THE MOUTH 



1005 



THE MorTH 



On the floor, in the centre, is the frtenuiu Hnfrute. In (lividin-r the fraenum for 

 tongue-tie, the scissors should he kept close to the bone, so as to avc.id tin- raninc 

 vessels. Of these, the ranine vein can he seen !.< ncath tlx- nnuoiis nMiiil)ranc; the 

 artery lies close to it, l>ut deeper. 



The orifices of Wharton's duet open on minute i)ai.illa' situated at the ends of 

 ridges of mucous menihrane whicii curve forwards and inwards to meet in tlie 

 middle line a Httle behind the sym])liysis of the jaw, on either side (.f the fnenum 

 lingu;e (fior. 670). Togetiier with Wharton's duet, or close to it, opens the duct 

 of Jiartholin, or chief duct of the sublingual gland. If the above folds be 

 traced backwards they correspond, as they diverge, to the ranine veins, and, more 

 deeply, to Wharton's duct and the lingual nerve (fig. 670). Under these ridges lie 



Fig. 670.— Side of the Face and Morrn Cavity, showixc; thk Tukkk 

 Sai.ivakv Glands. 



"S^^MMMi. 





SOCIA PAROTIDIS 



DUCT OF SOCIA 

 PAROTIDIS 



DUCT OF PAROTID 



Bristle inserted 

 into duct 



Freenum linguaB 



DUCT OF RIVINI 



SUBLINGUAL 6LAN0 



PAROTID GUNO 



Maaseter muscle 



Sterno-mastoid 

 muscle 



Posterior belly of 

 digastric muscle 



SUBMAXILLARY GLAND, 

 DRAWN BACKWARDS 



- Loop of fascia 



DUCT OF SUBMAXILLARY 

 GUND 

 Mylo-hyoid muscle 



Anterior belly of 

 digastrio muscle 



DEEP PORTION OF SUBMAXILURY GUNO 



the sublingual glands, the majority of whose ducts ojkh on tlif surtaee ot the 

 folds. Dilatation of one of these Kivinian ducts, more fretjUently dilatation of a mu- 

 ciparous gland, — and much more rarely dilatation of Wharton's duct. — constitutes 

 a ' ranula.' The submaxillary gland can be felt nearer the angle of the jaw lying 

 Itetween its fossa and the mucous jiiembrain'. ispecially if ])ressure is made from 

 outside. The attachment of the genio-hyo-glossi can l>e felt luhind the sym- 

 ]>hysis: the division of the muscles allows the tongue to come well out of the 

 mouth; but when both have to be divided, the tongue loses much of its steadiness, 

 and may easily fall back over the larynx during the administration of the anaw:- 

 thetic or, later on, in sleep. It should therefore be secured forwards for a while 

 with silk. While the mouth is widely ojien, the pterygo-mandibular ligament can 

 be seen and felt beneath tlie mucous membrane, behind the last molar tooth. Just 

 below and in front of tlie lower attachment of this ligament, the lingual nerve can 

 be felt lying close to the bone below the last molar. It can be divided here to give 

 relief from pain in incuralde cancer of the tongue, at a point where it cros.<es a line 



