102 t SPECIAL ANA'IOMY OF THE SKELETON 



rounded eminence, the maxillary tuberosity (tuber maxillare), especially prominent 

 after the growth of the wisdom tooth, rough on its inner side for articulation with 

 the tuberosity of the palate bone, and sometimes with the external pterygoid 

 plate. It gives attachment to a few fibres of origin of the Internal pterygoid 

 muscle. Immediately above this is a smooth surface, which forms the anterior 

 boundary of the sphenomaxillary fossa; it presents a groove which, running ob- 

 liquely downward, is converted into a canal by articulation with the palate bone, 

 forming the posterior palatine or palato maxillary canal for the descending palatine 

 artery and great palatine nerve. 



The superior or orbital surface (fades orbitalis) is thin, smooth, triangular, 

 and forms part of the floor of the orbit. It is bounded internally by an irregular 

 margin, which in front presents a notch, the lacrimal notch (incisura lacrimalis), 

 which receives the lacrimal bone; in the middle it articulates with the os planum of 

 the ethmoid, and behind with the orbital process of the palate bone; bounded ex- 

 ternally by a smooth, rounded edge which enters into the formation of the spheno- 

 maxillary fissure, and which sometimes articulates at its anterior extremity with 

 the orbital plate of the sphenoid; bounded in front by part of the circumference of 

 the orbit, which is continuous on the inner side with the nasal, on the outer side 

 with the malar process. Along the middle line of the orbital surface is a deep 

 groove, the infraorbital groove (sulcus infraorbitalis), for the passage of the infra- 

 orbital vessels and nerve. The groove commences at the middle of the outer 

 border of this surface, and, passing forward, terminates in a canal, which subdi- 

 vides into two branches. One of the canals, the infraorbital canal, opens just below 

 the margin of the orbit; the other, which is smaller, runs downward in the sub- 

 stance of the anterior wall of the antrum; it is called the anterior dental canal, and 

 transmits the anterior dental vessels and nerve to the front teeth of the maxilla. 

 From the back part of the infraorbital canal a second small canal is sometimes 

 given off, which runs downward in the outer wall of the antrum, and conveys the 

 middle dental nerve to the biscupid teeth. Occasionally this canal is a branch of 

 the anterior dental canal. 



At the inner and fore part of the orbital surface, just external to the lacrimal 

 groove for the nasal duct, is a depression which gives origin to the Inferior oblique 

 muscle of the eye. 



The internal surface (Fig. 71) is unequally divided into two parts by a horizontal 

 projection of bone, the palatal process (processus palatinus); the portion above 

 the palatal process is known as the nasal surface (fades nasalis). It forms part 

 of the outer wall of the nasal fossa. Below the palate process is the cavity of 

 the mouth. The superior division of the nasal surface presents a large, irregu- 

 lar opening, the maxillary hiatus (hiatus maxillaris), leading into the maxillary 

 sinus. At the upper border of this aperture are numerous broken cellular 

 cavities, which in the articulated skull are closed by the ethmoid and lacrimal 

 bones. Below the aperture is a smooth concavity which forms part of the 

 inferior meatus of the nasal fossa, and behind it is a rough surface which 

 articulates with the perpendicular plate of the palate bone, traversed by a groove 

 which, commencing near the middle of the posterior border, runs obliquely 

 downward and forward, and forms, when completed by its articulation with the 

 palate bone, the posterior palatine or palatomaxillary canal. In front of the opening 

 of the antrum is a deep groove, converted into a canal (canalis nasolacrimalis} 

 by the lacrimal and turbinated bones. The groove is called the lacrimal groove 

 (sulcus lacrimalis), and lodges the nasal duct. More anteriorly is a well-marked 

 rough ridge, the inferior turbinated crest (cm/a conchalis), for articulation with the 

 turbinated bone. The shallow concavity above this ridge forms part of the middle 

 meatus of the nose, while that below it forms part of the inferior meatus. The 

 portion of this surface below the palatal process is concave, rough, and uneven, and 



