Equine Dentistry Flashcards
What the deciduous teeth in a horse?
Incisors and premolars
What the permanent teeth in a horse?
Incisors
Premolars, molars +/- canines
What is the orientation of equine dental anatomy?
What does this mean for their food?
Anisognathous orientation (maxillary and mandibular arches or jaws are of significantly different sizes), with mandibular jaw narrower than mandibular., Allows for effective grinding, but produces sharp edges over time.
Do horse teeth grow?
Tooth does not ‘grow’ so will eventually fall out, usually at 25 years +
Continuously erupt
How many deciduous and permanent incisors do horses have?
What is their function?
Incisors – 3 deciduous, 3 permanent, prehend food in the mouth
What is the iinterdental space and what is often there?
Interdental space containing canines, permanent only, variable number, possible fighting role? Space between incisors and cheek teeth
What is the wolf teeth?
How many is there?
Wolf teeth – vestigial 1st premolar, variable number (0-4), no role – get in the way, no functional role
How many deciduous and permanent premolars do horses have?
Premolars – 3 deciduous, 3 permanent, form one functional unit with molar teeth
How many deciduous and permanent molars do horses have?
Molars – 3 permanent
Horses are hyposodont - what does this mean?
Hypsodont – ‘high crowned teeth’ - Hypsodont dentition, meaning they are characterised by high-crowned teeth and enamel that extends past the gum line. This provides extra material for wear and tear. Enamel continues beyond gum level
What are horses teeth constantly doing?
•Constantly erupting (not growing!) (c.f rabbit teeth)
- 2-5mm eruption/yr
- faster in younger horses vs old horses
- disparity in eruption vs wear –> dental disease
A horse walks into a bar. The barman confuses idioms with jokes and offers him a glass of water, but can’t make him drink
What kind of crown do horse teeth have?
Long reserve crown
Which teeth sit in the maxillary sinus
Upper 08-11
Can vary - but important RE infection
Which parts make up the calcified dental tissue?
Cement
Enamel
Dentine
What is the cement of the tooth?
- Fills infundibulum and upper cheek teeth and surrounds tooth
- Produced by cementoblasts, 65% mineral, 35% organic, covers external surface and infundibulum, subgingival cementum is part of the periodontal ligament complex and living tissue. Cement secreted in response to growth and infection/injury.
- Forms part of periodontal ligament
What is enamel as part of dental anatomy?
What properties does it have and what makes it?
- Hardest substance in the body
- High tensile strength
- Brittle and hard
- Secreted by ameloblasts, 98% hydroxyapatite crystals and 2% keratinous proteins. Inert, cannot repair itself. Brittle, but high tensile strength. Dentine and cementum absorb shock and allows sharp edges to shred roughage. – completely inert, cannot recover if damaged
Which part of dental anatomy cannot repair itself?
Enamel
Inert, cannot repair itself.
Brittle, but high tensile strength
What material protects enamel?
What is it made by?
Dentine
- Elasticity and compressibility protects enamel
- Dentine secreted by odontoblasts, 70% mineral, 30% organic. Elasticity and compressibility allows protection of enamel. Dentine protects pulp during wear and growth.
What is the function of pulp?
What is different about pulp in horse teeth?
Supplies nutrition to the tooth – all teeth
Multiple pulp forms in equine teeth
What does the peridontium comprise of?
What is its function?
-Comprises all structures linking the tooth with
the supporting bone
-The periodontium includes the gingiva, periodontal ligament, alveolar bone, and cementum. The periodontal ligament functions as a “shock absorber” enabling the tooth to be firmly suspended within the alveolus while permitting a slight amount of movement.
What does dentine provide a barrier between?
Why is this important with dental treatment?
- Dentine provides a barrier between the pulp and the occlusal surface
- Important as the BIGGEST risk during dental treatments is indirect or direct pulpal exposure
- Pigments oxidise so superficial layers are brown
- Pigment reduces towards pulp cavity
When do permanent incisors (01-03) erupt in horses?
01: 2-5 years
02: 3-5 years
03: 4-5 years
When do permanent canines (04) erupt?
4-5 years
When do permanent premolars (06 - 08) erupt?
06: 2.5 years
07: 3 years
08: 4 years
When do permanent molars (09, 10, 11) erupt?
09: 1 year
10: 2 years
11: 3-3.5 years
What are some things you can use to age a horse by its dentition?
- Largely inaccurate – especially older horses
- Eruption times most accurate method
- Shape of corner incisor – another more accurate indicator of age
- <10y wider than long
- ~ 10y square
- >10y longer than wide
- Dental star
- Infundibulum/mark disappearance
- Galvaynes groove
- ‘Hook’ on corner incisors
- Shape of occlusal surface – oval à triangular
At what age do you get appearance of dental star on the following teeth:
01 (central)
02 (lateral)
03 (corner)
01 - 5 years
02 - 6 years
03 - 7-8 years
At what age do you get disappearance of cups on the following teeth:
01 (central)
02 (lateral)
03 (corner)
01: 6-7 years
02: 7-11 years
03: 9-15 years
At what age do you get marks worn out on following teeth:
01 (central)
02 (lateral)
03 (corner)
01: 12-15 years
02: 14-15 years
03: 14-15 years
At what age does Galvaynes groove appear on 03 (corner) tooth and when is it at full length?
Appears 10y
Full length of tooth by 20y
At what age does the Hook appear on 03 (corner) tooth?
7 years and 13 years
When doing a dental exam, what do you want to know from the history?
- Dental work history
- Previous dental problems
- Feeding habits – quidding (response to mouth pain in which the horse loses or spits balls of semi-chewed food stuffs out of their mouth), salivation?
- Bitting/riding problems – head shaking?
As part of the dental exam, you should do a full clinical exam - what are you looking for?
What should you observe?
•Full clinical exam
- Body condition – weight loss?
- Concurrent disease
- Visual and manual exam of head
- Asymmetry, swellings, halitosis, nasal discharge
- OBSERVE MASTICATION!!!!
-Should chew in both directions equally when observed
for several chew cycles (20:20)
-Figure of 8 pattern, equally on both sides of mouth
How should you manipulate the jaw when doing a dental exam?
What are you looking for?
- A normal lateral excursion is roughly the width of 1½
teeth (should be even in both directions) - As lateral movement continues and the grinding surfaces
of the cheek teeth come into contact, the incisors should
separate approx. 2–6mm - All dental exams - full mouth speculum with light source and mirror!
- Grasp bridge of the nose with one hand and the ventral mandible with the other, move mandible to the side and listen to cheek teeth. Jaw should move freely without locking to either side.