Farber et al. Plast Aesthet Res 2020;7:72  I  http://dx.doi.org/10.20517/2347-9264.2020.152                                     Page 17 of 28
               Figure 14. Glabellar muscle anatomy. The corrugator and procerus are seen anatomically (top) with their bony attachments illustrated
               (middle) and their functional rhytid pattern (bottom)