Full-Arch approach

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billschaeffer
Full-Arch approach

This is another question that may be obvious - so please forgive me if it is;
We often see cases where the patient has a few failing teeth left in a jaw and who need to be planned as a full-arch case.
For ease of discussion, let's imagine a common scenario - a patient has only the lower canines and lower incisors remaining, and they are begining to fail.  The plan is to remove the remaining lower teeth, and to perform a standard All-On-4 type of treatment.
I can easily see how you can make a NaviStent to fit over some of the remaining teeth (the lower incisors and canines), and how that can be used to drill the distal osteotomies.
But how do you then drill the anterior osteotomies?  Surely the NaviStent is in the way.
Kind Regards,
Bill Schaeffer

David Burgess
Full Arch

Hi Bill
Great to have some discussion regarding use of dynamic navigation for complex cases. To date I have placed in the region of 60 implants using the Navident system for dynamic navigation, mostly for single and 2 unit cases. I am about to undertake my first edentulous case with the intention of placing implants in the upper canine sites to help stabilise a full upper denture. In this case the positioning and emergence profile of the implants is less critical, though dynamic navigation will be particularly useful as there is limited alveolar bone available. I am confident that the software will allow planning for placement of implants in to the optimum sites as far as bone available is concerned, and I will be able to insert locators into the existinf full denture afterwards. I do however agree that full arch cases will be more challenging.
An earlier comment queried the need to take the CBCT scan with a mock up in place with ball bearings for reference points. This I think will be unnecessary as the fiducial marker attached to the mini implant at an anteior fixing point obviates any need for either reference point location or measurement guides. I guess the mini implant itself could also be used to confirm callibration by comparing length on scan with true length. The scan could be taken with a mock up in place, relieved around mini implant. The teeth on the mock up do show nicely on the CBCT scan in the Navident planning software and virtual teeth can be added to overlay the mock up teeth precisely. This ultimately provides the necessary guidance for implant positioning in the software and latterly for site preparation.
The all on 4 concept is a little more tricky! I have managed to make secure stents on as few as 6 anterior teeth so if the plan is to have implants at 5s and 3s it is conceivable that the implants at 5s could be placed first wth the stent supported by the anteriors. It may then be possible to place abutments at 5s and add additional stent material distally to link to the 5s before cutting away some of the stent at the 3 sites allowing access and implant placement here without changing position of handle labial to the incisors. Just ideas at the moment, but will have a go when I get a chance and feed back on a case by case basis. There is still some figuring out to do but to date I have found solutions to most challenges!! Any other suggestions would be greatly appreciated.
Kind regards
David Burgess

billschaeffer
Thanks David - I saw the full

Thanks David - I saw the full-arch mini-implant thing in Paris at the EAO.
 
I have to say that my thought was how unstable that whole platform was on this single mini.  Any tiny movement in any axis and you've lost your positioning - and with no teeth to touch the bur against to guide you as to whether the whole thing's wrong!
 
My initial thoughts about Navident are that it works sensationally for 1 or 2 implant cases - but anything more than that requires a work-around to use it.
 
Kind Regards,
 
Bill Schaeffer

Rob Pounds
Hi Bill

Hi Bill

I have sent you a draft protocol for the prototype edentulous system.

It is proposed that one or two small bone screws are also installed in the cbct field of view to be used as accuracy check points prior to and during (eg when changing drill bits) treatment. If the mini implant is somehow rotated before or during treatment, the bone screws could be potentially used to realign it before proceeding. But the protocol anyway indicates there should be primary stability. As Luca also mentioned, if an excessive force is applied, then the system is designed to break away rather than risk damage to the patient's jaw.

Rob Pounds
Imaging & CBCT specialist

lcasalena
The anterior teeth are

The anterior teeth are beginning to fail. the option you have is to extract the teeth place a mini implant one on which you can secure the Navistent arm and scan the edentulous patient with a Navistent firmed on a mni implant.

lcasalena
Dear Bill

Dear Bill
the mini implant should have primary stability and user should pay attention not to move the jaw tag. As far as vertical pression the cap holding the Navistent arm has weakeness point designed to break in lieu of passing any insult onto the placed mini implant.
Ciao
Luca
 
 
 

billschaeffer
Thanks lcasalena - I guess I

Thanks lcasalena - I guess I'll just have to see it in action

Rob Pounds
Hi Bill

Hi Bill

Thanks for your questions, keep them coming. It is great to see good Navident experience being shared by everyone.

I will forward you a copy of the initial proposed protocol which has some more detail. Please remember this element is only prototype and is likely to evolve as direct result of clinical feedback from people using the system. This is why I am keen to get experienced implantologists like you on board now, as their direct feedback will help shape the future of the entire system.

Rob Pounds
Imaging & CBCT specialist

billschaeffer
Hi Rob,

Hi Rob,
I've just read the protocol for the full-arch and it looks a bit more sensible than I first thought!
Putting in a couple of widely-spaced bone screws as accuracy markers would make for very easy verification at surgery.
I still have concerns about the mini implant rotating with that long lever on it - but maybe that's not something to worry about and the bone screws would show that up easily.
 
How much is the Navident edentulous kit?
 
Kind Regards,
Bill

billschaeffer
I've just realised that this

I've just realised that this still doesn't solve the problem of the Navident edentulous kit not having the proposed tooth position on it.  Yes you will be able to put the implants inthe bone - but you will not know where the teeth are going  to be positioned.
 
I'm trying hard to imagine a full denture set up somehow stuck to the mini-implant for the scan - but then you'd not be able to have that there for the surgery as it would be in the way.
 

Rob Pounds
Hi Bill

Hi Bill
The denture will not be fixed to the mini implant.
As David suggested before, the idea is to relieve an area in the denture/scan prosthesis around where the mini implant and arm will be, to allow it to sit over (but not attached to) the mini implant and edentulous arm during the CBCT scan.  The planning will be based on the position of the proposed teeth which will show up in the CBCT scan.  During surgery the denture/scan prosthesis will not be needed as the location of the implants will have been determined.
Or am i missing something else?
As for cost of the edentulous kit, it is still prototype (the first ones only having been provided last week for first trial feedback) so it is not commercially available today.  I will discuss other costs directly with you.
Regards
 
Rob

Rob Pounds
Imaging & CBCT specialist

billschaeffer
Thanks Rob, that makes sense

Thanks Rob, that makes sense now!

Rob Pounds
No problem.  I think you need

No problem.  I think you need to get hands on with the system so you can start to see how it all comes nicely together.  Once we've gone through the basics and workflow in detail, I am confident many of your questions will be answered.
Thanks for creating such stimulating discussions.  Keep them coming!
Best regards
 

Rob Pounds
Imaging & CBCT specialist

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