Equine Dental Issues

A few of the most commonly occuring equine dental issues are detailed below.

Sharp Edges

Sharp edges known as enamel cusps will naturally develop over time as the horses teeth erupt. These sharp cusps will often cause soreness, lacerations and ulcers to the sides of the cheeks and to the tongue. Often horses with sores from these sharp cusps will find it painful to chew and they will give up and spit out a half chewed ball of hay. This is called quidding and is unfortunately a common occurrence.

Deciduous (Milk Teeth) problems

Between two and a half years and four and a half years the transition from deciduous (milk teeth) to permanent teeth occurs and concerns twenty-four deciduous teeth (12 incisors and 12 pre-molars). Often young horses have problems shedding the deciduous teeth which can a painful experience causing quidding, and difficulty masticating which can lead to bad habits such as head tossing etc due to the pain. Often deciduous teeth, otherwise known as caps, break in half because they have trouble being pushed clear by the erupting permanent pre-molar. These bumps are sometimes reffered to as teething bumps and will usually disappear overtime. (Generally these are not a problem so long as they are bi-lateral.) These bumps are sometimes reffered to as teething bumps and will usually disappear overtime. (Generally these are not a problem so long as they are bi-lateral.)

Between the ages of 2 1/2yrs and 5yrs it is most important to have the horse examined every six months by a BAEDT qualified member.

Wolf Teeth

Wolf teeth are vestigial teeth and come in many different shapes and sizes. Usually they are short crowned with a root two to three times the length of the crown.

These small conical teeth can often interfere with the bit and as a result they are often removed.This is due to the position of the tooth, which is normally just in front of the first upper cheek tooth on the maxilla (upper jaw) and occasionally on the mandible ( the lower jaw).

Wolf teeth in young horses (under 3) are usually easier to extract completely than wolf teeth in older horses. As the horse gets older the roots of the tooth ossify in the alveolar socket welding it self to the jaw bone.

Blind wolf teeth (unerupted wolf teeth) are usually problematic and are nearly always extracted.

Hooks

Hooks develop due to a misalignment of the molar arcades. This is commonly the result of an over-bite or under-bite (parrot mouth or sow mouth) of the incisor arcades. Unfortunatley for horses and other herbivores alike, the part of a tooth which is not in contact with an opposing tooth will not be worn down as it should do. This is how Hooks become dominant over time. Hooks can restrict the anterior/posterior and lateral movement of the mandible, and large hooks can cause extreme discomfort often leading to quidding, weight loss, choke and even colic.

Ramped Molars

Ramped molars are similar to hooks but have a more gradual slope to the tooth and can be found on the 1st lower cheek tooth or the last lower cheek tooth. Biting trauma can be caused by the soft tissue becoming pinched between the bit and the 1st lower cheek tooth. Ramps can also inhibit the natural anterior posterior movement of the mandible, this is particularly important in the ridden horse. Ramps can create problems to the molar arcade alignment and may put pressure on the temporal mandibular joint ( the hinge joint).

Excessive Transverse Ridges

Excessive Transverse Ridges are a series of washboard like ridges that occur across in the grinding function of the teeth,if these ridges become too exaggerated or irregular they will need to be reduced to a normal level.

Excessive transverse ridges can restrict the movement of the temporal mandibular joint, forcing the horse to open its mouth to get anterior/posterior and lateral movement of the mandible. This may sound unimportant but the correct function and movement of the mandible and temporal mandibular joint is vital for the horse. Whilst most would agree that normal ridging is important in the grinding function of the teeth, if these ridges become too exaggerated they will need to be reduced to a normal level.

Steps

A step occurs when the clinical crown of one cheek tooth is longer than those in the rest of the arcade. This usually occurs when a horse is either missing a cheek tooth, or is opposed to a damaged or impacted cheek tooth. The “step” in the molar arcade can restrict the lateral excursion, and anterior/ posterior movement of the mandible.

The Step should be checked on a regular basis and reduced as necessary.

Shear Mouth

Shear mouth is a result of increased table angles, due to poor mastication and chronic dental conditions. It is self perpetuating ( will only get worse if left untreated.) It can be on one side of the mouth or on both of the arcades and can be classified as a serious dental condition.

Wave Mouth

This term describes uneven wear of the molar arcades creating a roller coaster affect to the grinding table. This problem usually comes from a lack of dental attention as a young horse, impacted molars, which are slow or irregular in eruption or retained caps.

Wave mouth in horses seen at a young enough age, this problem can be corrected. However in aged horses this condition usually has to be managed.

Decayed Teeth

Teeth can become rotten or infected due to trauma, abnormal wear over a long period of time or old age. Chronic infection of the teeth can lead to general health problems, decayed upper cheek teeth can also cause infections of the sinus cavities (Sinusitis).


The History of Incisor problems in the

Domestic Horse

The incisor teeth are found at the front of the horses mouth and are used for nipping the grass. It is normal for the horse to have a set of twelve decidous incisors, which are replaced by twelve permanent incisors.

Ventral Curvature (Smile)

When the incisors are curved upwards at both sides when viewed head on, hence the term a ‘smile’.In this instance the lower corner incisors are too long, as are the upper central incisors. The problem with a smile, is that the incisors cam off each other and force the cheek teeth apart too early. It restricts the lateral excursion, and ‘grind’ of the cheek teeth. The problem is usually treated with the use of motorised equipment or in a mild case with the use of hand floats. However sometimes this dental condition cannot be corrected in one treatment.

Offset (Slant or Diagonal bite)

When looking at the incisors from the front of the horse, the incisors should look almost level. In some cases they are not and are clearly on a slant. This is called a‘slant mouth’. The horse with a slant has upper incisors which are too long meeting lower incisors which are too short on one side of the mouth. On the other side the problem is reversed. The result being a severe ‘slant.’ This type of situation is corrected using power work while the horse is sedated by the vet. It is also not uncommon for there to be quite severe cheek teeth problems, when the horse has slanted incisors. These problems have to be addressed at the same time.

Dorsal Curvature (Frown)

It is again corrected by realigning the incisor arcades, usually with the use of power tools.

Missing tooth

When a horse is missing a permanent incisor, or has a badly damaged incisor, a problem will develop over time. The problem being that as the incisors are erupting normally, they are usually worn by the opposing teeth. If one is missing the healthy opposing incisor can erupt into the gap. This can cause a blockage and can lock the incisors. This causes a blockage, and will ‘lock’ the incisors. As the healthy tooth continues to erupt, so the situation becomes worse. Horses with this problem may quid and will have to chomp their food with a vertical up and down hammering action. The treatment for this is to reduce the over long incisor with the use of motorised equipment. The tooth will always need regular treatment. The tooth will always need regular dental attention.

Overbite

Or commonly referred to as a ‘parrot mouth’.

This is not an uncommon problem, and is where the upper incisors protrude too far forward in relation to the lower incisors. It is also common to find large 1/6, 2/6 upper rostral hooks, and large 3/11, 4/11 lower caudal hooks on the molar arcades. In most cases a procedure known as an “incisor reduction” and corrective floating, is performed to restore anterior-posterior movement of the jaw, and to reduce pressure that this exerts on the Tempro-mandibular joint.

Underbite

Or commonly referred to as a “sow mouth” this is a fairly rare abnormality, and is where the lower incisors protrude too far forward in relation to the upper incisors. Again it is imperitive that this condition is managed on a regular basis.

Below: an example of an injury caused by a bit.