Dr. Cognetti has more years of ES surgical experience than Dr. Hackman so a longer surgical history. I think initially Dr. Hackman was cutting the styloids very close to the skull base so more of his patients were having trouble w/ facial nerve irritation which caused temporary post op lip droop & eyelid paralysis. As far as I know those problems resolved for most of our members who saw Dr. Hackman for surgery early on. More recently, it seems those problems are less prevalent after his surgeries so I’m guessing he’s refined his technique a bit.
I also recall reading (maybe on our forum) that Dr. Cognetti trained Dr. Hackman in doing ES surgery. Doctors Cognetti and Hackman