EXCESS OF LENGTH OF INCISORS OF UPPER JAW 137 



To determine the exact age, it is necessary to shorten, by the 

 imagination, the elongated teeth ; determine by a close exami- 

 nation what would be the form of the tables of the teeth were 

 they cut off to their proper length, what would be the form and 

 position of the cups and dental stars in such a shortened tooth, 

 and give to the animal the age which the alterations indicate. 



Cutting off incisors of great length in a young horse need 

 not be considered a fraudulent act on the part of the dealer, for, 

 while shortening of the long teeth of old age is a trick to deceive 

 the ignorant, who associate long teeth with great age, the short- 

 ening of the teeth of a young horse gives a table indicating a 

 greater age, and will not deceive the expert, who should always 

 examine any horse on purchase. 



EXCESS OF LENGTH OF THE INCISORS OF THE UPPER JAW. 



This anomaly constitutes what is commonly known as 

 parroUmouth (Figs. 145 and 146), on account of the analogy 

 in the appearance of the upper jaw to the corresponding beak 

 of this bird. The upper teeth may acquire a length of 2J 

 inches, and are frequently very much curved forward and down- 

 ward, while their posterior faces are worn away to a sharp bevel 

 by their contact with the inferior incisors. These latter are fre- 

 quently shorter. than normal, and the parrot's beak is formed by 

 the pincher and intermediate teeth, with only the internal border 

 of the corner teeth, while the rest of the latter is worn into a 

 deep notch. These deformities are frequently much greater on 

 one side of the jaw than on the other. 



In some horses five years old the upper jaw projects a line 

 or two in front of the inferior jaw, whilst the posterior surface 

 of the teeth in both jaws corresponds, which produces excessive 

 wearing of the posterior part of the upper incisors, leaving a 

 little line in front of their table, which predisposes to the formation 

 of parrot-mouth. Usually, however, parrot-mouth is only seen 

 in very old horses. It interferes more or less, according to its 

 development, in the prehension of food, especially with oats, as 

 the projection of the teeth interferes somewhat with the move- 



