Maxillary sinus

Anatomy of the maxillary sinus

The maxillary sinus or also Maxillary sinus is the largest sinus in the body. It is created in pairs and has the shape of a pyramid, with its base on the side of the nasal cavity and its tip tapering towards the zygomatic process. The maxillary sinus is thus located below the eye.

The maxillary sinus is with the middle nasal passage over the Semilunar hiatus connected. The roof of the maxillary sinus is often very thin and also forms the floor of the eye socket. The posterior border is pierced by various nerves and blood vessels, which are responsible for supplying the maxillary sinus, but also the teeth. The sensory innervation of the maxillary sinus takes place via the Maxillary nerve. The floor of the maxillary sinus borders the upper jaw and the hard palate. It also contains the Superior dental plexus, a plexus of nerves. The front wall is thick and corresponds to the front side of the jaw.

The maxillary sinus can vary in shape. In some people, it remains limited to the maxillary bone. With a pronounced airiness (pneumatization), the maxillary sinus can show various bulges. A distinction is made between the alveolar bay, the zygomatic bay, the infraorbital bay and the palate bay. The alveolar bay has a spatial relationship with the upper tooth roots. Removing the upper molars can create a connection between the oral cavity and the maxillary sinus. This can lead to the spread of germs and inflammation of the maxillary sinus.

The maxillary sinus is lined with ciliated respiratory epithelium, which is typical of the airways. In 25 to 50% of the maxillary sinus, small partitions can be found indicating the palate. These separations are called Underwood septa. The volume of the maxillary sinus can be up to 15 mL.

The growth of the maxillary sinus is completed by the age of 20.

Function of the maxillary sinus

The maxillary sinus is one of the areas of pneumatization in the human body. Pneumatization spaces are bone cavities that are filled with air. These are mostly covered with mucous membrane, but the exact function is not yet fully understood. It is believed that these cavities serve, among other things, to save weight.

The maxillary sinus serves to expand the surface of the nasal cavity. This is where the air you breathe is prepared for the lungs by being heated and humidified. The maxillary sinus also has a kind of protective function. It is lined with mucous membrane, which has fine hairs, the so-called cilia (Cilia). These cilia are mobile and are used to move mucus. The mucus contains inhaled particles such as dust, bacteria and pollutants. These undesirable substances or pathogens are "captured" on the mucus. With the rhythmic beat of the cilia, the mucus is transported towards the throat and swallowed with the saliva. This neutralizes potential dangers in the stomach and protects the lungs and body from diseases.

Furthermore, the maxillary sinus may also serve the sense of smell and voice training.

Diseases of the maxillary sinus

Inflammation of the maxillary sinus (Maxillary sinusitis) can originate either through the penetration of bacteria from the nose in the case of colds or from the teeth. Especially with purulent root inflammation (apical ostitis) the relatively thin bone layer of the floor of the maxillary sinus can be broken through and thus lead to a purulent inflammation of the entire maxillary sinus. Cysts from the root of the tooth can break through the floor of the maxillary sinus and also cause inflammation. The maxillary sinus can also be opened during tooth extraction or broken-off infectious root residues can enter the maxillary sinus. In rare cases, polyps or tumors can also form. If left untreated, the inflammation can spread to the other sinuses.

Maxillary sinus cyst

Maxillary sinus cysts are protrusions of the mucous membrane that are usually spherical. These cysts are found on the floor of the maxillary sinus in 4% of those affected. They can be hollow or just a local enlargement of the tissue crevices. The latter is called a pseudocyst. The cysts are about 1 cm in diameter, but usually do not grow. They usually only occur on one side.

Maxillary sinus cysts are often found incidentally on imaging tests (x-rays) and rarely cause problems. Occasionally, the cysts cause a feeling of heaviness or pressure in the upper jaw. If maxillary sinus cysts tear, it can lead to a yellowish discharge. Surgical removal is usually not necessary. However, if the cyst is causing discomfort, it should be removed. If a chronic maxillary sinus disease is suspected, it should be rinsed thoroughly.

The development of maxillary sinus cysts is not fully understood. It is believed that they arise as a reaction to infection or as a result of lymphedema. An important differential diagnosis is the dentogenic cyst, which can arise after tooth injuries or interventions.

Read more about the topic here: Jaw cyst

Maxillary sinus infection

The maxillary sinus infection or Maxillary sinusitis is a common respiratory disease. This inflammation affects the lining of the maxillary sinus and can be unilateral or bilateral. Maxillary sinusitis can be caused by viral or bacterial pathogens. Pathogens can either be inhaled via the air (rhinogenic maxillary sinusitis) or through a tooth root canal (dentogenic maxillary sinusitis) enter the maxillary sinus and cause inflammation there.

Allergens (for example pollen) can cause an allergic maxillary sinus infection. In some cases, facial bones injuries can also be associated with inflammation of the maxillary sinus (traumatic maxillary sinusitis).

Inflammation is favored by various factors such as anatomical constrictions or polyps. Most dentogenic and rhinogenic sinusitis are acute. If the inflammation lasts longer than 3 months, it is called chronic rhinosinusitis. An inflammation of the maxillary sinus is characterized primarily by pain, especially tenderness in the area of ​​the cheekbones. In addition, it is often accompanied by purulent nasal discharge and restriction of nasal breathing. In addition, there can be headaches, as well as fever and fatigue.

