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Pauline Moore
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Dear Dr Deb

A client's horse, a 9yr old warmblood, has just had a second tooth, an incisor, removed due to an abscess.  A molar was removed for the same reason less than a year ago.  The vet/dentist concerned reports that he is being confronted with having to pull abscessing teeth in young horses regularly and is blaming the overuse of power tools and consequent removal of too much tooth by previous dental practitioners.  My client has been told her  9yr old has the teeth of a 15yr old horse.

I've gone back over all my dental notes from your dissection courses but cannot make any sense of these claims that the dentist is finding 'pulp exposures' in all these young horses.  I've looked at the diagrams showing how the dentine, cementum and enamel wear down to give a rough chewing surface but cannot see how simple wearing down of teeth by either natural chewing or any form of dentistry tool would expose pulp in even a 15yr old horse.

My questions are:

Is it possible for a tooth abscess to be caused by too much tooth being taken down by a dentist?

Is it possible for a tooth abscess to be caused by the heat generated by a power tool?

What other likely causes could be responsible for a large number of young horses losing teeth to abscesses?

Best wishes - Pauline

Tasha
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I know I've read a paper that pointed to the death of teeth through overheating due to power tools. Perhaps dead teeth lead to abscesses? If I remember correctly the authors came up with the recommendation that a power tool should not be in contact with a tooth more than 30 seconds, any more than that risks killing the tooth and the tooth should be given enough time to cool down again if further work needs to be done. I'll try and track it down though I wouldn't be surprised if Dr Deb has it at her finger tips somewhere.

In NZ I have heard that some vets aren't particularly happy with what is being done by some lay dentists who are trained in an Australian school to use power tools for horse dentistry - too much tooth being taken away (especially the incisors) or the angles of the teeth being changed too drastically. At least that is the gossip.

For the last three/four years I've used a vet who trained in equine dentistry in Canada and has passed an Australasian veterinary exam in equine dentistry, he uses a specially designed power tool for equine dentistry and while he has picked up some interesting problems, there has never been a case of a tooth abscess in any of my ponies or in any other horses he treats down my way.

So perhaps it is not a problem that powertools are being used but that powertools are being used badly?

Last edited on Tue Mar 3rd, 2009 10:50 am by Tasha

Tasha
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Location: South Island, New Zealand
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I've found a couple of citations which seem familiar but it has been 2-3 years since I read the article and unfortunately I don't have access to the full journals anymore, doing distance learning through Massey definitely had some advantages. I found these citations in Pubmed.

J Am Vet Med Assoc. 2004 Apr 1;224(7):1128-32.

In vitro study of heat production during power reduction of equine mandibular
teeth.

Allen ML, Baker GJ, Freeman DE, Holmes KR, Marretta SM, Scoggins RD, Constable P.

Firethorn Equine Services, 5701 Lancaster-Circleville Rd, Lancaster, OH 43130,
USA.

OBJECTIVE: To measure the amount of heat generated during 3 methods of equine
dental reduction with power instruments. DESIGN: In vitro study. SAMPLE
POPULATION: 30 premolar and molar teeth removed from mandibles of 8 equine heads
collected at an abbatoir. PROCEDURE: 38-gauge copper-constantan thermocouples
were inserted into the lingual side of each tooth 15 mm (proximal) and 25 mm
(distal) from the occlusal surface, at a depth of 5 mm, which placed the tip
close to the pulp chamber. Group-NC1 (n = 10) teeth were ground for 1 minute
without coolant, group-NC2 (10) teeth were ground for 2 minutes without coolant,
and group-C2 (10) teeth were ground for 2 minutes with water for coolant.
RESULTS: Mean temperature increase was 1.2 degrees C at the distal thermocouple
and 6.6 degrees C at the proximal thermocouple for group-NC1 teeth, 4.1 degrees C
at the distal thermocouple and 24.3 degrees C at the proximal thermocouple for
group-NC2 teeth, and 0.8 degrees C at the distal thermocouple and -0.1 degrees C
at the proximal thermocouple for group-C2 teeth. CONCLUSIONS AND CLINICAL
RELEVANCE: In general, an increase of 5 degrees C in human teeth is considered
the maximum increase before there is permanent damage to tooth pulp. In group-NC2
teeth, temperature increased above this limit by several degrees, whereas in
group-C2 teeth, there was little or no temperature increase. Our results suggest
that major reduction of equine teeth by use of power instruments causes thermal
changes that may cause irreversible pulp damage unless water cooling is used.


PMID: 15074859 [PubMed - indexed for MEDLINE]

Aust Vet J. 2005 Jan-Feb;83(1-2):75-7.

Temperature changes in dental pulp associated with use of power grinding
equipment on equine teeth.

Wilson GJ, Walsh LJ.

School of Veterinary Science, University of Queensland, Queensland 4072.

OBJECTIVE: To quantify the temperature changes in the dental pulp associated with
equine dental procedures using power grinding equipment. DESIGN: A matrix
experimental design with replication on the same sample was followed to allow the
following independent variables to be assessed: horse age (young or old), tooth
type (premolar or molar), powered grinding instrument (rotating disc or die
grinder), grinding time (15 or 20 seconds) and the presence or absence of water
coolant. PROCEDURE: Sound premolar and molar teeth from a 6-year-old horse and a
15-year-old horse, which had been removed postmortem, were sectioned parallel to
the occlusal plane to allow placement of a miniature thermocouple at the level of
the dental pulp. The maximum temperature increase, the time taken to reach this
maximum and the cooling time were measured (n=10 in each study). The teeth were
placed in a vice and the instrument used on the tooth as per clinical situation.
RESULTS: Significant differences were recorded for horse age (P < 0.001),
instrument type (P < 0.001), grinding time (P < 0.001) and presence or absence of
coolant (P < 0.001). There was no significant difference for tooth type.
CONCLUSION: Thermal insult to the dental pulp from the use of power instruments
poses a significant risk to the tooth. This risk can be reduced or eliminated by
appropriate selection of treatment time and by the use of water irrigation as a
coolant. The increased dentine thickness in older horses appears to mitigate
against thermal injury from frictional heat.


PMID: 15971824 [PubMed - indexed for MEDLINE]

Pauline Moore
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Dr Deb - To add to my confusion, my client sent through the following extract from a dental book which appears to indicate dentine is continually being replaced at the occlusal surface - somehow I had visualized that dentine does not cover the chewing surface as the different materials with varying hardness are worn down at varying rates, hence the rough grinding surface.  Now I have no idea about anything.

Equine Dentistry Second Edition Edited by Gordon J Baker and Jack Easley  P99
“Being hypsodont, equine teeth have a prolonged eruption throughout most of their life. This is an evolutionary adaptation to compensate for wear at the tooth’s occlusal surface (at a rate of approx 2-3mm per year) due to the prolonged mastication (up to 20 hours per day) of forage which may contain abrasive silicates of phytoliths. To avoid pulpal exposure on the occlusal surface, dentine is continually laid down by odontoblasts throughout the life of the tooth. Excessive attrition of dentine with resultant pulpar exposure has been proposed as a route of infection into equine apical tissues. When dental attrition exceeds the rate of secondary dentine deposition, the pulp will eventually become exposed. The rate of dentine formation is dependent on the health of the layer of odontoblasts present at the periphery of the pulp. If this layer becomes compromised, either directly (eg from trauma or from thermal damage during dental treatments), or indirectly (e.g. from decreased or total loss of vascular supply) the resultant decrease dentine production may be insufficient to prevent pulpar exposure, the outcome is dependent on the tooth’s ability to withstand prolonged bacterial invasion”.


I know of no-one other than yourself, Dr Deb, who can explain the truth of what is really happening with these horses - your help is very much needed and appreciated.
Best wishes - Pauline


 

DrDeb
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Pauline, it's not like I wouldn't have wanted to answer this. But the question here requires a careful and complete answer, and it had to wait until I had several hours to compose.

The key to the solution to your quandary lies in the quotation from Easley's textbook. Easley is the leading veterinary researcher in equine dentistry, and his book gives good information.

You are telling me through your last post that you don't understand the differences between brachydont (low-crowned) teeth such as those we humans have, or that pigs or dogs have, vs. hypsodont (high-crowned) teeth such as horses, cattle, deer, and antelopes have. If you want an excellent picture, go to your copy of Gobaux and Barrier -- the classic illustration -- note the fine dotted lines marking the length of the incisors and the usual relationship of the occlusal "table" to the pulp cavity at different ages. With high-crowned teeth, just as Easley notes, the teeth continue to erupt through the gums for a longer time than that which is merely required to initially erupt the tooth and bring it up to a level where it comes into occlusion with its mate from the opposing jaw. And this is due to the fact that grass is gritty and abrasive, both from dust which is commonly on the outside of the blades, but also to glassy phytoliths which are part of the internal structure of the blade.

