Maxillary sinus

Ethmoidal air

cells • Paranasal sinuses: annotated CT - Ganzer Fall bei Radiopaedia

Cheng J, Paranasal sinuses: annotated CT. Case study, Radiopaedia.org (Accessed on 19 Nov 2022) https://doi.org/10.53347/rID-56635 • CC by-nc-sa 3.0 (modified)

Maxillary

sinus • Medial wall of the orbit and maxillary sinus (Gray's illustration) - Ganzer Fall bei Radiopaedia

Hacking C, Medial wall of the orbit and maxillary sinus (Gray's illustration). Case study, Radiopaedia.org (Accessed on 22 Sep 2023) https://doi.org/10.53347/rID-89502 • CC by-nc-sa 3.0 (modified)

Maxillary

sinus • Normal sinus CT (annotated) - Ganzer Fall bei Radiopaedia

Kennedy T, Normal sinus CT (annotated). Case study, Radiopaedia.org (Accessed on 22 Sep 2023) https://doi.org/10.53347/rID-78917 • CC by-nc-sa 3.0 (modified)

Sphenoid

sinus • Paranasal sinus development (Gray's illustration) - Ganzer Fall bei Radiopaedia

Hacking C, Paranasal sinus development (Gray's illustration). Case study, Radiopaedia.org (Accessed on 12 May 2023) https://doi.org/10.53347/rID-167766 • CC by-nc-sa 3.0 (modified)

Radiopaedia • CC-by-nc-sa 3.0 • de

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.

Summary

location: paired sinuses within the body of the maxilla
blood supply: small arteries from the facial, maxillary, infraorbital and greater palatine arteries
innervation: superior alveolar, greater palatine and infraorbital nerves

Gross anatomy

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 process of the maxilla. The roof is the orbital floor. The posterior wall forms the anterior border of the pterygopalatine fossa.

There are several recesses of the maxillary sinus :

infraorbital recess (superiorly)
zygomatic recess (laterally)
alveolar recess (inferiorly)
palatine recess (variable extension of alveolar recess)

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.

Arterial supply

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

Venous drainage

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

Lymphatic drainage

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.

Innervation

superior alveolar nerves
- posterior superior alveolar nerves: dental branches pierce the bone to supply the sinus mucosa
- middle superior alveolar nerves: supply the pre-molar teeth and overlying mucosa of the sinus
- anterior superior alveolar nerves: supplies canine and incisors and anterior wall of the sinus
greater palatine nerve
- minute branches from this nerve supply the medial wall of the sinus
infraorbital nerve
- perforating branches supply the roof of the sinus