The relationship between body posture and pressure in occluded maxillary sinus of man.

One of the most common symptoms in sinusitis is pain over the infected cavity increasing when the patient is bending forward or lying down. It is commonly thought that this increase in pain is a result of increased pressure in the paranasal cavities when bending forward. In this investigation we have found that changing the body position from sitting to recumbent or even to "head between knees" gives a manometrical pressure rise in the sinus that is too small to cause a pressure-mediated pain. The pain is probably caused by a dilation in the blood vessels of the infected mucosa when the patient is bending forward or lying down.