The lifespan of an animal in nature is limited by numerous factors, such as whether it can get enough food and water, disease, injury, and predation. But if the animal has a good environment and escapes disease, injury, and predation, then its lifespan will ultimately be limited by the durability of its teeth. In other words, the teeth are the weakest part of a good overall system. So horses and other animals that eat grass have evolved high-crowned teeth as a way of counteracting the tendency of their food to wear their teeth down to the gums -- and specific to your initial question, the mechanism also prevents premature exposure of the pulp cavity through providing a way for dentine to continue to be laid down at a rate that hopefully exceeds the rate of "attrition", which means tooth wear.

Now, it is not really possible here to go over the whole story of the development of teeth from embryo to birth and thence to old age. Suffice it to be said that there is a layer of cells which surrounds the pulp cavity (the odontoblasts) which have the capability to lay down dentine. If these cells are destroyed, they die, leaving the animal with no way to lay down new dentine. So much says Easley also.

Now we turn to the controversy concerning whether incisor reductions should be performed. There are no grounds in fact for the claim that incisor reductions of the appropriate kind should not be performed. As I said, the key to this lies in the same information quoted from Easley: under normal circumstances, when the odontoblast layer is healthy, the horse will lay down dentine at a rate that equals or exceeds the rate of tooth wear.

The question, then, must be: what is the rate of tooth wear in the individual domestic horse, and why were tooth reductions (cutting off excess incisor length) suggested in the first place?

All of the horse's teeth are hypsodont -- both the cheek batteries, as well as the incisor batteries. And when a horse grazes in the natural manner, he has the opportunity -- indeed the necessity -- of using all of his teeth. To graze, the horse uses his incisor teeth to grasp a bunch of blades. Firmly gripping the blades, he then somewhat sharply moves his head either rearward or obliquely side-to-rear, which has the effect of tearing off the blades. (A side note here: we have one dentistry instructor here in the U.S., a veterinarian, who teaches that the horse uses a 'scissoring action' to bite off grass blades. This is completely incorrect; the horse with a normal mouth never, under any circumstances, rubs the occluded incisors together from side to side; there is no 'scissoring' action at any time. However, there are many horses that have abnormal mouths whose incisors do rub together, coming into contact before the jaws are fully closed and centered).

What happens, however, when we bring the horse into the domestic environment is that, to greater or lesser extent, he is prevented from filling his belly by means of grazing. The domestic horse, to whatever extent he is fed hay and grain or pellets, bagged feed, etc., and to whatever extent he is held off pasture, will fail to that extent to obtain wear upon the incisor teeth. For the ONLY time the incisor teeth experience wear in the horse with a normal mouth is in the actual act of tearing off the upwardly-growing grass blades. Horses that are eating hay do not wear their incisor teeth appreciably.

What this results in, over time obviously, is the failure of the incisor teeth to shorten -- to wear down as an eraser wears down as it is rubbed -- as they were meant to. Incisors that do not receive wear still have active odontoblast layers, and they still have active cell layers external to the tooth as well, that act to push or "extrude" the tooth out of the socket every single day. The amount per day is miniscule but is pre-set to match the "expected" wear. (Note that at the opposite end of the spectrum -- much less common but as Easley mentions, possible -- you could have a horse on such extraordinarily gritty food that no amount of activity of the odontoblasts can keep up. Such an animal will then have premature exposure of the pulp cavities). So you see by both these examples that the whole thing is a question of balancing the rate of wear against the rate of development and/or extrusion from the socket.

When we have the common domestication scenario, that the horse's incisors are experiencing a lower-than-expected rate of wear, the result over time will be that the incisor teeth will accumulate length. They will be accumulating length, while at the same time the cheek batteries will be receiving normal rates of wear (because the cheek teeth occlude with every chewing stroke). I say the cheek teeth occlude -- but if the incisors are not reduced by SOMETHING, then eventually they will accumulate enough length that they will begin prying the jaws open from the front. In other words, the incisor teeth are going to come into contact (a) from side to side and (b) too soon in the chewing stroke, so that when the incisors are in contact, the cheek teeth are prevented from coming into contact -- the jaws are HELD OPEN by the over-long incisors. You see: in the normal condition, the horse is the ONLY grass-eating animal whose incisor teeth are designed to come into occlusion bluntly, across a broad surface, at such a height that when the incisors are in contact, the cheek teeth are within a credit-card thickness of being in contact, too (the "credit card space" allows for the thickness of the bolus; but it's OK in some individuals, or for temporary periods, for there not even to be this much space).

Now, if the situation becomes that your horse's incisors have accumulated excess length, so that he cannot close the cheek teeth, then one or more of the following MUST occur:

(1) He will begin suffering repeated "impactive" type colics, due to inability to properly reduce the bolus, i.e. he is swallowing particles longer than 1/2" (a horse with a normal chewing stroke reduces all particles to less than 1/8", the majority being the size of cornmeal particles or coarse grains of sand).

(2) He will increase his efforts to chew on his favorite side. All horses have a favorite side, but the degree to which they favor that side is not enough to cause the difference to show up for many years. But horses that are desperate will try harder, and if this is the strategy for a particular individual, quite soon there will be enough left-to-right difference in the dentition that it will re-shape the cheek teeth. Then, very commonly, the new shape will actually block the horse's ability to chew symmetrically -- now he is in a rut that he cannot get out of by any effort of his own.

(3) He will increase his efforts to bring the cheek teeth into occlusion. This works just like an orthodontic "treatment", and will result in the anteriorward rotation of the incisor teeth so that they become "bucked" or protruding to the front. Teeth like this give old horses the reputation of being "long in the tooth". Yes, exactly: they ARE long in the tooth. This can get so extreme that the horse has trouble closing its lips over the front teeth. At the same time, with these horses, there will be a thinning and upward bowing of the lower jaw, and an increase in the size and toughness of the masseter muscles on the jowls. The upward-bowing of the jaws, as well as the rotation of the incisor teeth, are classic examples of "remodeling" as a response to continual unidirectional pressure, i.e. the extreme efforts of the masseters to close the cheek batteries.

(4) Any extreme chewing effort can also have the effect of magnifying any pre-existing imbalance in the mouth. For example, if the horse has a tiny left-right difference, a tiny "hook" on the front or rear end of any cheek battery, a wee space between two teeth which would ordinarily make no difference, or any type of small anomaly relating to the development or eruption of the teeth, these will be magnified into "wave mouth", "Viking funeral ship", "train wreck", and all the other big classic malocclusion patterns that we see affecting the cheek batteries.

(5) And of course, anything that disturbs the normal formation of the incisor battery has a critical impact upon what goes on with the cheek batteries. So if the horse bangs his head on a post and knocks out a tooth....if he has supernumerary incisors....if two of the incisors come in crooked and "impact" or prevent the eruption of another incisor....if the horse has pain that he's chewing away from....if he retains the "caps" on one side ("caps" are remnants of the deciduous premolars that form the fore-end of the cheek battery in younger horses) .... then he will set the wear in the incisor battery awry. The mate to a knocked-out tooth will hyper-erupt until it protrudes beyond the "table" formed by its mates to left and right, and that will create a "lockmouth" -- because of course, the horse's chewing stroke is never to be up-and-down, but rather is down, over, obliquely up-and-across. The incisor teeth must not meet anywhere until the jaw is fully centered, right at the end of the stroke. If you have a lockmouth, the only way the horse can chew is up-and-down, and this in turn will cause him to pound the centers out of his cheek teeth. And THAT in turn will create the biggest "points" you ever saw, and not only that, points that keep coming back -- you can float 'em again and again, and they will keep coming back because you are not addressing the root cause of the problem. In fact, if you want to talk about traditional, supposedly "safe" equine dentistry, you can float a horse to death -- because each time you float the points, you ARE removing tooth substance, and if the practitioner does not know how, or does not believe in, reducing the incisors which are the actual cause, if you keep floating the horse you will eventually remove enough substance from the cheek teeth that NO amount of incisor reduction would be capable of bringing the cheek teeth back into occlusion. This is an important point -- see below.

You say, Pauline, that I am the one person in the world who can rightly answer this query, and you may be right: for to my knowledge, I am the only person who has gone to the effort (over the past decade and more) to look for, document, and properly interpret dental malocclusions in numerous different populations of fossil Equus and in old historical Equus such as my specimens from Roman Vindolanda. And what these studies show is that ALL of the classic patterns of malocclusion, whether affecting the cheek teeth or affecting the incisors, occur in both fossil and in some historical collections. BUT! And this is the big bottom line -- in all populations where it was either before domestication ever occurred, i.e. in Pleistocene or early Holocene equines, or in domestic populations known to have been kept in the field or commons, we see these same malocclusions develop to a TINY extent and only LATE in the horse's life. I can count on the fingers of one hand the number of caries I have seen in fossil horses, and equally rare is any malocclusion of the magnitude we COMMONLY see in modern domestic equines. So there is absolutely no question that it is our practices, our style of horsekeeping, that is causing these problems: whether that relate to processed feeds vs. pasture or to breeding selection and the accumulation of genetic diseases/genetic load -- probably both.

