2. Conformation of Dental Arcade
Three-point balance refers to the correct
function of:-
THREE-POINT BALANCE 1. The incisors
PLUS EXCURSION 2. The molars
3. The mandibular (jaw) joint
Three-point balance allows normal jaw
movements to take place and is achieved
by:-
• The removal of hooks
• The removal of sharp points which develop
on the outside of the upper and the inside
of the lower premolars and molars
• Adjusting the line of the incisors
3. Conformation of Dental Arcade
• A purebred horse shows better conformation of the lower molar
dental arcade fitting with the upper dental arcade than a crossbred
horse.
• Crossbred horses are more likely to have aberrant dental arcades
with regard to the width, length and contours of the top and bottom
jaws.
• The angle of the head on the neck also makes a difference as to the
fitting of the lower jaw to the upper jaw.
• The factors alter the acceptance of the bit & the consequential
muscle development & action of the horse
4. The jaw joint
• (Temporo-mandibular), [unlike limb joints generally] are
paired.
• As with all synovial articulations they are subject to the
traumatising effects of misuse.
• Persisting pain in one side of the dental arcades will cause
asymmetric functioning of both but more so on the affected
side as the horse attempts to minimise this pain.
• Osteoarthritis pain follows with even greater and further
pain on masticatory movements.
5. • Lips (especially upper) Sense of touch and ability to feel
and so involved in identification of
foodstuff
• Tongue Rostrally Sense of touch and feel of ingesta
Sense of touch for presence of
Caudally ingesta and sense of taste
• Teeth (through alveoli and Sense of pressure on bite and so
recognition of need to chew
deeper to roots)
•
Sense of pressure especially of
• Gums (bars) bit; important site of rein aid
6. • Hard Palate Sense of consistency of feed from
pressure; and sense of pressure from
feel up to pain as from the bit
Sense of touch of food pressure
• Inner cheeks
Proprioceptor sensations
• Jaw Joints
7. Remember
A bridle, bit and reins in the ridden horse is for riding
• Never tie up a horse by the reins
• Never lead a horse for any great distance by the
reins, certainly never with them still
– Over the head and/or
– In the martingale rings
– A chiffney bit should only be used in skilled hands
8. • All living tissues will respond to careful and
sensitive conditioning.
• Epidermal tissues, skin and mucous membranes
will sooner or later accept the usual sensory
inputs and do so repeatedly without chronic
inflammatory reactions such as fibrosing and
hardening.
• Repetition becomes habituation particularly in
association with bit aids: the horse becomes
used to the contacts without losing the automatic
ability to remember the input message and to
respond to it almost reflexly.
9. • ‘Mouthing’ a horse requires patience and
‘gentleness’ to the extent that the responses to
the aids can become almost conditioned; the
horse is almost a ‘step ahead’.
• Memory of early training painful input can take
longer to forget.
• Any interference from pain in these areas and the
associated evasion of the aids will variably
influence the horse’s way of going even to
disobedience and further misbehaviour.
10. Certain features of structure are important
• The lines of the upper and lower arcades do not follow in parallel: The
upper curves outwards and the lower describes a two converging
straight lines
• The distance between bars varies with
o Breeds
o Individuals within a breed
o Left side to right side in an individual
o Between upper & lower bars
• These affect the effective ‘room for the bit’ and so subsequent applied
bit pressure
11. • Tongue size, thickness and width relative to the space between the
mandibular arms will affect the
Cushioning effect of itself and that of the palate’s
venous plexus
Protective spread over the lower bars. These differences will
also affect the ‘room for the bit’
• The distance below the lower bars is always less than that between
the enclosing fleshy (muscular) cheeks which must not be over
compressed by the bit cheek pieces onto the rostral cheek teeth by
fitting a too narrow a bit based on the bony intermandibular space ie
the bars.
12. • In severe and/or repeated traumas a thrombosis
of the blood supply to the thin layer of surface
bone with subsequent ‘death’ of a sliver of that
bone which now becomes a foreign body until
such time as it is naturally sloughed off or
manually removed.
• Such an injury is known as a ‘broken jaw’.
13. Fore Quarters Hind Quarters
No collar bone Bony
Attachments
14. • HEAD CONFORMATION → JAW JOINT PAIN
• → One sidedness
• → Head Tilt
• → Uneven back muscle development
• → Poor saddle fit
• → Hind leg lameness
