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Horses Teeth

posted May 6, 2012, 7:12 PM by Claire Murray
Types of teeth in Mammals

When talking about teeth we can divide them into groups according to the pattern that the enamel is laid down and the type of crown they have Humans have BUNODONT teeth. They are characterized by cone shaped cusps that look like little volcanoes. The whole of the exposed crown of the tooth is covered in enamel in the same way as icing covers a cup cake

Horses have LOPHODONT teeth. The volcano like cusps have become confluent or joined to form lophs. If you look at the surface of a horse tooth you can see bands of enamel with softer dentine and cementum between the bands.








Fig 1. This is an upper molar from a 4 year old

Cattle and cloven hoofed ruminants have SELENODONT teeth. These teeth are similar to horses in that the enamel is formed in bands but the bands form crescents like the shape of the moon.

There are also differences in crown height: People have short crowned teeth that develop and erupt into full maturity relatively quickly and then they grow no more. These teeth are called BRACHYDONT and are designed to for soft food that causes little wear.

Horses have HYPSODONT teeth that are tall crowned. There is a generous surplus of reserve crown below the gum line that erupts at the same rate as it wears until this reserve crown has been used up at which time the tooth expires and falls out. This is a fantastic design nature has provided to deal with the abrasive effects of the tuff, dry food that horses have evolved to live in. It is also a very important point to remember because it is this characteristic that causes all sorts of problems for domestic horses.

Some animals such as rodents have teeth that are ever growing. It doesn’t matter how much they are used as long as they are supplied with nutrients they will continue to grow and erupt. These teeth are called HYPSELODONT


Position and types of horses teeth: Take note of this picture as the molars at the back of the mouth and incisors at the front of the mouth rarely get adjusted sufficiently, if at all by uneducated practitioners or if the horse is unsedated.


Incisors

If you part a horse’s lips, at the very front of its mouth you can see its incisors. A horse has 12 deciduous or baby incisors that are followed by 12 permanent incisors with six housed on the upper jaw and 6 on the lower jaw. These teeth are used for nipping or incising the food. If you view them at eye level, the line they meet at should be straight, giving the appearance of a smile. It is the incisors that are mainly used in ageing a horse using the set patterns of wear on the cups, dental star and enamel spot as indicators, along with Galvayne’s Groove, shape of teeth and hooks on upper corner incisors.














Canines

Behind the incisors are conical shaped teeth that are called canines. They are different from the other teeth in that they don’t hyper-erupt when not in wear and in fact we do not want them to ever come into wear. They are mainly found in males and their function is for tearing. In the wild, stallions will grab each other around the jugular vein, in the neck, using their canines and can cause serious injury. Obviously this is not something we want to happen in our domestic horses so these teeth are usually shortened and rounded to a suitable height.

The canines can also be known as: fighting teeth, tushes, fangs and bridle teeth. Sometimes they are mistaken for wolf teeth which is a serious mistake because unlike wolf teeth, canines have long curved roots that make them very difficult to remove. The only time they need removing is if they become broken or diseased.


Wolf Teeth

Wolf teeth are small vestigial (atrophied or functionless from the process of evolution) teeth that are not required any more. They used to be a grinding tooth millions of years ago, but have gone out of use due to a change in the diet of horses. It is very important that all wolf teeth are removed from ridden horses, even blind or un-erupted ones that are beneath the surface of the gum. This is because they are small and only have one root making them very sensitive. They are positioned right where the bit lies creating a painful situation for the horse that can be likened to you having a splinter and your clothing constantly brushing against it.


Premolars and Molars

At the back of the mouth are the premolars and molars. They are the chewing or grinding teeth and can collectively be known as the cheek teeth. It is important that they can meet together along the length of the arcade and that the full surface can be used for grinding. The wolf teeth are actually the first premolars but behind them there are three functional premolars in each arcade. They are deciduous teeth so they have baby teeth followed by the permanents which erupt at particular ages. Behind the premolars are three molars in each arcade. Molars are accessional teeth meaning that they have no deciduous predecessors. They develop as a permanent tooth from the beginning.

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