A marking bur is a rotary cutting tool used to score the bone at the site of an osteotomy. The use of a marking bur reduces the risk of crestal bone damage and helps to establish how deep an osteotomy will go. An osteotomy is any procedure which removes or changes the shape of the bone. In dental applications, it is performed in preparation for the placement of an implant or other dental prosthesis. Since there is a limited amount of bone available for implant placement even in a patient with substantial quality bone, the use of tools such as the marking bur helps the surgeon avoid mistakes in both angulation and depth during an osteotomy. This ensures that the bone available is not damaged due to a failed osteotomy and that a bone grafting procedure is not then needed to rebuild the lost bone.