Ear pain is one of the most common complaints that patients will have if they have almost any infection or other problem with their head and neck. While it is often simply a function of the excellent and varied innervation of the ear, it can also be a sign of something concerning. Because the ear is innervated with branches of nerves that supply the entire upper half of the body, pain or problems with many different body parts can be reflected and sensed in the ears. Common causes of ear pain include swelling in the neck, sore throats, sinus infections, and, of course, ear problems. Usually these problems resolve within a short amount of time, but when they persist for more than a few weeks at most, you should speak to your doctor
or with an ear-nose-and throat surgeon
AKA head and neck surgeon). He or she will be able to most effectively review your symptoms, your past medical history, and carefully examine your ear. As you have recently had a sinus infection, it is possible that inflammation of the eustachian tube is contributing to your complaints, but you should speak with your doctor to make sure this is treated.