I've had two absolutely horrible experiences both involving jaw implant procedures (I chose chin implant under Service Provided because jaw implant was not available).
During the first procedure the left jaw implant was placed improperly, it was too high and not all the way back. The second procedure went even worse. He again placed it too high. Moreover, he removed a bone spur on the right jaw but failed to properly close the suture sight... basically you could poke your finger through the inside of my mouth into the jaw.
Of course, i got a horrible infection. Luckily, a competent oral surgeon was able to treat the infection and I've had no further problems.
I've also never met a doctor who so consistently forces patients to wait for him to show up to appointments. Every time I've had an appointment, it started no less than an hour late. Ridiculous.