What Is Rhinology?

Rhinology and sinus surgery is a subspecialty that manages nasal and sinus problems. Common problems we treat are allergies, nasal obstruction, and sinusitis. Less common conditions, such as tumors of the sinuses or anterior skull base, can also be treated with minimally invasive techniques.

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What Are The Sinuses & What Do They Do?

The sinuses are hollow chambers placed within the bones of the face and skull. They are located next to the nasal cavity and are anatomically named the paranasal sinuses. Four sets of sinuses lie on each side of the nasal cavity: frontal, ethmoid, maxillary, and sphenoid sinuses. The frontal sinuses occupy the bone over the eyes in the forehead while the maxillary sinuses are under the eyes in the cheekbones. The ethmoid sinuses are actually a collection of sinuses, like a honeycomb, which lie between the eyes. The sphenoid sinuses are placed behind the nasal cavity and eyes, near the center of the head.

We don’t really know why we have sinuses, which makes it all the more frustrating when we have sinus problems. Many theories have been proposed, all of which may be correct. By creating air-filled chambers within the skull bones, the sinuses may serve to decrease the weight of the head. They also add resonance to the voice; when they are blocked up we sound like we are talking through our noses. In a more practical sense, the sinuses form a sort of "crumple zone" that protects the eyes and brain in case of a severe injury to the face.

We know that we don’t breathe through our sinuses and we don’t use them for our sense of smell either. When we breathe, air goes through the nasal cavity like a hallway with a divider running down the middle. That divider is called the septum, and in some people it can be crooked. When this happens, it’s called a deviated septum, and, if sufficiently crooked, can cause blockage of the airflow.

The sense of smell is actually located far back in the nasal cavity, within the ceiling of the hallway. The nasal cavity hallway has areas like rooms on either side that have very small doorways that connect them to the hallway. These rooms are the sinuses and the doorways can be only a few millimeters (1/16 to 1/8 of an inch) wide. When air passes up and down the hallway, some of the air within the sinus rooms does get exchanged and refreshed. This is why some people feel as though they can’t breathe through their sinuses. They are feeling the lack of air exchange with each breath.

The nasal cavity hallway and sinus rooms have a special type of wallpaper called mucosa that has a number of functions. The mucosa wallpaper secretes mucus that traps particles inhaled into the nose and keeps the wallpaper surface moist. It has proteins within it that form part of the immune system as well. The wallpaper mucosa not only produces this mucus but also transports it from within the sinuses to the opening and into the nasal cavity hallway. This is accomplished by the millions of microscopic hari-like structures on the lining cells of the nose and sinuses, called cilia. The cilia beat in a coordinated fashion to move the secretions and their trapped particles from the sinuses into the nose and from the front of the nose toward the back. In fact, under normal circumstances it takes only eight to ten minutes for the mucus to get from the front to the back.

The mucus goes into the throat where it is swallowed and the trapped particles are destroyed in the stomach. Despite producing a large amount of mucus that is transported constantly, we typically aren’t aware of this process unless the nose and/or sinuses become inflamed, as in sinusitis. Dryness in the nose can also interfere with the secretion transportation and can lead the mucus to dry out and crust, which can lead to symptoms of irritation and blockage in the nose.

As you can see, the nose and sinuses are intimately related. Their lining wallpaper appears to be the same and they react to inflammation as one unit. For this reason, many experts have advocated the term “rhinosinusitis” as a more accurate description of what is truly going on in the nose (Greek for nose is rhin, as in rhinoceros) and sinuses.