Restoration of angulated implants in the maxilla?

I installed four 12 mm Straumann implants in the maxilla which are not parallel and are very angulated because I was trying to avoid the sinuses. Originally we planned to connect 4 implants with a bar to retain an overdenture. Since the implants are so angulated, do you think I can still splint them with a bar? What do you recommend? Should I remove them?


22 Comments on Restoration of angulated implants in the maxilla?

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Richard Hughes, DDS, FAAI
10/13/2015
Any decent lab can correct this. You need to use non indexed UCLA abutments as a base for the bar.
Rut
10/13/2015
In a good day 2 separated bars maybe !!! Even so I personally would remove at least 2 of them
ez
10/13/2015
Look up all on four, nobel bio care. These appear to be an " all on four" case. Granted 8/9 could be more upright but I believe they will work just fine.
Vladimir
10/13/2015
AO4 will be a disaster in this case because ridge reduction is a must for a hybrid denture. It is a most common mistake when you try to use old existing implants for a hybrid restoration. I would call it a planned failure. If there is no sufficient reduction there is no good AO4/hybrid denture. So it is absolutely contraindicated for this clinical case.
Dr dave
10/13/2015
Remove them? Why? There are a ton of ways you can go. Two separate bars with a clip is an option. Straumann also now has an "all on 4" option like Nobel has had. Call your rep and they will point you in right direction. You also can just do locator abutments. Straumann makes them for angled implants also without the center plastic component. You can mix and match chair side to see what will engage with the "regular" locator caps and which need the angled ones. In the maxilla unless you are going to a fixed, or screw retained hybrid 4 locators will be extremely retentive, almost over kill in the maxilla. Personally it's standard of care for minimum 2 if rendering some edentulous in the mandible but no so in maxilla.
drt
10/13/2015
If you can get an impression of it, the lab should be able to cast a bar. Make sure you watch your torque, alternating screws and have a truly passive fit to bar. It should be fine.
Dennis Flanagan DDS MSc
10/13/2015
Angled implants have been well documented in the literature. They probably produce bone apposition under load. A Locator type retention is not possible here so you are forced to fabricate a bar overdenture or fixed prosthesis. Dennis Flanagan DDS MSc
michael johnson dds, ms
10/13/2015
The you can angle the posterior implants to avoid the sinuses but no need to angle the anterior implants. This can still be easily corrected with non engaging abutments to the implant level as discussed above. The more pressing problem is the possiblity of a lack of interarch space for the bar, clips, reinforcing metal framework and acrylic of an overdenture. Prior planning of the restoration is a necessity in any edentulous jaw. There needs to be at least 15mm of space between the ridge and the opposing occlusal plane to allow for all the hardware and not make the acrylic to thin. The angulation can be dealt with but the lack of interarch space may make restoring them a challenge. Best wishes!
Gary OMS
10/14/2015
I agree. You may need to make a shortened fixed bridge here, maybe angulated locators are possible but they aren't really meant for the maxilla.
Dr.Nitin Bhat
10/13/2015
Connecting all 4 implants in maxilla is not a good option as it compromises esthetics. Also to get passive fit & inter arch distance could pose a challenge. Two separate bars with clips or all on four are the best options to restore the case. I would never remove any of the implants
Tuss
10/14/2015
Hi, did you use a surgical guide or go in free handed? It does look like you have around +5mm bone over the sinuses so maybe a simple crestal lift and place a couple more implants incase one of the anterior implants is too tilted to incorporate in a bar. Also if you can fabricate a bar will it lay within the boundary (flanges) of a properly made denture for the patient? I would get a trial denture made (ignoring th e implants just yet) then make an implant level impression as see how it will work, last thing you want is showing metal or a bulky flange to hide the bar
BLF
10/14/2015
Back up and work out your prosthetic set up. Once you do this you will know better what your options are. Important: in the future this should ALL be worked out prior to Implant placement. All implants should be placed from a restorative perspective. If you place the Implants before working out the prosthetics, you end up limited by the position of the Implants and run the risk of have Implants that can not be restored or need to be removed. Anyway, that is advice for the future but I still think you need to back up a little bit before moving forward with this case 1) Fabricate an upper denture or at least a Wax tooth set up. (you will use this to determine: tooth position, clearance over the implants, where your implant screw access holes will be and whether you need a multi unit /multi directional abutment.) 2)You can have this set-up duplicated as a radiographic stent and a CBCT can be taken which will allow you to virtually measure from the Implant platform to your proposed occlusal surface. If you do not have a CBCT at your disposal, At least have a have a clear duplicate denture made with a trough cut through the lingual. You can then measure intraorally from Implant platform to Occlusal surface by sounding with a probe to bone/implant NOTE: ideally you would have this surgical stent at the time of surgery and have already taken a CBCT to see if bone reduction is needed. 