Equine Dental Providers of America



Equine Dental Providers of America

~Case of the Month~

Case of the Month: Equine Odontoclastic Tooth Resorption and Hypercementosis

By: Richard O Miller, DVM, IAED/AC

January 2013

EOTRH has been a hot topic lately, with at least one presentation delivered at every dental conference in the last two years. More material is in store for this coming year but up to this point, scientists agree that it is well named – Equine Odontoclastic Tooth Resorption and Hypercementosis, but still the cause is unknown. Extensive histological (microscopic) examination has been performed with little results. It is thought by some that the answer would be found at the interface of bone and tooth. Clinically, the most common form is the hypercementotic type but some report that if all possible cases were radiographed, many more of the odontoclastic type would be diagnosed. It is thought that the latter type is more painful. The former type does not seem to elicit as much response on digital pressure. The only treatment is extraction at this time and here is where opinion divides. The academic position is that the incisors are all infected and extract them all at once. Attempts at suturing this major defect has met with dehiscence and eventual second intention healing. A more conservative approach has been the extraction of the most severely affected teeth (as was done in the case above) , complete debridement and curettage of the sockets and allow the area to heal by second intention. The latter seems to give some relief and anecdotally appears to slow, if not arrest the progress of the disease. Eventually more extractions will be necessary.   Herbal supplements have been suggested as palliative but evidence of such are few.(photos courtesy of Ashley Yarborough)

Richard O Miller, DVM, AIED/AC

23411 Via Alondra

Coto de Caza, CA 92679

949-233-0707

richdent1@



January 2013 Case of the Month: EOTRH

Case of the Month: Dorsal Curvature

By:  Richard O. Miller, DVM, IAED/AC

 

February 2013

 

Slurpy is a 13 year old QM, gelding from the collection of Joao Kunz, DVM from Brazil.

"A dorsal curvature, or "frown" was noted, which can occur if the lower central caps shed too early or also if the loss of the upper centrals are delayed. It is also quite common to see curvatures develop in instances where there is incomplete tooth formation.

 

In this case, it appears the upper centrals are still deciduous and have never shed. This aberration could be congenital or been due to early trauma, preventing the development of permanent incisors. This condition results in a progressively decreasing percentage of occlusion. As lateral excursion take place, the dominant lower central incisors and the dominant upper corner incisors cam off of each other, which leads to a premature separation and decrease in cheek teeth occlusion.

 

In my opinion, this malocclusion promotes the development of steeper molar table angles. The photos shows my correction. Annual reduction must be done to prevent the return of this condition.

Case of the Month: Molar Fractures

By: Joao Kunz, Veterinarian, Brazil

March 2013

There is a paucity of information in the literature regarding the incidence of molar fractures but we know that they are not rare.  Arguably, the most common maxillary tooth to be so affected, would be the upper 9’s.   In this case, the attending practitioner had previously felt that the 109 was vulnerable to fracture, due to significant infundibular cemental defects and/or caries and this tooth was filled with a composite.   The latter seems to have retained its integrity and may or may not have prevented a fracture.   But the previous procedure could hardly help the 110 which sustained a rather large palatal fracture.   Luckily the fragment could be easily extracted (without disturbing the palatine artery!) and no sinusitis was clinically evident. 

Case of the Month: Canines 

By: Richard O. Miller DVM, IAED/AC 

 

April 2013

 

Canines: the poor stepchild of dentistry.  We all know canines are an issue but they receive very little attention until they are abscessed and require extraction.  Very few cases will present in this extreme fashion but even minor deposits of calculus contribute to gingivitis and gingival recession.   Canines are the only brachydont  teeth that most of us deal with and they seem to “march to a beat of a different drum”.  When they erupt, usually sometime in the fifth year, they are reduced to eliminate the sharp points that may ulcerate the tongue and prevent contact with the bit as it is introduced  into the mouth.  They can also be a hazard for the operator/horse person.  Beyond that, the canines receive little attention.   Since the canines are rarely in occlusion, they tend to accumulate calculus but why this occurs mainly on the lowers is a subject for discussion.  I personally recommend weekly brushing of canines with chlorhexadine,  especially for older cases that persistently accumulate calculus.    

Richard O. Miller, DVM, IAED/AC

23411 Via Alondra

Coto de Caza, CA 92679

949-233-0707

richdent1@



Case of the Month: 

DENTIGEROUS CYSTS 

By: Richard O. Miller DVM, IAED/AC 

 

May 2013

 

Dentigerous cysts are of a developmental dental origin and have been described in several species and areas of the body, but the classic presentation in horses, is rostral to the base of the ear.   In the latter area, they are also known as a Temporal Terratoma.  The unilateral condition is uncommon but an even more rare case of bilateral cysts is well documented on Facebook from the Academy of Equine Dentistry (March, 2010).  Swelling is variable and the only visible sign may well be as noted in this photo.    If the lesion is palpable it is usually firm and on extraction, will be found to be composed of several elements of bone, tooth material and soft tissue.

Many practitioners will never see one, let alone be required to treat a case, but the message is that when confronted with a draining fistula at the base of the ear, a dentigerous cyst must be considered in the

differential diagnosis.  

Quality radiographs and a thorough knowledge of the local anatomy should be a prerequisite to intervention.