Now we are in a position to judge what constitutes proper equine dentistry. The studies quoted on tooth-heating are quite accurate as to their idea of how hot the tooth has to get before you kill the crucial odontoblast layer. What is not stated (where, O where, are the critical reviewers for veterinary journals? I have often wondered --) is that: (a) the experiments were done on teeth from skulls, not on live horses; (b) they do not accurately reflect real field conditions, i.e. how hot real dentists' equipment actually gets patients' teeth; (c) they do not accurately or fairly represent the practices of competent, properly trained equine dentists; (d) they do not take into consideration the age or health status of the individual horse; and, unfortunately also (e) the articles were produced in a charged political atmosphere, as a way to scare customers and to give legal weight to arguments that equine dentistry should not be practiced by laymen -- in other words, overall it is dishonest science.

I have been observing equine dentistry for better than twenty years now, and have personally witnessed thousands of equine dental treatments, most which included incisor reductions, and I have seen ZERO tooth abscesses or killed (black and/or "dead") teeth as a result of such treatment. Long ago, incisor reductions as well as "table work" on the cheek batteries were still sometimes performed with hand floats, and then there was a switch to using cable-driven Dremels fitted with diamond cutting wheels. These made cutting the teeth easy and quick. Today, we have progressed to the point where several manufacturers make dental cutters and drills specifically shaped for the equine mouth. Some of these are fitted with small tubes that apply a continuous stream of cool water to the tooth being cut, just as do your human dentist's tooth cutters and drills. But even where water cooled equipment is not being used, it is sufficient in HORSES (whose pulp cavities are usually far deeper below the surface being cut than in humans) if (a) the cutting blade is sharp, and (b) the practitioner does not force the edge of the cutter into the tooth (this makes the cutting faster, but also raises the temperature).

Now, as to how much heating a horse's tooth can take: it largely depends upon the age of the horse. I have witnessed one incisor reduction, performed on an 18 year old mare by a practitioner in a hurry and using a dull blade. The incisor was heated until it glowed red! And the horse suffered absolutely no harm whatsoever -- the tooth never abscessed, never turned black, never died -- I had contact with this animal off and on for more than 10 years after the treatment was performed and I know she still had a full set of healthy, albeit geriatric, incisors on the day she died. If you tried this, however, on a younger horse, or perhaps on a different individual, the outcome might not have been so good. For exactly because of the dentine laying-down process mentioned by Easley, as a horse ages the pulp chamber retreats toward the root. It also becomes smaller and more senescent; those of the cheek teeth eventually actually die, but in the incisors the pulp chamber usually does not die or have its circulation completely cut off by natural processes before the horse dies.

So the point here is that the younger the horse, the more knowledgeable, careful and experienced the practitioner must be, because in younger horses the pulp chamber is closer to the occlusal table of the tooth. You may know whether the pulp chamber has been cut into during a reduction if blood spurs forth from the "star", which is the ghost of the top of the pulp chamber as visible on the tooth table. A tiny pinprick of a bleed is as deep as the practitioner dare go, for it signals the top of the pulp chamber and that capping layer of odontoblast cells. If the pulp chamber is cut into broadly, yes, certainly then bacteria will instantly invade and the likely result is an abscess while the tooth as a whole will probably die. What the knowledge, care, and experience" part of this relates to, then, is that you can't directly SEE where the top of the pulp chamber is in the incisor. You can see it absolutely on an X-ray, but X-rays are not generally taken in the field prior to dental treatment; instead, we rely on the practitioner's prior experience with horses of that age and type. And this is usually sufficient. Perhaps as training relating to equine dentistry improves in the world's veterinary colleges, we will see X-rays more commonly used, and absolutely nobody could object to that. But at the present time, most veterinary technicians who specialize in radiography are not trained to take good dental views, and I have seen only one practitioner who regularly did an excellent job taking this type of X-Ray.

This bring us, then, to the answers to your questions:

(1) Should incisor reductions be performed? Yes -- whenever a thourough and competent manual and visual examination demonstrates that they are necessary. Not to perform an incisor reduction when it is necessary is malpractice. The practitioner who lacks a full and correct understanding of equine oral biomechanics, as well as embryology, tooth ontogeny, phylogeny, and geometry, is inadequately trained whether he does, or does not, hold a veterinary license.

(2) Are incisor reductions safe? Yes -- when performed with the appropriate power equipment, with the horse appropriately sedated (sedation MUST BE performed by a licensed veterinarian, whether or not the treatment is performed by a layman).

(3) Excessive removal of tooth substance, whether during incisor reductions, in the creation of "bit seats", or in floating, is malpractice. Tooth substance has been removed in excess when the pulp chamber is exposed, when the odontoblast layer is harmed, or when the tooth has been weakened by the treatment.

You will see from the above that the statement "this 7 year old horse has the teeth of an animal twice its age" would be nearly impossible. But -- just possible -- if the horses this veterinarian is seeing are in fact being butchered by some incompetent practitioner wielding power equipment. If thye vet is treating abscesses caused by exposure of the pulp chambers in any of the teeth, then we have to believe that he is treating abscesses. What we do not have to believe -- or where you might say the break is in the logic here -- is that ALL incisor reductions should stop. Incisor reductions are no more dangerous than what is called "ordinary" floating, which also removes tooth substance.

As an aside: yes, there are ways other than dental treatment to produce pulp abscesses. All that is required is that the pulp chamber be invaded, and this is what the bacteria that cause tooth "cavities" (caries) are in business to do. We have in the last 20 years in the U.S., but it is a newer phenomenon in Australia, turned more and more to feeding bagged mixes that have huge amounts of molasses. Our skull collections document a steep rise in the number and seriousness of caries that exactly parallels the introduction and then increasing availability and popularity of these overly-sugary bagged feeds. It is possible that the veterinarian who is stomping and snorting about pulp abscesses is, in fact, seeing the effects of this type of feeding rather than incompetent dentistry. If he is seeing a lot of pulp abscesses in the cheek teeth, I would suspect feed before dentistry as the cause.

What is obvious from all of this is the importance of REGULAR dental maintenance beginning at birth. If the owner didn't wait until the horse is past 12 and starting to show those occasional colics or dribbling that feed or dunking or butting his hay because he can't chew the stems properly, then so much incisor would not have to be removed. Again: there is little danger in incisor reductions when the dentistry performed has as its object merely to bring the cheek teeth back into proper occlusion, and/or to eliminate blockages or asymmetries that are of small magnitude.

Now, to conclude, I want to repeat something I've said several times here before: I am looking for grownups in this system. I left the dental school where I had taught for a decade because the leaders in that school are unethical. They have no intention of playing by any agreed-upon set of rules: they supply their favorites with drugs under the table; they confer certificates and pseudo-degrees upon people who could not pass any of the certifying examinations now being offered in several places around the world; and they promote to high office people who are complete kooks. I witnessed the leaders of that school grant certificates primarily because they were afraid that the student "wouldn't like them" if the passing status was not conferred. I tried for years to get the leaders of that school to learn basic concepts of biology, embryology, and anatomy -- to no avail.

What they want, they say, is to have equine dentistry recognized as an "independent profession". This would be OK if what they really meant was that it be handled the same way as we handle human medical vs. dental treatment: both the doctor and the dentist are highly educated and trained, but their training, though it overlaps in some areas, focuses on different aspects of health care. I don't go to my doctor to have my teeth attended to, and I imagine you don't, either.

But this is not what this school of people means by "independent". What they mean is that they want not to be regulated at all. They want to be able to administer phamaceutical drugs without meaningful supervision by a veterinarian. This, because it so much reduces the inconvenience to them and the expense to their customers, and because it so much increases their freedom to act, and to practice, where they choose. For this reason the Board of Veterinary practice, along with the District Attorney's office in several U.S. states, has pursued and prosecuted a number of these guys. In my opinion, this has been the wrong tack to take, just as publishing "scare science" is the wrong tack to take. The right approach is to develop a meaningful certification examination, so that all those who wish to practice equine dentistry in a given state, or nationally, would know ahead of time exactly what they are required to know. This should be followed by a meaningful practical examination. The successful candidates would be issued legally-actionable certificates or licenses, and this is necessary so that when malpractice occurs -- and mind you, it occurs both among veterinarians and laymen -- the horse owner has a plain and well-trodden path to recompense and/or punishment of the offender. This is the same playing field your veterinarian has already agreed to, and it should apply equally to anyone in the animal health-care field.

