based Thermal Imaging  Compare the rewarming rates of normal and inflamed human gingiva  gingival temperature measurement Valuable objective method for the diagnosis of periodontal diseases  Infra-red thermography provides a non-invasive method
    • 45. Probeye Thermal Imaging Systems The camera's lOx lens provides a spatial resolution of 0.1 mm at a distance of approximately 15 cm from the gingiva. composed of indium antimonide which detects wave lengths from 2000 nm to 5600 nm Technique is no more in use
    • 46. Extra oral digital imaging
    • 47. Conventional tomography  Designed to image a slice or plane of tissue  Accomplished by blurring the images lying outside the plane of interest  It consists of an x ray tube and radiographic film rigidly connected which moves about a fixed axis and fulcrum  As exposure begins tube and film move in opposite direction simultaneously .  Objects located with in the fulcrum remain in fixed positions and are viewed clearly
    • 48. Used less frequently with the introduction of: MRI , CT and Cone beam imaging OPG is a variant of conventional Tomography
    • 49. Computed tomography Godfrey Hounsfield and Allan MacLeod Cormack (1979) shared Nobel prize  Consists of a x ray tube emitting finely collimated x ray beam directed through the patient to a series of scintillating detectors or ionizing chambers  Detectors form a continuous ring and x-ray tube moves in a circle with in the ring  Patients lie stationary and x ray tube rotates one turn .Then the table will move 1 to 5 mm to next scan
    • 50. HELICAL CT Introduced in 1989 The gantry containing x ray tube and detectors continuously revolve around the patient ,where as patients table advances through the gantry. Result is acquisition of a continuous helix of data. DETECTORS Gas filled ion chambers xenon Solid state detectors cadmium tungstate
    • 51. CT Image construction Computer algorithms use photon counts to construct digital CS images Images are displayed in individual blocks ----- VOXELS Each square of the image is matrix----PIXELS Each pixel is assigned a CT number representing tissue density CT number HOUNSFIELD units Range -1000 to 1000
    • 52. ADVANTAGES  Eliminates superimposition of images of structures outside area of interest  High contrast resolution – differences between tissues that differ in density < 1% - can be distinguished  Images can be viewed in axial coronal and sagittal planes
    • 53. Naito T et al. 1998, Pistorius A et al. 2001. Used Computed tomography (CT) in studies in relation to periodontal defects. CT does not offer any favourable cost benefit, dose exposure or therapeutic yield advantage in periodontal practice and is unlikely to find a routine
    • 54. CONE BEAM COMPUTED TOMOGRPHY  Developed in 1982 for angiography  Utilizes cone shaped source of ionizing radiation & 2D area detector fixed on a rotating gantry .  Multiple sequential images are produced in one scan • Rotates 360° around the head • Scan time typically < 1 minute
    • 55. • Image acquisition involves a Rotational scan of a x ray source and reciprocating area detector moving synchronously around patients head • Many exposures are made at fixed intervals to form basic images. • Software programs are used to reconstruct 3D images
    • 56. Image reconstruction
    • 57. INTERFACE CONE-BEAM CT MANAGEMENT SOFTWARE
    • 58. INDICATIONS Evaluation of the jaw bones Implant placement and evaluation  evaluation TMJ  Bony & Soft tissue lesions Periodontal assessment Endodontic assessment Alveolar ridge resorption  Orthodontic evaluation Airway assessment Need for 3D reconstructions
    • 59. panoramic cbct
    • 60. CT V/S CBCT  Conventional CT scanners make use of a fan-beam and Provides a set of consecutive slices of image  Conventional CT makes use of a lie-down machine with a large gantry.  Greater contrast resolution & More discrimination between different tissue types (i.e. bone, teeth, and soft tissue  Utilize a cone beam, which radiates from the x-ray source in a cone shape, encompassing a large volume with a single rotation.  a sitting-up machine of smaller dimensions  Commonly used for hard tissue  Ease of operation  Dedicated to dental  Both jaws can be imaged at the same time  Lower radiation burden
    • 61. Artifacts arising from metal restorations are more severe using conventional CT. artifacts that arise from metallic restorations are less severe with the i-CAT
    • 62. Kelly A. Misch et al . 2006 Compared radiographs with CBCT Results: Three-dimensional capability of CBCT offers a significant advantage in linear measurements for periodontal defect All defects can be detected and quantified. Mol A and Balasundaram 2008 Evaluated The NewTom 9000 CBCT scanner Results: Better diagnostic and quantitative information on periodontal bone levels in three dimensions than conventional radiography can be obtained B. BEZAK et al 2010 Assessed reliability and accuracy of Cone Beam Computed Tomography (CBCT) against CAL . CBCT measurement protocol is reliable. Accuracy of CBCT measurements correlates with CAL gold standard measurements.