Richard O. Miller, DVM, IAED/AC

23411 Via Alondra

Coto de Caza, CA 92679

949-233-0707

richdent1@



Case of the Month: Diagonal Bites 

By: Richard O. Miller DVM, IAED/AC 

 

June 2013

 

This is obviously an extreme case that would not often be seen, but once corrected (in one session without exposing pulp), the cause was obvious, as the 303 is missing.  But the reason for some cases is not at all obvious and invite  contributions from those that frequent this site.   There is a school of thought that suggests incisor correction is unnecessary but it is only logical that a malocclusion of this magnitude, would cause considerable difficulty in mastication let alone seriously compromising temporo-mandibular joint (TMJ) function.   Opinions on both sides of the issue can be found in the literature but the facts are, out of 4000 cases measured with the instrument shown ( Maphorse 1, patent pending), nearly fifty percent presented with a diagonal bite of greater than two degrees, so this condition is quite common.  Also, logic suggests that horizontal/level incisors (zero degrees) is correct and normal.  

More food for thought is that DGL-3 malocclusions are twice as common as DGL-4,  in the large population studied (IGFP Proceedings – 2013).   The reason for this is unknown at this time and data refuting or substantiating this difference is invited.

 

Richard O. Miller, DVM, IAED/AC

23411 Via Alondra

Coto de Caza, CA 92679

949-233-0707

richdent1@



Case of the Month: Resolution of Facial Swelling

By: Richard O. Miller DVM, IAED/AC

Photos By: Dr Lizzie Dietrich, Brazil

 

July 2013

The facial swelling on this Mini reminds us that all maxillary dental pathology does not lead to sinusitis.  The post extraction  picture shows that the mid-sagital fracture of the 208 had sustained considerable periodontal detachment.  The resulting inflammation had deformed the maxillary bone as a path of least resistance rather than invade the rostral maxillary sinus or the nasal cavity.  A question often asked following extraction and complete resolution of pathology, is “Will the facial curvature return to normal?”  In my experience it will and this case shows near complete resolution in four months.  Experience of others is invited.

 

Richard O. Miller, DVM, IAED/AC

23411 Via Alondra

Coto de Caza, CA 92679

949-233-0707

richdent1@



Case of the Month:

Peripheral Cemental Necrosis (PCN)

By: Richard O. Miller DVM, IAED/AC

 

August 2013

 

PCN is not an emerging disease and probably has been with us for some time.   But once a condition has a name, then we think in terms of incidence.  My data base is following this condition but as yet I can best say that “I see it once in a while”.   It does not seem to be related to age, as evidenced by these images of a 5 yr. old Tb contributed by Graeme Martin from South Africa.  If you consider the bit seats severe, please don’t blame Graeme, as he was only the photographer!  For the first few years that I recognized this condition, I was unable to photograph them well because they always occurred  on the lower 9’s,10’s and 11’s – a difficult area to visualize, even with a mirror.  In the recent year, I have seen evidence of cemental necrosis in other areas but not near so graphically as pointed out in Graeme’s photo of the incisors.  Just as I say that it is an occasional finding, I do have two clients who each have five horses and four are affected – one of which is depicted in this photo of a 110. It has been brought to my attention by Lizzie Dietrich, DVM and Rebecca Green, RVT, that this condition has been reported in the literature as a sequel to Tetracycline therapy .  If any toxic exposure should occur during dental development, it could certainly explain the prevalence in only certain teeth but the photos also point out some other features.  Damage can be only superficial – resembling phyto-staining or the erosion can be 2-3 mm deep.  Also the lower 6’s suggest that regeneration of cementum can occur.   Since much of the roll of the cementum is to protect the much harder but brittle enamel,  one would suspect that micro and macro fractures and occasionally complete collapse of the molars will occur.  Just that has occurred in this case and others that I have seen.

Richard O. Miller, DVM, IAED/AC

23411 Via Alondra

Coto de Caza, CA 92679

949-233-0707

richdent1@



Wolf Teeth

Case of the Month: Wolf Teeth

By: Richard O. Miller DVM, IAED/AC

 

September 2013

 WOLF TEETH.  Why such a mundane subject?  Because it is often disregarded as such a routine procedure that casual observation only, will cause some embarrassing omissions.  The image of the buccally deviated 205 would be hard to miss but the sharp 206 hook just caudal to it, could be more of a performance problem.

Far more critical to performance might be this image of bilateral lower wolf teeth that were missed initially due to their close proximity to the 6’s.  

The image of the 400 arcade on initial observation was thought to be a severe 406 ramp due to the close proximity of the 405 and 406, but a closer look revealed it to be a very sharp wolf tooth that had severely ulcerated the cheek.

( photo contributed by Becca Green and Lizzie Dietrich, DVM.)

Richard O. Miller, DVM, IAED/AC

23411 Via Alondra

Coto de Caza, CA 92679

949-233-0707

richdent1@



Case of the Month: "Things are NOT always as they Seem."

By: Richard O. Miller DVM, IAED/AC

October 2013

This photo was contributed by Joao Kunz, DVM from Brazil.  At

first glance it would be easy to assume that the rather large ramp had caused

the tongue ulceration.  Certainly, it is sharp enough to have done so.  But a

closer look just caudal to that ramp, revealed a sharp piece of wood that was lodged in the diastema between the 306 and 307.  The last case I had seen

similar to this, had been radiographed – searching for a fracture, but of course nothing was seen as wood is not radio opaque.  Excess salivation was a feature in this case and is often seen with fractures and foreign bodies.  But, contrary to some of the literature, excess salivation is not usually a symptom of even extreme molar malocclusions.  So there are two things to ponder:    A ramp such as this will often cause periodontal disease, widening the space between the two teeth and further inviting foreign bodies.  And there is no substitute for a thorough oral exam.

 

Richard O. Miller, DVM, IAED/AC

23411 Via Alondra

Coto de Caza, CA 92679

949-233-0707

richdent1@



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