Some patients have upper teeth which may partially sit within the sinuses. The sensation to these teeth are supplied by nerves which sit in the floor of the sinuses. When fluid or mucus forms within the sinus cavity (which happens in sinusitis), the nerves can be triggered by moving fluids and cause the sensation of tooth pain. Telltale signs of this sinus related tooth pain include pain when moving your head around, as well as ongoing sinus related symptoms. It is still best to have the tooth assessed by your dentist to ensure there are no other potential causes of tooth pain that could worsen if ignored.