Now, I say I have been looking for grownups in this controversy, and I have been disappointed with the attitude of some of the laymens' groups. I have equally been disappointed with some of the veterinarians. I know of cases where a veterinarian submitted to being taught by a highly skilled layman, then went back to his home university and published papers detailing what he had learned yet without giving any credit to the man who had actually taught him; the veterinarian claimed he had learned it all in vet school. How totally ungentlemanly, and how totally unprofessional -- something that veterinarian Tom Allen of Missouri , who learned his dentistry from laymen, has stated in a letter he shared with me addressed to the AVMA and AAEP. I have personally witnessed veterinarians who were among the worst dental practitioners I have ever seen or could imagine. I have photographic evidence of malpractice, leading to the death of a horse through the total misinterpretation of the teeth, by a veterinarian. I have heard veterinarians say things that proved they were mixed up, or even quite ignorant, about equine oral biomechanics and tooth development. And -- maybe this is human nature -- but unfortunately, the least knowledgeable and most incompetent veterinarian is almost always the one who screams loudest when the highly-trained, more experienced layman comes to town who can be the one who finally satisfies the dental needs of horses in the area.

And this is the real bottom line: the horses need us to grow up and get real about providing proper, competent equine dental services. There are groups all over the world now (and I know because I am working with several of them), composed of veterinarians who ARE properly trained and who ARE willing to work in a gentlemanly, professional manner with laymen who are totally willing to work WITH the vets and under their supervision when that is needed to protect the safety and health of the animals, and who ARE willing to study hard for a meaningful test and then be legally regulated in practice.

You as consumers, and some of you as alternative health-care practitioners, can and should look with a wary eye upon anyone who offers equine dental services. This Internet memo is far from sufficient to teach all that there is about "horse teeth", but may serve as some guideline. I do have hopes for the rational resolution of this problem, so that it ceases to be a controversy. For indeed, if every veterinarian now licensed quit practicing anything but equine dentistry tomorrow, we would still not be able to supply the needs of all the domestic horses that would benefit from seeing a dentist. There is plenty of room for all concerned, and my hope is to see committed individuals working together to provide the services that all our horses need. -- Dr. Deb

 

Tasha
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Location: South Island, New Zealand
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I know that this has been Pauline's thread but I wanted to say thank you Dr Deb for the information you make so freely available in your forum. Your answer is as insightful as ever, and has allowed me to make a paradigm shift. I apologise for my first post to this thread being so anti-layman dentist and I freely acknowledge that out in big wide world there are laymen out there who are great dentists and there are vets who are bad dentists.

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Dr Deb,  thank you once again for such a wonderful reply.

I'm still pondering on the likely cause of these abscesses as, in my own mind, I am confident that poor dentistry is not responsible.  I'm getting the impression that most, if not all, of these reported abscess cases are occurring in the coastal areas of northern NSW and southern Queensland which are predominantly pastured with imported tropical high-sugar grasses such as kikuya etc.  Prior to the last 9 months or so, these areas have been in severe drought for a long time but since then have had an abundance of rain and a consequent abundance of grass.

I have read that magnesium is essential for producing hard tooth enamel and know that horses exposed to high-sugar pastures are in need of extra magnesium to assist with metabolizing the excess sugars, so I'm wondering if these horses could have become magnesium deficient (and/or other minerals also) during the drought period and therefore are using whatever magnesium resources they have for food processing and other essential body systems rather than maintaining good quality tooth enamel.  Could this be a factor in a horse developing caries that then allow entry of bacteria to the tooth pulp?  Does the naturally occurring sugar in grass start to be released at the beginning of the digestive process in the mouth?  Or does that happen at a later stage in the stomach or intestines?  Could grass sugars alone be responsible for dental caries in cases of magnesium deficiency even without sugary processed feeds?

Any thoughts would be appreciated.

Best wishes - Pauline



DrDeb
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Pauline -- have a look in your copy of the Poison Plants book (p. 309) under Kikuyu, and you will see that it is associated with 'big head', which is a syndrome ('nutritional secondary hyperparathyroidism') involved with the disturbed/inadequate metabolism of sugar, magnesium, and calcium -- the latter two, of course, being essential tooth-building minerals. So if foals are being raised on Kikuyu grass or hay, yes, they could certainly wind up with poorly-mineralized teeth and bones.

So you have that route to go. Meanwhile since posting the above, I have thought of a couple of other things to add, as to likely causes for tooth abscessing/premature exposure of the pulp cavity:

(1) In cheek teeth: if the horse has not had incisor reduction/reshaping when it should have been done, and if this has forced the loss of jaw excursion (i.e. its ability to travel through the whole lateral extent of the chewing stroke); and if this in turn has resulted in the animal pounding the centers out of the cheek teeth, then this will certainly, in addition to creating big, persistent 'points' as discussed above, also tend to unroof the twin pulp cavities that lie toward the centers of the cheek teeth.

(2) In either cheek teeth or incisors: excessive reduction of tooth substance is not the only cause for abscessing in 'sound' and normally-developed teeth. The most common cause of tooth abscesses is that the teeth have been cracked, and/or that an extraction was performed but the practitioner failed to remove all the sherds. If even one bit of the tooth is left in the alveolus, it will abscess, and this can be a real mess when a better practitioner has to go in and pick out small sherds. In the old days, teeth were sometimes fractured by old-fashioned molar cutters -- and it happened to even the best of practitioners, simply because this is a difficult operation, particularly as you get toward the back of the mouth. This is one major reason why rotary power equipment is MUCH better -- incisors are not the only teeth that may need to be reduced, and adapted rotary power equipment never causes cracking or fracturing. Note that horses who pick up hay, or to graze, among small gravel can sometimes by accident get a rock in the bolus and chomp down on it and thus crack their own teeth -- I have seen two cases where this was the likely etiology, as no dentist had seen those horses and they were kept on range.

(3) The more you have teeth that are poorly-mineralized, the more likely it is that the centers of the infundibulae (the 'enamel lakes' or 'fossae' of the cheek teeth, the 'cups' of the incisors) will not be fully infilled with cementum as they should be. They will not be filled all the way to the top, and there may also be a hole which is of toothpick-diameter or larger that goes right down the center from the occlusal table to the base of the crown internally. When the infundibulae have a hole in them like this, the hole provides an easy route of entry for bacteria that goes deep down into the tooth. When a horse with unfilled infundibulae eats, he will pound the foodstuff down into the cylindrical infundibulum. So common is this phenomenon that we know what the grassy diet of Pleistocene horses was, through simply picking the grains and bits of blade out of the infundibulae -- for they remain there even after death and fossilization! What we find in the teeth of Pleistocene horses are the normal 'wild' grasses that used to occur, and still occur, throughout the undeveloped parts of the Northern Hemisphere. These grasses do not cause caries -- I've said above these are very rare in fossil horse populations. However, if the foodstuff is sugary, such as are many of our so-called improved grasses, or if it is sugary bagged feed, then caries are sure to follow. But caries that attack the inner surfaces of the infundibulae cannot be seen except on X-ray. The enamel coating which defines the margins of the 'lakes', especially in the cheek teeth, is mostly thinner than that which jackets the external aspect of the teeth; hence, caries that begin within the infundibulum will likely progress faster than those that begin just above the margin of the gums.

I don't really believe that the horse you're describing is the victim of incompetent dentistry. I've heard the particular veterinarian you're speaking of make similar claims against tooth reductions before, so that clients think he's their only last hope; but interestingly, his rates are extremely high. So rather than have your clients think that they must choose between what this guy is offering vs. euthanasia, I would suggest that the horse owner seek the opinion of several of the best lay and veterinary dentists she can locate in her area. No question, if the teeth are abscessing, they must be extracted. But the rates she is being quoted are of a size that tells me that this vet intends to do lay-down surgery with full anaesthesia and clinical post-op care. Perhaps that really is going to be necessary; one must judge on the merits of the case. However, it may also mean that he does not know how, or lacks the skill and experience, to perform stand-up extractions, which are universally much less expensive. One of the great contributions of the lay dentists has been to improve the speed and efficiency of extractions in many, if not all, cases. -- Dr. Deb

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Hi Pauline

I understand your frustration as there is so much information out there and it is extremely difficult when you get two specialists in the same field with conflicting evidence. 

There is growing evidence that some Australian trained equine dentists are using their tools incorrectly.  My advice to you would be to look at the science.  Horses teeth should not be filed down to leave the pulp exposed, this will age the horses’ teeth dramatically.  It leaves the tooth exposed and to put it in simple terms, if you did that to a humans tooth, you would be sued and charged. 

