Radiographic Interpretation of Dental Abnormalities

Radiographic Interpretation Process for Localizing Abnormalities

  • Step 1: Localize the Abnormality

    • Anatomic position (epicenter)
    • Localized or generalized
    • Unilateral or bilateral
    • Single or multifocal

E.g of bilateral abnormality is seen in Paget’s disease in the mandible

Step 2: Assess the Periphery and Shape

  • PERIPHERY
    • Well defined
    • Punched out
    • Corticated
    • Sclerotic
    • Soft tissue capsule
    • Ill defined
    • Blending
    • Invasive
  • SHAPE
    • Circular
    • Scalloped
    • Irregular
  • Step 3: Analyze the Internal Structure

    • Totally radiolucent
    • Totally radiopaque
    • Mixed (describe pattern)

Example, bone has trabeculae


Step 4: Analyze the Effects of the Lesion on Surrounding Structures

  • Teeth, lamina dura, periodontal membrane space Inferior alveolar nerve canal and mental foramen
  • Maxillary antrum Surrounding bone density and trabecular pattern
  • Outer cortical bone and periosteal reaction.

Step 5: Formulate a Radiographic Interpretation

Classification of Developmental Anomalies of Teeth

1. NUMBER

Hypodontia

Hyperdontia

2. SIZE

Microdontia

Macrodontia

3. SHAPE

Gemination

Fusion

Concrescence

Accessory cusps

Dens invaginatus

Ectopic enamel

Taurodontism

Hypercementosis

Accessory roots

Dilaceration

4. STRUCTURE

Amelogenesis imperfecta

Dentinogenesis imperfecta

Dentin dysplasia type 1

Dentin dysplasia type 2

Regional odontodysplasia


Radiographic Analysis of Lesion Effects on Surrounding Structures

Teeth, lamina dura, periodontal membrane space

  • Inferior alveolar nerve canal and mental foramen
  • Maxillary antrum
  • Surrounding bone density and trabecular pattern
  • Outer cortical bone and periosteal reactions

Teeth, Lamina Dura, and Periodontal Membrane Space

  • Lesions with an epicenter above the crown of a tooth (i.e., follicular cysts and occasionally odontomas) displace the tooth apically
  • Lesions that start in the ramus such as cherubism may push teeth in an anterior direction.
  • Some lesions grow in the papilla of developing teeth (i.e., lymphoma, leukemia, Langerhans’ cell histiocytosis) and may push the developing tooth in a coronal direction

Inferior Alveolar Nerve Canal and Mental Foramen

  • Superior displacement of the inferior alveolar canal is associated with fibrous dysplasia.
  • Widening of inferior alveolar canal with the intact cortical boundary may indicate the presence of a benign lesion of vascular or neural origin.
  • Irregular widening with cortical destruction may indicate the presence of a malignant neoplasm growing down the length of the canal.


  • Outer Cortical Bone and Periosteal Reactions: The cortex of bone may remodel in response to a lesion.
  • A slowly growing lesion – allow time for the outer periosteum to manufacture new bone so that the resulting expanded bone appears to have maintained an outer cortical plate
  • A rapidly growing lesion outstrips the ability of the periosteum to respond, and the cortical plate may be missing
  • An onion-skin type of pattern can be seen.
  • most commonly seen in inflammatory lesions and more rarely in some malignant lesions
  • (e.g., leukemia) and in Langerhans’ cell histiocytosis