Replacing Mandibular Posterior Case: Best Treatment Plan?

The diameters quoted are not narrow. The lenghths are short. I think the longterm problem will be peri-mucositis/ implantitis due to severe lack of attached keratinised tissue. I think the case is beyond lingual reflection and a sub epithelial connective tissue graft will be needed. This should be performed: -pre implant or -post implant on exposure. -NOT AT TIME OF PLACEMEMT> So if you feel confident and have been trained then do the soft tissue work or refer to a perio specialist or somenone with a special interest in perio, and then place and restore yourself. Cheers

Well said Dr Booth and that is why lower molars can be the most difficult implant in the mouth . This could be a nice case for the "trapdoor" technique due to the advantageous shape of the mandible ( See Meisinger site and Dr Ernie Fuchs ) Peter

Dear Dr F. 4.2mm and 5mm diameters are not small diameters. They are medium diameters. The ridge looks too narrow for them. Try one piece narrow diameters that are around 2.5mm and you can avoid bone grafts and finish your case faster and your patient will be grateful for the lower charges.

Thank you for your answers! I meant I haven`t used till now implants of short lengths, not of narrow diameter (I made a formulation mistake when posted the case). So, do you think will be any other long term problem (other that ToBooth and Peter showed) if I place two mplants of 6.25 mm length and 5 mm diameter? My concern is if these two implants will be able to stand for the force specific to this area of jaw during mastication. P.S. : Mr Chow, I think you meant to place two 2.5 mm implants for each root of a molar, am I right? What about the length?

Dear dr F I'm against to short impants, First step: vertical augmentation- cortico cancelous bone block graft ( auto like M.Pikos or Allo+ bone marrow like Denis Smiler), after 3 months soft tissue correction of lack of attached keratinised gingiva ( perio surgery spreadind attached gingiva zone and/or puros dermis/alloderm implantation, next 2-3m implantation, 2 staged

This is a very difficult case and you mus for warn the Pt that he may need to be happy witha partial. To do this I think I would first do a free gingival graft to create attached gingival tisue. As you know it would be best to make an upper retainer tht will cover the sight since it is not very comfortable as it heals adn they will tell you about it and their friends adn family. Once this is healed I would fal a large full thickness fla from the acending ramus to the loer right canine and decorticate the entire ridge. I would use a Medrtonic Infuse colagen x-small mixed 50/50 with Curasan. I would bone tack a titanum supprted cytoplace teflon membran adn arch it so tht I could creat a mm or two more height and width and suture the site tension free and wait 4-6 months adn thne place implants. Just an Idea that might work. I would have to :1. tell the pt that to do this will be costly, and #2 iwould not promise anything until the graft takes.Kepp referring back to the possiblity tht a partial may be the only choice.

Dear Dr F i wouldn't think that placing this short implants is good option long term, no matter what the Co. says about them. i assume u will be using bicon. Besides the patient is missing three teeth and u r only planning two implants only. I think u may be pushing the case too far. The best plan for this patient if he is looking for a fixed option is to Augment the ridge (Hard & Soft tissue) and then hopefully place your implants. One other thing i have noticed from the 3d model is that the upper teeth are over erupted. have u checked this clinically? This may further complicate your restorative plan!Best Of Luck

Difficult case. Please correct me if I am wrong, Infuse is only FDA approved for bone augmentation in the maxillary arch. Off label use of Infuse has resulted in some very severe medical complications - that being said go for the grafts first.

Dear Dr. Filipov, You do not need two 2.5mm diameter minis for each root of the molar. One for each root will be more than enough and anatomically more correct, and if you join the crowns together, you can use three minis for two molars. In this particular case, four minis will be quite sufficient. You can place them up to 10mm long into the bone and if you think that may be too long, snip off one or two mm with your trusty cutter. You can check out my cases and if you go to the osseonews discussion on narrow diameter implants, you can see the surface areas of minis as compared to conventionals and why they are comparable because the minis are usually placed longer and in multiples. Cheers!

The maxillary arch has to be accounted for. The supraeruption presents a significant restorative issue. Its not just that there might be enough bone. Soft tissue is a surgical issue. Wax up an ideal with a corrected upper scheme first. I have a few very "long" posterior implant crowns on small implants that are working but it isnt the ideal situation. 2 implants and not considering the upper arch is to me just under engineering the case. Just my opinion. Bill

Dr F If you consider that there is a lot of wear on the teeth, this could be an indication that the patient is a clencher, and this would subject the implants to greater forces, therefore the treatment plan would require possibly over-engineering the case. I cannot see the scans very well, but if you take into account staying away from the IA canal about 2 mm and flattenning the crestal bone (unless you plan to leave part of the implant exposed and graft), you can only place short implants, and it may not be a good idea on a patient with parafunctional habits in the posterior region. About the vertical augmentation discussed earlier, in my experience, it is not predictable, (that is why Bruce is telling you to remind the patient that a partial denture may be her solution)and you still would not be able to gain enough ridge height to place a 10 or 11 mm implant. Finally, placing minis in this situation, where the anatomy requires wider implants to better support the functional load is in my opinion, contraindicated. Good Luck!

Dr. F great work up on your implant case...Although, Is kind of hard to read the scan. If, you're thinking a bridge with two implants, then where do you place the first implant...? which it should be on the #29 area...from your 3D image you have no bone over the foramen..then, you may have to move distally to first root of # 19,and another distally to this one in an Ideal inter implant distancce, with cantileaver on #29 which, is not the most ideal situation...depending on bone avalavility, minimun 10mm long implants,not smaller 3.7 in diameter,and finally, IMOOP....I,would get my feet wet with a more straight forward case....

