“…For minimal rotation of the maxilla during protraction, when the force is applied inferior to the occlusal plane, the effective point of force application has been reported to be at the lateral incisors ( Canut and Dalmases, 1990 ), the canines ( Nakano and Miura, 1980 ;Ngan et al , 1997 ), the fi rst premolar ( Proffi t, 1992 ;Ko and Kim, 1995 ), and the fi rst molars ( Tanne et al , 1989 ). In clinical research using cephalometric analysis, the displacement of ANS and point A in the group protracted with a separated midpalatal suture was found to be larger than in the group where a labiolingual appliance and protraction device was used ( Baik, 1995 ;Ngan et al , 1997 ;Baccetti et al , 1998 ;Filho et al , 1998 ;Saadia and Torres, 2000 ).…”