Maxillary sinus

The maxillary sinus (or antrum of Highmore) is a paired pyramid-shaped paranasal sinus within the maxillary bone which drains via the maxillary ostium into the infundibulum, then through hiatus semilunaris into the middle meatus. It is the largest of the paranasal sinuses.

Described as a pyramid, the maxillary sinuses have a base on the lateral border of the nose, with the apex pointing towards the zygomatic process of the maxilla. The floor is formed by the alveolar section of the maxilla while the roof forms the floor of the orbit. 

Like the other paranasal air sinuses, these can vary in size. Large maxillary sinuses can extend to the alveolar process of the maxilla to the point where the roots of the molar teeth can project into the space.

Unlike the other paranasal air sinuses, the opening of the sinus is found on its superior end. This ostium communicates with the nasal cavity via the posterior end of the hiatus semilunaris.

Small arteries from the facial, maxillary, infraorbital and greater palatine arteries pierce the bony walls of the maxillary sinus.

Venous drainage anteriorly is via the sphenopalatine vein and posteriorly via the pterygoid plexus and the facial vein.

Lymph from the maxillary sinus drains to the submandibular group of lymph nodes via the infraorbital foramen or the aforementioned communication with the nasal cavity. 

It is present at birth and it develops until around the age of 14 years.

Head and neck anatomy
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Article information

rID: 25379
System: Head & Neck
Section: Anatomy
Tags: stub, refs
Synonyms or Alternate Spellings:
  • Antrum of Highmore

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    Figure 1: in magenta on annotated CT
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