Dynamic Contribution to Eyebrow Position
Methods/Technique:
In order to let the patients experience temporary paralysis (or paresis) of the frontalis muscle we started to offer xylocain nerve block. Even though some obviously have experienced brow elevation with aging, most patients instinctively dislike the thought of brow lowering. Nevertheless, many of these will definitely look much better with lower eyebrows and a smooth forehead. When this can be temporarily demonstrated in the mirror, it is easier for the patients to decide what they want. A litterature search did not reveal any published data on this. It has further become clear that the litterature on eyebrow position, focusing mostly on static factors and surgical procedures often neglects the highly important dynamic contribution of muscular tension and balance. Data enableing quantification of muscular contribution to brow position seem to be absent.This led to a pilot study of 11 patients where standardised photography was undertaken at rest, at maximal brow elevation, and following complete frontal nerve block with xylocain. Brow excursion and position was measured at the medial and lateral canthi as well as the midpupillary line, in relation to the horizontal plane connecting the medial canthi. The patients were all women between 41 and 65 years of age. Exclusion criteria were palpebral ptosis, botox treatment less than 6 months before as well as previous browlift.
Results/Complications:
Maximal voluntary mid brow elevation from rest varied between 2 and 8 mm, with a mean of 6 mm. Lowering from resting position after nerve block varied from 0 to 7mm, with a mean of 3mm. Total vertical brow excursion from maximal elevation to paralysis varied from 4 to 13 mm with a mean of 9mm.
Conclusion:
This pilot study confirms the hypothesis that the dynamic contribution to eyebrow position at rest is very strong in some patients, less so in others. The material is too small to allow further conclusions and further studies are required to clarify which are the determining factors. Xylocain frontal nerve block has proved to of great help in selecting patients suitable for botox treatment of horizontal forehead lines in the dynamic forehead.