Unfortunately the number of cases in which poor dental work has resulted in abscesses is on the rise.   I have consulted a number of vets, surgeons and dentists both in the equine and human field and they all agree, you should never file the tooth down so the pulp is exposed.  There is no scientific or logical reason for doing this and can be considered cruel. 

You should consult a equine dentist who is also a vet as he/she will have the means to x-ray your horses mouth.  A vet who specialises in equine dentistry has a greater understanding of the physiology of the horses mouth and has the background medical experience that a normal dentist would not.

Hope this helps.

 


 

 

 

 

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Dear Horssemicro: so much is obvious from the extensive information I have given above. No one questions that premature exposure of the pulp that occurs as the result of dental procedures is malpractice. If there is a practitioner out there who is cutting so deeply into the teeth that the pulp cavities are exposed, whether that individual is a veterinarian or a layman, they need to be stopped.

This does NOT mean that incisor reductions should not be performed.

Premature exposure is in my experience very rare, as is heat-induced damage to horse teeth from rotary equipment.

So again I want to emphasize: the MOST COMMON reasons for pulpal abscessing are:

(1) The premature exposure of the pulp cavities in cheek teeth due to the failure of the dental practitioner to properly equilibrate the mouth, i.e. their failure to reduce the incisors as part of the proper treatment for an animal that is pounding the centers out of its cheek teeth. In this case, it is the abnormal up-and-down action of the jaws (forced on the animal because the shape or length of the incisors prevents normal side-to-side excursion) that unroofs the pulp cavities, not any dental procedure.

(2) Fractures to the teeth, which come either from accidents during cheektooth reductions using molar cutters, incomplete extractions that leave sherds in the alveolus, or instances where the horse has hurt himself by biting down on a rock (cheek teeth) or by cracking his muzzle against a post (incisors).

(3) Caries that penetrate to the pulp cavity, either from the gumline externally, or via the infundibulum (especially in cases of incomplete/poor mineralization of the teeth).

It is my purpose, Horsemicro, in this Forum to dampen or eliminate the expressions of anyone who posts for "political" reasons. If you are a veterinarian making noise about "an increasing frequency of pulpal exposures", then before I permit you to mention this again, you will have to present survey documentation of the trend you think you see. And, you will also have to show that the increase is, in fact, due to poor dental practices rather than any of the array of other (and more likely) causes which I have outlined above. Scare tactics and political posturing will not be permitted here. If you have good information to share, then you may do that. I want to see that your primary motivation is to help the horses, rather than to help yourself or line the pockets of some guru whom you follow. So, as a prerequisite to permitting you to post here again, I will require in your case that you post using your true name. Transparency must be the first law in this discussion. -- Dr. Deb

horsemicrobiology
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Hi Dr Deb

 I am from Qld, Australia, please forgive me as I am new to this forum, are you aswell from Queensland Australia?  Secondly, are you a Dr, Vet?  Thank you for your quick reply.  I believe that talking about this issue is the first step to resolving and I think its great that we are able to share our different knowledge.

 I have been lucky enough to view an array of photos taken of these horses mouths where their front teeth have been filed down by a diamond drill to expose the pulp, this in conjunction with the overheating of tools has lead to pulp death. 

Pauline - it is this reason that human dentists have water that squirts out while they are filing down our teeth.  Unfortunately the photos I studied show clear misuse of tools and have ruined these horses teeth beyond repair.  The pulp cavity, as we all know should be hard, but in these horses they are as extremely soft as the vet who took these photos was able to stick one of his probes right into it.

Obviously there are other reasons that can cause tooth abscesses, however in the case it is my belief that alot of them have been caused by poor dentistry.  It is a shame because I do not believe these people know the damage they are causing. When I consulted experts they couldn't find any logical reason for these people doing this.

I am extremely interested in seeing how this unfolds over the next few months and years.  Dr Deb people here are starting to send complaints into the board about this so it will be interesting to watch how it unfolds. 

Looking forward to your reply

 

 

 

DrDeb
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Horsemicro -- this will be your last opportunity to communicate in this Forum under a pseudonym. You will henceforth post under your own true name, as I do, and as Pauline Moore does. If you post even one more time under a pseudonym, we must assume that you have something to hide, and such persons are not welcome here. Posts from you under any name but your own from henceforth will be pulled, and your access to this Forum will be blocked.

I am not from Queensland, but have taught there, in NSW, and in SA for years. I am quite familiar with conditions in your part of the world. I am also personally acquainted with many veterinarians and laymen in your country who practice equine dentistry. I know who is confused and who is not, and as I have already said, there are problem veterinarians as well as problem laymen.

As to my qualifications, you may view them by going to "Friends of the Institute", where the brief bio is posted. My degree is Ph.D. and the title is vertebrate paleontology, a degree which requires extensive training in animal anatomy.

For better than 25 years, I have taught equine anatomy to anyone who cared to either read the publications, or enroll in a class. My work has been featured in every major horse publication, and I am a major contributor to the prestigious Animal Science Encyclopedia published by Elsevier Scientific. I have been an invited speaker to many veterinarians' organizations, and to dental organizations where the audience included both laymen and veterinarians. My anatomy classes are now recognized by the American Association of Equine Practitioners, a subgroup of the American Veterinary Medical Association, for continuing education credit for licensed veterinarians. This is a great honor, and an acknowledgement that the education and experience of a non-veterinarian can, at a high level, be of benefit to licensed veterinarians. 

Your own fears and concerns about equine dentistry might be greatly relieved if you would sign up for one of the anatomy classes which we have scheduled for this April in Tamworth, NSW. Contact and enrollment information is posted under "Catching up with Dr. Deb".

Our readership here should also be alerted to the fact that currently, there is a telephone campaign -- I do not know who is promoting it -- within Australia, where horse owners are aggressively being solicited to testify against lay dentists. This is an underhanded way of pressuring people who don't always have all the facts, and who are not in a position to discriminate, into testifying. It's a tactic that has previously been tried, without great success, in the U.S. In other words, it is politics, not science, and should be beneath the notice of quality practitioners AND horse owners alike. 

There is a movement currently, worldwide, to bring the most qualified people into the field of equine dentistry. Many veterinarians do not care, or are not physically able, to perform the tasks that equine dentistry would require. In view of the fact that there are many horses who need care, and owners who are demanding better care, we are working to develop meaningful training and certification which ANYONE -- licensed veterinarian or layman -- who wishes to practice equine dentistry would have to pass. This is the right way to go. It is absolutely foolish to assume that just because someone has a veterinary license, that that automatically qualifies them to practice animal dentistry. Animal dentistry requires extensive, specialized training and I am one of those in the international community committed to seeing that we make all the changes necessary to see to it that any animal that needs it receives proper help from a qualified practitioner. --

Dr. Deb Bennett, Ph.D., Director

Equine Studies Institute

Livingston, California

 

 

Last edited on Sun Mar 8th, 2009 11:28 pm by DrDeb

JTB
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I was looking up Tooth abscess and found this excellent thread-- bumping it so I can find it again later. I have a new vet/dentist coming this week as Little might have a tooth abscess. I am doing some study to refresh my memory :-)
Many thanks for the wonderful information provided in this forum.
Kind Regards
Judy

DrDeb
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Judy, I'll be interested to hear the whole tale about this, especially since I know the horse well. And if the vet takes digital XRays if you could ask him to give you copies on a disk, and then possibly EMail some of them to me. Cheers -- Dr. Deb

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We see the vet/dentist on Thursday and I will happily give you copies of any x rays and let you know the tale. :-)
Thanks heaps.

JTB
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The horse dentist/vet came and checked out Little's teeth and lump. At present the lump is not worrying her so it was decided to let it all be, he floated her teeth as she had some sharp bits to take care of. All looked good in her mouth with nothing looking like it was brewing. If the lump flares up the next step is x-rays.
Many Thanks
Judy

DrDeb
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Judy, you didn't mention a lump before. Please describe size, exact location, whether it is hot now or has ever been hot, and how it palpates (hard like a rock, soft but firm, soft and squishy, etc). Lumps that appear on jaw or skull are almost always something to be concerned about. Let me know. Cheers -- Deb

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Hi Dr Deb,
I tried to attach a picture but it is too big and I don't know how to make it smaller. I will try and Email it to you.

The lump has never been hot. It is on the off side a couple of inches below her eye, in the sinus region, I thought it looked like it could be tooth root level, hence the abscess idea. It is hard and never worries her when ridden or palpated. It is about the size of an old Aussie 50c piece. It got a bit puffy for a week and I thought it was bothering her a little bit then but still not hot. No eye or nose discharge. The puffyness was not there when the vet came just the hard as bone lump.

