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Updated: Jun 23, 2026
Three-Dimensional Cephalometric Landmark Annotation Demonstration on Human Cone Beam Computed Tomography Scans
Published on: September 8, 2023
The ethmo-frontal angle: a new anatomic and radiologic landmark for use in sinus surgery
Samuel S Becker1, Peter A Beddow, James A Duncavage
1Department of Otolaryngology-Head and Neck Surgery, Vanderbilt University Medical Center, Nashville, TN, USA. sam.s.becker@gmail.com
Objective:
To identify anatomic and radiologic landmarks to assist with frontal sinus surgery.
Study Design:
Retrospective review.
Subjects And Methods:
Sinus CT scans of 50 patients were evaluated with respect to a new radiologic and anatomic landmark, the ethmo-frontal angle (EFA).
Results:
Right-sided EFA ranged from 135 to 171 degrees. Left-sided EFA ranged from 136 to 167 degrees. Measurements of both sides displayed a normal distribution. When right and left sides within individuals were compared, there was no correlation to indicate a high degree of variation between any particular patient's right and left side EFA.
Conclusion:
The EFA is a new landmark to assist otolaryngologists during surgery on and around the frontal sinus. Normal values for this angle have been presented. Surgeons should be aware that asymmetry in a patient's EFA is common, and each side should be examined individually.
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