Modern Equine Dentistry

April 26, 2024 31 view(s)

MODERN EQUINE DENTISTRY

Hooks, points, oh my!

By: Dr. Vicky Johnson, DVM

Click Here to view Dr. Vicky Johnson's presentation from the seminar on April 20th, 2024:

Today's Topics

Anatomy lesson
The oral exam
The 'float'
Common detnal issues/pathology
Common myths in dentistry

A Mouth Unlike Yours or Mine

Horse's teeth are unlike many other mammal's, but similar to other grazing herbivores
Their teeth are 4-5" long when at their full adult length
Not all adult cheek teeth are present until 4 years old
As horses grind their food, they slowly grind away some of the surface of the tooth, which is 'replaced' as more tooth is erupted
This means the older a horse is, the 'shorter' the crown of their tooth is

Dental Terms

The mouth is divided into 4 quadrants called 'arcades' and are numbered – Upper R 100s, Upper L 200s, Lower L 300s, Lower R 400s
Start assigning numbers with the tooth closest to 'midline'
Incisors (3 per arcade) are teeth # 01-03
Canines (if present – 1 per arcade) - tooth # 04
First premolar "wolf tooth" (if present – 1 per arcade) - tooth # 05
Second, Third, Fourth Premolars – teeth # 06-08
First, Second, Third Molars – teeth # 09-11
Second premolar – third molar collectively called the 'cheek teeth'

General Tooth Anatomy

Equine teeth are formed by layers of different dental tissue
This creates the complex anatomy of the tooth and allows for grinding
Arguably the most IMPORTANT part of dentistry to understand why we float, what we float, and how we float

The Oral Exam - more than just teeth

When performing an oral exam - we look at the entire oral cavity including:
- Teeth
- Tongue
- Palate
- Gums
- Lips
- Cheeks
Most important - the mirror exam

Odontoplasty aka The 'Float'

A masonry term to smooth a surface
We use it to describe the act of using files to remove sharp enamel points, excess ridges and overgrowths
Targeted treatment to only certain tissues in the mouth
Use of power floats, hand floats, small hand pieces
The average horse needs a sedated oral exam and float every 12 months. Horses with pathology may need floated sooner, some middle aged horses with good dental anatomy may only need done every 18-24 months.

Small Points, Big Problems

Points can lead to ulcerations in the cheek, tongue or other surrounding tissue that can be painful
Points that make the horse chew differently to avoid pain can cause excess forces to be put on other teeth
Horses chewing to avoid contact with points can also lead to or exacerbate the formation of diastemata, or gaps between the teeth that affect the horse's periodontal health

Other Common Pathologies

We categorize problems into either dental or periodontal diseases/conditions to best describe their appearance and location
Not all issues require immediate attention, some do. Not all require treatment (even long term), but some do
It is important to consider the entire mouth when assessing dental and periodontal disease, as they can often be related or secondary to another problem

Most Common: Malocclusions - Overgrowth/Overwear

Overgrowths and overwear are most commonly caused by conformation of the horse's skull/mouth
Can also occur due to:
- Lost teeth (due to age or other)
- Fractured teeth
- Change in chewing pattern
- Breed (minis and donkeys)

Correction Takes Time and Training

Reducing overgrowths needs to be done tactfully and carefully (think back to anatomy lesson regarding the location of the pulp horns)
Correcting these overgrowths can help the horse maintain a more normal mouth over time, not to mention the horses are more comfortable and able to chew appropriately

Diastemata

Diastema (singular) / diastemata (pleural)
Gaps between the teeth that occur due to drifting, feed packing, change in chewing pattern, pain (enamel points)
Can be open (like a channel) or valve (top of diastema is pinched off)
Often have significant feed packing
Treatment varies

Fractures

Can occur in a variety of ways on a single tooth
Fractures that involve the sensitive structures of the tooth are (almost always) candidates for extraction
Fractures where teeth are mobile, infected, or have other co-morbidities may require extraction

Tooth Root Abscesses

Often come from fractures through pulp horns (either large or fissure) that allow bacteria into pulp canal and travel up to root to set up camp
Can and will cause a sinus infection if certain teeth develop infections
Long term antibiotics usually not helpful due to heartiness of bacteria and poor penetration of medication

EOTRH

Stands for "Equine Odontoclastic Tooth Resorption and Hypercementosis"
Acts like an autoimmune disorder where the body begins attacking the roots of the teeth – almost always affects the incisors but can affect the canines and second premolars (even the rest of the cheek teeth but less commonly)
No way to stop or prevent this disease
Treatment is the removal of all affected teeth
Recommendations vary on number of teeth to remove

A Few Common 'Myths'...

#1 Power tools harm the horse
- Any tool in the hands of someone inexperienced, or if it's not being used appropriately can cause damage
  - Think about the great bit debate in your riding discipline!
  - Training, understanding, and quality control
- Comfort may depend on experience
- Power tools, when used correctly, are safe, specific and efficient tools to perform dentals
#2 Minis and donkeys need less frequent care
- Almost always the exact opposite
- These types of equids are more represented amongst horses with malocclusions, and therefore need routine dentistry to address their
  oral health
- Just like any horse they should be assessed at least once a year
#3 My older horse doesn't have any teeth left, so he doesn't need a dental
- Very horse – to – horse dependent, but unless he truly doesn't have any teeth left, we still like to assess these guys once a year
- They can get horrible diastemata packing with rotting feed, huge overgrowths, and loose teeth that expire when falling out that all
  need addressed
- Screening for older horses that may start to be losing 'normal' dentition – this helps us guide you in modifying their diet to help with weight and avoiding choke
#4 Vets don't like dentistry . . . . I don't like it, I love dentistry!!

The contents of this presentation, including all photographs, are property of Dr. Vicky Johnson. Any additional resources used were cited alongside diagrams. Reproduction and/or redistribution of this presentation without explicit permission is strictly prohibited. Dr. Vicky Johnson; 2024