Radiographic Interpretation(Peri-apical and OPG)

Presented by:Syed Moiz Rafiq

Objectives:

• The students should know the normal anatomy of the tooth under dental radiograph.

• The students should interpret the pathology of the tooth under dental radiograph.

What is dental radiograph ?

Dental radiography :

It is the art of producing an image or picture for intra-oral or extra-oral structures on a dental film using X-rays.

Dental radiographic views

• Intra oral : -Peri-apical -Bitewing -Occlusal• Extra oral : -OPG -Cephalometry -Sialography

Periapical radiograph

• Periapical radiograph:

It is the most frequently used intra-oral view radiograph, which shows the entire tooth and surrounding structures on the film.

Need for prescribing peri-apicaldental radiograph

• Extent of carious involvement in the tooth

• Interproximal decay under the contact point

• Periapical pathological changes

• Traumatic injuries to dento-alveolar process

• Periodontal diseases

• Dental anomalies

• Occult diseases

• Prognostic assessment during treatment planning

• Post obturation assessment of endodontic therapy

• Working length measurement during root canal therapy

• Implants

Normal Radiographic Anatomy(Peri-apical)

Normal radiographic anatomy

• ENAMELMost radiopaque structure

• DENTINESlightly lighter than enamel

• PULP CAVITYRadiolucent lines within the tooth

• ALVEOLAR CRESTGingival margin of the alveolar process appear as a radiopaque line

• PDL SPACENarrow radiolucent line around tooth surface

• LAMINA DURARadiopaque line representing tooth socket

Radiographic interpretation:

Interpretation :

• Step by step analytical process that provides an exact idea of the clinical problem and helps to achieve the final diagnosis of any particular lesion.

The importance of interpretation:

• Radiographic interpretation is an essential part of the diagnostic process. The ability to evaluate & recognize what is revealed by a radiograph enable us to detect diseases, lesions & conditions which can’t be identified clinically.

Steps of interpretation

• Localization.• Observation.• General consideration.• Interpretation.• Correlation.

Localization:

• Localized or generalized• Position in the jaw• Single or multiple• Size

Observation:

• All shadows, other than the localized shadows of the normal landmarks must be observed.

• For example: shadows in crowns, cervical area, roots, restorations, size of root canals, periodontal membrane space, periapical area, alveolar crest, foreign bodies, integrity of bone

General consideration:• A radiograph shows only 2 dimensions of a 3

dimensional object (width and height but not the depth)

• Cervical burnout: usually appears as cervical Radiolucency and misinterpreted by caries; this occurs due to less density and more penetration of rays.

• Pulp exposure: never to be determined from radiograph but only the proximity to the pulp.

Interpretation:• Studying the features of teeth and bone:

Teeth Study the whole tooth,(crown, root, enamel, pulp), number of teeth and finally supporting structures, (Periodontal membrane space, lamina dura , alveolar crest)

Bone:

Changes in bone may include:1- Changes in density.2- Changes in the margin3- Changes inside the lesion.4- Effect on surrounding tissues.5- Changes in structure

Correlation:

• The final step is to correlate all of the radiographic features to reach a radiographic differential diagnosis.

• Then to draw a final diagnosis, we have to correlate other data as case history, clinical examination, and other diagnostic aids with the radiographic differential diagnosis

Dentine

Pulp chamber

Root canal

enamel

Metallic restoration

P/d ligament

Lamina duraalveolar bone

Periapical radiograph interpretation:

Enamel

• Caries of the enamel : appears as radiolucent area

• Enamel hypoplasia: appears as radiolucent area surrounded with radiopaque margins

• Amelogenesis imperfecta: all the enamel appear as radiolucent area

Dentin:• Caries of the dentin: appears as radiolucent

area

• Dentinogenesis imperfecta: dentin appear as radiolucent area surrounded by faint radiopaque margins

• Dense in dente: appears as radiopaque structure within the tooth surrounded by radiolucent margin

• Internal resorption: radiolucent lines on the apex or lateral side of the root dentin

Pulp:

• Calcification of the pulp: appears as a localized area of radiopacity, if the calcification is generalized it appears as a generalized area of radiopacity

• Shell tooth: appear as wide pulp chamber

Cementum:

• Hypercementosis: appear as radiopaque area covers the cementum line

• Cementoma: appears at the apex of the tooth as a radiolucent area in its early stages and converted into radiopaque at the terminal stages

PDL space:

• Normally appear as radiolucent line surround the root surface

• Widening of the space as a result of osteolytic process e.g, osteolytic osteoma

• Narrowing of the space as a result of osteoblastic process e.g, scleroderma

Pdl space

Widened pdl space Narrow PDL space

Lamina dura:

• Normally appear as radiopaque clear continuous band covers the alveolar bone i.e, lining the socket and covers the crest of the alveolar bone

• Discontinuity of the lamina dura indicate pathological changes

Lamina dura pathology

Normal lamina dura Loss of lamina dura

Alveolar bone:

• Bone resorption either horizontal or vertical• Bone loss: Alveolar bone heightAlveolar bone healthGeneralized v/s localized alveolar bone loss

Horizontal bone loss Vertical bone loss

Metallic restoration :

• Restoration done on tooth showing radio-opacity.

Status of root filling (RCT) :• Radio-opacity on the whole pulp chamber can

be seen.

Dental Implant :• Dental implant shows obvious shape and

radio-opacity on radiographs

Follow up:

OPG radiographs :

• OPG radiographs:

An Extra-oral technique which produces a radiograph with wide view of the maxilla and mandible.It's also known “pantomography” “Rotational panoramic radiography”

Indications for OPG radiographs:

• Gross caries

• Pain related to a whole quadrant

• Orthodontic assessment

• Pre-operative assessment

• Mandibular fractures

• Cysts, tumors , developmental anomalies

• Assessment of TMJ

• Periodontal disease

• Impacted tooth

• Implants

Normal Radiographic Anatomy(OPG)

OPG Radiographic interpretation :

Describing the Lesion

• 1. Size• 2. Shape• 3. Location• 4. Density• 5. Borders• 6. Internal Architecture• 7. Effect on adjacent structures

Nolla stages (dentitional status) :

• Panoramic radiographs shows unerupted tooth and help to diagnose nolla stage and dentitional status.

Impacted tooth :

• Impacted tooth are identified on OPG radiographs easily as the teeth are displacement and tilted.

Fractures :• Bone displacement, broken mandible gives

the diagnosis of fracture.

Tumors/lesions:

• Ill-defined borders with sclerosis and ground glass appearance gives the diagnosis of lesion.

Cyst:

• Presence of radiolucency , corticated borders , locularity and displacement of tooth shows the diagnosis of a cyst.

Restoration material :

• Restoration can be diagnosed by radiopacity on tooth structures.

Thank you!