Bitewing Radiography Notes

Learning Outcomes

  • Assess bitewing image characteristics for diagnostic use.

  • Adopt a systematic approach for interpreting bitewing images.

  • Recognize common observations on bitewing radiographs.

Cardinal Rule

  • Radiographs are an adjunct to thorough history, clinical examination, and diagnostic tests.

  • Do not diagnose based on radiographs alone.

Uses of Bitewings

  • Detect primary and secondary caries.

  • Monitor caries progression and non-carious tooth loss.

  • Evaluate pulpal anatomy and changes.

  • Evaluate restorations and periodontal/crestal bone status.

  • Detect calculus deposits.

Characteristics of a Good Image

  • Minimal magnification, sharp, minimal shape distortion.

  • Good contrast & density, free from artifacts.

  • Structures of interest fully captured.

Achieving a Good Image

  1. Correct exposure settings: mA, kV, time for good density/contrast.

  2. Correct placement: detector and beam positioning.

  3. Correct processing: chemicals for film, software for digital.

  4. Good viewing conditions: orientation, dim lighting, light box, magnification.

Steps in Interpretation / Diagnosis

  • Assess image quality, then interpret systematically.

Assessing/Critiquing the Image

  1. Exposure factors – density, contrast.

  2. Detector orientation.

  3. Horizontal/vertical detector position.

  4. Horizontal/vertical beam angulation.

  5. Central ray/beam position.

  6. Rotational position of collimator.

  7. Image sharpness.

  8. Overall diagnostic quality.

Interpreting the Image: Be Systematic

  • Examine the complete image; assess non-dental structures first, then teeth last.

  • Learn normal tissue appearance.

  • Consider lesion position.

Radiographic Limitations

  • Superimpositions in 2D images.

  • Low sensitivity: Requires significant mineral loss to detect lesions.

  • Anatomy variations.

Things to Note on Bitewings

  • Non-dental pathology, teeth present, bone levels, PDL space, crestal bone.

  • Restorations, calculus.

  • Caries, non-carious tooth loss (NCTL).

  • Pulp chamber size/position.

Normal Radiographic Anatomy: Note

  • Crowns and roots of posterior teeth.

  • Enamel and dentine thickness.

  • Pulp chamber & pulp horns size.

  • Crest of alveolar bone, PDL space.

Abnormalities Relating to Tooth Number & Position

  • Agenesis (Hypodontia, Oligodontia, Anodontia).

  • Supernumerary teeth.

  • Unerupted teeth (Delayed, Ectopic, Impaction).

  • Crowding, Malposition/tilting.

Abnormalities Relating to Tooth Structure & Form

  • Enamel/dentine abnormalities (appearance, thickness, shape, caries, NCTL, fractures).

  • Pulp chamber, pulp horns, pulp canals abnormalities (size, shape, pulp stones, resorption).

Caries

  • Caries detection is primary use.

  • Describe location, extent, shape, and type (primary, secondary, arrested).

Occlusal Caries

  • Often diagnosed clinically; look for radiolucent line in dentine.

Proximal Caries

  • Begins apical to contact point; describe depth.

Buccal & Lingual Caries

  • Superimposed; confirm with clinical exam.

Secondary (Recurrent) Caries

  • Radiolucency around restoration margins; check for defective restoration or poor hygiene.

Abrasion

  • Pathological wearing; confirm clinically.

Attrition

  • Physiological/pathological wear; flattened edges.

Erosion

  • Reduced enamel thickness; examine clinically.

Periodontal Pathology

  • Assess alveolar bone height and loss (horizontal/angular).

  • Look for calculus, overhangs, tilted teeth.

Restorations

  • Metallic or non-metallic; check overhangs, contacts, contour.

Other Findings

  • Calculus, amalgam tattoo, implants, foreign objects.

Other Pathologies

  • Recognize abnormalities and advise tutor; further views may be needed.

Radiographic Artifacts
Cervical Burnout

  • Radiolucent areas due to x-ray penetration; mimics caries.

Mach Band

  • Radiolucent line in dentine; optical illusion mimicking caries.