Many Thanks for you interest.
Cheers Judy

DrDeb
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Judy, to change the size of an image  you need some kind of software that is meant for processing images. Common packages are Photoshop, Photoshop Elements, Picture Editor. Your laptop or mainframe might have come with one of these already installed; look through your programs list.

When you find/obtain the software, boot it so that the program opens. Then browse to the file that is the image you want to send me/post in the Forum. Open that image.

Then go to "image", then click on "size". You will see two measures of size:
1. the width X height of the image;
2. the pixel density given as "dpi" (dots per inch).

Steps:
First, select the width to be 5.8 inches. The software will probably have a little sub-menu that lets you specify inches, cm's, tenths of an inch, etc. Once you select the image width, you don't have to worry about the height because (unless the button that locks the width to the height is unchecked), when you change the width the height will change in exact proportion.

Second, select the pixel density to be 300 dpi.

This will create a file of about 8 megs, which should post just right in the Forum. Before posting, you need to save the file. Save it in .jpg format -- use the sub-menu that will appear when you click "file" and "save as" (do not click the button that just says "save"; use "save as"). So you save it as a .jpg, and that's the format that will transmit over the Internet the best, and is also compatible with our Forum software.

After you save your file "as" a .jpg and post it in the Forum, you should also save it again as a .tiff. This costs more memory but guarantees that the file will not degrade over time. NEVER re-save a .jpg image as a .jpg; over the long haul, this creates the same effect as photocopying a photocopy, then photocopying the copy of the photocopy, etc.: eventually the whole image will just be "static".

I do really want to see the photo. Cheers -- Dr. Deb

DrDeb
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OK, I just received the image of the lump by EMail. I did forget to mention the alternative to learning how to use Photoshop, and that's called "ask the husband" -- LOL.

Little has a fractured molar, Judy. You need a consult immediately with a licensed veterinarian who has experience in equine dentistry. You need a diagnostic XRay right away, as a first step before deciding what else must follow.

Depending upon the training of the professional you employ, the fractured tooth will be removed (it MUST be removed) either through the mouth, or else by trephination of the skull. Trephination involves cutting a hole through the lump, through the skin and bone overlying the top of the bump. It is actually in many cases more convenient, especially as per the after-care that will be necessary, to do it that way; but intra-orally is fine too.

It's a good thing you've been taught how to have a good relationship with your horse. Unbroke, frightened, self-defensive horses often do not do well with dental surgery after-care, because what it will involve is you needing to pack the empty tooth socket with some kind of antiseptic-soaked gauze daily, and perhaps also apply a little counter-irritant at the direction of the surgeon. The object will be to get the empty alveolus to fill in with granulation tissue as soon as possible, so that when the mare chews she does not drive food material right up the empty alveolus, like a chimney, straight into the sinus where it will provoke a further, and worse, abscess.

So the vet is going to take XRays to determine which tooth is fractured and the nature of the fracture; and then he's going to extract that tooth. The extraction can be done as a stand-up procedure whether it is a trephination or an intra-oral procedure; but it can also be done as a full-anaesthesia laydown. I've seen it done very skilfully by laying the horse down on a clean, grassy lawn; but also of course in a clinical setting on an actual surgical table. Full anaesthesia is more expensive; if it can be done as a standup, it will be less costly. But you must do as the surgeon advises.

You do not have a lot of time before you will have a pussy discharge from the nostril on the affected side. There will not be a discharge from the other nostril, as it is not connected to the source of the pus. Look for increasingly foul breath and for the horse to go off its feed and/or show some signs of mild colic. Again -- do not delay, because all these things will only get worse; this sort of problem cannot self-repair and the horse cannot help himself. Let me know what your veterinarian says. Cheers -- Dr. Deb

Attachment: Judys pony mare Little abscess lump SM.jpg (Downloaded 110 times)

JTB
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Wholly shit on so many fronts. I have a lot of photos stored as jpegs thinking they would be fine, I need to go and look at them and see if they are 'fading' will have a play with the reducing the photo size as I have an old photoshop but it always is a mystery to me. Thanks so much for the information on the photos, I was going to ask Hubby but he wasn't around when I was trying to post them. :-)

Poor Little!! How would she have fractured a tooth!!! I took my colt to Massey to be gelded as he had a retained testicle a few months ago. I have contacted the excellent Vet there to see who he would recommend. My Vet/Dentist said it was out of his hands if the lump flared up--needed further treatment. We have a local Vet/dentist who are closer, they might be the best bet for the xray. I will get onto it and keep you posted Dr Deb. Thanks so much for you time and will keep you up to date and send any Xrays.
Best Wishes
Judy and Little

DrDeb
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Another horse probably kicked her in the head. Or else, she bit down on a pebble. Or -- her teeth are badly out of equilibration and the tooth that split is the first molar, the "M1", which is the oldest tooth in the head and the first to wear out with age. Of the three possibilities, I'm betting on "bit down on a pebble" since Little isn't geriatric I believe.

As to Photoshop: anybody at any time who has a question concerning Photoshop can write in here and ask me -- I've been using it since version 1.0 and can probably assist with that, or anything else having to do with graphics manipulation or production. Cheers -- Dr. Deb

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Many Thanks Dr Deb re the photoshop will have a play making the images postable then start on my next scheme for Photoshop as I really want to get a handle on it for looking at hooves and all sorts of stuff!

Re Little's tooth, everyone's Birdies have flown away for Christmas so it will be mid Jan before I can get anything done.

I can get my usual vet to do the initial x ray and if there is anything further she would probably go to Massey or I can use other local vets who have two vets who do the dentistry. Both lots are away for the break.

Merry Christmas and Happy New Year to all who post and learn from this valuable forum. Huge thanks to you Dr Deb for all your energy and generosity for providing us with the space to learn so much about our friend the Equine.

Best Wishes
Judy and Little

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Hi Dr Deb and All,

Last Friday Little had her x rays of her lump. I got the results back yesterday.

She has a fracture on tooth number 107, plus a small abscess and now will have it extracted or I am getting a price on something called 'Endodontic treatment' when they try and save the tooth. Have you heard of this Dr Deb? I might have spelled it wrong.

I am waiting for a copy of the xrays and will post once I get them. Many thanks for the heads up on this.

Kind Regards
Judy and Little

DrDeb
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Judy, if it is possible to save a fractured equine tooth, this is technology so new that I am unaware of it.

'Endodonty' just means dental treatment done with reference to the inner parts of teeth. The commonest 'endodontic' human treatment is root canal, or nowadays, also putting in the metal peg that anchors an implant is also called 'endodonty'.

Anyway, no human procedure will be anything like what would be done on a horse. And I would be very cautious around new technology. At the very least I would ask for a second opinion, from another veterinarian. If it could be done, it would be wonderful as saving you a certain amount of after-care. However, I would also foresee certain complications that could arise, so that ultimately you would wind up extracting a failed attempt to repair the tooth anyway.

Are you going to do this before our clinic? Because it's definitely going to bother Little to be ridden with a fractured tooth. Do you have another horse you could ride? Cheers -- Dr. Deb

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Thanks again for the help, I will just get the tooth extracted. Little will have time off from riding now till she is fully recovered. She has had this lump since October so I am wondering if it would be better to act early Feb or could I leave it till the end of Feb? If I leave it till later I will have time to prepare my young horse for the clinic :-) I am happy to come and audit but riding is soooo much FUN!

What preparation can I do with Little to help her after care, so she is okay with it?

Best Wishes
Judy and Little

DrDeb
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Well, Judy, normally I would say 'don't wait to get the horse some help,' and indeed I already did say that. However, I trust your observations with Little. If you honestly can say she is not in much distress; if she continues to eat her full quantity of feed each day, even if more slowly than normal; and if your vet says 'OK', THEN I will say it's fine for you to come and ride in the clinic. Being at the clinic will only delay the extraction a few days. I admit, also, to desiring to meet your young horse and having you work with him under my eye at the clinic. Here's our opportunity to get started with one, entirely on the right foot so to speak.

As to what to do to make aftercare more pleasant for all parties concerned: the more you work with Little's head beforehand, the better. Most horses frankly do not like having their head, especially the muzzle, handled. So, this is not about giving treats, but about teaching Little that it feels good to have her muzzle handled. Once they're introduced to it, many horses love having their gums massaged -- i.e. you work your fingers around the front teeth as far back as the canines/bars. If she takes to this, it will be much easier for you to get into her mouth to change packing, which I expect will be needed.

