Maxilla Bone

00:00 The Maxillae are a pair of large pyramidal bones which make up the entirety of the upper jaw.

00:06 They contribute to the formation of the majority of the floor and the lateral wall of the nasal cavities as well as the floor of the orbital cavities.

00:15 Similar to our discussion of the previous zygomatic bone, we should divide the Maxilla into parts.

00:20 Anatomically, the maxilla has: A body: And the body has four surfaces, these are the Anterior, Infratemporal or Posterior, Orbital and Nasal surfaces.

00:35 It also has four processes, namely: the zygomatic, frontal, alveolar and palatine.

00:42 Let's commence our discussion with the body of the maxilla and its various surfaces.

00:48 The body of the maxilla is roughly triangular.

00:51 And as mentioned in the previous slide has several surfaces.

00:55 Let's take a closer look at these surfaces and see what anatomic landmarks are located within each.

01:02 The anterior surface is quite broad, and there are several notable structures located here.

01:08 We have the incisive and the canina fossa.

01:14 We have the infraorbital foramen, the infraorbital margin which is the superior border of the anterior surface, and this margin acts as a line of demarcation between it in the orbital surface of the maxilla.

01:29 Medially, there is a concave nasal notch and anterior to it the nasal spine which is formed when two pointed processes of the two maxillae come together.

01:42 Lastly, the anterior surface of the maxilla offers attachment to several muscles of the face, such as the orbicularis oris, levator anguli oris, nasalis, etcetera.

01:57 The infratemporal surface is located posterolateral to the anterior surface.

02:03 The point of separation between them is a line that can be drawn down from the zygomatic process of the maxilla.

02:11 This surface also has several notable points which include the alveolar canals, which transmit posterior alveolar vessels and nerves and the maxillary tuberosity, which is the site of articulation with the pyramidal process of the palatine bone, as well as a site of attachment for several fibers of the medial pterygoid muscle.

02:35 The orbital surface is smooth and triangular.

02:39 It forms most of the floor the orbital cavity.

02:42 Important anatomic landmarks on the orbital surface include the lacrimal notch, which along with the ethmoid and palatine bones forms the opening the nasal lacrimal duct, the anterior edge of the inferior orbital fissure which is formed by the posterior edge of the orbital surface, the infraorbital groove which lies centrally and obliquely descends, opening up as the infraorbital foramen.

03:12 This allows the passage of the infraorbital vessels and nerve.

03:18 And the last surface is the nasal surface.

03:20 This surface is located on the anterior and medial side of the maxilla.

03:26 It contributes to the formation of the lateral wall, the nasal cavity and features the following anatomic landmarks; superiorly the nasal surface features a maxillary hiatus which is the opening for the maxillary sinus.

03:42 Aterior to the hiatus is a lacrimal groove which contributes to the formation of the nasal lacrimal duct.

03:50 Below the nasal surface is concave and corresponds to the inferior nasal concha.

03:56 more anteriorly a conchal crest is present where the inferior nasal concha attaches.

04:03 The posterior area, the nasal surface is rough and articulates with the palatine bone.

04:10 Here a greater palatine groove for vessels and nerves of the same name is present.

04:16 This concludes our discussion of the maxillary body and its surfaces and now we move on to the various processes of the maxillary bone.

04:24 Maxillary processes are points of articulation with its surrounding bones.

04:29 As I mentioned previously, there are four such processes.

04:35 The first of these processes is a zygomatic process.

04:39 Through this middle shaped projection, the maxilla articulates with the maxillary process of the zygomatic bone.

04:47 Second is the frontal process.

04:50 This process extends posterosuperiorly and joins with the nasal surface of the frontal bone.

04:57 Additionally, the frontal process also contributes to the formation of the ocular margin, the lacrimal fossa and to the closure of some of the ethmoidal air cells that we talked about before.

05:11 Third is the alveolar process.

05:14 This process is socketed to house the roots of the upper teeth.

05:18 The fourth and the last process is the palatine process.

05:22 The Palatine process is a thick, flat shelf that contributes to the formation of the nasal floor as well as the osseous hard palate when it joins with its contralateral half and the horizontal plate of the palatine bone posterior.

05:38 Through the palatine process pass many neurovascular foramina which permit the passage of various vessels and nerves.

05:45 Most significant of these foramina are the incisive fossa and the palatine groove.

05:51 These allow for the passage of the greater palatine artery and the nasal palatine nerve into the nasal cavity