Doctor F, I've been solved difficult cases like this by using computer guided surgery. To do that, you will just need to provide your patient a tomographic guide and a new cone beam TC. You will probably need to use 2.0 or 2.5 implant diameter, but much longer ones. Normally I place an explinted provisional bridge right after flapless surgery. So, make yours and your patient lives easier avoiding grafts, periodontal procedures etc. Total treatment time no longer than 4 months (five to seven office sessions). Regards.

The smallest implant you can place with some degree of confidence, predictabilty and with research bckup is either a 6mm length/ 4 mm width or a 5 mm length / 5 mm width implant, you have to meassure if such an implant fits into your case. considering that: -you must leave at least 1mm from the upper cortex of the mandibular canal to the bottom of the implant as a security margin. - you need at least 0.5 to 1 mm of bone surounding the top of the implant, this accounts for at least 5-6 mm bone width. It seems to me that your case doesnt have enough bone to be restored with  small implants, but I'm not really sure because the CT has to be meassured carefully. This leaves us with the following options: - bone regeneration to treat a dehiscence in such a low vascularized  bone is not a good choice. - Vertical augmentation is not a choice unless you treat the overerupted upper molars. Anyway Vertical augmentation in such a highly resorbed case present  a high failure rate. -  I'd treat the case repositionig the  Inferior Alveolar Nerve And placing two standard implants, because it is the most relaible approach, you have to discuss deeply with the patient the pros and cons of such a surgery, because there is a chance of about 15% of NSD, but what is the chance of hitting the nerve with another approach?    

Implants aren't always an option. This may be that case.

There is a lot of interdental space from the bone to the maxillary arch. You could place mini implants in this bone, but be careful of the lateral forces from the uppers with such a long moment arm with mini implants. Too much "micro movement" will cause any implant to fail. If I were restoring this arch with mini implants I would use a computer generated stent from a CBCT scan. I have done a few of these for mini implants, and it makes me feel a LOT better about avoiding nerves, especially that mental foramen area. Even a flap won't give you the kind of guidance that a stent provides. It is really fun to do minis with the stent - just get it in place, drop in all the pilot holes. Then I remove the stent and place the implants into the pilot holes with hand instruments so I can feel the progress and keep them straight.

Thank you for your involvemnt in solving this case. I have to discuss with my patient showing him all the benefits and inconvenients of partial denture verus implants (taking in to account all the aspects you debated) and keep you in touch. Thank you again!

Dear Dr. F. In my experience, since 1995 i'm treating patients like yours, usualy with 3-4 implants 2.8mm diameter and 10-13mm lenght. Usualy with screw reteinerd bridge. About vertical augmentation-in general this is weiste of many and time becouse of poor vascularized bone.There is no such a thing " Where the anatomy requires wider implant"! You need the bone not only to place the implant, you need that bone to suport the restoration after all as well.

You might want to consider sending your case for review to Shatkin First Lab in Buffalo NY, Dr. Todd Shatkin would review the case and give you a treatment plan using mini dental implants and enable you to place the mini's and the restoration in one treatment visit using his patented FIRST technique.I use this lab and system qiute often and get great results Good Luck!

There is a way to place longer than 5mm implants here. There is adequate width of bone lingual to the canal where you can place your implants. Better make a steady surgical template, opaque markers of where you would angle your driling and CT again as a final double check before converting it into your surgical guide. Prosthetically use custom abutments to correct the orientation.

im agree with Dr. Morales Schwarz ,i think this is the only way to treat pts ideal way

Actually posterior mandibualr augmentation considered to be one of the most difficult area in the mouth. JOMI supll ( 2009) showed that the mean amount of the height gain after posterior manidbular augmentation measured between 4- 4.5 mmand mean amount of the width is 4- 4.5 mm. ( the range was between 2- 7 mm ) . In my experiences augmentation more than this amount can lead to significant increase in post operative complication mostly wound dehiscence. So augmentation of this case can be done with this point that after augmentation 8- to. 10 mm in length and 3.5 - 4 mm diameter implants could be placed not more. Actually decision making regarding upper teeth could be benifitted by having periapical view of upper teeth. As a matter of fact if the teeth have normal healthy periodontium , and have prognosis more than 50% in the following 5 years and it has to be saved, the may be root canal treatment and post core crown would be an option. Regarding nerve tranposiotion described by dr Morales ; although it is more reliable than posterior augmentation and reduce the time of the total rehabilitation of the patient , but there one i portant risk and it would be nerve dysesthesia. Actually after nerve transposiotion we can place longer implants , wider implants , the cost reduced, the time saved, interarch can be saved, there is no donor site morbidities and....., but one and one nerve alteration response ( which is not actually predictable) is great anough to completely frustrated the pateint. So i belive augmention of the deficient posterior mandible would the choice option.

Dr. Carlos A. Boudet please try some Infuse for your ridge height before you say it is not predictable to gain vertical height. BMP will work wonders to gain a lot of height. Please do not tell me it is too expensive. Check with your rep. I am placing it in every bone grafting patient and it is only costing me $200 per patient for the BMP. I am giving my patient the best and making a profit. It is time for everyone to wake up. BMP should be the standard of care for all bone grafting patients.

Dear Dr F, it is interesting to see how the world responds to this common problem. Yes there is more than one option but there are some fundamental requirements no matter what treatment is carried out. 1. The over-eruption of the maxillary teeth needs to be addressed. 2. The band of keratinised tissue needs to be increased. 3. The implants of choice in the posterior could be a unilateral subperiosteal implant or a ramus blade. 4. In the lower right 5 region it would be possible to do partial nerve lateralisation to be able to place one implant if a ramus blade is placed. One surgery, great result By the way a sub can be cast on a 3D model.