COMPLICATIONS WITH NERVES, SINUSES, ETC. 147 



"The two first upper grinder teeth are separated 

 from the nasal cavities by a thin bone, which is easily 

 eaten through. When caries attacks their roots, the 

 inflammation extends itself to the membrane lining 

 these cavities, and a perforation of the osseous partition 

 may establish communication between Vae mouth and 

 the nose. Under the influence of interstitial suj^pu- 

 ration, the osseous membrane is destroyed to an enor- 

 mous extent. The aliments pass through the dental 

 fistula into the nose and are expelled by it along with 

 the product of the morbid secretion of the pituitary 

 membrane. 



"The third grinder is situated near the maxillary 

 sinuses, from Avhich the root is separated by a thin dia- 

 phragm. It deserves to be specially noticed on account 

 of an anatomical peculiarity, which renders caries of 

 this tooth very much to be dreaded. We refer to the 

 position of large fascia (bundles) of the superior maxil- 

 lary branch of the fifth pair of nerves, which make 

 their exit upon the face by the submaxillary foramen, 

 and which are placed immediately over the root of this 

 tooth. It is easy to imagine the pain that may follow 

 nervous complications in caries of the roots of the 

 third grinder. 



"The position of the fourth, fifth, and sixth grinder 

 teeth, immediately below the vast maxillary sinuses, 

 from which their roots are separated by thin osseous 

 partitions, gives to caries of these teeth, and to the 

 complications which it induces, a special . character, 

 which demands that we should speak of it somewhat 

 in detail. These teeth communicate with the sinuses 

 as easily as the first and second do with the nose; but 

 the case is far worse for the horse, there being so little 

 outlet for the pus. 



