Yes, a sinus infection can cause a toothache. Your doctor can give you antibiotics that will clear up the infection and should take care of the toothache. It does take a few days, however, for the pain to go away.
Sinus problems can make you think you have a toothache. The pain is real but the tooth is fine. Focus on the sinus problem with either garlic or antibiotics.
Yes. It depends on the type of sinus problem. Saline solution sprays at a pharmacy would probably fix it. If it is causing a toothache with a wisdom tooth (like I have), I would suggest getting the wisdom tooth pulled.
If the sinus problem has been going on for a while it can worsen and cause other pains like toothache. Zicam is a good medicine to clear up sinus congestion.