FRII
適用: Class II , Division 1&2
咬腊: Vertical – 3-mm in bicuspid area; Anterior/posterior –Take bite with mandible advanced 3 -4m m
FRIII
適用: Class III
咬腊: Minimal—approx .1-mm in molar area; Anterior/posterior—Take bite with mandible in most retruded position
FR IV
