RESUMEN
The authors give a short orientation about the age related parameters of the incisors based on the literature. They examined the question of breed differences with respect to the age determination of horses in the different counties, especially in regard to the English Thoroughbred. In this context they present a new parameter as well as a new approach in data-processing. The cup depth and the yearly abrasion showed high breed-specificity. The relative abrasion indicated that the most intensive wear out is typical for the Thoroughbred. The cup depth and the yearly wear out were different according to the incisor's type in respect to the merged Thoroughbred populations of the two countries. The deviations observed in the cup depth can be explained by body size differences of the breeds. The degree of the absolute and the relative abrasion of the cup can also be associated with the early utilisation (racing) and with the intensive feeding (concentrate). The authors assume that the selection for the early utilisation of the English Thoroughbred resulted in an automatic change of the well inherited chronology of dentition; i. e. the earlier maturity of dentition. In of the bone system manifests also in the narrowing of the teeth. As the recent cup depth values deviate from the earlier ones, the authors suggest correcting the age of the disappearance of the cup from the current 6-7-8 years to 5-7-9 years for the English Thoroughbred.
