Horse teeth age will have between 36 and 44 teeth. All equines are heterodontous, which means that they have different shaped teeth for different purposes. All horses have twelve incisors at the front of the mouth, used primarily for cutting food, most often grass, whilst grazing. They are also used as part of a horse's attack or defence against predators, or as part of establishing social hierarchy within the herd. Immediately behind the front incisors is the interdental space, where no teeth grow from the gums. This is where the bit is placed, if used, when horses are ridden. Behind the interdental
Impacted wisdom teeth the mandible. Another study on 5000 army recruits found 10,767 impacted wisdom teeth. The frequency of impacted lower third molars has been found to be 72% and the frequency of retained impacted wisdom teeth that are free of disease and symptoms is estimated at 11.6% to 29% which drops with age. The incidence of wisdom tooth removal was estimated to be 4 per 1000 person years in England and Wales prior to the 2000 NICE guidelines. Wisdom teeth have been described in the ancient texts of Plato and Hippocrates. "Teeth of wisdom" being from the Latin, "dentes sapientiæ", which in