Equine dentistry

Question 1

Adult horses have ? teeth.

Each of the 4 quadrants have?

Answer 1

Adult horses have 36-44 teeth.

Each of the 4 quadrants have:
* 3 incisors
* +/- 1 canine (usually only stallions, geldings, not often mares)
* +/- 1 wolf tooth
* 3 premolars
* 3 molars

Juvenile horses have 24 deciduous teeth:
* 4x 3 incisives
* 4x 3 premolars

Question 2

Juvenile horses have ? deciduous teeth.

Answer 2

Juvenile horses have 24 deciduous teeth:
* 4x 3 incisives
* 4x 3 premolars

Image of adult horse.

Question 3

Eruption of deciduous teeth at what age for which teeth?

Answer 3

Incisors:
* 01 incisors - 8 days
* 02 incisors - 8 weeks
* 03 incisors - 8 months

Premolars:
* 06
* 07
* 08
All Between birth and 2 weeks of age.

Foals don’t have deciduous canine teeth or back molars. Wolf teeth can erupt at 6+ months old and they do not have deciduous predecessors.

Question 4

Eruption of permanent teeth in young horses at what ages for which teeth?

Answer 4

Incisors:
* 01 2,5 y
* 02 3,5 y
* 03 4,5 y

Canine:
* 04 4-5 y

Wolftooth:
* 05 6+ months

Premolars:
* 06 2,5 y
* 07 3 y
* 08 4 y

Molars:
* 09 1 y
* 10 2 y
* 11 3,5 y

Question 5

anisognathia

Answer 5

the upper and lower jaws of the horse have a different width

Question 6

Horse teeth Adaptions to eating grass include:

Answer 6

• Occlusion surface is uneven
• Teeth are tightly next to each other forming one unit
• Upper jaw is wider than lower jaw
• Occlusion surface has an angle
• Interdental space: lengthens the nose to allow
  screening for predators while eating
• Hypsodont teeth
• Can use one or the other side of the mouth for
  mastication.

Question 7

Anatomy of the hypsodont horse tooth compared to small animal brachydont teeth.

Answer 7

In horses, dentin is exposed and this is normal. Dentin is found on the occlusal surfaces. In small animals dentin is meant to always be covered by enamel.

In horses, enamel invaginates between cementum and dentin. In small animals it def isn’t so.

In horses, cementum runs deeply, centrally in the tooth. In small animals cementum is only found around the attachment areas of the teeth roots.

Question 8

Equine tooth height?

Describe equine tooth wear.

Answer 8

• Very long→ 10-12cm
• Reserve grown under the gingival line→ emerges from bone (“grows”) according to wear.
• Wears during eating → about 2-3 mm/year.
• If very short reserve grown left→ teeth loosen (this is expected with age).
• Decreased roughage/more concentrates lower the rate of wear due to less side-to-side movement but can result in more overgrowths, more sharp points, excessive angulation (shear mouth”).

Question 9

Tooth anatomy
* Pulp =
* Dentine =
* Enamel =
* Cementum =
* Infundibulum =

Answer 9

• Pulp = innermost structure; contains nerves and vessels
• Dentine = surrounds and protects tooth pulp; main
  structure of tooth.
• Enamel = strong, but brittle; between dentine and
  cementum which protect it. Does not recover if damaged. Allows to grind high-fiber food.
• Cementum = outer layer; bone-like structure. Covers the crown and responsible of dental attachment to alveolar socket .
• Infundibulum = a cup or funnel shaped invagination of enamel on the occlusal surface of equine incisor and maxillary cheek teeth. NOT in mandibular teeth.

Question 10

Infundibulum: invagination formed by
enamel; filled with cementum. What’s the point of these?

Answer 10

• Increases the occlusal surface and
  makes tooth stronger.
• Only in maxillary premolars and molars and incisors
• 2 cups in each tooth in each (see image, marked IC)

Question 11

Describe horse teeth Occlusal surfaces.

Answer 11

Horse teeth occulsal surface is highly uneven naturally. Should never be levelled, unless clear irregularities, wrong angulation as this will result in unnecessary wear and these are necessary for food-grinding.

• All dental materials have different hardness:
  enamel → dentine → cementum
• They wear at different speeds too:
  cementum → dentine → enamel

Question 12

Oral examinations should be conducted on what horses when?

Answer 12

Every horse from 2 years old onwards.
As a rule: at least 1x per year per horse.

Young, old, severe pathologies should be examined
every 6 months.

ALL horses need check-up and care.

Question 13

The only was to assess equine dental health is to?
Why?

Answer 13

The only was to assess equine dental health is to sedate, and get inside the mouth to have a proper look.

A Good BCS and normal eating pattern do NOT mean all is well and that there’s no issues or need to check on the horse’s teeth.

Obvious problems equal severe pathologies.

Question 14

“My horse is under 2 years old. Do its teeth need floating?”

