Chance finding in female 26 years in the axial and coronal views of well defined uniformly dense opacity 11 x 10 x 7mm in a right posterior ethmoid air cell.
This is most likely a benign Osteoma.
Osteomas are frequently found in the Frontal sinuses and less often in the Ethmoid air cells and maxillary sinuses. In the Frontal sinuses they can cause erosion of the inner cortical bone of the Frontal bone with inflammation of the meninges.
Surgical removal is usually uneventful with complete recovery of the patient. When found in dental CBCT images referral to an ENT surgeon is recommended.
Dr Douglas K Benn DDS, PhD, Dipl. Dental Radiology (Royal College of Radiologists, England)
Oral and Maxillofacial Radiologist