B. Permanent: 



First incisor (II) 21/2 years 



Second incisor (12) 3 V2 years 



Third incisor (13) 4 V2 years 



Canine (C) 4-5 years 



First premolar or wolf-tooth (PI) 5-6 months 



Second premolar (P 2) 2 V2 years 



Third premolar (P 3) 3 years 



Fourth premolar (P 4) 4 years 



First molar (Ml) 9-12 months 



Second molar (M 2) 2 years 



Third molar (M 3) 31/2-4 years 



(The periods given for P 3 and 4 refer to the upper teeth; the lower ones may erupt 

 about 6 months earlier.) 



The Incisive Arcades 



When the incisors are viewed in profile, the angle between the upper and lower 

 incisors becomes more acute with age. 



Schematic Drawing of Incisors, Irregular Wear 



Illustration depicts teeth of excessive length, which may have resulted from too-acute 

 angulation at an early age, improper wear, or maintenance of the horse of a soft diet. 

 Each line on the corner tooth represents approximately 1 year's grow^th. If table 

 (occlusal) surfaces of incisors indicate age of 10 years and teeth were as illustrated, 

 showing 10 lines, the age of the horse may be estimated as 20. (Number of lines added 

 to indicated age of table surfaces equals estimated age.) 



11-17 



