Monday, April 24, 2017

Apple a Day

I went to an equine dentistry dinner talk last Wednesday that I thoroughly enjoyed. The speaker is one of the veterinarians that have influenced modern equine dentistry. A lot of the tools that we have now are because of him and his practice is 90% dentistry. The university brings him in to help teach the 4th year equine dentistry class. Between 12 students, they will perform dentals on over 600 horses for the course.

It definitely got me excited about taking this class in a couple years! At this point I have a handful of dentals under my belt so I'm beginning to understand the basic technique for a healthy equine mouth and I can't wait to learn more.

Drunk Jetta after I did her teeth

The speaker, Dr. Greene, was thoroughly engaging and obviously excited to share what he knows. This was a client education presentation, so not as academic as I would have liked, but I really liked what his message was for the general horse owner.

Some general notes from points that stuck with me:
  • It's important to evaluate the horses mouth in it's natural position, but it is not necessary to perform your dental in a natural position once evaluated if you are proficient enough in how the horse's mouth works
  • The horse's mouth moves in an ovoid pattern when chewing
  • Unlike humans who have a layer of enamel over the whole of the crown of their (brachydont = short crown) teeth, horses have layers of enamel, dentin, cementum on their (hypsodont = long crown) teeth 
  • The cementum is what becomes discolored due to the natural pigments in forage, this is normal
  • Tartar can accumulate around the canine teeth (something I hadn't seen before!)
  • Something I've heard many times: you NEVER take away all the ridges on the occlusal surface of the teeth, horses need a rough surface for chewing. You level things out so the teeth are better able to move against each other and don't get hung up on each other
  • Dentals are necessary because horses are meant to be grazing course forage for 16-18 hours a day which most modern horses do not do, many horses also have poor mouth conformation, and are asked to carry a bit. The natural silica in plants is what helps wear down the teeth
  • The purpose of a dental is to ensure the horse has a comfortable chewing pattern in addition to make carrying a bit more comfortable - aka COMFORT is the primary goal
  • The horse's tongue occupies the entirety of the space in the mouth at rest. When putting a bit in the mouth, it flattens the tongue and can push it against sharp points on the lingual surface of the mandibular molars (inside bottom teeth). The cavesson can push the cheeks against the points on the buccal maxillary molars (top outside teeth). This is why it's important to remove sharp points
  • He puts a bit seat in EVERY horse that is going to be asked to carry a bit. The bit pulls the corners of the lips inwards which can push against the edge of the first molar. While there is no scientific evidence that this improves the horse's comfort, there is also no evidence that it is harmful. He believes that it is important to make every effort to make the horse comfortable
  • A bit seat entails taking off a millimeter or two of the leading edge of the first molar (not aggressive, not going to have any negative effect)
  • He uses motorized tools in all horses except geriatric horses that can't handle the sound or feel of a motorized tool
  • While hand tools are virtually impossible to take off too much tooth (unless you have incredible amounts of muscle) motorized tools have allowed us to not only treat so many more issues in horses that previously went untreated, but horses can also be done much quicker (= less sedation and stress needed) and with less mechanical stress on the veterinarian (in case you didn't know, being a large animal veterinarian is incredibly hard on your body)
  • While he thinks it's important for veterinarians to work with Equine Dental practitioners, they cannot legally practice on their own, they must be under supervision of a vet. While they may be very knowledgeable about the mouth of a horse, they are not knowledgeable in other areas, such as the pharmacodynamics and pharmacokinetics of anesthetics on the horse which can be very bad if you administer a drug that interacts with another drug that the horse is on or if you have a horse with liver or kidney problems
  • Additionally on the topic of equine dentists - since there is no governing body there is no certification program and thus no repercussions on a dentist for doing a bad job, whereas if your vet does a poor job you can report them to the board
  • He also mentioned a disease called Equine Odontoclastic Tooth Resorption and Hypercementosis (EOTRH) which I'd never heard of and can happen relatively commonly in the PNW - they do not know what causes it yet and there is no treatment except for tooth extraction. It looks pretty crazy!

Overall, a great talk and I'm really looking forward to taking the Equine Dental 4th year elective!


  1. I learned a lot from this post! Thank you. I was just chatting with some boarders at a barn I train at about why horses in the wild do fine without dentals. We discussed natural foraging habits of horses v. those of domestic horses. (Also, the fact that wild horses don't live as long and are often somewhat skinny.) I had never heard of EOTRH and am going to go do some reading now...