    • 63. Brently A. et al 2009  Compared the measurements from digital IR and CBVT images to direct surgical measurements for the evaluation of regenerative treatment outcomes.  Compared to direct surgical measurements, CBVT significantly more precise and accurate than IRs.  CBVT may obviate surgical reentry as a technique for assessing regenerative therapy outcomes Walter C et al..2011- Suggests that cone-beam CT may provide detailed information about furcation involvements in patients with chronic periodontitis and so may influence treatment planning decisions
    • 64. MICRO CT The term micro the pixel sizes of the cross-sections are in the micrometer range . Microtomography KNOW AS Industrial CT Scanning uses X-rays to create cross-sections of a 3D-object Used in animal studies analysis of bone biopsies without destruction of samples
    • 65. Denta scan DentaScan is a unique computer software program provides computed tomographic (CT) imaging of the mandible and maxilla in three planes of reference: axial, panoramic, and oblique sagittal .
    • 66. Uses ♣ visualization of internal bone morphology in three dimensions ; precise treatment planning ♣ In cross sectional view, observation regarding bone quality, density can be made ♣ pre-operative planning of endosseous dental implants and subperiosteal implants ♣ to visualize the bony structures pre- operatively
    • 67.  Dentascan CT provides information of the internal structures that cannot even be gained by direct intra-operative visualization  the precise location of the mandibular canal  the location of the floor of the maxillary sinuses
    • 68. Dr Urvashi shah, Dr Subraya bhat Utilization of denta-scan for treatment planing in patients with infra-bony defects Infra-bony defects better visualized by denta-scan compared to intra-oral radiographs
    • 69. Computer program for assessing oral implant site Uses raw data from CT along with advanced computer graphics Advantages: • assessment of bone volume, bone height &quality • proper length of implant can be selected • Clear visualization of inferior alveolar canal SIMPLANT
    • 70. Digital tomosynthesis (DTS)  Digital tomosynthesis (DTS) is a limited-angle tomographic technique  only small rotation angles (a few tens of degrees) with a small number of discrete exposures are used.  provides some of the tomographic benefits of computed tomography (CT)  at reduced dose and cost
    • 71. K Ogawa et al 2010 Developed a new dental panoramic radiographic system based on a tomosynthesis method This system allowed the extraction of an optimum- quality panoramic image regardless of irregularities in patient position  the authors could freely reconstruct a fine image of arbitrary planes
    • 72. C Beda in 2010 proposed the Use of both DTS and CBCT reconstruction methods as an integrated solution for providing tomographic data in dental application
    • 73. OPTICAL COHERENCE TOMOGRAPHY  Optical coherence tomography (OCT) is an optical signal acquisition and processing method  an interferometric technique, employing near- infrared light. Layperson's explanation “a technique for obtaining sub-surface images of translucent or opaque materials at a resolution equivalent to a low-power microscope.”
