The paired bones that form the upper jaw and hold the upper teeth
Maxilla (plural maxillae) — the upper jaw.
Anatomy · Bones
Maxilla
The upper jaw
Skull · facial bones
The maxillae are a pair of pyramid-shaped bones that fuse at the midline to form the upper jaw, holding the upper teeth. Each contributes to the floor of the orbit, the side wall of the nose and most of the hard palate, and each contains the largest of the paranasal sinuses. They are the keystone of the midface.
How to spot them
- ▸A pair of bones forming the upper jaw and central midface, joined in the midline below the nose
- ▸Carries the upper teeth in a horseshoe-shaped alveolar process
- ▸A hole just below the lower rim of each eye socket, the infraorbital foramen, transmits a sensory nerve to the cheek
- ▸Four processes: frontal, zygomatic, alveolar and palatine
What to know
The largest of the paranasal sinuses lies inside it, just below the eye socket, and is hard to drain because its opening is high on its medial wall
Maxilla — the maxillary sinus, most often involved in sinus infections.
Its broad horizontal processes form most of the hard palate, and if they fail to fuse before birth a cleft results
Maxilla — the palatine processes (cleft palate).
A foramen a centimetre or so below the lower orbital rim transmits the nerve that supplies the upper lip, side of the nose and cheek
Maxilla — the infraorbital foramen, the exit of the infraorbital nerve.
A prominent vertical bump on its front face overlies the root of the upper canine
Maxilla — the canine eminence, between the incisive and canine fossae.
Its frontal process runs up beside the nose to meet the forehead bone, helping form the groove for the tear duct
Maxilla — with the lacrimal bone it forms the lacrimal groove and nasolacrimal canal.
Its lateral process meets the cheekbone and contributes to the arch of the cheek
Maxilla — the zygomatic process.
Key ideas
- Body plus four processes: frontal (up), zygomatic (out), alveolar (down, carrying the teeth) and palatine (in, forming the palate).
- The body has four surfaces: orbital, nasal, infratemporal and anterior.
Quick-fire facts
- •The maxillary sinus is the largest paranasal sinus, typically holding about 10 to 15 ml
- •The floor of the maxillary sinus is formed by the alveolar process, so the roots of the upper molars lie close to it
- •The maxilla forms most of the floor of the orbit and the lateral wall of the nasal cavity
- •The incisive foramen behind the upper central incisors transmits the nasopalatine nerve
- •The greater and lesser palatine foramina lie in the palatine bone, not the maxilla
- •The maxillary tuberosity behind the last molar has alveolar foramina for the posterior superior alveolar nerve
- •The infraorbital margin gives attachment to orbicularis oculi
- •The canine fossa gives origin to levator anguli oris
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Sources
- TeachMeAnatomy — The Maxilla
- OpenStax — Anatomy and Physiology 2e, 7.2 The Skull