Oral Medicine and Radiology for BDS

Why this subject matters (in the exam)

The subject is examined through theory papers, a clinical or practical examination and a viva. The exact scheme differs by university, so confirm it from your own syllabus and past papers. Theory answers reward structure: definition, aetiology, clinical features, investigations, differential diagnosis and management. The clinical component tests whether you can take a history, examine a lesion systematically and reach a reasoned provisional diagnosis. In the radiology viva, examiners usually ask you to identify a film, name the technique, point out landmarks and recognise common errors. Because these skills are demonstrated rather than recited, practice in the department counts for as much as reading.

High-yield topics

• Diagnosis and case history: components of a case history, general, extraoral and intraoral examination, and investigations that support a diagnosis.
• Oral mucosal lesions: leukoplakia, lichen planus, oral submucous fibrosis, candidiasis, erythroplakia, pemphigus vulgaris, mucous membrane pemphigoid, recurrent aphthous stomatitis and herpetic infections.
• Potentially malignant disorders and oral cancer: tobacco and areca nut related changes, early detection, biopsy principles and referral.
• Orofacial pain: trigeminal neuralgia, glossopharyngeal neuralgia, temporomandibular disorders, burning mouth syndrome and referred pain.
• Salivary gland and systemic disease: xerostomia, Sjögren's syndrome, sialolithiasis, and oral signs of diabetes, anaemia, HIV infection and nutritional deficiencies.
• Medically compromised patients: dental care in cardiac disease, hypertension, diabetes, bleeding disorders, pregnancy and anticoagulant therapy.
• Medical emergencies in the dental clinic: syncope, anaphylaxis, hypoglycaemia, angina and seizures.
• Radiation physics: X-ray tube, production and properties of X-rays, and factors controlling beam quality and quantity.
• Radiographic techniques: paralleling and bisecting angle periapical techniques, bitewing and occlusal views, and common errors.
• Extraoral and advanced imaging: orthopantomogram, lateral cephalogram, TMJ views, cone-beam computed tomography, ultrasound and MRI in outline.
• Processing and image quality: developing and fixing, darkroom faults, digital sensors and artefacts.
• Interpretation: normal landmarks, caries, periapical and periodontal lesions, cysts, tumours and fractures.
• Radiation biology and protection: biological effects, dose units, the ALARA principle, shielding and operator safety.

How to study this subject

Treat the two halves differently. For oral medicine, use a fixed template for every lesion: definition, aetiology, clinical features, investigations, differential diagnosis and treatment. Then compare look-alike lesions side by side, such as lichen planus against leukoplakia, or pemphigus against pemphigoid, because examiners often ask for exactly these differentials. Link each name to a clinical photograph.

For radiology, begin with physics in plain language and keep the X-ray tube diagram ready for redrawing. Learn each technique as a list of steps: patient position, film or sensor placement, beam angulation and likely errors. For interpretation, view real radiographs and name the landmarks aloud; reading about the mental foramen is not the same as finding it on a film. Present cases in the department the way you would in the viva, with a short history, findings and a provisional diagnosis.

Revision strategy

Begin revision several weeks before the examination and keep it active. Prepare one-page summaries for each lesion group, each technique and each pain syndrome, and revise from these rather than full chapters. Redraw key diagrams repeatedly, since they carry marks in theory papers. Solve previous-year university questions and note which topics recur. Spend the final days on viva-style revision: spot diagnoses, landmark identification, technique errors and radiation protection points.

Preparation with PrepElephant

PrepElephant offers topic-wise question practice and revision tools that help you test recall after studying a topic. Use them to check differentials, techniques and definitions, and to keep weak areas in rotation. Clinical examination and radiograph interpretation still have to be built in your college department, with real patients and real films.