RE: Lingually displaced deciduous lower canines in labradoodles

Gerry Henry — Fri, 21 Aug 2015 15:52:57 GMT

Agreed; again thanks to all who contributed.

RE: Lingually displaced deciduous lower canines in labradoodles

Virginia Campbell — Wed, 19 Aug 2015 19:22:13 GMT

If your client is selling 30 labradoodle pups a year they can buy their own boat outright ;-) The forum poster loses all credibility with the single statement about being happy to breed from valuable PRAA carriers- it.s not as if there aren't enough clear Labs, or even Standard poodles, to breed from and still keep a diverse gene pool.

RE: Lingually displaced deciduous lower canines in labradoodles

Evelyn Barbour-Hill — Wed, 19 Aug 2015 15:56:19 GMT

[quote user="Gerry Henry"]My dilemma is this, I see these pups for neutering at 8 wks and I don't see them again.[/quote]

See what I mean about taking all factors into consideration? Yours seems an excellent policy in the circumstances.

RE: Lingually displaced deciduous lower canines in labradoodles

Evelyn Barbour-Hill — Wed, 19 Aug 2015 15:49:03 GMT

Hey, I I haven't finished with him yet.

"Ball therapy is nothing more than playing fetch with your dog using a tennis ball" Well, actually, there's a teensy bit more to it than that. The ball has to fit the area of the jaws concerned quite nicely. (Maybe a tennis ball does fit in an eight week old Labrador Retriever crossed with a Poodle, it could be so, I don't see vast numbers of that particular cross-breed) And the dog has to mouth it in the correct manner, frequently. Again, playing fetch may be enough.... or it may not. Finally, anyone with any knowledge of canine dentistry knows that tennis balls cause astonishingly rapid wear of teeth and are to be avoided.

"and it saves your purchaser hundreds or thousands...they will be grateful to know about it." Quite so. Which is why any veterinary surgeon who knows anything about orthodontics will be recommending it, if when all factors are considered it is to be recommended.

Mr. Dentist seems to be wrting in response to a question from some breeder. The way he says "your purchaser" makes it look as if he is suggesting that the breeder sell a puppy with an obvious malocclusion, telling the grateful purchaser "yeah, the teeth are like that, just play fetch with a tennis ball and they'll come right, so no, no discount , no refund"

" it is not a health issue or a genetic disease" Well, yes, if he's a breeder....... Mandy Rice-Davies to that.

RE: Lingually displaced deciduous lower canines in labradoodles

Gerry Henry — Wed, 19 Aug 2015 15:44:43 GMT

Thanks Evelyn, I'm most grateful for such a detailed response.

My dilemma is this, I see these pups for neutering at 8 wks and I don't see them again. We remove the canines if they are impinging on the hard palate, we let the client decide if they are not but we record our opinion and advice at the time. I probably do thirty a year and of the thirty we might get one that is referred later for crown amputation, so either it works or it wasn't going to be a problem in the first place! I think I am going to continue to insist on removal of impinging teeth, when all is said and done I can't believe its not uncomfortable, as for the others, we will have to wait and see. Thanks again for your input.

RE: Lingually displaced deciduous lower canines in labradoodles

Evelyn Barbour-Hill — Wed, 19 Aug 2015 15:29:34 GMT

Wow. That took a bit of digesting. I don't agree precisely with your policy, but this owner of two dental practices (I suppose he's a dentist?) is not correct either, despite having a few correct points.

Let us pass over the grosser insults. As a professional, this guy ought to know that being a human dentist does not make him an expert on veterinary dentistry (sad to say, some human dentists do have this attitude – we had one on this very forum a while ago) and his wallet-raping new boat comments are not just a joke coming from a dentist, they disgrace his profession.

I haven't had time to compose an essay so this is going to look like an assemblage of facts in random order yet all of significance .

We are all aware of the physiology and deciduous nature of deciduous teeth, I think, and we are also aware of the anatomical relationship of each permanent tooth to its deciduous precursor. Perhaps many of us are also aware that the physiological process leading to the shedding of deciduous teeth is not completely understood (in humans or dogs) but it is certainly not the same as that which leads to expulsion of a foreign body or a bone sequestrum (do human dentists really "often" leave bone fragments behind?), or even the hernia repair mesh expelled by "someone" this guy has "heard of".

Most of us have observed that jaws grow in mismatched ways in the puppy, yet may arrive when fully grown at a perfect occlusion and orthognathia. It is as if (this may not be the true physiology, but it is an analogy)) the mandible, although it has the same target as the maxilla, grows independently of the maxilla, while the more rostral part of the mandible grows independently of the more caudal part . (Remember these are, anatomically, "flat bones" and do not have epiphyses). Each bone might put on its growth spurts at different times, but the final size achieved is the same. Or, if the dog's genes script a prognathia or brachygnathia, the final result will be a prognathia or brachygnathia.

