Frontonasal duct Definition
It is the passage that moves down from the frontal sinus and opens into the ethmoidal infundibulum. The frontal sinus drains into the middle meatus through the frontonasal duct. Each of the frontal sinuses consists of this passage.
Frontonasal duct Location
This duct is located in a narrow vertical position. It may occasionally be discerned on sagittal sections though not in frontal projections. The deepest point of the skull base is behind this duct.
Frontonasal duct and Frontal Sinusitis
In case of Frontal Sinusitis, patients often experience episodes of painful symptoms. The pain usually begins in the morning and aggravates in the afternoon only to subside gradually with approaching night. This is attributed to the blockage of the Frontonasal duct. In frontal sinusitis patients, the passage is partially obstructed. During the night, this passage becomes completely blocked. By the following morning, air collected inside get absorbed and the sinus gets filled with discharge. This leads to facial tension and pain. When a patient returns to an erect position in the morning, the passage reopens though only partially due to the natural breaking up of the congestion of its mucosal lining. The discharge flows down through the duct, aided by gravity. However, air fails to enter through the narrowed duct. The accumulation of negative pressure within the sinus results in vacuum facial pain. This gets corrected naturally once the sinus drains completely and air refills the cavity. The painful sensations can improve as a result.
Frontonasal duct Damage
If the duct gets accidentally damaged in some way, it can give rise to problems with sinus drainage in future. Penetrating or blunt trauma to the duct can lead to a disruption of the structural integrity of the bone or mucosa. In such cases, an operative reconstruction may be required. The type of reconstruction is based on the extent of injury to the passage.
Frontonasal duct Pictures
Here are some carefully chosen Frontonasal duct images that will help you understand the position and appearance of this passage. You can use these Frontonasal duct photos for reference.
Picture 1 – Frontonasal duct
Picture 2 – Frontonasal duct image