Canines

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Canines are the fighting teeth in males horses, not to be confused (as it often the case) with wolf teeth. The canines are generally much larger than wolf teeth and are situated in the interdental space closer to the incisors than the premolars. They are less common in mares but if present are generally much smaller than those found in males, though I have met several robust type mares with a full set of impressive male canines! Due to the fact they are the only teeth in the horse’s mouth that are not designed to occlude with its opposing partner, (the lowers sit in front of the uppers), they tend to become very long and sharp. This can squash and lacerate/scar the tongue. They also are inclined to accumulate tartar which if left untreated can lead to gingivitis and further down the track periodontitis.

Wolf Teeth
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Wolf teeth are relatively small, shallow rooted teeth, situated at the beginning of the molar arcades. They are more commonly found on the upper arcades but can also present in the lower arcades. Not all horses have wolf teeth, but if they do, they usually have erupted by the time the horse is 18 months old. Extraction of these teeth is highly recommended, if you are planning on using a bit in the horse’s mouth, due to the fact that the bit will lie directly on the wolf tooth area – interfering with the bit pressure and in many cases causing head flicking, tilting and general discomfort and resistance to any contact when being ridden.

Incisor Issues

Wedge/Diagonal Bite
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An offset or diagonal bite line on the incisors, visible when viewing the teeth, front on. This hinders unilateral excursion (sideways movement) of the mandible, which limits the horse’s flexion, as well as its ability to masticate.

Ventral /Dorsal Curve

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Also referred to as a “smile” or “frown”. This is where the outer corner incisors have an upward or downward curve to the occlusal surface. In both cases bilateral excursion is limited which in turns affects performance, and reduces proper mastication.

Missing or Supernummary Dentition

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Absent teeth can occur as a result of congenital defects or due to direct trauma to the mouth. Traditionally, the opposing teeth erupt into the diastema, resulting in limited excursion of the mandible, and subsequent performance problems. Similarly, supernummary or extra teeth can also occur due to congenital defects or direct trauma to the mandible or maxilla at a young age, resulting in damage and damage to the permanent tooth buds.

Retained caps

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This term is used for deciduous teeth (often referred to as baby teeth) that do not shed at the appropriate time. This can be a common occurrence in some types of horse; miniature horses in particular, due to their smaller head size. Retained baby teeth can cause considerable discomfort to the young animal and hinders the natural balance of the horse’s mouth.

Overbite/Overjet

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This is where there the upper incisors protrude over the lower incisors. An overjet is subtle and means there is partial occlusion of the upper and lower dentition. Where an overbite occurs there is no contact between the upper and lower arcades – also commonly referred to as “parrot mouth”.

Underbite/Underjet

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This is where there the lower incisors protrude over the upper incisors. An underjet is subtle and means there is partial occlusion of the upper and lower dentition. Where an underbite occurs there is no contact between the upper and lower arcades – also commonly referred to as “sow mouth, or monkey mouth.”

All of bite issues prevent the jaw from moving freely. The longer this remains uncorrected, the more severe it will become, due to corresponding hooks, ramps and transverse ridges of the cheek teeth arcades. These malocclusions place a downward and backward pressure on the mandible, creating pain and discomfort in the temporomandibular joint (TMJ).

Overcrowded Incisors

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This problem is mainly seen in horses with small/fine heads – predominantly miniature breeds, sometimes Arab and Welsh mountain breeds, where there quite literally isn’t enough space for the permanent teeth to erupt correctly, and so the result will be overlapping of teeth. The horse’s mouth is specifically designed so that all the teeth have an opposing partner to grind against (the exception to this are the canines, see below). If overcrowding occurs it will result in limited function of the mouth. Furthermore food will collate in the diastemas and folds which will lead to gingivitis and possibly periodontal disease later on.

Expiring/Aging Incisors

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As horses mature and reach their 20s their teeth will show signs of wear and as the eruption of the teeth slows, it is common that some teeth may expire. Whilst this is a natural progression of an older mouth, it is important to keep the rest of the mouth as balanced as possible and if teeth loosen it is vital that it be extracted in order to return comfort and function to the horse’s mouth.

Molars


Hooks
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This is a point or peak which most commonly is found on the upper premolars (the first large tooth in the cheek arcades). Varying in size as you can see from these photo examples.

Ramps
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These are ski jump like points that are commonly found on the last molar in the lower cheek arcades

High/Protuberant Teeth
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A distinct bump or large tooth in the cheek arcades, where one tooth erupts longer than the adjacent teeth. This often arises due to retained deciduous teeth, missing teeth or large hooks and ramps.

All of the above issues inhibit anterior-posterior movement of the jaw as well as effective mastication. The longer this remains uncorrected, the more severe it will become. These malocclusions place a downward and backward pressure on the mandible, creating pain and discomfort in the temporo-mandibular joint (TMJ).

 
© Amanda Winstanley