But, also, the final length of a jaw, and/or any associated malocclusion, can be influenced by extrinsic influences too. Which important point we will refer to again.

There are several ways in which lingual displacement of mandibular canines might arise (and a dentist unaware of this is just displaying his ignorance of orthodontics). Just a little consideration will show that it could be due to relative brachygnathism, relative prognathism or to a genuine relative narrowness of the mandibular structure (this last would be the true "base narrow", if you wish to employ that stupid term).

Certainly, a jaw disparity observed at 8 weeks of age is quite likely to have vanished at 6 months of age (but it may not have, and the more dogs one sees the better one gets at guessing which will not correct themselves).

It is often stated that lingually displaced canine teeth must be extracted, as they will physically block the emergence of the permanent teeth at the correct angle. I do not subscribe to this view. I cannot believe that the flimsy and naturally weakening attachment of the deciduous tooth can physically block the vastly bigger permanent canine tooth. However it is a matter of common observation that if the deciduous canines are lingually deviated, so will be the permanent ones. There are many influences on the angle of the erupting permanent tooth, and quite small ones have notable effects (hence for instance the buck teeth in children produced by thumb sucking; or for instance, the way in which some orthodontic conditions in humans can be corrected by simple "lip bumpers") So I would not deny the possibility of the deciduous tooth having a certain local physiological effect influencing the pre-eruption permanent. Moreover, there may be no genetic influence over the angle of eruption of the teeth (though personally I think there is), but there is certainly genetic influence over jaw length disparity and that is a common cause of lingual displacement.

"This is precisely why braces are not put on baby teeth nor on children until 10-14 years of age." Yeah. Nor on puppies until 7 or 8 months of age at least.

" I have seen Narrow base canines in a few pairings that have pierced the roves of the puppies mouths. This is not painful. We may want to humanize it assume that it feels like a puncture but it is different. " Yes, we know it's not a puncture, it's a patho-physiological response to excessive pressure. Of course, when it goes right through the palate, the difference is academic. But when you've "seen it in a few pairings" you know it's OK anyway. And can confidently assert, on what evidence is unclear, that it is "not painful". You might be right, indeed I would hazard a guess that you are, but that is because I can hypothesise that the proprioceptors and the pain receptors will adapt, not because I assert it.

Now then. If the displaced deciduous teeth have made themselves a pit in the opposing palate, they have formed a new occlusion and they are locked in that occlusion. If this has occurred while the deciduous teeth are functional, well attached and not resorbed, this lock will be exerting light forces upon the bones involved and is quite likely to have an effect upon bone growth. Oh yes it will. Ask an orthopod: if you put two kirschner wires at right angles to a mandible in an 8week old puppy, and join them with a neutral elastic, will there have been an effect on growth of the mandible and a consequent effect upon occlusion, by the time the puppy is 16 weeks old?

So, my policy. At eight weeks old, obviously at first vaccination the teeth and jaws get a thorough examination. If the lower canines are lingually displaced, we try to determine the cause and advise accordingly. As regards immediate treatment: if there seems to be little impingement on soft tissues, I don't firmly recommend extraction, but I do discuss the possibility and make a choice after bringing all other factors into consideration; and monitor closely (we'll be seeing the dog again at 10 weeks, probably 12, and then every four weeks till it's fully grown anyway).

If there's significant impingement on soft tissues, I recommend extraction: it might not be absolutely vital, but who can say for sure? Let us give the patient he benefit of the doubt, seeing as it's not expensive (would need an awful lot of them for an instalment on a boat.......)

If the puppy is older and the deciduous tooth is resorbing and happily contemplating exfoliation, generally I'd do nothing at that point. On the other hand, it could be good to give the tooth a little bit of help along to complete its final journey..... no hard and fast rule for me, each case will be judged according to circumstance.

If the rostral mandible is obviously narrow, or otherwise mis-matched, but the canine teeth have achieved a normal occlusion for themselves, I don't suggest any treatment. I can't really see the point of extracting them. We could discuss this further.

I think Mr. Dentist is just another know-it-all breeder (could be a judge, from his tone?) who has allowed his profession as dentist to aggravate the cleverclogs aspect of his affliction. I'd ask your client whether they wish to trust his opinions or those of a veterinary surgeon who actually knows something about the dentition of dogs, not least from experience of a good few of them not all of which were crosses between Labrador Retrievers and Poodles.

Hmm, do you think I should delete that last paragraph?