Discipline: Veterinary Medicine
Single examination of the dentition of 534 male and 551 female captive Philippine cynomolgus monkeys (Macaca fascicularis) was used to establish a method for age estimation in this species. The number of teeth as determined by gingival emergence and morphological type of the tooth were used as criteria in age determination. High correlation was observed between age and total dentition (r=0.92 for males and r 0.90 for females). Two methods for age approximation are suggested: (1) determination of most recently added tooth, and (2) age estimation using total dentition. The first method is more accurate than the second but certain problems exist when the permanent premolar and canines are observed to be the latest addition to the dentition due to their erratic time of appearance. On the other hand, the second method is faster but less accurate because of the wide age ranges involved when total dentition is used for age estimation. It is therefore suggested that the two methods be used in combination to obtain a more reliable estimate of the age of cynomolgus monkeys. Sexual differences noted include earlier appearance of deciduous lower canine teeth in females than in males, and the earlier appearance of the first lower premolar in the males than in females. Moreover, the permanent canine and third molar appeared earlier in females than in males.