Hi Minh
I have seen posts on this before and found it again under - After Treatment Issues � Swelling,turkey wattle?
I have also seen it called turkey waddle and dulap and most people who have had it say it disappears with time, some using massage techniques.
If you have a look you will find more information here ;
http://oralcancersupport.org/forums/ubbthreads.php?ubb=showflat&Number=69614&page=1In my case with surgery only I put back the weight I lost plus some

so I have to call mine a double chin and scar down the middle that looks tighter now from the neck dissection. A bit light a zipper not done up properly!
That's the wonderful thing about the forum. With a little research you can usually find the answers and there is always someone who can point you in the right direction or can answer your questions.
Now after not much sleep last night try and have a nap sometime today

Gabriele