It’s normal to have swelling for so long. Continue the prescription as being suggested by your dentist. But as you have told that swelling has reached to neck, it is quite serious. You need to get it checked with your dentist since it is symptoms of serious infection.
Is there any swelling in the neck region? Can he breathe and swallow normally?
Yes the pain has gone. Today he can open his jaw wider and most of the swelling under the jaw has subsided. However the swelling under his tongue seems worse.
Sometimes swelling can remain for quite awhile especially if its had time to swell that much all over the face. Sometimes the bacteria can travel rapidly through the spaces between the tissues. Are the rest of his symptoms improved or has it remained the same?