Free gingival graft harvest

Some tips on free gingival grafts I picked up at the course:

-Measure your surgical site before cutting. The palatal tissue is taut and will tend to shrink after it is released from the bone so tend to make the graft wider and long than you think you need.
-When cutting the outline of the graft you need to overlap your cuts at the corners. This is because the scalpel blade is rounded up towards the tip and so the tip of your blade will not be at the full depth required (see Figure 1)
-A 15 blade is wider than a 15c and so is more useful to reflect the tissue when harvesting

                                       Figure 1: Overlap the cuts to ensure that the corners of the harvest are at the                                        required depth. If you don't the tissue will tear at these important sites

-The graft needs sufficient thickness to survive. You want 2mm of tissue thickness. If you under cut then the graft will necrose, if you over cut then you can trim the tissue back before placement. your outline cuts must be deeper than 2mm to ensure that it is possible to release 2mm of tissue when you reflect the harvest site. Keratinised tissue has a lower blood supply than non keratinised tissue so it needs sufficient thickness to survive.
-Free gingival graft harvests are a one handed procedure. Don't handle the graft with tweezers during the release or you'll tend to change the angle of the tissue and risk cutting through the graft.
-The technique of releasing the harvest is called "turning the corner". Your first incision is 90 degrees to the tissue at the long edge of the tissue (outline incisions), then use the flat side of the blade to push the adjacent tissue out of the way and incise along the same line at 60 degrees to the tissue along the long edge of the graft. Then run your scalpel back along the same line at 30 degrees to the tissue. Then finally you should be able to fit your scalpel parallel to the tissue at 2mm depth (Figure 2).

"Turning the corner"- Free gingival graft harvest: 1. Cut the outline of the graft deeper than required ~3mm depth ensuring to overlap the corners of the outline. 2. Use the flat of the blade to compress the adjacent tissue and reenter the outline cut at an angle of 60 degrees to the tissue. You should only be aiming to cut and release the corner at the base of the graft. The aim of this exercise is to allow the blade to cut under the graft with 90 degree corners. 3. Take the blade and compress the adjacent tissues further cutting at 30 degrees to the tissue. 4. Slide the blade parallel to the tissue 2mm under the soft tissue. 5. Use fluid one directional movements along the length of the graft. When you reach the edge of the graft take your scalpel back to the original side and cut further along the width of the graft. Don't remove the scalpel from under the graft as it will be difficult to find your way back in again. This is difficult as you may not be able to see the blade through the tissue but it is important to watch the angulation of the blade at the handle to ensure you are parallel to the base of the tissue at all times. When you are near the end you can hold onto the tissue with your tweezers but ensure not to pull the tissue to release it. IT should just fall away when you have completed your cut.

-Ensure that your dental assistant keeps her suction away from the graft or they may suction up the graft
-Hemostasis of the harvest site can be achieved by placing surgicel over the exposed tissue and applying pressure sutures over them. Histoacryl can be used over the top if required.
-The end goal of the graft is to have a clean cut piece of keratinised tissue with 90 degree corners. The wound edges are the most important and thin edges due to a poor attempt at turning the corner will result in this tissue at the wound edge i.e suture site. This will result in graft necrosis at the wound edge and loss of primary closure. This will extend and complicate healing and may result in failure of the graft.