Answer 14

• Yes!
• More often than adults→ mostly every 6 months until 5 years old is recommended.
• Youngsters often have teeth with very sharp edges (cause buccal mucosal ulcers).
• Teeth are changing from deciduous to permanent.
• Removal of wolf teeth is advised (might interfere with bit use).

Question 15

Describe wolf teeth.

Answer 15

• Rudimental first premolars
• Not in all horses
• Erupt between 6-18 months
• Sometimes up to 24 months
• Sometimes “blind” (say below the gingiva without eruption, these need removing)
• Can be in Upper or lower jaw, More often in upper. Some horses can have all four wolfteeth present.
• Uni-or bilateral
• Removal before training is common.

Question 16

Describe Removal of wolf teeth.

Answer 16

Mostly an easy, short procedure.

Vaccination status should be checked beforehand. Vaccinate against tetanus if not already vaccinated.

• Done in Sedation
• Use Local anesthesia
• NSAIDs
• +/- nerve blocks (infraorbital/mandibular)

Using elevators and luxators, detach tooth from gingiva. NB! Palatine artery at risk from elevators, be careful. Cut the periodontal ligament.

Use forceps but Not too early and use them As close to the root as possible. Jiggle and remove. Check that root is intact. Check the alveolus with a mirror.

Take your time: easy to break the root (try and dig out with currette or a small piece might just be left behind if it won’t come out).

Horse should be 2 weeks without a bit while they heal.

Question 17

Answer 17

not wolf tooth, this is an overgrown hook of 06

Question 18

Oral examination procedure: preparation. (7)

Answer 18

• Age and use of the horse?
• Problems with eating, in training?
• Previous dental history.
• General clinical examination
• External evaluation (packing food, facial symmetry, LN-s etc.)
• How is the horse eating?
• Give sedation using Xylazine/detomidine +/- butorphanol.

Rare side-effect of xylazine is overt aggression. Combine with butorphanol to avoid this reaction. Or just use detomidine.

Question 19

Oral examination steps. (8)

Answer 19

• Evaluate incisors
• Apply mouth gag
• Flush the mouth
• Inspect the whole oral cavity with dental mirror, probes.
• Work on aka file down sharp edges, irregularities, other pathologies.
• Flush again, check teeth again
• Withold food until sedation wears off (approx. 2 hours)
• Do documentation, recommendations for future tx.

Question 20

Minimal equipment required for equine dentals. (6)

Answer 20

• Good source of light
• Mouth gag
• Dental mirror – you can’t see unless you look and you can’t look without a mirror!
• Different probes, explorers
• Diastema forceps
• Headstand/dental halter (needs hanging up) (these are for fixing the head into place)

Question 21

Different equine dental speculums.

Answer 21

McPhearson
Millenium
AlumiSpec (expensive but very light and reliable)
Conrad (type at EMU)
Capps
Gunther (offset)

Question 22

What are these?

Answer 22

the half moon ones are usually better cause older horses’ incisors can be quite uneven so they stay on these better.

the wiggly ones at bottom right are used when you need them off the incisors.

Question 23

Answer 23

dental halter

Question 24

Answer 24

dental head stand

Question 25

Oral exam: describe endoscopy. (5)

Answer 25

* Allows better visualization of pathologies. * Allows to show findings to owner. * Allows to save images/video and compare later. * Simplifies referral cause you have images to forward. * Irreplaceable during advanced procedures (e.g. endodontics).

Question 26

Which upper molars are connected to the sinuses and which sinuses?

Answer 26

The first 2 upper molars are not connected to the sinuses, the next 2 are connected to the rostral sinus and the last 2 are connected to the caudal sinus.

Question 27

Describe Hand floats. (4)

Answer 27

* Suitable to use if you only have few dental patients and mostly good dentition. * Many different types of hand floats (see image). * Careful: easy to damage mucosa with these. * Even if you travel with motorized equipment, always keep some hand floats on hand due to tight mouth/limited space e.g. ponies, last molars.

Question 28

Describe Motorized rasps. (2)

Answer 28

Irreplaceable if you have a bigger amount of dental cases and more severe pathologies, advanced work. Modern ones have a battery for Conveniency and Safety. They stop when the horse bites down on them.

Question 29

Answer 29

Question 30

Sharp tooth edges are commonly found in which teeth, where? How do you correct them?

Answer 30

buccally in maxillary teeth and lingually in mandibular teeth. * They cause ulcers and pain. * Often “hooks” on 311, 411 and 106, 206. * Often caudal and cranial together. * Often bilateral. Using handrasp: in 45 degrees angle (see image), rasp the whole row, centered in the middle of the rasp. Aim is not to make edges rounded, but to remove sharpness!

Question 31

Answer 31

severe rostral hook of 06

Question 32

Answer 32

severe mouth wave

Question 33

Answer 33

position the rasp should be held when rasping sharp edges

Question 34

Answer 34

rostral hook and sharp edges that need filing down

Question 35

Problems overgrown teeth cause.

