Diagnostic imaging is an integral part of the diagnostic process in clinical dentistry. Radiographs are often obtained as part of a  complete examination. Appropriate radiographic interpretation is used along with clinical information and other tests to formulate a differential diagnosis. A radiograph is a two dimensional image of a three dimensional object. 

Role of radiographs 

• Clinical examination phase 
• Diagnosis( confirm/exclude)
• Treatment planning
• During treatment
• Follow up

Guidelines for suggesting Dental Radiographs 

• Its important to make radiographs only after a clinical examination. 
• Order only radiographs that directly benefit the patient in diagnosis &treatment. 
• Use the least amount of radiation exposure . 

Clinical situations that need radiographic examinations 

• Deep/ proximal Dental Caries 
• Periodontal Diseases 
• Dental Anomalies 
• Growth&Development assessment
• Dental Malocclusion 
• TMJ Disorders 
• Implants 
• Paranasal Sinuses 
• Trauma 

RADIOGRAPHIC INTERPRETATION depends on:

• Clinical examination. 
• Quality of diagnostic image. 
• Number &type of available images. 
• Viewing conditions. 

Step 1: Localize the abnormality 

• Localized or generalized 
• Position in the jaws 
• Single or multifocal 
• Size 

Step 2: Assess the periphery &shape 

• Is the periphery of lesion well defined or ill defined 
• Shape of lesion 

Step 3: Analyze the internal structure 

• Air,Fat,or Gas 
• Fluid 

• Soft tissue 
• Bone marrow 
• Trabecular bone 
• Cortical bone &dentine 
• Enamel 

• Metal 

Step 4: Analyse the effects of the lesion on surrounding stuctures. 

• Teeth,lamina dura,periodental membrane space. 
• Inferior alveolar canal&mental foramen. 
• Maxillary antrum. 

• Surrounding bone density&trabecular pattern. 
• Outer cortical bone&peiosteal reaction. 

Viewing Conditions  

• This should be done in a quiet, darkened room. 
• At least two good, evenly-lit viewing boxes are required. 
• A bright light illuminator is required for relatively over-exposed areas. 
• Mounted in holder. 
• Appropriate size of viewbox to accommodate film. 
• Magnifying glass-detailed examination of small regions. 

Routine assessment of radiographs

• Ensure that the radiograph is the one of the patient being examined,  check the date, card number. 
• Ensure two orthogonal projections are available. 
• The radiographic views are named according to the direction the primary beam enters and leaves the tissue and the body part being examined. 
• The position of the patient during exposure should be known, and left/right markers should be identified. 
• The radiograph should be of high technical quality with respect to positioning, centring, collimation, exposure and development, and should be free from artefacts. 

 Article by Dr. Siri P. B.