Case Report: Ectopic third molar in the maxillary sinus with infected dentigerous cyst assessed by cone beam CT

F1000Res. 2020 Mar 25:9:209. doi: 10.12688/f1000research.22466.2. eCollection 2020.


Ectopic development of teeth in nondental areas is uncommon, especially in the maxillary sinus. A panoramic radiograph is the routine diagnostic radiographic examination performed for this type of eruption, although cone beam computed tomography (CBCT) is highly recommended for further localization of the ectopic tooth and assessment of the characteristics of any associated lesion before a surgical procedure. We report a case of a 13-year-old female student who presented with purulent discharge posterior to the upper right second molar with a bad taste and foul odour. Radiographic examination revealed a maxillary third molar tooth located at the posterosuperior aspect of the right maxillary sinus with a hyperdense lesion surrounding the crown, obliterating the sinus cavity. Both the tooth and dentigerous cyst were surgically removed under general anaesthesia through Caldwell-Luc antrostomy. After a three-month follow-up, the patient was symptom free and had an uneventful recovery. The rare and critical location of the reported third molar along with the infected dentigerous cyst indicates its complete enucleation to avoid complications as recurrence or malignant transformation.

Keywords: Cone Beam CT; Ectopic; Maxillary Sinus; Molar; tooth Eruption.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Cone-Beam Computed Tomography
  • Dentigerous Cyst* / diagnostic imaging
  • Dentigerous Cyst* / surgery
  • Female
  • Humans
  • Maxillary Sinus / diagnostic imaging
  • Maxillary Sinus / surgery
  • Molar, Third / diagnostic imaging
  • Molar, Third / surgery
  • Tooth Eruption, Ectopic*

Grants and funding

This research was funded by the Deanship of Scientific Research at Princess Nourah bint Abdulrahman University through the Fast-track Research Funding Program.