Position of lower incisor in relation to upper incisor. RxMxR shows the maximum retrusion calculated with the radiograph. GgMxR shows the maximum retrusion obtained with the George Gauge. 66% shows the position of the lower incisor with 66% of maximum protrusion. GgMxP shows the maximum protrusion obtained with the George Gauge. Values obtained with the George Gauge with 2 mm of vertical opening are shown on the figure; −6 mm for maximum retrusion; + 9 mm for maximum protrusion, + 4 for 66% of total advance.