Mandibular fractures

Re: Mandibular fractures

Evelyn Barbour-Hill — Thu, 24 May 2012 01:36:36 GMT

Sounds good.

I'd risk a small wager you will be able to remove the feeding tube soon and the dog will eat OK per os as it were, if a bit messily.

My opinion about feeding tubes is "why mess with a PEG tube when you can do it all with an oesophagostomy tube?" I guess it's personal preference.

Re: Mandibular fractures

David Mills — Thu, 24 May 2012 01:10:55 GMT

Ex fix applied today with 2 pins either side of causal fracture site; insufficient room for more; conventional bar used. M1 removed as exposed roots and rostral aspect. Interdental wiring applied to cranial fracture sites. Post op and intraop alignment seem very good. Dog already looking vastly more comfortable; thanks for all the very helpful responses.

We have elected to keep the oesophageal tube in place currently. There was a question about a PEG tube being used instead. Not directly relevant here, but for tape muzzling candidates, any preferences? For long term recovery my preference would be PEG tube for easier maintenance but this is opinion based only, no evidence.

Re: Mandibular fractures

Rachel Perry — Wed, 23 May 2012 07:01:58 GMT

Hmm it would appear P2 is missing at the rostral fracture site. As the apex of the canine is at the level of the mesial (rostral) root of P2 I think there's a real risk of disruption to the blood supply and hence future vitality of the tooth. I think the superimposition makes it difficult to tell if the root is fractured too. It would also appear that the fracture line goes through the crown of M1? In which case be prepared to extract both these teeth once healing is complete. If costs are an issue - which they presumably are if it's a charity case- then maybe go for the cheapest least invasive option ie tape muzzle/ Mikki muzzle (hint: turn them inside out so the seams don't rub and collects less crud that way). But there does seem to be caudal displacement of the caudal fragment from digastricus pull which may mean sub- optimal healing, but not necessarily non-functional healing. If the canine teeth occlude normally when the mouth is closed with muzzle on I think this would work fine- it's a young dog so healing will obviously be rapid. If you have experience of interdental wiring & acrylic this would allow you to stabilise all fragments in one. Any gingivitis caused reverses rapidly once the appliance is removed.

Re: Mandibular fractures

Evelyn Barbour-Hill — Wed, 23 May 2012 00:23:07 GMT

I would dearly have liked to see an intra-oral true VD view of the mandible, but no matter.

From these pictures, I'm not sure that either of the canine tooth roots is fractured, in fact I think they are not. There would be two ways in which it might be dictated that one or the other had to be extracted (or considered for endodontic treatment): a) if the root was broken, b) if the fracture line has swerved around the apex of the tooth and damaged the blood supply to the tooth without breaking it; quite a common situation. But: in any case I would not extract the tooth at this point: that would remove a potential useful fixation point and it would risk making things much worse. Wait till the bone has united solid.

With the more caudal fracture on the left, it looks as if the fracture line goes right down the alveolus of the tooth (as it often does, naturally) but I think the apices have escaped damage; on the other hand, I bet this tooth is much compromised and it probably won't survive. I can't tell you for sure whether to extract it now or after bone healing. If you adopt my suggestion below for treatment, then I would keep it in for now if it seems solid and all you can see is a side of exposed root in the fracture site, but extract it now if it's at all mobile or you can see more damage. If you go for external fixation, or crossed wiring, you might as well extract it now (carefully!).

What I would do in this case would be interdental-wiring-plus-acrylic, and muzzling with tube feeding. Were I uncertain about stability of the caudal fracture, I would do crossed bone wiring as well. Only you can decide about this, as you handle the fragments.

Interdental wiring plus acrylic works, despite its theoretical mechanical unsoundness (a charge that can be levelled at external fixation, too), but I reckon this one needs the support of the muzzle too. The advantage of the muzzle is that it in effect uses the upper jaw as a splint, and as I said almost ensures the correct occlusion. Also, these teeth are very young and the wiring will have to be very careful.

External fixation could work too, if you feel more comfortable with that, but I cannot at the moment see how you would get adequate pins rostral to the rostral fracture.

That's my view.

