Practitioners must get along with the horse while performing (prophylaxis and equilibration) gnathological
procedures. These procedures are noninvasive, considered normal animal husbandry and revolve around
and are based upon improving the processes of deglutition and performance. Quite often we hear the terms
floating and leveling of teeth. I have a problem with these words because there are no straight lines in the
head of the horse, including the arcades of the teeth. Bones and teeth of the head are made up of arcs,
domes, and curves for support and strength. When most people talk about floating and leveling teeth they
really don’t mean we should float things flat and level things up but if we look in the dictionary this is
exactly what these words mean so a misunderstanding of the task begins.
Equine Gnathology Defined
Equine gnathology is the study of masticatory systems, including their physiology, anatomy, functional
disturbances, and treatment. Gnathology is doing extremely accurate prophylaxis and equilibration,
verifying the work as it progresses, applying all well founded gnathological principles, and rechecking
the work continually. The heart of equine gnathology revolves around efficient comfortable mastication
and optimum performance.
Natural Balance Dentistry® Paradigm
Natural Balance Dentistry focuses on neuromuscular equilibration, restoring bio-mechanical motion of
the jaw, bringing comfort and balance to the TMJ. From increasing muscle mass and maximizing
performance to optimum dietary absorption, from comfort to balance, it all starts with the mouth.
Anterior/Posterior guidance of the mandible is an important concept to understand when defining the
equine dental paradigm. A/P guidance is the forward and backward movement of the mandible, which
is supported by the length and angle of the incisors as well as the molar table surface to surface contact.
In Natural Balance Dentistry®, A/P guidance would be the forward and backward movement of the
jaw, supported by anatomically correct length and angle of the incisors as well as maximized surface to
surface contact of the molar tables to allow full bio-mechanical range of motion to the TMJ, making it
anatomically correct to the entire horse.
Another concept we refer to in Natural Balance Dentistry® is Centric Relation and Centric
Occlusion. This is the harmonious relationship between the occlusal surface of the incisors, molars and
TMJ, which produces stability, balance and guidance in all three during rotation and translation of the
mandible. Centric Relation refers to while the equine is at rest while centric occlusion refers to rotation
translation and having the incisors, molars and TMJ centered and balanced throughout.
In Natural Balance Dentistry® we address the incisors first to restore anterior/posterior movement and
centric relation/occlusion to the TMJ, which results in proper stabilization. Normal incisor table angles
should range between 8 -10 degrees off a parallel line drawn forward along the lower bars.
Maintaining incisor table angles may be performed in the following fashion:
1. Minor incisor table adjustment through filing
2. Incisor table angle change to increase occlusion of the cheek teeth allowing normal lateral
excursion and anterior/posterior (rostral/caudal) movement of the mandible through all head
positions.
3. Incisor table angle change and crown height reduction to increase occlusion of cheek teeth
allowing normal lateral excursion and anterior/posterior (rostral/caudal) movement of the
mandible.
Maintaining a proper table angle of 15-18 degrees, where the upper and lower opposing arcades have
matching curve of occlusion and curvature of Spee and Wilson, allows the occlusal surfaces to meet
and masticate food particles through use of parallel matching biomechanical planes.
As mentioned previously, the curvature of Spee and Wilson will correlate to the inclination of the
arcades. It is this inclination of the teeth which creates stability and guidance. The size of the curve
will produce angles that are anatomically correct for that particular horse.
All gnathological equilibration should strive to accomplish a more perfect occlusion of the cheek teeth
and incisor batteries during engagement while:
1. Enhancing maximum lateral translation and anterior/posterior (rostral/caudal) movement of
the mandible.
2. Enhancing the process of swallowing, food movement and comminution through the cheek
teeth batteries.
3. Enhancing performance by alleviating any painful conditions.
4. Maintaining natural battery and arcade crown height and table angles that complement
individual biomechanical actions of the bony joints and related tissues of the head.
Dental equilibration should not prematurely age any of the dentition. The paradigm for dental
equilibration should be based on wear and abrasion of horses’ teeth in their normal environment,
meaning the environment in which they evolved. For instance, hard dry native grass and a dry climate
where they would be grazing throughout the year.
Acurate Aging of Horses
Competent and accurate aging is imperative for the equine gnathological practitioner. Without accurate
aging, costly mistakes often occur causing much pain and trauma to the horse and worry for owner and
handlers. Excessive recovery times often interfere with planned activities for many individuals. It is
difficult to perform proper and competent gnathological procedures without accurate aging of
individuals.
Aging horses correctly is important for many reasons. Foremost is to determine individual function,
state of development and wear for any given individual. Is the animal old enough to perform the
desired tasks and activities? Is the individual too old to perform the desired tasks and activities? Do the
tasks at hand fit the particular individual? Types of care and maintenance normally vary with age of the
individual. What will we feed and how will we treat any given individual? How old is it? How much
does it weigh? What is its overall condition?
Another important reason for understanding dentition development and the dental progression is the
