A method of assessing the angulation and extent of impaction of mandibular third molars, first described by G. B. Winter in 1926. A line drawn along the occlusal surfaces of the erupted mandibular molars demonstrates the axial inclination of the wisdom tooth; this also gives some indication of the depth of the tooth in the mandible. A second line, extending from the surface of the bone distal to the third molar to the crest of the interdental septum between the first and second molars, indicates the amount of alveolar bone enclosing the impacted tooth. A third perpendicular line is drawn from the second line to the amelo-cemental junction on the mesial surface of the impacted tooth (elevator application point) and is used to determine the depth of impaction of the tooth within the bone.