Re: Mandibular fractures

David Mills — Tue, 22 May 2012 23:33:00 GMT

Yes, sorry, original post didn't work, above is an edit

Re: Mandibular fractures

Louise6732 — Tue, 22 May 2012 23:26:44 GMT

Evelyn I was able to view the rads by copying and pasting the web address into a new window

Louise

Re: Mandibular fractures

David Mills — Tue, 22 May 2012 22:54:11 GMT

Here are the rads:

http://img560.imageshack.us/img560/564/dsc01819l.jpg

http://img138.imageshack.us/img138/8494/dsc01820i.jpg

http://img94.imageshack.us/img94/698/dsc01821rn.jpg

First two are R lat, third L lat. Have close ups somewhere if required.

Damage is more than I'd imagined. The fracture to the L rams is complete, and open and the two lower canine roots are also fractured. Do these need removing at the same time?

Re: Mandibular fractures

Evelyn Barbour-Hill — Tue, 22 May 2012 21:39:13 GMT

[quote user="John Rimmer"]

Hmm. Would appear to be 2 against 1. But only one has DipEVDC, and Malcolm does promote the importance of diplomas...

[/quote]

Re: Mandibular fractures

John Rimmer — Tue, 22 May 2012 20:35:40 GMT

Hmm. Would appear to be 2 against 1. But only one has DipEVDC, and Malcolm does promote the importance of diplomas...

Re: Mandibular fractures

Evelyn Barbour-Hill — Tue, 22 May 2012 09:40:05 GMT

It's the fracture near the canine tooth that bothers me in regard to surgical methods.. Radiographs will tell us more.

Muzzle methods almost - almost - ensure the maintenance of occlusion, if the fracture is not grossly displaced or unstable.

Re: Mandibular fractures

Malcolm Ness — Tue, 22 May 2012 08:50:50 GMT

I echo much of what Evelyn says.

Ex Fix over plates every time - plates are mechanically inappropriate and the need for good screw purchase is confounded by thin mandibular bone. Added to that the fact that there are very many places that you just can't place screws (tooth roots, nerve exits etc etc). Inter-dental wiring has two major diadvanteges - the inevitably small and weak implants are inevitably placed in a mechanically poor location and their use invariably involves damage to gum margins, tooth structure etc Extensive radiography adds little - it is not difficult to predict where tooth roots might be given a superficial knowledge of anatomy and knowing the position of the crown.

If you hold the bones stillish for a week or two then they will heal, so getting the fracture to heal is not the major aim - restoration of functional anatomy is the holy grail and that means restoring perfect dental occlusion. You can't possibly asses dental occlusion with an endotracheal tube in place so I would very strongly advise (once the dog is anaesthetised and tubed conventionally) that a pharyngostomy incision is made and the ET tube is redirected out through that leaving the mouth free for you to work on.

Place Ex Fix pins (ideally pins with positive profile threaded ends) where the fracture and the anatomy will allow - aim for 3+ pins either side of the fracture. Instead of a conventional connecting bar use acrylic set in a flexible tube that has been skewered over the ends of the pins. There are some commercially available kits available for this (APEF, marketed in UK by Vet Instrumentation). However, plastic anaesthetic tube (1/2 or 1 inch diameter) filled with DIY shop acrylic or Technovit serves just as well.

If acrylic is not available then a suitably pre-bent connecting bar can be used but that is technically more difficult and can compromise reduction/maintenence of occlusion.

Success is directly related to the degree to which you can maintain functional dental occlusion and the use of ex fix in this way allows you to check occlusion and normal TM joint motion before you "fix" your implants.

Re: Mandibular fractures

Evelyn Barbour-Hill — Mon, 21 May 2012 23:39:07 GMT

Radiographs awaited with interest, but first thoughts:

It's essential you know if tooth roots are involved in the fracture lines as this might make extraction necessary after fracture healing, or even before.

Any of your three options could do fine including the tape muzzle, but that option requires the most nursing care and attention.

Either of the surgical methods could do fine, but it's extremely important none of your holes go through a tooth root and of course you don't want to go through the mandibular canal either. That means you'd be very lucky indeed to get a plate that's just right. External fixation usually works jolly well. Something else that's worked well for me is crossed wiring but I'm not sure you could do that on the fracture by the canine tooth.

Re: Mandibular fractures

James Laidlaw — Mon, 21 May 2012 23:21:44 GMT

I think I recall tape muzzles can be good for stabilising if you can control pain, but need to be tight enough to maintain stability but loose enough to allow breathing/fluid intake. There are great dental specialists all over the uk for more advice-one group I've never had ANY problem with contacting for advice on anything. I'm sure someone with better knowledge will put their 2p in tomorrow though.