Yes, it is possible for sinusitis or a middle ear infection to cause pain in the upper back teeth. This is a phenomenon known as referred pain.
Referred pain occurs when you perceive pain coming from an area that is not diseased. This is due to the sensitization of adjacent nerves. Neurochemical changes that occur as a result of a disease process in the area supplied by one nerve (the sinus) can sensitize another nerve running close by as the nerve branches converge in the brain. The brain then perceives the source of pain to be also located in the structure supplied by the adjacent nerve (the upper back teeth).
If it is indeed referred pain from the inflamed sinus lining that you are experiencing, then the symptoms should stop once the upper respiratory tract infection has cleared up. Your medical GP should be able to sort this out for you.
However, there is the possibility that the pain may be coming from a diseased upper tooth and this is something that your dentist can exclude by examining your teeth and taking xrays to check for infections/abscesses within the bone.
Sinusitis can also be picked up on certain types of dental xrays. I would urge you to see your dentist as soon as possible to make sure that your pain is indeed coming from the sinus and not from an underlying dental infection.
