THE MANDIBLE 27 



maxilla, thus forming the lower part of the septum of the nose. It 

 is this part of the septum which is sometimes bent to one side, or 

 "deflected," and it often presents a "spur" on one of its surfaces. 

 (The vertical plate of the ethmoid and the vomer together form the 

 bony septum, Fig. 26.) 



Articulates with 

 ethmoid 



Groove for nerve , ^^ 



Posterior border 

 Articulates with 

 hard palate 



FIG. 17. THE VOMER. (Morris.) 



Mandible (inferior maxillary, or lower jaw-bone, mandibula) . 

 The only movable bone in the skull. It consists of a body having 

 on either side a ramus (or branch) which is attached by ligaments 

 to the temporal bone 



The body is the lower portion, shaped much like a horseshoe 

 with a thickened border (the alveolus) which bears the lower 

 teeth. 



FIG. 18. THE MANDIBLE. 



i, Body of bone; 2, ramus; 3, symphysis; 4, incisive fossa; 5, mental foramen; 7, 

 depression for passage of facial artery; 8, angle of jaw; 10, coronoid process; n, 

 condyle; 12, sigmoid notch; 13, alveolar border: a, incisors; b, bicuspids; c, canines; 

 m, molars. (Sappey.) 



On each side is an opening called the mental foramen, which is in a line 

 with the infraorbital and supraorbital foramina, already mentioned. 



Each of these three openings transmits an important nerve, artery, and 

 vein, bearing the same name as the foramen. See Surgical note, p. 308. 



The ramus extends upward from the body, and ends in two 

 processes, one of which is the condyle; it is this condyle which 

 articulates with the temporal bone to form the temporo-maxillary 

 joint. 



