Crestal Sinus Lift with Osteotomes: Minimum Height?

I've read you need 5-6mm and can lift predictably 3-4mm but some people say they can get 5mm. Perfs start to happen when you push 5mm though (from what threads I've read on this blog).

Nice experience shared sir. Kindly elaborate as to what density bone would you recommend in such cases where in 3 mm bone height exists and a sinus lift is to be done using osteotomes ? Do u prefer preparing the osteotomy to a lesser diameter in such cases so as to achieve better primary stability ? Thanks for the info.

Why did you place an implant in the # 16 area? This is a third molar area. This ares is difficult to access for both surgery and prosthetics and is of little use. The minimum vertical bone height needed for an uplift is 4 mm. The rule of thumb I use to determine the ammount the sinus membrane can be raised is: 2x what you see minus 2 mm. However, I do raise more than this due to graft shrinkage.

The implant was placed in maxillary right first molar region. #16 is mentioned as FDI system of tooth numbering.

The point is that it all depends on the PNR angle (much like lateral windows sinus lift) and how much bone is on the inner vault. The amount of bone between the crest and the lower part of the sinus is not really important, as long as you have at least 4mm and a good PNR angle with bone on the palatal vault. If the osteotomes are initially directed towards the PNR and the palatal vault, a great amount of stable intracortical space can be created and you can insert a 10-13mm implant. If the osteotomes are directed straight you'll get 3mm easily; but the same amount of lift can be obtained directly with the tip of the implant by underpreparing in lenght, or with piezosurgery.

This technique we are familiar with is dependent on herniating a volume of bone into the antrum, as such it is reliant on preparing an osteotomy short of the floor of the antrum and making a greenstick fracture upwards carrying the unprepared bone at the end of an osteotome. Tatum would have been the first to do this and he and Misch taught the technique, written up by others in the literature. Your CT image shows a sizable septa with height, I guess this allowed you to drill to 5mm. If the bone is only 5.8mm in height you would not drill to 5mm and then use osteotomes - more risk of lining perforation and inadequate volume of bone at the end of the osteotome. I am doubtful of the valsalva test of lining integrity. When the technique herniates bone, the floor of the site can be probed. Of course if the ostium is not patent for any reason the valsalva would not be expected to move the lining. All in this looks like a very competent placement and should be successful long term for a first molar. Heights lower than 5mm are much more challenging for implant stability and the extra height developed is not contributing to this initial situation.

In my opinion is that it all depends on the PNR angle (much like lateral windows sinus lift) and how much bone is on the inner vault. The amount of bone between the crest and the lower part of the sinus is not really important, as long as you have at least 4mm and a good PNR angle with bone on the palatal vault. If the osteotomes are initially directed towards the PNR and the palatal vault, a great amount of stable intracortical space can be created and you can insert a 10-13mm implant. If the osteotomes are directed straight you'll get 3mm easily; but the same amount of lift can be obtained directly with the tip of the implant by underpreparing in lenght, or with piezosurgery. Alternatively, a shorter implant (4-6mm in lenght could be used).