Radiographic Aids in the Diagnosis of Periodontal Diseases

Radiographic Aids in the Diagnosis of Periodontal

Diseases

PRESENTED BY :DR DEEPAK KOCHAR

READER DEPTT. OF PERIODONTICS

RADIOGRAPH• Radiograph is an adjunct to clinical examination but not a substitute for

it.

• It reveal alterations in calcified tissues.

• It is a valuable aid in - Diagnosis of periodontal disease. - Determination of the prognosis. - Evaluation of outcome of the treatment.

• Radiograph does not reveal minor destructive changes in bone . The radiographic image tends to show less severe bone loss than that actually present. “ Bone loss is always greater than it appears in the radiograph ”

• Slight radiographic changes in the periodontal tissues means that the disease has progressed beyond its earliest stages.

The earliest signs of periodontal disease must be detected clinically.

NORMAL INTERDENTAL SEPTA Width , shape & the angle of the alveolar crest of inter-dental septum normally vary according to the convexity of the proximal tooth surfaces &

the level of the CEJ of the approximating teeth.

The height of the alveolar crest lies at a level 1- 2 mm below CEJ of adjacent teeth.

Lamina Dura is radioopaque border (white line )adjacent to periodontal ligament and at alveolar crest. It represents the bone surface lining the tooth socket.

Crest of interdental bone is normally parallel to a line drawn between the cementoenamel junction of adjacent teeth (arrow). Note also the radiopaque lamina dura around the roots and interdental bone

INTRA ORAL PERIAPICAL RADIOGRAPH (IOPA)

Prichard established following 4 criterias to determine adequate angulation of periapical radiographs –

• The radiograph should show the tips of molar cusps with little or none of the occlusal surface showing.

• Enamel caps & pulp chambers should be distinct.

• Inter proximal spaces should be open.

• Proximal contacts should not overlap unless teeth are out of line anatomically.

• Two intraoral projection techniques are used for periapical radiography-

(i) Paralleling technique. (long cone technique) (ii) Bisecting angle technique.

Long Cone Paralleling technique is better than bisecting angle . It cause less distortion & produce more realistic image of the level of alveolar bone

Bitewing Radiographs

Bitewing radiographs are used – (1) To visualize the crowns of the posterior teeth

and the height of the alveolar bone in relation to the cementoenamel junctions

(2) To detect interproximal calculus & caries

They more accurately exhibit the bone levels than

periapical views because of projection geometry.

• Schematic diagram of • periapical (A) • and • bite-wing (B) radiographs.

• Angulation of the x-ray beam and the film on the periapical radiograph distort the distance between the alveolar crest and the cementoenamel junction (CEJ) (compare a-b versus a1-b1).

• In contrast, the projection geometry of the bite-wing radiograph allows a more accurate depiction (a-b) of the distance between the alveolar crest and the CEJ (a-b).

Radiographic appearance of periodontal diseases

• Fuzziness & a break in the continuity of the lamina dura at the mesial or distal aspect of the crest of interdental septum.

These are earliest radiographic changes in periodontitis.

• A wedge shaped radiolucent area at mesial or distal aspect of crest of septal bone.

• The height of the inter dental septum is reduced and finger like radiolucent projections extend from the crest in to the septum.

PERIODONTITIS

Radiographic changes in periodontitis

A, Normal appearance of interdental bone.

B, Fuzziness and a break in the continuity of the lamina dura at the crest of the

bone .Also there are wedge-shaped radiolucent areas at the crest of the

interdental bone.

C, Radiolucent projections from the crest into the interdental bone indicate extension

of destructive processes.

D, Severe bone loss

FURCATION INVOLVEMENT

• The slightest change(fuzziness) in the furcation area should be examined clinically, especially if there is bone loss on adjacent roots.

• Diminished radiodensity in the furcation area in which outlines of bony trabeculae are visible suggests furcation involvement

• Whenever there is marked bone loss in relation to a single molar root, it may be assumed that the furcation is also involved.

