Thank you for your query.
I can understand your concern. Steroid
shot will certainly not help you in the problem. You should resort to exercises to strengthen the muscles around the jaw and chin. It is difficult to explain the cause of the "flutters" so many years after surgery but the most possible explanation can be regeneration of the nerves which may be causing it.
I hope I have answered your query to your satisfaction.
Wishing you all the best.
Rajiv K Khandelwal