516 DISEASES AND INJURIES OF THE FACIAL EEGION. 



height of its activity. When the animal is three years old,eight 

 permanent molars are being cut, and four permanent incisors are 

 in active growth within the gums. At four years of age the 

 same number of molars are cut, and the same number of incisors 

 are at a more advanced stage of growth within the gums, in 

 addition to the canine teeth, w^hich make their appearance about 

 this time. 'No wonder, then, that the eruption of so many teeth 

 is a source of irritation and fever. 



The best treatment is to throw the animal off work, turn him 

 to grass if the weather permits, or into a loose box in a well- 

 ventilated spot, and give him rest until the process of dentition 

 is completed. If the gums are red and swollen, lancing them 

 will prove a source of great relief. This operation is easily 

 performed in the anterior portion of the mouth, but is rather 

 difficult at the posterior part ; however, it may be done with a 

 proper instrument, the gum-lancet of the dentist on an extended 

 scale being the most suitable. If the temporary teeth seem to 

 hinder the eruption of their successors they are to be removed. 



SUPERNUMERARY TEETH. 



Small supernumerary teeth are often met with in the front of 

 the molars called " woK's teeth." They have been supposed to 

 be a cause of ophthalmia, but this can scarcely be. They can 

 produce no inconvenience ; but if requested to extract them the 

 practitioner can hardly refuse. The best method is to remove 

 them with the tooth-forceps. 



The question as to the influence of the teeth upon diseases of 

 the eye might perhaps be deemed worthy of discussion, inasmuch 

 as the dental nerve is a branch of the same nerve as that 

 supplying the eyes wdth common sensibility, namely, the fifth. 

 The older writers maintain that moon-bhndness was due to the 

 wolf's tooth, and the first procedure in the treatment was its 

 removal. 



Now-a-days, however, the supposition is not tarried quite so 

 far, and the utmost that can be said is that the irritation of teeth- 

 ing may be an exciting cause of ophthalmia in animals whose 

 constitutions are hereditarily or otherwise predisposed to the 

 disease ; and the removal of supernumerary teeth, lancing the 

 gums, or the withdrawal of offending teeth, may very possibly be 

 followed by some remission of the ophthalmic symptoms. 



