Whenever you breathe through the nose, air will pass through your sinuses to the lungs. Your sinus is only hollow, full of air cheekbones. They are lined with a pink film, similar to the pink lining in your mouth.
When your sinus inner layer is infected or inflamed, it is called sinusitis.
Many people eventually came to the emergency room of a dental school with the pain of toothache. Upon inspection, we sometimes find that their teeth are healthy. The real cause of their pain is sinus infection or sinusitis.
