FACE AND FRONTAL REGION OF HEAD 133 



by a pad of fat, the suctorial pad, and by a strong layer of 

 fascia which must be carefully removed. As this is being 

 done the dissector will find, both superficial and deep to 

 the fascia, a number of small glands, the molar salivary 

 glands. The ducts of these glands pierce the buccinator and 

 open into the vestibule of the mouth. One or two buccal 

 lymph glands also are sometimes found resting on the super- 

 ficial surface of the buccinator. 



Dissection. After the dissection of the buccinator and the molar glands 

 is completed, remove the stitches from the lips ; evert the lips and dissect 

 the mucous membrane from the deep surfaces, in order to expose the 

 muscular slips which attach the orbicularis oris to the alveolar margins of the 

 upper and the lower jaws, and to display the mentalis muscle. As the lips 

 are everted the dissector should note that a fold of mucous membrane, the 

 frenulnm labii, passes from each lip to the gum of the corresponding jaw in 



FIG. 61. Arrangement of the Fibres of the Buccinator Muscle 

 at the Angles of the Mouth. 



the median plane ; and as the mucous membrane is removed a number ; 'of 

 small labial salivary glands, which lie in the submucous tissue, will be 

 seen. They are readily felt in the living subject by pressing the tip of the 

 tongue against the inner surfaces of the lips. 



Musculi Incisivi Labii Superioris et Inferioris. These 

 are four small muscular bundles, two upper and two lower, 

 which attach the deeper part of the orbicularis oris to the 

 alveolar margins of the jaws in the regions of the upper and 

 lower lateral incisor teeth. 



Musculus Mentalis. When the incisive muscles of the 

 lower jaw are detached from the bone and the lower lip 

 is further everted, a distinct muscular bundle will be found on 

 each side, springing from the outer surface of the socket of the 

 canine tooth, under cover of the quadratus labii inferioris. 

 The two bundles converge and blend together, between the 

 medial borders of the musculi quadrati labii inferioris, to 

 form a single bundle which is inserted into the skin of the 

 chin. It is an elevator of the skin of the chin, 

 ii 9 & 



