These Mosquito forceps with fine serrated tips can be used in dentistry or orthodontics to grasp cotton, brackets, ligature ties, tie Kobayashi hooks etc. 
By gently pushing the handles together you lock the grip, then press harder after the third click gently pull grips apart to open the tips.
How to use the Mosquite forcep for ligature ties, just gently close the locking handle, grab the ligature tie, click the grip, lock and twist