Dentistry2018-12-20T13:09:27+01:00

Dentistry

Routine monitoring of the oral cavity and the teeth is most important to maintain the health of your horse’s mouth. Through preventive monitoring, problems in the horse’s mouth can be recognized and treated at an early stage. Clinical signs of a dental problem are usually only shown when horses can no longer deal with the situation. At that point, the problem is often already in an advanced stage which makes treatment more difficult and extensive.

Removal of sharp points is surely beneficial to the horse and can easily be done without sedation. But there is a lot more to equine dentistry than this! The purpose of a dental treatment is to make sure that all teeth are wearing evenly and with the same amount of pressure.

During a proper dental treatment the dentition is balanced or equilibrated. This ensures that all teeth are in contact and that pressure and wear are evenly divided while eating. In this way the teeth will last longer and thus, the horse will live longer. Correct equilibration also ensures freedom of movement of the mandible relative to the upper jaw. This results in a functional and comfortable mouth so the horse will feel and perform better.

Balancing a mouth is not easy, it requires theoretical and practical training, experience and more advanced practical training to become good at it. Also it requires a wide variety of instruments to do a good job.
In order to perform a proper examination and treatment, it is almost always necessary to have the patient sedated. When sedated, the horse becomes a bit dull and the jaw muscles relax. The horse is calm and the head is not moved as much. In this way a better and safer treatment for horse and vet are ensured. Also, at the end of the treatment, the precision work of equilibration can be better checked when the patient is sedated.

During treatment, it is important to work carefully and controlled in order to only remove tooth material where this is needed and to prevent opening of the pulps, which contain blood vessels and nerves of the elements. If a pulp is accidently opened, it must be treated and sealed to prevent infection and possible disease of the element. Clinical signs of disease due to opened pulps are often not clinically visible until years later. At that time, therapy by means of an extensive pulp treatment or extraction of the element are often the last treatment possibilities.

Unfortunately, many horse owners still assume that performed work without sedation was optimal. Years later however, on many of these patients dental-related problems are diagnosed that could have been treated a lot sooner.

In order to perform a thorough oral examination the need of a number of basic instruments is straightforward.

First of all, a full mouth speculum with which the mouth is opened by means of two plates on the incisors is necessary. In the past, one often used a spiral mouth gag that was pushed between the premolars. Especially when this instrument is made out of metal, the risk exists that too much pressure from the jaws on the instrument cause a molar to fracture. With the use of a full mouth speculum, the oral cavity can be examined completely and the left side of the mouth can easily be compared to the right side. A bright light source is also important for a thorough oral examination. Cheek teeth can also be palpated manually but to have a closer look at emerging problems such as caries or periodontal disease, a good light source is crucial.

To have a closer look at caries, periodontal disease and open dental pulps one can make usage of a dental mirror and probes in various types and sizes. These instruments can also be used to remove decayed food material from diastemata between teeth.

Instead of a dental mirror, nowadays more and more use is made of a dental camera, or dental scope. Cameras or scopes have been used for quite some time for examination of the respiratory tract and stomach and during joint -and abdominal surgery. Next to being able to have a closer look in the mouth, the dental scope allows other people to look in the mouth via a screen and also images of clinical findings can be made and saved. The dental camera also improves the accuracy of an oral examination, it is very useful when performing surgeries such as tooth extractions and during endo-treatments.

When a serious problem is diagnosed during an oral examination it is often advised to make X-ray images of the area in question. Using an X-ray image, structures located in the alveolar socket and structures surrounding the elements can be viewed and evaluated. X-rays of the horse’s head (teeth and sinuses) are some of the hardest images to take and to evaluate.

When still in doubt concerning a problem after X-rays, it is useful to make a CT scan of the horse’s head. Today, a CT scan can be performed on the standing horse under sedation. Although it is a relatively expensive procedure, a CT scan gives a lot of information about structures in the horse’s head with which most often a correct diagnose can be made and proper therapy can be started/performed.

If an element needs to be removed from the oral cavity, first is started with a normal oral extraction via the oral cavity. The relevant element is loosened from its surrounding structures such as the mucous membranes and the connection bands between the tooth and the alveolar bone. As soon as the element sits loose enough in the tooth socket, it can be extracted using an extraction forceps.

Fractures of the clinical crown of a tooth can be found during a dental check and it is recommended to have such an element examined more closely. During the oral extraction of a abnormal, rotten tooth it can also happen that the clinical crown fractures. If the clinical crown of a cheek tooth is fractured, a normal oral extraction becomes difficult because extraction forceps can no longer be placed on the tooth. In case of a fractured incisor it is most often still possible to extract it using elevators to loosen and remove the element.

In the absence of the clinical crown of a cheek tooth, other extraction techniques need to be applied. During a minimally invasive buccotomy a small incision is made in the cheek thru which a portal (working channel) into the oral cavity is created. Through this portal the element can be loosened. Next, extraction can be performed by placing a long screw into the tooth via the portal. If this technique fails to work, the tooth can be segmented into several pieces via the working channel which then can be removed piece by piece.

Another approach is the minimally invasive trepanation and repulsion of the tooth. A small hole is drilled into the jaw towards the apex of the element. Next, a thin Steinman pin is placed on the tooth and by means of pressure the tooth is pushed into the oral cavity.

After extraction, it is important to check the tooth socket properly so that no fragments remain in it. The socket must be well taken care of after extraction so that optimal healing of the ‘wound’ will take place.

