Are wisdom teeth connected to the sinus cavity that i always suffer from sinus infections after extraction?

They can be: Upper wisdom teeth can be impacted. They are extremely close to the maxillary sinus. Although most wisdom teeth are removed without complications or developing infection, it can happen. Your provider can put you on a round of antibiotics if necessary. Post operative visits are almost always free. Hope this help!

See answer details: Any maxillary molar can anatomically have a root within the maxillary sinus, however incidence is minimal. When this occurs the soft tissues should be closed over the extraction site. Antibiotic coverage is appropriate and post surgical instructions should included not blowing the nose for a couple of weeks. Routine extractions rarely caused sinus infections

Not very common: An opening into the sinus after the removal of maxillary wisdom teeth occurs once in a while. The good news is small sinus perforations will close spontaneously and no additional treatment is needed.