Radiology · patient case question
The separate radiolucency between the roots of #8 and #9 is most likely:
Patient case: The Bridge That Never Settled
Patient: 58-year-old male
Chief Complaint: “That front tooth aches when I bite, and a little bump keeps coming and going on the gum.”
Background: Anterior maxillary fixed bridge placed five years ago. Root canal treatment on tooth #9 two years ago. No relevant medical history.
Medications: None
Vital Signs: BP 128/78 mmHg · HR 74 bpm · RR 16 · T 98.4°F
Findings: Tooth #9 is tender to percussion and gives no response to cold. A small red, raised lesion is present on the labial gingiva apical to #9, which the patient reports drains intermittently. A periapical film shows a radiolucency at the apex of #9 and a second, separate radiolucency between #8 and #9.
Show answer and explanation
Correct answer: D. The incisive foramen (nasopalatine canal)
- A. A lateral periodontal cyst occurs most often in the mandibular canine-premolar region, along the lateral root surface, and is uncommon in the anterior maxilla midline.
- B. An OKC is typically a larger, well-corticated lesion of the posterior mandible or ramus and would not present as a small midline interdental lucency.
- C. A periapical granuloma would be centred ON the apex of a NON-VITAL tooth. This lucency sits interdentally between the roots, and #8 has not been described as non-vital.
- D. CORRECT. The INCISIVE FORAMEN projects in the midline between the maxillary central incisors as a well-defined, often heart-shaped or ovoid radiolucency. It is a normal anatomic structure and the single most common cause of a midline anterior maxillary radiolucency. Confirm by changing the horizontal angulation — an anatomic structure SHIFTS relative to the roots, while a true periapical lesion stays anchored to the apex — and by pulp-testing both centrals.
Note: The rule: if the lucency moves when the beam angle changes, it is not endodontic. If it stays glued to the apex, it is.