A recent study helps back up the suggestion that using hyaluronic acid (HA) dermal fillers together with botulinum neurotoxin-A (BoNT-A) may help the fillers last longer. In the study, which appears in the January issue of Plastic and Reconstructive Surgery, Dr İsmael Küçüker and colleagues from the Ondokuz Mayıs University Faculty of Medicine in Samsun, Turkey, performed a study using rabbits in which a small amount of HA filler was injected under the skin in front of each ear. This area was chosen because it is similar to the forehead region in humans, explains a media release from Wolters Kluwer Health. On one side, HA filler alone was used. On the other side, HA filler was combined with BoNT-A to paralyze the muscle in that area. After 3 months, MRI scans were performed to compare the amount of filler remaining on the two sides. Read more at Plastic Surgery Practice.