The ethmo-frontal angle: a new anatomic and radiologic landmark for use in sinus surgery.

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.