Book One -- The things that sustain and support the entire body, and what braces and attaches them all. [the bones and the ligaments that interconnect them] | Chapter 9 On the Twelve Bones of the Upper Maxilla, Including the Bones of the Nose

Fourth maxillary bone

The fourth bone (L, L in figs. 1 and 2) [maxilla] of the maxilla is by far the largest of them all; it receives all the teeth on its side, and is surrounded by various sutures, reaching various places here and there according to its own varied shape. First, it ends at that suture [sutura zygomaticomaxillaris] which separates the first bone from the fourth—which is seen at the same time in the hollow of the temples (ff in fig. 4, ch. 6), in the anterior region of the maxilla (from a to b in fig. 1), and in the eye socket (from b to D in fig. 1). Then, the fourth bone is terminated by the sutures separating it from the second [os lacrimale] and third [os ethmoidale] maxillary bones; these sutures (from X along C to c, then to d) run the entire length of the lower part of the eye socket and in the anterior region of the second maxillary bone. In addition, near the point between the brows the fourth maxillary bone ends at the suture [sutura frontomaxillaris] (from X to Y in fig. 1) that separates the upper maxilla from the frontal bone. This length of suture runs from the anterior part of the second bone to the outer side of the nasal bone, on that side where you are now looking at the bones of the upper maxilla: that will be the fifth maxillary bone [os nasale]. The fourth is separated from it by the suture [sutura nasomaxillaris] (from Y to e in fig. 1) extending from the top of the nose near its outer side downward the length of the nasal bone. Along the course of the nasal foramina [cavitas nasi], the fourth maxillary bone is separated from the septum [septum nasi] of those foramina by a suture [sutura vomeromaxillaris] (g in fig. 1)


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running along the lowest part of the septum [vomer]. In the posterior portion, the fourth bone is distinguished from the cuneiform [ala major ossis sphenoidalis], both in the eye socket (from D to H in fig. 1) and next to the innermost tooth [dens molaris III] (N in figure 1, e in fig. 2) [processus pyramidalis ossis palatini], at the point where a suture [sutura sphenomaxillaris] separates the cuneiform bone from the upper maxilla. At the end of the palate toward the inside, the fourth bone is separated from what we call the sixth bone [os palatinum] of the maxilla, located here with its partner at the foramina [apertura nasalis posterior] of the nostrils, by a transverse suture (from u to t in fig. 2) [sutura palatina transversa]. The fourth bone has all these sutures in common with its conterminous bones; another suture (from t through x to z in fig. 2) [sutura intermaxillaris] comes in to the fourth bone of the left side and the right side following the longitude of the palate, 34 visible not only in the palate, but also in the nasal cavity. This same suture (h in figure 1) is also seen in the anterior part of the maxilla under the nostrils where the furrow [philtrum] of the upper lip is located. Here is it evident that the suture belongs to the fourth bone of either side, though it should be considered a line rather than a suture. Out of this crowd of sutures terminating the fourth bone, it is gathered without difficulty that it is connected to sixteen bones: 35 for it is joined to the first, second, third, fifth, and sixth bones of the upper maxilla, then to the frontal bone, cuneiform, and eighth bone of the head, viz. the septum [vomer] between the foramina of the nose, and finally it is attached to its own mate, the fourth bone of the other side; likewise, when eight teeth are also attached to the fourth bone, the upper maxilla is adorned with sixteen teeth. The present bone makes up most of the sides and lower area of the nostrils, and near these sides it is quite hollow 36 and not at all solid, but rather elegantly like waxen images that are hollow inside. 37 In addition to its other foramina, this bone has one (L in the eye socket of fig. 1, then B) that begins in the lower region of the eye socket and extends downward into the anterior part of the maxilla. 38 Where this first begins in the eye socket, its upper part for a notable distance consists of a kind of bony scale; but when it reaches the anterior part of the maxilla, it now appears deeply carved in the bone, and there is even a noteworthy interval to be seen between the perimeter of the eye and the upper part of the foramen. This interval is very often not continuous, but has a suture 39 (i in fig. 1) belonging to this part of the fourth bone (where the foramen is located) and peculiar to it. I shall explain in my general discourse on all the foramina of the skull what is thought to be the use of this foramen; for the present I have made passing mention of it only to give a better description of the suture belonging to the fourth bone, lest by chance someone might see it and believe it adds to the number of bones, or that it runs deeper than from the periphery of the eye socket to the foramen. Another foramen [foramen incisivum] (z in figure 2) presents itself in the front of the palate in the region behind the incisor teeth, common to the fourth bones of the upper maxilla and looking from the palate into the nasal cavity. At the sides of this foramen a suture (a, a in figure 2) [sutura incisiva] sometimes appears, or rather a line, filled with cartilage in children, which reaches more or less to the anterior side of the canine teeth. But it never goes so deep that the fourth bone of the maxilla could be considered divided into more parts because of it; this happens (as I shall say a little later) in dogs, monkeys, and pigs, where the suture dividing the fourth maxillary bone in two is conspicuous not only in the palate but also outside on the anterior surface of the maxilla (n on the dog’s skull in figure 1), and does not at all resemble a joint between bones and their epiphyses. 40



Book One -- The things that sustain and support the entire body, and what braces and attaches them all. [the bones and the ligaments that interconnect them] | Chapter 9 On the Twelve Bones of the Upper Maxilla, Including the Bones of the Nose