Start practicing

Radiology · patient case question

The adenomatoid odontogenic tumor is characteristically associated with which structure, and from what does it originate?

Patient case: Radiographic Differential — Impacted Canine

demo: 19-year-old male

chief: Referred for evaluation of a retained primary canine.

history: Non-contributory.

meds: None

findings: Panoramic radiograph shows tooth #6 impacted high in the maxilla with an associated well-defined radiolucency surrounding the crown. Images below illustrate two of the entities under consideration.

  1. The follicle of an impacted tooth, arising from odontogenic epithelium — remnants of dental lamina or reduced enamel epithelium
  2. The periapex of a non-vital tooth, arising from the rests of Malassez
  3. The inferior alveolar canal, arising from neural tissue
  4. The maxillary sinus lining, arising from respiratory epithelium
Show answer and explanation

Correct answer: A. The follicle of an impacted tooth, arising from odontogenic epithelium — remnants of dental lamina or reduced enamel epithelium

  • A. Correct. AOT is a developmental benign odontogenic tumor that envelops the follicle of an impacted tooth — most often a maxillary canine in a teenage girl. Histology shows spindle-shaped epithelial cells in rosette-like structures with a fibrous capsule and scattered calcifications.
  • B. Malassez rests give rise to radicular cysts, not AOT.
  • C. Neural origin describes a schwannoma or neurofibroma.
  • D. Respiratory epithelium origin describes sinus pathology, not an odontogenic tumor.

Note: AOT is the “two-thirds tumor”: two-thirds in females, two-thirds in the maxilla, two-thirds associated with an impacted canine, two-thirds in the second decade.

Practice Radiology questions Radiology study notes

More Radiology practice questions