TRANSCRIPT:

Okay, so let's go ahead and take a look at a direct sinus lift scenario. In this specific patient we have that's come into the office, we have an edentulous space we're going to say here at number 14. The patient would like an implant in this site, and we've measured on CT scan that the area here only has about 2 millimeters of bone. So we know that we do not have enough bone to do an indirect sinus lift, so we're going to start to work towards our direct sinus lift. And I've got Ivan here that's going to help me with this procedure as well.

The first thing that we want to do with the direct sinus lift, we are going to need access to the bone, so we are going to plan our incision. Now when planning the incision there's a couple things to consider. One, remember that we always want the base, meaning the apical portion of the flap, to be wider here than it is here. That allows the flap to maintain adequate blood supply. The second thing that we want to consider is that we want the incision to be far enough away from our access, our bony access to the sinus, that the incision line does not lie over the access window.

We also want to make sure that the incision along the crest is either mid-crest or slightly palatal. Again, to get it a little further away from our access, so that we do not run as high a risk of a dehiscence or an oral-antral communication. So we're going to go ahead and start this incision line distal to where we're planning our window, so that it will not be over the window access. I'm going to use my 15 blade and work up here to the crest.

I am going to do, I prefer a papilla sparing incision, so I'm not going to cut through that adjacent papilla if I can't avoid it. I'm going to come up either to mid-crest or just slightly palatal, and then I'm going to turn anterior with my incision. Keep in mind back in this area, we do have the greater palatine foramen back here and the greater palatine nerve, so you don't want to dip too far palatal and nick that artery. That's a bad day as well.

So we're going to keep moving forward. As we come forward and I feel that I am out of range of where I'm planning my osteotomy window, I'm then going to track down. Remember, if you can see, I'm angling out. I'm keeping that base of my incision wider. I'm keeping the base of the incision wider than the crestal portion, and that's to ensure adequate blood flow to the flap once it's reflected. At this point in time, I'm going to take my periosteal elevator, and we're going to start to reflect our flap.

We're going to keep the tip of that elevator on bone, always on bone, and working to create a nice subcrestal plane. Once we get that tissue to start reflecting, I'm going to flip to my wider end here, and we're going to reflect that tissue. You do need a decent amount of reflection so that you can see and access your site. I like to use a Minnesota retractor that Ivan has here to keep that flap reflected during surgery. Now, this particular model does not show it, but keep in mind, as we discussed during our anatomy, apical to this portion down in this region, you're going to have the infraorbital nerve.

If you reflect high enough, sometimes you're going to see that nerve. Be aware that it's there. You do not want to push excessively on it. You clearly do not want to cut it. It is a branch of the trigeminal nerve, and it does affect sensation in the area. Now that we have adequate retraction and visualization of the lateral maxillary wall, we're going to go ahead and start planning our bony osteotomy into the sinus.

Lesson Summary

In this scenario, the patient has an edentulous space at number 14 and wants an implant in that site. However, a CT scan shows that there is only about 2 millimeters of bone in the area, making it unsuitable for an indirect sinus lift. Therefore, the dentist will perform a direct sinus lift.

When planning the incision for the direct sinus lift, there are a few considerations to keep in mind. The base of the flap should be wider at the apical portion than at the crest to maintain adequate blood supply. The incision should also be far enough away from the bony access to the sinus to avoid complications like dehiscence or oral-antral communication. The incision along the crest should be mid-crest or slightly palatal to keep it further away from the access window.

To perform the incision, the dentist will start distal to the planned window to avoid overlapping. Using a 15 blade, they will work up to the crest, preferably using a papilla sparing incision to avoid cutting the adjacent papilla if possible. Then, they will turn anterior with the incision, being mindful of the greater palatine foramen and nerve to avoid damaging them.

Once the incision is made, the dentist will use a periosteal elevator to start reflecting the flap, keeping the tip of the elevator on bone to create a subcrestal plane. They may switch to a wider end of the elevator to continue reflecting the tissue for better access to the site. It's important to be aware of the infraorbital nerve in the region, especially if it becomes visible when reflecting the flap, as damaging it can affect sensation in the area.

With the flap adequately reflected and the lateral maxillary wall visualized, the dentist will proceed with planning the bony osteotomy into the sinus.