CorpusHuman Anatomy
SkeletalBone

Maxilla

Maxilla

Also known as: maxillae, upper jaw

The paired bones of the upper jaw. Together they form most of the face, the upper dental arch, the anterior hard palate, the floor of the orbits and the lateral walls of the nasal cavity, and contain the maxillary sinuses.

Show on body map Skull — Lateral View

Overview

Each maxilla has a pyramidal body containing the maxillary sinus, the largest paranasal sinus, and four processes. The frontal process rises to meet the frontal bone and forms part of the medial orbital margin (anterior lacrimal crest); the zygomatic process articulates with the zygomatic bone; the palatine process meets its fellow in the midline to form the anterior two-thirds of the hard palate; and the alveolar process bears the sockets (alveoli) of the upper teeth.

On the anterior surface, ≈1 cm below the infraorbital margin, the infraorbital foramen transmits the infraorbital nerve (terminal branch of V2) and vessels. The orbital surface forms most of the orbital floor and carries the infraorbital groove and canal. In the anterior palate the incisive foramen transmits the nasopalatine nerves and sphenopalatine vessels. The maxillary sinus (≈15 mL in adults) opens high on its medial wall into the semilunar hiatus of the middle meatus — a poor drainage position — and the roots of the upper molars and premolars often project into its floor.

The maxillae articulate with every other facial bone except the mandible.

Location

Central face, between the orbits and the upper teeth.

Parts & subdivisions

  1. Body and maxillary sinus
    Largest paranasal sinus; drains into the middle meatus.
  2. Frontal process
    Medial orbital margin; anterior lacrimal crest for the lacrimal sac.
  3. Zygomatic process
    Articulates with the zygomatic bone (cheek).
  4. Palatine process
    Anterior two-thirds of the hard palate.
  5. Alveolar process
    Sockets for the upper teeth (gomphoses).
  6. Infraorbital foramen
    Infraorbital nerve (V2) and vessels.
  7. Incisive foramen
    Nasopalatine nerve and terminal sphenopalatine/greater palatine vessels.

Anatomy

Articulations

Frontal, ethmoid, nasal, zygomatic, lacrimal, palatine, inferior nasal concha, vomer and opposite maxilla (intermaxillary suture); occasionally the sphenoid.

Ossification

Intramembranous from several centres beginning ≈week 6; the premaxilla (incisor-bearing segment) fuses early.

Development

From the maxillary prominence of the 1st pharyngeal arch; the primary palate from the medial nasal prominences and the secondary palate from the palatine shelves, which fuse in weeks 9–12.

Function

  • Holds the upper teeth
  • Forms the floor of the orbit, the lateral nasal wall and most of the hard palate
  • Transmits masticatory forces to the cranium via buttresses
  • Shapes the midface

Clinical significance

Le Fort fractures

Le Fort I — horizontal, above the alveolar process (floating palate); II — pyramidal, through the nasal bones, orbital floor and infraorbital rim (floating maxilla); III — craniofacial dissociation through the orbits and zygomatic arches.

Cleft lip and palate

Failure of fusion of the maxillary and medial nasal prominences (cleft lip) and/or of the palatine shelves (cleft palate).

Maxillary sinusitis and dental pain

Proximity of molar roots means sinusitis can mimic toothache and dental infection or extraction can open an oroantral fistula.

Compiled from standard anatomy and physiology references — see the Skeletal System sources. For education only; not medical advice.