Hi..
Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concern...
As per your complain and presentation of symptoms it seems that you might have a
Dry Socket which is leading to redness and ulceration and the gap that you have experienced is an unhealed socket with medicated dressing in it which is placed to promote healing..
Another cause that can also cause similar symptoms is a left over piece of root of tooth that may be causing infection, sinus formation and pain.
Running nose is not alone a sign of sinus perforation but it cannot be ignored as there are a chances of sinus perforation after molar extraction..
You need an immediate consultation with an Oral Surgeon and get evaluated along with an IOPAR ( x ray) and a full mouth x Ray known as
ORTHOPANTOMOGRAM (OPG) so that exact cause of the problem is ruled out and treatment can be done accordingly..
As for now in case of
severe pain you can take
TRAMADOL 50 mg (ULTRAM) but if pain is moderate
Ibuprofen can be taken..
Hope this information helps..
Thanks and regards..
Dr.Honey Nandwani Arora..