Evaluation of supratrochlear artery depth and course variations by Doppler ultrasonography along the glabellar frown lines for safer filler injections.

Based on the findings of this study, safe filler injections to correct the glabellar frown lines can be possible with intradermal injections just below the ryhtide. In the glabellar region, subcutaneous and supraperiosteal injections seems to be risky.