Image Interpretation
Image Interpretation
Who is Responsible for Interpretation and Diagnosis of Radiographs?
Hygienist
Dentist
Both hygienist and dentist
Interpretation vs Diagnosis
Interpretation:
Definition: Explanation of what is viewed on a dental image.
Diagnosis:
Definition: The identification of disease by examination or analysis, encompassing several processes:
A thorough review of the medical history.
Review of dental history.
Clinical examination.
Imaging examination.
Clinical or laboratory tests.
Sequence of Exposure
Choice by the practitioner
Recommended Methods:
Start with bitewings or anterior radiographs for ease of patient.
Taking bitewings first is suggested to minimize retakes of periapicals with overlapped contacts.
Sequence of Interpretation
Examine the overall number of teeth and note any missing teeth.
Begin at the patient’s maxillary right posterior (#1) and move:
Across the maxilla to the left
Down to the mandibular right
Back across the mandible.
Look for restorations or pathology.
Review apices and surrounding bone.
Review bitewings from the patient’s right to left (your left to right).
Film Mount
What Are You Looking For?
Unerupted teeth.
Missing teeth.
Impacted teeth.
Dental caries: Assess size and shape of the pulp cavities.
Bony changes: Determine the level of alveolar bone and presence of calculus.
Roots and periapical areas.
All areas not previously examined, e.g., remaining areas of jaws and sinuses.
Ideal Interpretation Setting
Image Quality:
Good images with proper exposure and coverage.
Reminder: "Can’t see what you can’t see."
Computer Monitor Factors:
Brightness, resolution, and size.
Lighting:
Ideally dim or not extremely bright.
Normal Anatomy
Radiographic Normal Anatomy: Teeth and Supporting Structures
Teeth
Enamel
Dentin
Cementum (appears similar to dentin on radiographs)
Pulp chamber
Dentinoenamel junction (DEJ)
Cementoenamel junction (CEJ)
Radiographic Anatomy: Periodontium and Bone
Lamina Dura
RO line around the tooth.
Periodontal Ligament Space
RL line/space surrounding the tooth.
Bone Types:
Trabecular (cancellous) Bone (Spongy bone)
Cortical Bone
Developing Tooth
Follicular Space:
Expected size: < 4mm.
Radiographic Anatomy: Anterior Maxilla
Lateral (canine) fossa
A depression between teeth.
Radiographic Anatomy: Posterior Maxilla
Inverted “Y” (antral Y):
Junction of the floor of maxillary sinus and floor of nasal cavity.
Located in the canine area.
Visibility depends on the vertical angle (VA) of the beam.
Other Notable Features:
Nasal fossa
Maxillary sinus
Floor of maxillary sinus.
Radiographic Anatomy: Maxillary Sinus Floor
Additional Components:
Zygomatic process of maxilla
Coronoid process.
Genial Tubercles Overview
Genial Tubercules:
RO circle surrounding RL dot indicating features like the lingual foramen and the inferior cortical border of the mandible.
Panoramic Anatomy
Concepts in Panoramic Images:
Structures are flattened and spread out including:
Zygomatic arch
Condyle
Hard palate
Mandibular foramen
Mandibular canal
Mental foramen
Orbit
Zygomatic process of maxilla (malar process)
Pterygo-maxillary fissure
Coronoid process.
Ghost Images in Panoramic Images
Description:
A ghost image of hard palate and opposite mandible as a prominent feature due to technical errors related to removable dentures in imaging.
Air Spaces in Panoramic Images
Visible air spaces include:
Soft palate
Palato-glossal air space
Naso-pharyngeal air space
Glosso-pharyngeal air space.
Soft Tissue Shadows in Panoramic Images
Shadows visible include:
Soft palate
Nose
Tongue
Ear.
Descriptive Terminology in Radiographic Findings and Pathology
Important descriptors:
Density: Both radiolucent and radiopaque conditions.
Location: Relative positioning of findings.