3) base on your clearance, Implant positions, patient finances, etc you can determine your best prosthetic option. You will need to look up how much clearance you need for each type of prosthesis (bar overdenture, fixed hybrid, fixed copy mill prosthesis, monolithic Zi, etc) and then proceed from there. You may not have room for a bar or a hybrid prosthesis if bone reduction was not completed at the time of surgery or you may...but you need to back up to determine this. Based on the angulation of your Implants, you will likely need multi-unit abutments which I believe Staumann now offers. Call your rep. You might consider 2 more posterior implants (After you have completed your prosthetic work-up and taken a CBCT) and a fixed Monolithic Zirconia bridge as this will require less clearance ( ie10-12mm). My final thought, It seems you are trying to offer your patients great options and you are trying to do the right thing. However, Find a good course on planning for the full arch implant case. These cases are ALL about the plan and you can find yourself and the patient in a world of trouble without proper planning. Best wishes -BLF
David robinson
10/15/2015
Can't tell the angulation from this X-ray , need a CBCT . They may not be as angulated as you think .
CRS
10/15/2015
Line of draw in divergent implants?
BLF
10/15/2015
CRS, what are your thoughts on using multiunit abutments to correct for the divergent implants. This would not solve possible clearance issues but may be an option to correct the divergent angulation issues? Thanks, BLF
CRS
10/16/2015
This will not be a popular response but what I would do is at the post op X-ray, remove the divergent implants and line them up parallel. According to the film there is adequate room, bone and anatomy to do this. Hopefully an operative splint or clear acrylic denture with holes drilled in it would be used. With good preplanning this situation can be avoided. I wish folks would stop posting that letting this go is okay to soothe feelings. That's the point of a post op film before the implants are integrated, in the long run a better result with a small delay short term for fixing this. Different scenario if the implants are already integrated. I feel that is the best course for the patient long term takes commitment and integrity. The sinus is not the problem. What I don't get is that as restorative dentists drilling parallel and lining things up is part of good crown and bridge technique. It is very easy to get disoriented in an edentulous case, few landmarks and splints are not perfect. Implants are restoratively driven and there is no such thing as an easy implant. Just fix it and provide optimal care vs doctoring it up with lab work.
Richard Hughes, DDS, FAAI
10/17/2015
CRS, my response is not touchy feely. It is a prosthetically viable option and without putting the patient through any more surgery. I agree this surgical result is not optimal. Yet it is still a viable case as is. I sometimes tilt implants to obtain optimal bone. The implants may be to wide! I don't know what the implant surgeon was thinking in this case. As I stated earlier there is a most viable prosthetic bailout.
CRS
10/18/2015
Sorry I disagree I have a different standard, if I sent this is a restoring dentist I would be creating a problem for him or her. I don't have a problem correcting this at the get go, thinking long term. I agree that this is a viable prosthetic bailout and respect that. If bone is needed I graft or expand and the treatment plan is modified at surgery. Patients do appreciate the extra care taken. The way I read the post it seems okay the implants are divergent now what do I do? Read the responses all on four without adequate clearance? Implants are restoratively driven and if this surgeon was comfortable working around the anterior sinus wall and grafted if necessary then the implants would have been placed parallel. I just don't like the excuse. I feel a team approach is best one can't do everything well. I am always impressed with what my prosthodontist comes up with and my restorative colleagues always educate me. Sometimes an honest answer to a post may be unpopular, prosthetics and implant surgery are complex just because one can place implants I think they should be placed optimally in this case based on the information I would correct it. Clinical correlation is always advised. Thanks.
Richard Hughes, DDS, FAAI
10/16/2015
This case is easily treatable with non engaging or non indexed UCLA patterns as a component to fabricate a bar for an overdenture. Uniabutments could be used with a screw retained FPD. Is there enough inter arch clearance for an overdenture?
Richard Hughes, DDS, FAAI
10/16/2015
Implants placenta in the maxilla are rarely not off axis. Drs Jack Lemons and Bob James did early work on off axial implants. And I mean early. So did Dr Linkow.
DR.M
11/1/2015
Ask your implant company for multi-unit abutments, you might be able to correct enough to fabricate the bar.
Tuss
11/2/2015
As others have said earlier - you need to see how the implants line up against a denture set up to the correct tooth setting. Worst case you up-right the implants with standard engaging UCLA's and make milled abutments with lateral set screws, fabricate a either a bar or a fixed bridge back to a first molar occlusion but drop the second premolars (bi's). Again, propr planning before you put the implants in would have stopped this from happening but we're still seeing this stuff time after time on here so makes one wonder if people pay attention to detail.

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