Furcation involvement indicated by triangular

radiolucency in bifurcation area of mandibular first

molar

Periodontal abscess Appears as discrete area of radiolucency along the lateral aspect of the root . Its appearance depends on the Stage of the lesion & Location of the abscess

Localized Aggressive Periodontitis Bone loss in the incisors & first molars

Bilateral , angular /vertical defects and arc like destructive patterns in first molar region

Localized aggressive periodontitis --- Radiographs showing localized, vertical, angular bone loss associated with the maxillary and mandibular first molars and the central incisors.

TRAUMA FROM OCCLUSION• Increased width of the periodontal space.

• Thickening of the lamina dura and sometimes condensation of perialveolar cancellous bone.

• A vertical/angular bone loss.

Skeletal disturbances manifested in the jaws

• Osteitis Fibrosa Cystica• Paget’s disease • Fibrous Dysplasia • Langerhan’s cell histiocytosis • Multiple Myeloma • Osteopetrosis/Marble bone disease • Scleroderma

ADVANCES IN RADIOGRAPHIC ASSESSMENT

• DIGITAL RADIOGRAPHY

• SUBTRACTION RADIOGRAPHY

• C.A.D.I.A. (Computer Assisted Densitometric Image Analysis)

• CONE BEAM COMPUTED TOMOGRAPHY(C.B.C.T)

DIGITAL RADIOGRAPHYADVANTAGES:(1) Ability to produce a image that can instantly be viewed by patient & dentist.(rapid image capture & display)

(2) Reduction in radiation received by patient by as much 50% to 80% when compared to conventional radiography.(low x-ray exposure)

(3) Images can be altered to achieve task specific image characteristics eg. density & contrast can be lowered for evaluation of marginal bone and increased for evaluation of implant components.

(4) Digital imaging also enables dental team to conduct remote consultations( in tele diagnosis & video conferencing)

(5) Computerized images can be stored, manipulated & corrected for

under & overexposure

(6) Edge enhancement

There are 2 digital radiography methods - 1.Direct method 2. Indirect method.

1. Direct Method/RVG (radio visio graphy )- This method uses a Charge Couple Device (CCD) sensor linked with fiberoptic or other wire to computer system. CCD receptor is placed intraorally as traditional films & images appear on a computer screen which can be printed or stored.

2. Indirect Method - This method uses a phosphor luminescence plate, which is a flexible film like radiation energy sensor placed intraorally & exposed to conventional x-ray tube.

A laser scanner then reads the exposed plates & reveals digital image data.

SUBTRACTION RADIOGRAPHY

• Radiographs are taken with identical exposure geometry – serial radiographs

• This technique relies on conversion of serial radiographs into digital images.

• The serially obtained digital images can then be superimposed & resultant composite viewed on a video screen.

• This technique facilitates both qualitative & quantitative visualization of even minor density changes in bone by removing the unchanged anatomic structures from image.

DIAGNOSTIC SUBTRACTION RADIOGRAPHY

• This technique combines the use of a positioning device with specialized software designed for digital image subtraction.

• This software system applies an algorithm that corrects angular alignment discrepencies & provide flexibility in imaging procedures.

Computer Assisted Densitometric Image Analysis. (CADIA)

Video camera measures the light transmitted through radiograph and the signals from the camera are converted to gray scale images.

The camera is interfaced with an image processor and a computer that allow the storage and mathematical manipulation of the images.

Advantages: Measures quantitative changes in bone density over

time.Higher sensitivity, reproducibility and accuracy as

compared to Digital substraction analysis.

Cone-Beam Computed Tomography(CBCT)

• Very accurate three-dimensional imaging technique

• Much less radiation exposure as compared to conventional CT Scans.

• Very useful technique for implant patients.

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CONCLUSION• Conventional and advanced imaging systems have proven a

boon for diagnosis in periodontology. Further advancements are also expected in near future.

• These systems are technique sensitive & not free from mechanical errors so a clinician should also consider clinical signs & symptoms while reaching to final diagnosis for a periodontal condition.