- DR. IBRAHIM SHAIKHMDS III

DEPT. OF PERIODONTOLOGY & IMPLANTOLOGY

SEMINAR NO. - 8

Radiographic Aids In Diagnosis of Periodontal Diseases – Part A

DATE : 17/05/2016

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CONTENTS1. Introduction.2. History.3. Radiographs.4. Interpretation of radiological examination.5. Interpretation in relation to periodontal

diseases.6. Advances in radiographs.7. Limitations of radiographs.8. Implant imaging (Briefly).9. Conclusion.10.References.

3Introduction

4History

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HISTORY• Discovery of X-Rays - November 8th , 1895

Forms of tube used by Roentgen in 1895–1896 for the production of X rays.

Wilhelm Conrad Roentgen(1845 – 1923)

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HISTORY• First Dental Radiograph – 12th January, 1896

Dr. Otto Walkoff(1860 – 1934)

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HISTORY• First Intraoral Dental Radiograph – Early 1896

Dr. Edmund Kells(1856 – 1928)

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HISTORY• First Intraoral Dental Radiograph – Early 1896

9Radiographs

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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

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RADIOGRAPHS

INTRA ORAL

IOPA, BITEWINGS

& OCCLUSAL

EXTRA ORAL

OPGS

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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.

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Intra Oral Periapical Radiographs

Bisecting angle technique Central ray is directed at right angles to a plane

bisecting the angle between long axis of teeth & film.

Makes the bone margin appear more closer to the crown.

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Extra Oral Periapical Radiographs

Newman And Friedman 2003Limitations with intraoral periapical radiographic imaging: Advancing age Anatomical difficulties like large tongue, shallow

palate, restricted mouth opening, Neurological difficulties, and size of radiographic

sensor

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Extra Oral Periapical Radiographs

Chen et al in 2007 Developed a sensor beam alignment aiming device for

performing radiographs using this technique

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Bitewing RadiographsRecords the coronal part of upper & lower dentition along with periodontium.

Uses: To study height & contour of interdental alveolar

bone. To detect interproximal calculus. To detect periodontal changes

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Bitewing Radiographs

Horizontal bitewing radiographs Useful for proximal caries

detection. Limited use in periodontal

treatment and treatment planning if bone loss is advanced.

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.

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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

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Extraoral Radiographs

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.

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Orthopantomograph

Technique for producing single tomographic image of facial structures including maxillary and mandibular arches with their supporting structures.

Based on principle of the reciprocal movement of x-ray source and image receptor around a central plane known as image layer.

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Orthopantomograph

Image distortion Lingual structures would be projected higher than

buccal surfaces Less details than intraoral images Production of ghost images

Limitations of OPG

It can be used as a alternative for intra oral full mouth series when combined with bite wing radiographs

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Panoramic radiographs may not reveal alveolar bony defects as accurately as periapical radiographs.

But question is whether there is any additional therapeutic yield from greater accuracy from IOPAs

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

Tugnait et al. 2000,2005

Pepallasi EA et al. 2000

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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 i.e. 0.08 % reported paraesthesia.

Panoramic examination is a safe preoperative evaluation tool.

Vazquez et al 2007

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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 e.g. 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

Digital Radiography

Advantages

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Based on use of Charged Couple Device.

Radio – X-ray generator connected to sensor. Visio – storage of incoming signals during exposure and

conversion to grey levels. Graphy – digital mass storage unit connected to various

video printout devices.

Radiovisiography

Duret F et al 1988

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Radiovisiography

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

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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

The RVG system when compared with conventional uses considerably reduced levels of radiation to produce an image immediately after exposure.

Mouyen F et al 1989

Adosh L in 1997

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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.

The radiographic measurements overestimated interproximal bone loss as compared to the intrasurgical measurements.

A.R. Talaiepour et al in 2005

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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

Digital Subtraction Radiography

Zeidses des Plantes 1935

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Base Line After One Year Bone Gain

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

Ortmann 1994

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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

Standardization

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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

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Extra Oral Digital Imaging

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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, the tube and film move circumferentially simultaneously .

Objects located with in the fulcrum remain in fixed positions and are viewed clearly.

Conventional TomographyGodfrey Hounsfield and Allan MacLeod Cormack 1979

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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

Conventional TomographyCT Image Construction

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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

Conventional TomographyAdvantages

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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.

Naito T et al. 1998; Pistorius A et al. 2001

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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.

Cone Beam Computed Tomogrphy

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INTERFACE CONE-BEAM CT MANAGEMENT SOFTWARE

Cone Beam Computed Tomogrphy

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Evaluation of the jaw bones. Implant placement and evaluation. Evaluation TMJ. Bony & Soft tissue lesions. Periodontal assessment. Endodontic assessment. Alveolar ridge resorption. Orthodontic evaluation. 3D reconstructions.

Cone Beam Computed TomogrphyIndications

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PANORAMIC CBCT

Undistorted

CS, Axial, Coronal Sagittal views

Separated structures

Distorted images

Only one layer view

Superimposition

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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.

Lower radiation burden.

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CT V/S CBCT

Artefacts arising from metal restorations are more severe using conventional CT.

Artefacts that arise from metallic restorations are less severe.

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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.

Kelly A. Misch et al . 2006

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

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Compared the measurements from digital IR and CBCT 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 re-entry as a technique for assessing regenerative therapy outcomes

Brently A. et al 2009

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

48Interpretation of Radiographs

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Detailed understanding of three dimensional anatomy and how structures appear radiologically.

Know the differences in radiologic anatomy in a 2D & a 3D radiograph.

Must possess knowledge of diseases which are potentially assosciated with all structures in the FOV.

Must be aware and knowledgable of all different imaging modalities.

Optimal viewing conditions are essential.

Interpretation of Radiographs

Basic Prerequisites

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Recognizing the presence of an abnormality.

Radiologic evaluation of a lesion – o Location.o Shape and Contour.o Border.o Internal appearances.

Adjacent anatomic structures

Interpretation of the findings.

Interpretation of Radiographs

Key Steps in Interpretation

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References1. Clinical Periodontology And Implant Dentistry; Jan

Lindhe; 6th Edn2. Oral Radiology-principles And Interpretation; Stuart C.

White; 5th Edn3. Clinical Periodontology; Newman, Takei, Klokkevold,

Carranza; 10th Edn

4. Radiology In Periodontics – A Review ; J. Indian Academy Of Oral Medicine & Radiology; 2013; 25 (1); 24-29.

5. P.F. Van Der Stelt; Modern Radiographic Methods In The Diagnosis Of Periodontal Disease; Adv Dent Res 7(2):158-162, August, 1993

6. Bragger U: Digital Imaging In Periodontal Radiography- A Review; J Clin Periodontol 1988: 15: 551-557

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PART B1. Interpretation in relation to periodontal

diseases.

2. Advances in radiographs.

3. Limitations of radiographs.

4. Implant imaging (Briefly).

5. Conclusion.

6. References.

Next Presentation – On Thursday 19/05/2016

Journal Club Presentation By– 1.Dr. Leena Parmar2.Dr. Reshma Avadh

THANK YOU

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