    • 74. OCT is well-suited for periodontal diagnosis pocket morphology, and attachment level are digitally recorded quantitative information of thickness and character of the gingiva, root surface irregularities, and the distribution of subgingival calculus Otis L.L et. al. 2004 demonstrate the capacity of OCT to determine gingival thickness and the shape and contour of the alveolar crest. Xiang et al. (2009) OCT imaging can offer three-dimensional imaging of periodontal soft tissues and bone at a very high resolution . Identify active periodontitis before significant alveolar bone loss occurs. Reliable method for determining attachment level
    • 75. TACT-tuned aperture CT  Based on the principles of tomosynthesis  Low cost,low dose ,3D Imaging stystem  Series of radiographs taken from different angles  Soft ware (work bench) stacks the basic images and reconstruct in to multi planar images  Caries detection  Vertical root fracture  Helps to detect osseous defects around implants  Detection and localization of osseous changes in crestal bone
    • 76. Onanong Chai-U-Dom in 2002  Compared the potentials of conventional and TACT DSR detecting simulated bone-gain in periodontal defects, in vitro  TACT-DSR provide greater sensitivity and technique flexibility in detecting periodontal bone-gain than standard DSR. Nair M K et al in 2002  Compared the diagnostic efficacy of tuned-aperture computed tomography (TACT) and conventional two- dimensional direct digital radiography (DDR) in an in vitro environment for detecting bone loss in mid-buccal and lingual crests.  TACT-IR performed significantly better than DDR
    • 77. SMALL VOLUME CT  Form of CBCT  utilizes small field high resolution detector to generate high resolution 3D volume  Generally comparable to size of intraoral radiographs van Daatselaar 2003 based on comparison made between a full CT geometry and a local CT geometry. “local CT of dental structures appears to be a promising diagnostic instrument.”
    • 78. MRI Magnetic resonance imaging  does not involve the use of ionizing radiation  it involves the behaviour of protons in a magnetic field.  Hydrogen protons are used to create the MR image.  The image itself is another example of a tomograph or sectional image that at first glance resembles a CT  Used for imaging intracranial and soft tissue lesions,
    • 79.  The patient is placed within a very strong magnetic field (usually between 0.5–1.5 Tesla)  patient’s hydrogen protons, behaves like magnets to produce the net magnetization vector (NMV ) which aligns itself readily with the longaxis of the magnetic field  Radiowaves are pulsed into the patient by the body coil transmitter at 90° to the magnetic field  Hydrogen atoms to resonate(store energy )  When radio frequency is turned off ,the stored energy is released from body and detected as a signal in a coil in scanner  Reconstruction of image
    • 80. USES IN HEAD AND NECK REGION  Assessment of intracranial lesions involving particularly the posterior cranial fossa, the pituitary and the spinal cord.  Investigation of the salivary glands  Tumour staging  Investigation of the TMJ to show both the bony and soft tissue components  Implant assessment Schara et al 2009 In an invitro study evaluated the used the use of MRI to characterize inflammation and healing process in periodontal tissues It was concluded that MRI can characterize the type and healing process of inflammation
    • 81. BONE SCANNING or RADIONUCLIDE IMAGING IN contrast to X-ray, CT, MRI which require structural or anatomic changes to be recorded,this technique assesses biochemical alteration in body It Is a nuclear scanning test that identifies new areas of bone growth or breakdown. It can be done to evaluate damage to the alveolar bones,and monitor conditions that can affect the periodontium (including infection and trauma)
    • 82.  radioactive tracer eg. 99m technetium pertechnetate substance is injected into a vein in the arm. Areas that absorb little or no amount of tracer appear as dark or "cold" spots, which may indicate a lack of blood supply to the bone (bone infarction) or the presence of certain types of cancer Areas of rapid bone growth or repair absorb increased amounts of the tracer and show up as bright or "hot" spots in the pictures. Hot spots may indicate the presence of a tumor, a fracture, or an infection.