Which technique is used depends on the situation, but the goal of a successful extraction is the removal of the entire element with as little damage as possible to surrounding structures. In this way, the risk of complications is minimized.

Today, almost all extractions can be performed on the standing horse under deep sedation and with the usage of nerve blocks.

EOTRH stands for Equine Odontoclastic Tooth Resorption and Hypercementosis. It is a disorder of the incisors and sometimes the canines and first premolars are affected as well. It is a disease that is mainly seen in older animals. Compared to other breeds EOTRH is diagnosed more often in Icelandic horse.

EOTRH is a progressive disease that slowly develops. The outer incisors are almost always affected first after which the other incisors are affected as well. Symptoms of the condition include, inflammation of the gums (retraction, red colour, fistula), increased amounts of tartar on the elements, movable teeth, thickening of the roots, increased salivation and halitosis (stinky breath). Horses often have chronic pain which make biting into dry bread or carrots more difficult.

The disorder is characterized by two processes which manifest themselves in and around the incisors. First of all, resorption of tooth material by certain cells (odontoclasts) occurs from within the teeth. This causes the teeth to become brittle and fracture very easily. In the other case, certain cells (cementoblasts) start producing large amounts of cementum around the roots. These processes can be seen independently or as a combination of the two.
The exact cause of EOTRH is not yet known. It is known that an autoimmune factor plays a role, and that increased amounts of certain bacterial colonies, the ‘Red-complex’ bacteria, are present around the gums of affected elements.

Unfortunately, there is no drug treatment to cure the condition. Progress of the disease can at an early stage be slowed down using anti-inflammatories, anti-inflammatory mushrooms, antibiotics and regular cleaning and disinfection of the teeth and gums. Pressure on the incisors can be reduced with an incisor correction. Because clinical signs are often only seen at a late stage of the disease, the only treatment option is extraction of the affected elements.

After removal of the affected elements (which may be a couple or all incisors), horses very quickly learn to eat without these teeth. Concentrate food, hay but also grass will be eaten without any difficulties. Before performing the surgery, it is important that the rest of the teeth are well equilibrated because these remaining teeth will have to take over the pressure of the removed elements. By eliminating the chronic pain, after surgery, the patients show much more ‘joie de vivre’ which is reflected in the behavior of these animals.

Periodontal disease is a condition in which the supporting tissues around the elements (soft tissues such as the gums and periodontal ligaments that attach the elements in the alveolus) are inflammed. Periodontal disease is caused by micro-organisms which cause infection and inflammation. The condition can be divided into different stages of severity. If the inflammation is not treated in time it will cause pain in the mouth. Horses start to smell from their mouths and show difficulties while eating. Often, they start quidding during which cigar-like rolls are made from the hay while chewing. Rolls are dropped out of the mouth and can be found in the stall.

In horses, periodontal diasease is mainly secondary caused by abnormal wear of the dentition and diastemata. A diastema is a small gap between two elements in which food material gets stuck. Present bacteria increase in number and start fermenting these food materials and cause inflammation.

Periodontal disease is first treated by balancing the mouth and by treating present diastemata and possibly formed pockets. Infected areas are cleaned with dental picks and rinsed with water. If necessary, diastemata are mechanically widened preventing food to get stuck between the teeth. After thorough rinsing and disinfecting the diastemata can also be filled. After treatment, the patient can receive antibiotics and anti-inflammatories to a certain period of time. In extreme cases, the periodontal disease is in an advanced stage, in which the only solution is extraction of the element. This is especially the case when the element is movable.

Relatively new within the field of equine dentistry is the prophylactic (preventive) treatment of infundibular necrosis or caries. The cheek teeth in the upper jaw of the horse all contain two infundibula (dental cups) which are filled with cementum. Cementum is the softest tissue within an element. When food and bacteria are pressed into the cementum, a small cavity can be formed by fermentation processes. At first this does not look dramatically but when the fermentation process continues, the cavity gets bigger and more food is pushed in. Produced acids during fermentation eat their way into the infundibulum. The element becomes weaker and the probability of a fracture during chewing increases. Also, the infundibular necrosis can extend towards one of the pulps, cause pulpitis and possibly a tooth root abscess (apical infection).

In order to prevent further decay the infundibulum can be treated. Treatment is similar to caries treatment in humans. Abnormal tissue is removed using a drill, the cavity is disinfected and filled. Results of this treatment look good so far and during the upcoming years, this treatment will be applied more and more.When a pulp has been opened, whether due to trauma or during a too aggressive dental treatment, it is possible to save the element by performing a pulp treatment. Depending on the time between occurrence and treatment part or all the pulp tissue needs to be removed from the root canal. The canal is treated, and closed so that food and bacteria do not get the opportunity to cause an apical infection. If a pulp remains open, it is likely that the element eventually will have to be extracted.

With respect to acute opened pulps, it should be clear that the more quickly a good treatment is performed, the better. The longer the time between occurrence and treatment the more extensive treatment will be. At the same time the chance of success is reduced. An acute opened pulp must therefore be seen as an emergency.

The sinuses of the horse are made up of several communicating compartments on each side of the head. They communicate with the nasal cavity via two small passages. In case of a sinusitis, one or more compartments may be involved.

In order to clarify the cause of the sinusitis, or to treat the sinus, a small hole can be made through the skull into a sinus compartment. Next a small camera (endoscope) can be used to examine different compartments. Abnormal tissue can be removed through the opening and a catheter can be placed to flush or treat the sinus for a few day days in order to improve the healing process.\