Maxilla

Dr Andrew Dixon ◉ and Dr Yair Glick ◉ et al.

The maxillae (or maxillary bones) are a pair of symmetrical bones joined at the midline, which form the middle third of the face. Each maxilla forms the floor of the nasal cavity and parts of its lateral wall and roof, the roof of the oral cavity, contains the maxillary sinus, and contributes most of the inferior rim and floor of the orbit. Its alveolar process houses the teeth.

Gross anatomy

The body of the maxilla is roughly pyramidal and has four surfaces that surround the maxillary sinus, the largest paranasal sinus: anterior, infratemporal (posterior), orbital and nasal. It also has four processes: zygomatic, frontal, alveolar, and palatine. It articulates with the following bones: frontal, ethmoid, nasal, zygomatic, lacrimal, inferior nasal concha, palatine, and vomer.

Anterior surface

has vertical protrusions overlying the roots of the teeth, with the canine eminence being the most prominent of these
the incisive fossa runs medial to the eminence and the canine fossa is lateral to it
above the canine fossa lies the infraorbital foramen, which transmits the infraorbital vessels and nerve
above the infraorbital foramen lies the maxillary part of the infraorbital margin
the anterior nasal spine is a vertical midline protuberance, with the nasal notch forming its deeply concave lateral border

Infratemporal surface

Forms the anterior wall of the infratemporal fossa.

Orbital surface

triangular in shape; forms most of orbital floor
articulates with lacrimal bone, orbital plate of ethmoid, and orbital process of palatine bone
posterior border forms most of anterior edge of inferior orbital fissure
infraorbital groove passes centrally, transmits infraorbital vessels and nerve, and continues anteriorly as infraorbital canal, which opens into infraorbital foramen
the canalis sinuosus, which transmits the anterior superior alveolar nerve and vessels, branches off of the infraorbital canal

Nasal surface

maxillary ostium opens from maxillary sinus into hiatus semilunaris
nasolacrimal groove is anterior to ostium; comprises two-thirds of the nasolacrimal canal circumference
conchal crest articulates with inferior nasal concha

Zygomatic process

Pyramid-shaped projection at which anterior, infratemporal and orbital surfaces converge.

Frontal process

located between the nasal and lacrimal bones
contributes to the lacrimal fossa
its medial surface is part of the lateral nasal wall
closes anterior ethmoidal air cells
articulates posteriorly with middle nasal concha, superiorly with nasal part of frontal bone

Alveolar process

Contains eight sockets on each side for upper teeth; socket for canine tooth is deepest.

Palatine process

horizontal; projects medially from lowest part of medial aspect of maxilla
forms a large part of nasal floor and anterior three-fourths of hard palate
contains two grooves posterolaterally that transmit the greater palatine vessels and nerves; additionally, many vascular foramina and depressions for palatine glands
midline incisive fossa behind incisor teeth
intermaxillary palatal suture runs posterior to the fossa
two lateral incisive canals from nasal cavity open in incisive fossa and transmit terminations of greater palatine artery and nasopalatine nerve
superior surface forms most of nasal floor