There are several reasons for this but I am confused by the timing of your symptoms.
What was the reason for your second surgery?
The surgery, liposuction, or chin implant could all potentially produce the findings you are reporting.
Nerve injuries can be temporary or permanent. Recovery can be hours to days to weeks to even years depending on the extent and nature of the insult.
EMG's in combination with an ENG may indicate complete or recovering nerve injuries. Repair is generally only successful when the injury is identified as it occurs and immediately repaired. Recovery may occur even in the instance of complete transection without repair.
I know this all sounds confusing and you should discuss this with your surgeon who is the best person to answer your questions