The treatment of maxillary sinus inflammation is conservative and alleviates symptoms. The administration of decongestant nasal sprays can, among other things, improve breathing. If there is evidence of bacteria or fungi, antibiotics or antimycotics are appropriate. In the case of a viral infection, antibiotics are ineffective.

You can find more information on this topic at: Antibiotics for an inflammation of the maxillary sinus

Maxillary sinus suppuration

The cause of an antrum ulcer is mostly viral infections. These lead to inflammation of the lining of the maxillary sinus and consequently to suppuration. Bacteria can rarely cause the inflammation.

Maxillary sinus infections often lead to a feeling of pressure and pain in the area of ​​the maxillary sinus. In addition, they lead to headaches and toothaches. Occasionally there is a fever and decreased performance and fatigue. The suppuration can spread along the maxillary sinus and thus affect the eyes, nose and brain.

Before therapy can be initiated, the cause should be determined. A detailed medical history and physical examination are often crucial. In addition, a swab (of the nasal secretion) can be taken. An endoscopic examination is usually only necessary if the course is severe. Therapy is usually based on combating symptoms. Nasal sprays or drops, pain medication if necessary and avoiding physical exertion make sense. If there is evidence of bacterial infestation, appropriate antibiotic therapy should be considered.

You might also be interested in: Inflammation of the jaw

Maxillary sinus cancer

Maxillary sinus cancers are malignant tumors that arise in the maxillary sinuses. It is a rare condition that more often affects men. The tumors find their origin in the mucous membrane cells of the maxillary sinuses, which degenerate due to mutations and multiply in an uncontrolled manner. Smoking and alcohol consumption are risk factors for malignant tumors in the maxillary sinus area.

A distinction is made between squamous cell carcinoma, which emerges from the surface cover cells, and adenocarcinoma, which resembles glandular tissue. The latter form occurs particularly often in people who (work) come into contact with hardwood fine dust and leather dust. Those affected often complain of restricted nasal breathing on the tumor side as well as bleeding and changes in odor. In later stages, pain and a change in the shape of the nose due to tumor growth may occur.

A nasal endoscopy with sampling and imaging for the purpose of staging is performed for diagnosis. Depending on the type and progress of the disease, therapy consists of either surgery, radiation therapy, chemotherapy or a combination.

Symptoms of maxillary sinus disease

A distinction is made between acute and chronic maxillary sinusitis. An acute inflammation of the maxillary sinus causes severe pain and discharge from the corresponding nostril. The secretions are either slimy or purulent, depending on the cause and severity of the infection.

An increased body temperature should also be measured. With chronic sinusitis, the patient notices a feeling of pressure in addition to the nasal discharge. The cause is a thickened mucous membrane that can block the exit to the nose. At night, the secretions also get into the pharynx due to the horizontal position.

Diagnosis of diseases of the maxillary sinus

In addition to the patient's complaints, the X-ray shows a shadowing of the maxillary sinus. Shading can also be detected by means of a light source in the closed oral cavity. In addition, there are secretions from the nose.

Therapy of maxillary sinus diseases

The connection to the nose allows rinsing to be carried out. In addition, steam baths can bring relief. The best therapy, however, is the use of antibiotics. An antibiogram is used to determine the antibiotic that shows the best effect. This is either applied directly into the maxillary sinus or by taking tablets. If a connection between the maxillary sinus and the oral cavity is established after tooth extraction, the defect must be closed with a mucosal flap. Surgical therapy is necessary if the root of the tooth has entered the maxillary sinus. Tumors and polyps also require surgery. The maxillary sinus is opened from the oral cavity, the foreign body is removed and the inflamed mucous membrane is cleared out. The opening to the nasal passage is widened so that the secretions can drain off better. A tamponade is performed, which can be removed after a few days.


If you have a cold, you should avoid blowing your nose too hard so that no germs can get into the maxillary sinus through the connecting duct. Purulent inflammation of the root tips must be removed, either by extraction of the relevant tooth or by a root tip resection.

Read detailed information on: Procedure for a root tip resection


The healing of an inflamed Maxillary sinus is thanks to the therapy with Antibiotics or an operative supply very well.

Dental implants

The expansion of the Maxillary sinus is sometimes an obstacle for the insertion of an implant in the posterior region if there is not enough bone material available. This is the case when after Tooth extraction or bone loss the maxillary sinus has subsided. Then the increase (Sinus lift) of the maxillary sinus floor using the body's own bone or bone substitute material to create space for the insertion of the implant.

Figure skull from the front and from the left (upper jaw blue)
  1. Upper jaw -
  2. Zygomatic bone -
    Os zygomaticum
  3. Nasal bone -
    Nasal bone
  4. Tearbone -
    Lacrimal bone
  5. Frontal bone -
    Frontal bone
  6. Lower jaw -
  7. Eye socket -
  8. Nasal cavity -
    Cavitas nasi
  9. Upper jaw, alveolar process -
    Alveolar process
  10. Maxillary artery -
    Maxillary artery
  11. Under eye cavity hole -
    Infraorbital foramen
  12. Ploughshare - Vomer

You can find an overview of all Dr-Gumpert images at: medical illustrations


The Maxillary sinus is created in pairs and is located within the upper jaw. Their expansion is very variable and therefore often represents an obstacle during implantation. Inflammations of the maxillary sinus can either come from the nose or from the Teeth go out. The therapy consists either of the administration of Antibiotics or through surgical interventions.