Functionality in Equitation: Look At The Mouth

Dressage

Training Your Horse

A good mouth is calm, sensitive and relaxed with a reasonable amount of foamy ”lipstick” visible on the horses lips. It is a result of progressive training well done, which helps the horse to use his body in a healthy and balanced way through the levels.

The way we ride clearly affects the horse’s mouth, as the neck and the masticatory system have a close and important biomechanical connection. The frame of the neck affects directly the mouth and jaw functions. For this reason we should clearly care about a good posture and the frames we use in our daily training.

Contact Related Problems

Understanding different kind of contact related problems in ridden horses became one of my main interests in 2013 since I got to learn precise problem solving techniques from my trainer Colonel Christian Carde.

At a clinic in Finland he listed 3 commonly seen mouth types:

1. The dry mouth: the mouth is dry at the beginning, during and at the end of the work. The horse is usually tense and moving with stiffness.

2. The very foamy mouth: foam is found on the neck and shoulders of the horse. The horse can´t swallow normally because of quality of the contact, the frame or the tightness of the noseband.

3. The fresh mouth = the good mouth. The horse is relaxed and there is some saliva, like wearing a light foamy lipstick. The foam is evenly visible on both sides.

View of m. masseter, nerves and fascial structures
below the skin on the horses cheek

Then there are of course a lot of variations of these with different tension related symptoms. A tense horse may be restless or almost deadly quiet in the mouth, there may be different tongue, contact and neck related problems and often the rider ends up testing many different bit models and materials.

While it is good that there are options, usually the sustainable solution is found in good simple equipment and training techniques. Horses have very individual mouth and head anatomy, which means the equipment we use need to fit them correctly to avoid discomfort which can lead to stress and different compensations. The bit is one important part of good communication and well being of the horse, but this is only where the works starts.

A Closer Look at the Masticatory System

Upper jaw (left) is wider than lower jaw (right)

The equine masticatory system can be divided into passive (teeth, bony structures, temporomandibular joint) and active systems (musculature and nerves). Adult horses have 36-40, up to 44 permanent teeth. The bit is located between the incisor teeth and molars, at the bars that are located on both sides of the mouth. Horses have a wide upper jaw (maxilla) and the lower jaw (mandible) is narrower than the upper jaw. The tongue and hyoid bone are located inside the lower jaw between the cheeks.

If the horse becomes tense and is resisting the bit in any way, he will create tension in the facial muscles and fascial structures, tightening the m.masseter which is the largest muscle in the face. This will create tension in temporomandibular joint (TMJ) area, which is highly sensitive and important area for the balance of the horse. TMJ also affects the front limb movement and a painful TMJ may even be shown as front limb lameness, often combined with very sore neck muscles (often m. bracchiosephalicus and some other structures).

The TMJ also has a strong connection with the horse’s poll and the tongue which play an important role in the horse’s rideability and quality of the movement. Tension always affects all muscle chains in the body and it can change how nerves and other structures are able to work. Problems in the masticatory system are usually resulting from changes in how the system is loaded in training or daily life.

Tension on the Lower Jaw

Habits can make big changes that affect teeth and
thereby symmetry of the horse

If the rider uses too much or a too long period of pressure on the rein, it will create a lot of tension on the horses lower jaw. This kind of overuse of rein can cause direct damage where the bit is located, on the tongue or soft parts of the mouth and cheeks. Some horses will try to get behind the vertical in their frame because tension or pressure on the tongue and tension on the throat area affects breathing - they may try to create more room to breathe.

If the horse is grinding its teeth or constantly opening the mouth, it is also a very clear sign of tension or anxiety, that should not be accepted as only a bad habit and then masked by cranking the noseband.

Grinding the Teeth

Sometimes riders tell that their horse feels otherwise 'ok to ride', but he is still grinding his teeth. Grinding the teeth always creates a lot of tension and it can cause similar problems as bruxism does on human. This should not be taken lightly. There may be pain, stress or discomfort behind the behaviour, and this must be addressed carefully as this behaviour also causes more of the pain, stress and discomfort. It is very important to help the horse out of this habit, even if it may not always be easy to find the reason.

Light Frame, Behind the Leg

Diastemas are relatively common finding and possibly
related to contact problems

The horse can also be stiff in the mouth, jaw and neck even if the rider is not using strong pressure on the reins. The rider would usually feel that the frame feels fine, but the horse seems to become behind the leg. Riders often also tell that the contact is light, but this is a wrong kind of lightness. When this happens, the rein contact actually tends to become almost non existing and the horse is closing the frame too much, getting behind the vertical. This neck position changes the muscle function in the neck and changes the function of TMJ and the whole lower jaw and tongue.

It needs to be corrected by focusing on the basics: the quality of the rein contact (forward thinking hand), balance (opening the frame) and impulsion (horse in front of the leg) in training.

The key to better performance is to manage keep these sensitive areas as relaxed as possible during the training. I will give you some ideas in the next part of this series.