Size: Dimensions of the lesions.
Shape: Configuration description.
Border: Characteristics of the edges.
Effect on Adjacent Structures: Observing displacement or resorption effects.
Terminology in Interpretation
Density
Radiolucent: Areas that permit more X-ray penetration (appear darker).
Radiopaque: Areas that resist X-ray penetration (appear lighter).
Mixed Density: Radiographic findings showing both characteristics.
Lesion Locations
Common locations include:
Periapical
Pericoronal
Anterior / Posterior
Medial / Lateral
Superior / Inferior
Mandibular
Alveolar
Condymal (neck or head)
Assessments should be presented as per provided numeric indications.
Size of Lesions
Considerations:
Extent relative to critical anatomical features.
Measurements can be taken in digital formats as approximations.
Shape of Lesions
Unilocular:
Definition: A single rounded structure
Multilocular:
Definition: Presence of multiple rounded areas
Border or Periphery
Borders can be classified as:
Thin or thick
Opaque/corticated
Interrupted
Smooth
Scalloped
Effect on Adjacent Structures
Lesions can:
Displace adjacent structures.
Resorb adjacent structures.
Expand spaces.
Caries Overview
Definition:
Dental caries is a multifactorial disease arising from the interaction of three principal factors:
The tooth
The plaque
The diet.
Other Contributory Factors: Include tooth composition, fluoride treatment, immune system response, and microbiome influences.
Process of Demineralization: Represents the physiological effect rather than the disease itself.
Lactic Acid Production: Resulting from the fermentation of fructose by Streptococcus mutans during the caries process.
Clinical Appearance Variability:
Early stage: White, chalky spots.
Older, arrested lesions: Darker shades (black or brown).
Spread of Caries
Differences in Spread by Tissue Type:
Enamel:
Composed of tightly packed mineralized acellular hydroxyapatite crystals, leading to slower spread.
Dentin:
Structure: 45% inorganic apatite, 30% organic matrix, and 25% water. This composition results in greater demineralization rates compared to enamel.
Cavitation:
Generally occurs after the involvement of dentin and may proceed to the pulp, leading to necrosis or destruction of the tooth structure.
Clinical Appearance of Caries
Interproximal Caries
Incipient Caries
Description:
A form of caries limited to enamel, requiring clinical examination for detection.
Moderate Interproximal Caries
Description:
Extends more than halfway through the thickness of enamel but does not involve the dentino-enamel junction (DEJ).
Advanced Caries
Description:
Progresses past the DEJ with minimal spread into the DEJ, but does not extend more than halfway toward the pulp.
Severe Interproximal Caries
Description:
Extends through enamel, into dentin, and more than half the distance toward the pulp.
Occlusal Caries
Incipient Occlusal Caries
Description:
Not visible on a dental image, relies on clinical detection.
Moderate Occlusal Caries
Description:
Extends through enamel and into the dentin along the DEJ.
Severe Occlusal Caries
Description:
Extends through enamel and into dentin beyond the DEJ.
Buccal or Lingual Caries
Description:
Emits a circular radiolucency without connections to the interproximal side. Best assessed clinically due to overlap.
Root Caries
Description:
Involves only the roots of teeth below the cervical region, following gingival recession and bone loss.
Recurrent Caries
Description:
Results from improper cavity preparations or defective margins and appears as a radiolucent area beneath restorations.
Rampant Caries
Definition:
“Growing or spreading unchecked,” characterizing advanced cases affecting multiple teeth.
Mimickers of Caries
Cervical Burnout
Description:
A radiolucent artifact that resembles carious lesions, presenting as a collar-shaped area between the CEJ and alveolar bone.
Radiolucent Restorative Materials
Description:
Materials such as composites and silicates appearing radiolucent, needing clinical validation.
Attrition
Description:
Incisal or occlusal wear on teeth that provides sharper delineation compared to caries.
Abrasion
Description:
Wear from external friction, presenting well-defined horizontal appearances.