Frozen Chin Muscles 2 Years After Genioplasty/chin Osteotomy?

over two years ago I had a genioplasty/chin osteotomy done to my chin to move it slightly forward, with two screws Overall it has been fine for the last two years with 90% of function and sensation back to normal. It was not till 2 months ago when i was away on vacation that I had a bad habit of chewing my lower lip gums. After a night out while chewing my lower lip gums I woke up the next day and my chin muscles was 70% frozen, pain and numb skin. It has not improved in the 2 months. Help?