Answer 35

* Disturbs normal mastication greatly. When you've removed a tooth, the opposing one should be filed down q6months otherwise it grows too long. BUT, You can't file too much at once. Risk of opening the pulp cavity→ root infection. * Observe the pulp with a mirror/endoscope.

Question 36

Diastema and periodontal disease.

Answer 36

Diastema = abnormal widening/gap between teeth Periodontal disease = loss of tooth attachment to the bone, gingival reduction and pocketing, accumulation of feed particles and bacteria. Diastema prevalence increases with age but is preventable with regular oral examinations. Earlier diagnostics = better prognosis * One of the most common reasons for tooth loss in horses. * One of the most painful conditions in a horse’s mouth. * Bad smell from mouth, slow/abnormal eating patterns, weight loss. * Diastema's will gather more and more material over time which in turn widens the diastema causing a vicious cycle. * But also, often no cinical signs! ## Footnote Use your diastema forceps or alligator forceps to remove stuck material from the diastema.

Question 37

How do you treat a pathological diastema?

Answer 37

* Cleaning: use picks and probes and water jet (water pressure similar to wound irrigation). If painful, use a local. * Correct underlying reasons for the development of the diastema. * Filling the gap has been done. * Or Widening the gap completely or only partially.

Question 38

Describe infundibular caries and its grading.

Answer 38

carious lesions that originate within the infundibulum that is impacted with feed. The acidic bacterial by-products of feed decay slowly leading to demineralisation of dental hard tissue. Only present in maxillary teeth as mandibular teeth do not have infundibulums! Grade 0 - no macroscopic visible caries. Grade 1 - caries only affecting the cementum. * class 1, small pitting * class 2, extensive destruction and loss of cementum. Grade 2 - caries affecting cementum and adjacent enamel. Grade 3 - caries affecting cementum, enamel, and dentin. Grade 4 - caries affecting the integrity of the tooth e.g. apical abscess or secondary fracture.

Question 39

Answer 39

Infundibular caries

Question 40

The most common teeth to have indundibular caries?

Answer 40

109 and 209 because these are the oldest teeth in a horse's mouth Remember eruption ages of adult teeth: Incisors: * 01 2,5 y * 02 3,5 y * 03 4,5 y Canine: * 04 4-5 y Wolftooth: * 05 6+ months Premolars: * 06 2,5 y * 07 3 y * 08 4 y Molars: * 09 1 y * 10 2 y * 11 3,5 y

Question 41

Describe tooth Fractures in horses.

Answer 41

* Evaluation is difficult without dental mirror/ endoscope. * Is the pulp chamber open? * Is there Apical infection? Consider taking xrays to evaluate the above. ## Footnote Left: crown fractured off, root remaining in the alveolus.

Question 42

Answer 42

worn at an angle from grabbing food from a hard surface over time

Question 43

Answer 43

diagonal incisors, diastema on the left with these, be suspicious about the cheek teeth

Question 44

Answer 44

calculus formation, check renal values (can be secondary to renal failure)

Question 45

Answer 45

underbite

Question 46

Answer 46

small, micro fractures at occlusion surface edges not too significant

Question 47

Answer 47

past trauma has caused 1 incisor to become displaced. this needs correctly. displaced incisor has worn down side of lower tooth.

Question 48

Answer 48

1 too many teeth, a 4th incisor monitor that it doesn't damage surrounding tissues

Question 49

Answer 49

incisor trauma. fairly simple to correct with wires. NB the wires may come off during the process and need replacing. ## Footnote Feed pelletted hay cubes for 6 weeks while they heal.

Question 50

Describe these teeth.

Answer 50

Canines * Interdental space, root is long and angled back sharply. * Erupt at 4-5 years old * Mostly stallions, geldings; only 20-25% mares, usually less. * Rarely cause problems * Owners sometimes confuse these with wolf teeth which are farther back.

Question 51

Describe aged horse’s mouths.

Answer 51

* Enamel has worn off in older age. * Teeth are smaller and weaker. Chewing is difficult. * Diastemas, food packings, inflammation * Short reserve crown so Tooth loosening and loss. * Sometimes very uneven in height.

Question 52

EOTRH

Answer 52

equine odontoclastic tooth resorption and hypercementosis * Common in old horses * Only affect the incisors * Very painful (Carrot test, horses with EOTRH won't bite it) * Tx is removal of teeth * Horses can live well without incisors

Question 53

Answer 53

equine odontoclastic tooth resorption and hypercementosis EOTRH

Question 54

When should oral exams in addition to routine control be performed?

Answer 54

Changes in eating habbits * Slowed eating * Abnormal eating patterns, horse continuously flushing the mouth, mouthing after eating. * Food not chewed properly and found in paddock (pic) * Favoring one side of mouth * Bad smell from mouth * Smelly nasal discharge, especially one-sided * Weight loss * (Repeated) colic or esophageal obstruction episodes * Problems in training (!) * Part of PPE (prepurchase physical exam)