Well I went to my Orthodontist for the monthly checkup ... and my teeth were n't moving fast enough so they had to put a power chain on . Little did I know that a ' power chain ' was a torture device for one 's mouth . Felt numb and okay after the visit , had lunch and went to work . Could n't sleep at all that night , and when I started to doze , my alarm went off and it was back to work .
Question: What is the narrator getting worked on ?
The answer to the above question:


Their teeth .