112 The Tonsil 



towards the middle line of the fauces by toothed forceps, and then 

 slicing it off with a blunt-ended bistoury, the edge being kept in the 

 vertical plane. Should the point of a knife be directed outwards, the 

 whole depth of the tonsil and the superior constrictor might be 

 traversed, and the internal carotid wounded ; but such a disastrous 

 accident is very unlikely to happen. Occasionally a malignant ulcera- 

 tion of the tonsil implicates the artery. 



Adenoid vegetations are the result of hypertrophy of the lymphoid 

 tissue, which, like scattered tonsillar elements, are placed in the 

 mucous membrane of the upper and back part of the pharynx, and 

 constitute a * pharyngeal tonsil.' 



Quinsy (acute tonsillitis) is associated with difficulty of swallowing 

 and breathing ; pain extends along the Eustachian tube ; and because 

 the inflamed mass is moved in deglutition that act is painful. If 

 abscess have formed, or with the view of preventing its occurrence, 

 the tonsil should be punctured, from before backwards, by a guarded 

 bistoury ; or, as the tissue is very soft, the swollen tissue may be 

 painted with cocaine and the abscess opened by a backward thrust of 

 the dressing-forceps. With ordinary care, however, there is no risk 

 whatever of wounding the artery when operating upon the tonsil with 

 a knife. 



The gums consist of a layer of mucous membrane which is closely 

 connected with the alveolar periosteum. The periosteum is continuous 

 with the thin layer in the sockets of the teeth, and when caries attacks 

 a tooth the inflammation may spread and give rise to a>sub-periosteal 

 alveolar abscess, or gum-boil. The pus being bound down by the 

 dense membrane, there may be much pain until the gum-boil breaks 

 or is lanced. Necrosis may follow this sub-periosteal suppuration. 



For the stipply of the gums the vessels and nerves of the jaws, 

 teeth, palate, and lips contribute branches. 



THE TEETH 



The temporary teeth are, in each half-jaw, two incisors, one 

 canine, and two molars giving a total of twenty. The permanent set 

 number thirty-two : thus, two incisors, one canine, two bicuspids, and 

 three molars. 



The root of the third molar, or wisdom-tooth, shows but a trace 

 of fangs. It often issues clumsily and painfully through the tender 

 gum, and causes much swelling in the mouth and in the neighbouring 

 lymphatic glands. Sometimes the process is accompanied by profuse 

 suppuration. 



Structure. The chief part of a tooth is made of line branching 

 tubes of dentine, which imbibe nutriment from the pulp-cavity. The 

 pulp consists of connective tissue, cells, and twigs of nerve and 

 artery. 