I am, however, not absolutely clear on what your aftercare regimen is going to be -- because I don't know how they're going to do the surgery. If they trephine her, i.e. extract the tooth by making a hole in her face and then they take it out by pullling it upwards -- that has the advantage of not needing to get into her mouth two or three times per day. However, nowadays intra-oral extraction is far more common. They might also trephine her just for your convenience, Judy; the cutting of a hole in the bone of her face is actually not a big deal, for the bone in that area is rather thin. This is why it can swell up so when there is an abscess/buildup of pus putting pressure on it from below. So, ask your surgeon what the specifics of your aftercare regimen are going to be, and then write me back if you need to for more suggestions on handling. What we want to avoid is getting the mare resentful so that it becomes a daily fight resulting in needing to tranq her in order to change her packing. -- Dr. Deb

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Thanks again Dr Deb for the feedback. I have contacted the Vets to check if they feel it would be okay to leave it till after the clinic and should hear next week. Little has managed to gain 10 kgs since the lump appeared.
I would very much like your guidance with my young horse, China. Will see what falls into place.
Best Wishes
Judy and Little (who is enjoying her gums being massaged :-))

Last edited on Fri Feb 1st, 2019 07:21 am by JTB

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Hi All,

I am seeing if I can post these at the right size. These are Little's xrays and apparently they show a tooth root fracture and a small abscess. I am not sure of the offending area as I haven't had a sit down with a vet to show me what I am looking at. The offending tooth will be extracted early March. She continues to be her normal self. Cheers Judy

Attachment: Little0003-2-crp.jpg (Downloaded 27 times)

Last edited on Sat Feb 16th, 2019 06:16 am by JTB

JTB
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second image.

Attachment: Little0001-1-crp.jpg (Downloaded 27 times)

Last edited on Sat Feb 16th, 2019 06:15 am by JTB

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It worked! Thanks for the tips Dr Deb!

Attachment: Little0005-crp.jpg (Downloaded 83 times)

Last edited on Sat Feb 16th, 2019 06:12 am by JTB

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Hi Dr Deb, Little finally gets her tooth out next Monday...April the 1st! Be so good to have this sorted.

Re the converting the jpg image to tiff, so the images keep longer with no loss of quality. Is there a way of doing this for multiple images at once or do I do each one by itself?
I have spied the post of images wanted, yipee will have a look at my collection. Super fun clinic thank you for coming.
Kind Regards
Judy

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Judy, so far as posting images into the Forum, so far as I know, you can only put in one image per post. So if  you want to post three images, for example, you post the first one and then "reply" to yourself two more times.

As for converting .jpg's to .tiff's (or the reverse), yes, either .tiff or .bmp are the only two formats that do not involve compression upon re-save. In other words, with a .jpg or a .png or any other format, if you take that image that's in that format and open it and then maybe you work on it or change something about it and then you hit "save", the algorithm selectively removes pixels. Different formats, i.e. .jpg as opposed to .png for example, use different criteria as to exactly which pixels they remove, but all of them remove them. That means that if you save a .jpg once, and then open it and save it again, and keep doing this, eventually the image will degrade to pixel mush. This is similar to what happens when you make a photocopy of a photocopy of a photocopy...
eventually it's so "dirty" and so full of "static" that the image is obscured.

I know of no way to batch-convert .jpg's to .tiff's or the reverse. To convert a .jpg to a .tiff you just "save as" a .tiff. Please note the big difference between "save" and "save as" !

Let us know how Little's surgery goes, and thanks very much for noticing I need photos of students doing their "homework" at home. The new website is going to be AWESOME. Cheers -- Dr. Deb

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Little had her tooth extracted on the first of April. They ended up removing it through her mouth and no hole was made in her skull. The hole the tooth had come from was not packed with anything and 16 days later she is eating soaked hay and looking like nothing has happened. I have attached some pictures of the tooth. The vet/dentist who removed the tooth was excellent. He found a small dental remnant which is pictured. It took two hours to gently wriggle the tooth...well the dentist was sweating and we were cold....Then more x rays were taken to make sure all the tooth was gone. It has started to go a bit squashy on the root tips so it was high time it came out. A good job done. :-)

Attachment: tooth 1.jpg (Downloaded 40 times)

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Root of the tooth.

Attachment: tooth2.jpg (Downloaded 41 times)

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Some of the students who watched the extraction enjoyed sticking a needle into the hole!

Attachment: tooth3.jpg (Downloaded 41 times)

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Eight year old Little's tooth next to a 25 year old Shetland tooth that was so wiggly the dentist was able to remove it quite easily.

Attachment: tooth6.jpg (Downloaded 41 times)

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Judy, "a bit squashy" would hardly describe it, I think....it should have stunk to high heaven.

The reason the students wanted to put a wire or needle into the tooth root was that they were probing for a defect in the way the tooth formed. There has to have been a reason why Little got the abscess in the first place; these things don't just develop out of thin air. So either the tooth is in fact fractured -- which your vets are saying is not the case and that's what the XRays show too, no fracture; or else there was a malformation.

This would show up clearly in the one view of the tooth which you do not present, which is the occlusal or chewing surface...if you get time, it would be nice to see this view. There must be a channel through the length of the tooth whereby food material can be packed down through it, through the length of the tooth and into the depths of the tooth, and then ferment and rot, and eventually with continued chewing or pressure from the bolus in the mouth, this stream of tiny rotting particles gets pushed all the way through the length of the tooth and emerges through the tooth root into the maxillary sinus. The large radiolucent (clear black) area on the XRays shows the amount of pus which had accumulated in the pony's maxillary sinus, the pressure from this expanding wad of pus being great enough to actually warp the bone of her face outward to form the bump that warned you in the first place that something was amiss.

I attach an image of the interior structure of a horse's cheek tooth (any of the three large premolars and three large molars that comprise the cheek-tooth row in each quarter of the mouth, of which the extracted tooth is one, to wit, the third from the front, which is the most posterior premolar tooth). You see in the drawing I attach a couple of things:

(1) Horse teeth are formed of three biogenic materials, enamel, dentine, and cementum (colored differently in the drawing). These materials appear to be interfolded when you look at the occlusal surface of the tooth -- the enamel in real life not being purple, but having a whitish appearance similar to cloudy quartz crystal. The dentine and cementum are both in actuality yellowish, although the dentine is of two types, primary and secondary, with the secondary dentine a darker yellow verging on brown.

(2) I said the three tooth materials 'appear' to be interfolded when you look at the occlusal surface. In actuality what you're seeing on the occlusal surface is a cross-section of a bundle of tubes the size of small straws. The surfaces of the tubes are highly wrinkled -- look closely at the wiggliness of the enamel outlines -- but nonetheless when you turn the tooth 90 degrees and consider its length, its length is the length of the bundle of tubes and its circumference is the circumference of the bundle plus the bundle's rather thick wrapping. The bundle's wrapping is cementum, so that the bundle is wrapped like a hot dog cooked inside of a biscuit (do you do this in New Zealand? They're good at a barbecue, and in America they're called 'pigs in a blanket').

(3) The deficit of which I spoke above is rather common, and represents a failure during the development of the tooth which occurs before the tooth erupts, while it is still developing inside the horse's skull or jaws. The failure is of the deposition of cementum. The generative tissues which lay down the fibrous architecture of the tooth and then precipitate the mineral substances which make the tooth hard are a perfect template for the tooth's complex interfolding. But some of those foldings or wiggles are so tiny that the generative tissue in that area is either too thin or never forms, so that whatever tooth substance that particular ply of tissue was supposed to have laid down never gets laid down. This is especially likely to happen with the cementum, which is found in two places in cheek teeth -- on the outside, as I mentioned previously, to form the 'blanket' for the pig-in-a-blanket. But it also is supposed to pack the infundibulae -- the infundibulae are supposed to be filled with cementum from the tooth base near the roots, all the way to the occlusal surface.

The infundibulae are marked on the drawing; they are also called enamel lakes, because their 'shorelines' are formed by enamel. Visualize them as an enamel tube filled with cementum (green) that runs the length of the tooth from root to occlusal surface, as the illustration shows. When an infundibulum doesn't fill with cementum during development, the tooth erupts into the mouth having a hole in it, i.e. one of the tubes is empty or partly empty. When food gets packed down into the dark, airless base of the empty tube, it ferments and produces acids which then erode the enamel 'cup' and the dentine zone which are supposed to separate the root from the infundibulum. Notice that the purple enamel at the bases of the infundibulae is comparatively thin.

There is also another possible channel where a wire could be passed through a tooth, and that would be through the so-called 'dental star' which represents the appearance of the distal end of the pulp cavity at the occlusal surface. These are never supposed to be open under any circumstances, because the pulp itself is full of thousands of tiny arterioles, i.e. it has a rich blood supply, and if the pulp cavity is opened the tooth will bleed and then it will most certainly abscess.

