RELATIONS OP THE MOUTH WITH THE HEAD. 43 T 



CHAPTER VI. 



ANATOMICAL AND PHYSIOLOGICAL RELATIONS OF THE MOUTH 

 WITH THE DIFFERENT PARTS OF THE HEAD. 



THE mouth, from the detailed description already given, 

 it will be perceived, is a very complex apparatus, com- 

 prising organs of the greatest variety, in form, size, deli- 

 cacy and adaptation, and embodying functions equally 

 various and useful, as seen in the multitude of duties they 

 perform, their surprising promptitude and harmony of 

 action, and their universal sympathy and relation with all 

 the various parts composing the head ; and we may add 

 the rest of the body likewise, as we shall have to show in 

 the proper place. So close and so essential is this mutual 

 relation of the mouth and head, that they cannot exist 

 separately. 



It is only necessary here to make a very general enu- 

 meration of these relations with the mouth, so as to impress 

 especially upon the dental student their magnitude and 

 importance. 



The mouth, it will be recollected, consists of the anatomi- 

 cal elements of bone, muscle, blood-vessel, nerve, gland, cellu- 

 lar, mucous and adipose structure; which, variously combined, 

 constitute the upper and lower jaw, the teeth, the gums, 

 the tongue, the palate, the tonsils, the cheeks, &c., in a 

 word, all the parts forming the walls of the cavity of the 

 mouth, as well as the various organs contained within it. 

 Now each one of these elements, and of the several organs 

 they form, has a relation more or less direct and intimate 

 with the other portions of the head. 



The upper jaw-bone is connected to a number of the bones 

 of the cranium and face, thereby forming one continuous 

 whole, containing numerous cavities of various sizes and 

 uses, as the cavity of the cranium for lodging the brain ; 

 the orbital and nasal cavities, the maxillary sinus, &c. The 

 loiverjaw, by its articulation with the temporal bones, pre- 

 sents a fulcrum and lever, which, in connection with the 



