Ridge mapping is a measurement procedure to ensure that the diameter of an endosseous screw implant does not exceed the dimensions of available bone. The long-term success of implants is a prime aim. To achieve this, it is essential for the initial evaluation of the dimensions of the resorbing alveolar process to be absolutely accurate. Ideally, an implant should be covered by at least 1 mm of bone on all sides. The major problem is estimating the thickness of bone, since the mucosal contour can mask the actual dimension of the alveolar ridge. Use of ridge mapping with the Wilson Bone Caliper makes possible a reliable evaluation procedure at the initial stage of treatment planning. Schlagwörter: bone dimension, implants, ridge mapping