In a normal horse, the act of chewing and the wear that this produces on the tooth are coordinated with the deposition of secondary dentine, which is there in order to keep the pulp cavity roofed over. Also, certain cells in the pulp are pressure-sensitive and as the tooth wears down these cells signal the pulp to continually retreat toward the roots so that there is no danger of the distal end being broached. However, it can occur that secondary dentine is not laid down quickly enough, or that something the horse is eating is creating an acid environment in its mouth, or that the grind is out of equilibration enough that the horse can't clean (and this creates an acid mouth also), and under those circumstances you essentially get a cavity in the tooth which opens the dental star at the top. Food then gets packed into that, which ferments and acid-erodes the secondary dentine, thus broaching the pulp cavity and quickly leading to abscessing.

So what the students were doing with the wire was probing into the tooth roots to see if they could get the wire to emerge through one of the infundibulae or else the dental star at the occlusal surface, because this would prove the existence and position of an open channel.

Your lesson in equine anatomy for the day. Cheers -- Dr. Deb


Attachment: Horse tooth 3 materials infundibulae SM.jpg (Downloaded 38 times)

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I haven't used Photoshop in years, but it does have the ability to run a "batch" program. I would think you could batch convert the files from one format to another.

Dr. Deb, doesn't Photoshop do this?
Other imaging handling programs may have a similar feature.

I can explain more the process I used to use in Photoshop if that would be helpful.

Very interesting thread. Thank you for sharing.

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Aloha, I don't understand your comments. Are you in the wrong thread? -- Dr. Deb

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Sorry! Judy asked above (see 2nd post above on this page) about converting multiple JPGs to TIFs.

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Oh. Well, I have no way to do that on my computer and never have had. If someone else knows how to do that, well the knowledge would certainly be handy. Be aware that I am still running Windows XP (with back versions of all software, which I had previously purchased) but peoples' comments would probably apply to later DOS's. Cheers -- Dr. Deb

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Thanks Aloha, I have stopped worrying about doing batches of photos as I had the wrong end of the stick. I have it all sorted out now!

Dr Deb, thanks for the tooth anatomy lesson, I had lots of questions about it and you have answered them, I was going to try and find the answers in my notes from when you came and did the teeth talk years ago. I have attached the images you requested. There are two black holes in the chewing surface, I have poked a needle into these holes and it goes in about two millimeters without me pushing too hard!

As an aside- I have the tooth in a plastic bag in the fridge and how am I best to preserve it, the Shetland tooth was dry and just needed a wash when it came out so I didn't 'do' anything to it. Shall I leave it out in the sun for the flies to clean up?

I took the tooth to my own dentist and he was only mildly interested, wanted to know how they got it out.

Is this issue likely to flair up in some of Little's other teeth if it is a malformation?

Thanks heaps for your time.
Kind Regards Judy

Attachment: tooth4.jpg (Downloaded 21 times)

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Another photo without the Shetland tooth.

Attachment: tooth7.jpg (Downloaded 21 times)

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Aha. Well, you can see for yourself that two of the infundibulae do indeed have deficits, they are not completely filled with cementum, so that you can see a 'hole' on the occlusal surface. The inner edges of the deficits are smooth rather than eroded and rough; the latter would indicate caries. The dental stars and secondary dentine are normal.

Now, the tooth as a whole as viewed from the outside appears somewhat abnormal; it is plumper at the center than most, and somewhat twisted or spiraling. This may indicate that the tubes wander or spiral in about the same degree. Sometimes also, when serial sections are cut of a tooth (cutting it into slices like a loaf of bread), one finds that the infundibulae (or sometimes the pulp tubes) pinch off down to a tiny pinprick in the middle but reappear at normal size as you go out to either the root or crown ends. But it may also be that the infundibulum is clogged with packed food debris -- and I actually think this likely even if the tooth is somewhat malformed.

This will be cleared out as you clean the tooth up. Just put it in a pot of water and set the pot outdoors in some sunny spot. There, all the fleshy remnants and the blood, as well as any food particles, will rot. This technique of specimen preparation is called 'maceration'. You'll need to keep the pot topped up with water, and leave it for quite a while -- since it is coming winter now in NZ, you are probably looking at next spring or even later.

Alternatively, you can prep the specimen on the stove. Get a pot and put a layer of wire in the bottom -- this can be a folded piece of wire screening, or perhaps you have a big pot that's used for canning and they come with wire 'bumpers' that you put in the bottom so the glass jars aren't sitting right flat on the bottom of the pot when it's on the fire, which might overheat them and cause them to burst. That's the idea here too; the specimen must not be allowed to touch any of the metal surfaces of the pot.

Once you've fixed it up so this won't happen, then put the pot on 'simmer' -- not boil -- and give it an hour. Then, using tongs, remove the tooth (it will be very hot) and lay it on a paper towel until cool enough to handle; then rinse and try your wire again.
You may need to 'simmer' two or three times to get it as clean as possible. Use a small, intense flashlight to look up into the roots to see if there's still material up in there, or probe gently with your wire to see if any rubbery-like material comes loose.

DO NOT put lye in the water; that will decalcify the specimen, and for the same reason, DO NOT bleach it with household bleach after you finish. You can put a little Pine-Sol (stuff you mix to mop the kitchen floor with) in the water; that will make the specimen smell nicer and the mild kind of soap they make that cleanser with will help clean the specimen without damaging it.

The other thing I wanted to mention is, notice how much bigger the openings for the pulp at the root are in Little's tooth are, than in the more worn tooth from the old pony. This is because, as the horse and its teeth age, the circulation to the pulp gradually dies and the pulp itself gradually dies at the root end. As this happens, the cells that maintain the tooth and that lay down cementum close the holes in the tooth roots through which the circulation to the pulp enters, until those openings are no bigger than pinholes. Then when the dentist comes to help the horse get rid of an old, loose tooth it comes out easily. Little's tooth was not 'supposed' to come out at such a young age, so the surgeon had to work at it considerably to get the vessels feeding the pulp to break. You probably, at some point, if you were in the surgery room, heard a 'sucking' sound from the tooth; that's the moment when the circulation got broken.

Further, horse teeth are held into their long sockets, which are like farm silos, by strong ligaments which span from the inner surfaces of the sockets to the exterior surface of the tooth. These ligaments help the tooth erupt iteratively as it wears, so that the height of the cheek tooth battery within the mouth is continuously maintained. But when extracting a young tooth, the dentist has to break a whole length of them because younger teeth are longer. In the geriatric pony, there were hardly any stabilizing ligaments left, and indeed if the dentist hadn't happened to come along, the pony would have spat the expired tooth out itself at some point.

The last thing is this: your occlusal-view shots make this show up very clearly. Notice that on the lingual (tongue) side of the tooth which shows in the photo, (and almost certainly also on the buccal or cheek side of the tooth), there is a rough, eroded band which would have been located just above the gum when the tooth was still in the mouth. This is the result either of feeding sugary bagged feed, something else sugary, or else the whole dentition is far out of equilibration so that the horse can't fully excurse the jaws (move them from side to side) when it chews and thus cannot clean the buccal pouches. Do you have 'Wheat Thins' crackers in NZ? I'm sure if not sold by that name there is something similar: thin, crisp little squares with a sweet-nutty flavor but BOY do they stick to one's teeth. So you take your tongue and you put it in the space between your teeth and your cheek and you work at cleaning the gummy stuff off the outsides of your teeth. Or maybe you use your finger or a toothbrush. But the horse has no fingers and no toothbrush, and he also cannot put his tongue into the buccal pouch.

Little's teeth are not out of equilibration, however; I have mentioned this for the benefit of other readers. In her case, the eroded band -- which is called 'gum line caries' -- is the result of something sugary in the diet. What could that be in her case? Ordinary sugary grass doesn't cause gumline caries, and neither does ordinary hay. Is she getting some kind of numnuts or sweetfeed?

Insofar as she has gumline caries, I also have to suspect that once you get your tooth cleaned up by maceration or simmering, you will be able to pass the wire cleanly through.

And by the way thank you VERY much for the photos -- they'll appear in our new ESI website when that's ready, probably in another month. Cheers -- Dr. Deb

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Thanks heaps for this reply, Dr Deb, this has been such a learning experience on so many levels.
I opted for putting the tooth in water out near the back door so I can keep it topped up, it is looking cleaner on the outside already.
Re Little's diet, she hasn't had sweet feed or pony nuts while she has been with me, she has been getting sugar beet rinsed and soaked while her tooth socket is healing and all her hay soaked. She gets adlib grass hay with the Shetland herd usually. Chaff and Copra was the feed of choice but I have moved the herd over to chaff Meadow/Timothy/ Oaten and sugar beet as the quality of the copra was not good enough, I had found weeny stones in it that I blamed for the tooth issue!!
I brought her from a riding school and I can't imagine them feeding her sweetfeed but she was in another home prior to that.
Best Wishes
Judy and Little




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