How Do I Change the Angulation of the Osteotomy Site?

first, take check films at 5, 10, and 13 mm especially if you are a beginner. second, you cannot change directions with tapered drills- they are more for side cutting than end cutting. you need to change the direction of your osteotomy with a small diameter drill. i use a precision drill, like a spear point, i then correct with a 2.0 pilot (strait)if need be. . After these two drills go to depth, changin the direction is difficult. Usually what happens is you drag the osteotomy to one side and create an ovoid osteotomy. this leads to less bone implant contact. beginners will usually have their orientation off to the mesial as this is the natural arc of your hand pressure. remember, the apex of the canine usually leans to the distal. to sum up, be patient. take a lot of check films, and if you are going to change directions, do it with a small diameter strait (not tapered) drill. there really is no excuse for a crooked implant. if you have been patient and the patient has bone, it should always go well.

I have started to do that, taking radiographs at 5, 10 before i finally reach 13. and now i have learnt that i really helps. thank you so much for your kind reply Dr sb...

using a paralleling pin after the first twist drill can give u a good indication about the direction of the osteotomy. i suggest using a small round bur or a small diameter (1.8 or 2.0 mm) pointed drill to help u re-orient the direction of ur osteotomy.

Changing angulation is not a big problem unless you have reached your final diameter and can be done effectively with normal twist drills. Simply redirect the drill and when angulation is deemed suitable, progress to the final diameter. If you are at your final diameter before detecting the angulation problem you will likely not have very good primary fixation unless you can drill deeper or can change the implant diameter to a larger one. Changing position is a whole other matter and in this case you will need a long tapering side-cutting bur such as a Kirshner to actually move the osteotomy entrance position (available from Salvin). If you have taken the drill size close to final diameter before detecting a malposition it may be prudent to abort the implant placement, close, and make a new attempt a few months later. The worst thing is to have a malpositioned implant that is integrated.

Dear Dr. Dennis, Thank you for your kind reply. I still had this doubt... which drill will I be using to redirect (of course not the final). As in the example I gave, can i use the NP13 to change the angulation. Can I say "the drill which made it wrong is the drill which will correct it and the higher drills but not the final drill"

Dear Dr.Juneja, If you are going in with a NP drill it has a final diameter of approximately 3.5 mm. Your final size for RP will be 4.3 mm. This will give you approximately .8 mm. of enlargement when you go to your final drill. If your angle of correction is not too extreme and you do it in one pass you should be OK. It would be better however if you made your correction from a narrower pilot drill of 2.5 - 2.8 diameter but unless you really ovoid out the osteotomy with the NP I think it will be fine. Also because you are using Replace implants they are very suited to primary stabilization as you are putting a tapering implant into a tapering osteotomy. Best, Dennis Nimchuk

Dear Dr. Dennis, Thanks a lot for the precious piece of advice. Regards Dr. Manish Juneja