    • 83. Other radioactive isotopes used are – iodine(131 I), gallium(67 Ga) & selenium(74Se) γ scintillation camera is used to capture photons and then convereted to light and to voltage signal Signal is constructed to planar image that shows radionuclide in the image
    • 84. Advanced nuclear imaging • Single photon emission computed tomography • Positron emission tomography
    • 85. Positive bone scans are detected in beagle dogs with advanced experimental periodontitis kaplan 1975 ,Jeffcoat et al 1985 Jeffcoat et al1985 –There exist a significant association with high intake of 99mTC and bone loss in moderate to severe periodontitis Sensitivity of 83 % and specificty of 84 % Reddy et al 1991 scintillation camera images following radiopharmaceutical administration is accurate in detecting bone loss
    • 86. IMPLANT IMAGING
    • 87. In 2000, the American Academy of Oral and Maxillofacial Radiology (AAOMR) recommended “some form of cross-sectional imaging be used for implant cases “ conventional cross-sectional tomography be the method 2012
    • 88. 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 Practitioners should have appropriate training in operating radiographic equipment and competence in interpreting images from the modality used
    • 89. Initial examination • PANORAMIC RADIOGRAPHY SHOULD BE USED AS AN IMAGING MODALITY RECOMMENDATION 1 • USE IOPAs TO SUPPLEMENT PANORAMIC RADIOGRAPHY RECOMMENATION 2 • DO NOT USE CROSS SECTIONAL IMAGING AS AN INITIAL DIAGNOSTIC AID RECOMMENDATION 3
    • 90. Preoperative site specific imaging •establish characteristics of residual alveolar bone •determining orientation of RAR •identifying local conditions restricting implant placement • match imaging findings to the prosthetic plan
    • 91. RECOMENTATION 4 cross sectional imaging of any potential implant site RECOMENTATION 5 CBCT considerd as the imaging modality of choice for imaging implant sites RECOMMENDATION 6 CBCT should be considered if need for augmentaion or other site development procedure is present
    • 92. Postoperative imaging In the absence of clinical signs use IOPAS or OPGs Patient has mobility or altered sensation use cross sectional imaging /CBCT Implant retrieval CBCT
    • 93. DICOM Standard The Digital Imaging and Communications in Medicine  facilitate communications between imaging devices and systems. By dictating specific data and interface requirements, DICOM ensure that devices-- particularly devices made by different suppliers--can communicate with one another. :
    • 94. Transmission and persistence of complete objects Eg images,docs Query and retrieval of objects Printing images on film Work flow management Quality and consistency of image apperance DICOM address five primary areas of functionality:
    • 95. RADIOGRAPHS IN PERIODONTAL DISEASE DIAGNOSIS & MANAGEMENT Features of periodontal diagnostic interest are apparent on radiographs Relationship exists b/w clinical attachment and radiographic bone height Radiographs can be used in all stages of periodontal care Tugnait et al 2000 Considered a provoking review
    • 96. Full-mouthsurveys of paralleling periapical radiographs have been considered to be a ‘‘gold standard’’ for periodontal diagnosis and treatment planning or a panoramic radiograph supplemented by selected intra- oral radiographs , numbered less than four per patient reach the ‘‘gold standard’
    • 97. EXPOSURE FROM X RAYS
    • 98. Radiography must not be a substitute for clinical investigation X-rays as a component of periodic examinations cannot be condoned. Radiographic examination in clinical periodontology is only justified if changes in treatment plans from those treatment plans developed on the basis of clinical examination supplemented by any already available radiographs are anticipated TO CONCLUDE…….
    • 99. Advanced imaging systems like CTs,CBCTs, have enabled better visualization of periodontal structures and pathologies in3D thus helping in better diagnosis and treatment planning The cost factor and other technical difficulties have limited their cliniclal utility but their utility as a research tool is unquestionable FURTHER IMPROVEMENT S ARE WARRANTED IN FIELD OF DIGITAL IMAGING And in near future these imaging techniques will become routine diagnostic tools

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