area of overall strength and soundness of the individual. When teeth deviate from normal patterns, you
can bet the horse is at risk in some form. Primary teeth retained beyond normal shedding times may
indicate insufficient or unbalanced mineral intake. Information from the teeth paint a historical picture
for each individual. Learning to interpret the pathology of this dental puzzle through understanding of
the teeth and correct aging should be every practitioners goal.
Finally, it is important to know the accurate age of a horse so that you do not inadvertently take off too
much of the crown, and by doing so, potentially shorten the lifespan of the horse by prematurely taking
years off a horse's utilization of their teeth. Many times when you look at a horse 25 years of age you
will see worn out tables on the molar teeth. There is no reserve crown left to erupt into occlusion. When
the horse runs out of reserve crown it is out of true grinding power for the root of the tooth is made
mostly of dentin and cementum. This material is too soft to grind the food properly so with older
horses, you may want to do very little, if any, dentistry.
Principles of Balance & Equilibration
Careful visual observation is paramount before practicing dentistry on any equine regarding symmetry
versus asymmetry. The way I look at this is to imagine all twinning parts laterally from the vertical
medial facial plane; they should be mirror images of each other, typically meaning eyes, ears, nostrils,
muscles, bones and other physical features should balance anatomically from side to side.
Asymmetrical features give away limiting physical attributes that often involve varying dental
pathologies. External palpation techniques involve the touching of various anatomical body parts to
determine variations in pain, sensitivity, tone, size and shape. Unilateral muscle enlargement in any
individual pairing muscle of mastication may indicate dental involvement. Typical situations would be
one masseter, temporalis or pterygoid muscle larger than their counterpart.
The Stomatognathic System
The stomatognathic system is a complex chain that involves the teeth and dento-alveolar
joints, temporo-mandibular joint (TMJ), the skull, jaw, hyoid apparatus, sternum and all of their
muscular and ligamentous attachments and nerves, including proprioceptors involved with
balance and posture. Functionally, the connections of the brain’s tough coating to the skull,
first two cervical vertebrae and associated structures can mechanically engage the remainder
of the spine through to the sacrum, which is the site of the most distal dural attachments.
Therefore, abnormalities of skull and TMJ function can potentially have repercussions for
locomotion and posture far beyond the direct inputs to the vestibular centers of the brain from
the sensory nerves of the TMJ. If the posture and movement of the horse is altered in this
way, it can create compensatory changes throughout the horses' entire body, affecting him
from head to toe.
The TMJ is supplied with a lot of nerves, because of its dual function in mastication and as a
contributor of postural information. The highest concentration of mechanoreceptor (sensory
nerves that report shape change) cells is found in the periphery of the disc and its
attachments. The articular surface of the equine TMJ is functionally concentric with the
curvature of Spee, which is the complex curvature of the occlusal surfaces. The most
profound implication of this relationship is that any change made in the curve of the occlusal
surface through human intervention will result in neurologic adaptation, cartilage and bone
remodeling in the TMJ and concurrent functional changes in the entire stomatognathic
system. These changes may affect head position, center of gravity and balance as receptors
reset in response to changes in jaw movement via the lateral ligaments to the joint capsule.
This proprioceptive (position signaling) array, similar to that found in the soles of the feet and
upper cervical muscles, suggests that data about the position of the disc and forces acting
upon its capsular suspension system are used by the central postural system to perform
balance and righting tasks.
Basic Floats
Basic floats or removal of points are detrimental to the whole horse because doing so may
result in diminished angulation of the molar arcades, resulting in lack of equilibration and
occlusal surface. Additionally, if the incisors are not addressed, that would compromise
centric relation and occlusion.
By simply doing a basic float, you can diminish inclination/angles, which affects the bite plane
and centric relationship. It also affects neurology by creating a lack of occlusion to the
arcade, which sends partial/no proprioception to the proprioceptors. From there, it extends to
the meridians which translate to the rest of the body. It can create issues with mastication,
terminating with colic, choking and improper manduction. Malocclusion creates instability to
the TMJ which affects performance and balance.
Gnathological Related Training Issues
Training Issues:

Reduced Air Flow From Dental Cysts

Excess Pressure on Tongue, Bitting Issues

Improper Head Sets

Due to locking and blocking teeth

Horses can’t round up or flex at the poll

Poor Disposition and Temperament

Retained Caps

Wolf Teeth

Hooks and Ramps
In summary, most equine dentistry involves prevention. If the gnathological work is performed on a
timely basis , the maintenance process is simple, and major health complications can be avoided. Each
horse is an individual and Natural Balance Dentistry® considers the whole horse and all of its
environmental factors in developing a maintenance plan. Most horses that have a good experience with
gnathological practice look forward to the next session and even try to help the practitioner.
Finally, financial savings for the client can be incredible in the long run when equines are properly
maintained. Properly maintained animals will have:
1. Reduced pain and suffering
2. Lower feed costs
3. Less frequent injuries to riders, drivers and others
4. Live pain free longer lives
5. Less stress due to oral pathology
6. Better attitudes