A.0.1~0.2mm B.0.2~0.3mm C.0.3~0.4mm D.0.4~0.5mm E.0.5~0.6mm
A.2~3mm B.3~4mm C.4~5mm D.5~6mm E.6mm以上
A.牙齦上方至少4mm B.牙齦上方至少6mm C.牙齦上方至少7.5mm D.與牙齦平齊 E.以上都不對