Maxillary Bones (Maxilla)

Maxillary Bones (Maxilla)

• Form the majority of the skeleton of the face and the upper jaw
• Contain the maxillary paranasal sinus
• Articulate with the opposite maxilla and the frontal, nasal, vomer, and ethmoid bones; inferior nasal concha; palatine, lacrimal, and zygomatic bones; and the septal and nasal cartilages
• 2 maxilla bones (maxillae)
• Parts:
  • Body: major part of the bone, shaped like a pyramid, contains the maxillary paranasal sinus
  • Frontal process: extends superiorly to articulate with the nasal, frontal, ethmoid, and lacrimal bones, forms the anterior boundary of the lacrimal fossa
  • Zygomatic process: extends laterally to articulate with the maxillary process of the zygomatic bone
  • Palatine process: extends medially to form the majority of the hard palate, articulates with the palatine process of the opposite side and the horizontal plate of the palatine bone, incisive foramen is located in the anterior portion
  • Alveolar process: the part of the maxilla that supports all of the maxillary teeth, extends inferiorly from the maxilla, each maxilla contains 5 primary and 8 permanent teeth, alveolar bone is resorbed when a tooth is lost

Nasal Bone

• Inferior portion forms the superior margin of the nasal aperture
• Forms the bridge of the nose
• Articulates with the nasal bone of the opposite side, the nasal portion of the frontal bone, the frontal process of the maxilla, and the perpendicular plate of the ethmoid
• Inferior portion of the nasal bones attaches with the lateral nasal cartilages and septal cartilage
• 2 nasal bones

Lacrimal Bone

• Small and rectangular in shape, thin and fragile
• Forms a small portion of the medial wall of the orbit
• Articulates with the frontal process of the maxilla, orbital plate of the ethmoid bone, the frontal bone, and the inferior nasal concha
• The region that articulates with the frontal process of the maxilla forms the lacrimal fossa, the location of the lacrimal sac
• The inferior part of the lacrimal forms a small portion of the lateral wall of the nasal cavity
• 2 lacrimal bones

Vomer

• Shaped like a "plough"
• Forms the posterior inferior part of the nasal septum
• Articulates with the perpendicular plate of the ethmoid, maxilla, palatine, and sphenoid bones and septal cartilage
• Posterior border does not articulate with any other bone
• 1 vomer bone

Palatine Bone

• Forms part of the nasal cavity and the hard palate, L-shaped
• 2 palatine bones
• Parts:
  • Perpendicular plate: vertical rectangle, notch on the superior border articulates with the sphenoid bone, forming the sphenopalatine foramen, small orbital process helps form part of the orbit, forms part of the wall of the pterygopalatine fossa and the lateral wall of the nasal cavity
  • Horizontal plate: forms the posterior portion of the hard palate, superior to the horizontal plate is the nasal cavity, on the medial part is the posterior nasal spine, greater palatine foramen is on this plate
  • Pyramidal process: extends posteriorly and inferiorly from the junction of the perpendicular and horizontal plates, lesser palatine foramina are located here

Inferior Nasal Concha

• Curved bone that forms part of the lateral wall of the nasal cavity
• 2 inferior nasal conchae
• Lies within a curve in the lateral wall of the nasal cavity
• Articulates with the maxilla and perpendicular plate of the palatine, lacrimal, and ethmoid bones

Mandible

• Forms the lower jaw
• Described as horse shoe shaped
• All muscles of mastication attach to the mandible
• 1 mandible
• Parts:
  • Body: mental foramen is located on the body