Hi..
Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concerns..
As per your complain it seems that pain in the gums of upper teeth along with sinus dripping and coughing up phlegm can be due to
Sinus infection or
Sinusitis..
As the floor of maxillary sinus lies close to the root tips of upper teeth therefore inflammation of sinuses can cause pain in gum of upper teeth..
I would suggest you to consult an Otolaryngologist and get evaluated and a thorough clinical evaluation
and investigations like PNS view x ray or MRI scan can help in diagnosis and treatment can be done
accordingly..
You can be advised a course of antibiotics, anti-inflammatory painkiller like Ibuprofen, decongestants
like Pseudoephadrine, do saline
nasal irrigation, steam inhalation and use a humidifier in your room..
You can also be advised decongestant nasal sprays containing
Xylometazoline or
Oxymetazoline..
Avoid spicy and chilled foods..
Do warm compresses around nostrils..
Hope this information helps..
Thanks and regards.
Dr.Honey Nandwani Arora.