A simple and reliable landmark for identification of the supraorbital nerve in surgery of the forehead: an in vivo anatomical study.
OBJECTIVE
In this in vivo study, we set out to determine the reliability of the medial margin of the iris as a landmark for the course of the supraorbital neurovascular bundle at the supraorbital rim.


METHODS
Seventy-five patients (73 women and 2 men) undergoing endoscopic brow lift procedures were enrolled, for a total of 150 sides. With the patient focused on a distant point, a line was constructed preoperatively along the mid-sagittal plane, tangential to the medial iris. After general anesthesia and initial dissection, a 27-gauge needle was placed (without the aid of the endoscope) through this line, parallel to the mid-sagittal plane at the orbital rim. Measurements were then taken following creation of the optical cavity. Measurements were taken from the course of the deep (lateral) branch of the supraorbital nerve to the needle. In addition, measurements were taken from the course of the supraorbital nerve to the course of the supratrochlear nerve.


RESULTS
In 84 sides, the needle was at the nerve; in 48 sides, the needle was less than 1 mm to the nerve; and in 18 sides, the needle was 2 mm from the edge of the nerve. Overall, the nerve was an average of 0.56 +/- 0.7 mm from the needle, and in no case was the nerve course greater than 3 mm from the landmark. The supratrochlear nerve was located medial to the supraorbital nerve an average of 9.0 +/- 1.0 mm.


CONCLUSIONS
Based on our findings, the medial iris, as opposed to the mid-pupil line, serves as a reliable topographical landmark for the course of the supraorbital nerve at the supraorbital rim.
Cuzalina
Angelo L
AL
Private Practice, Tulsa Surgical Arts, Tulsa, OK, USA.
Holmes
Jon D
JD
D002508:Cephalometry / Q000379:methods*; D005260:Female; D005546:Forehead / Q000294:innervation* / Q000601:surgery; D006801:Humans; D007498:Iris / Q000033:anatomy & histology; D008297:Male; D009915:Orbit / Q000294:innervation*; D044465:White People