This video is the second part in the series on the bone grafting procedure. It shows the operation done to extract a piece of bone from the lower jaw. A part of the mandible (lower jaw bone) is sliced out. The excavated bone is used to fill up the gap on the upper jaw bone.
This procedure involves deep cuts and pulling away of the gum tissue around the mandible. Precise measurement and cutting is required as is shown in the video. Since there is a lot of slicing of the skin, viewer discretion is advised. But if you want to know how the operation is carried out, then this is a nice video to find out.