Fig. 1From: The displacement of teeth and stress distribution on periodontal ligament under different upper incisors proclination with clear aligner in cases of extraction: a finite element studyThe 3D maxillary models of three different incisors proclination conditions. a Small torque(ST):U1-SN = 100. b Middle torque(MT): U1-SN = 110. c High torque(HT): U1-SN = 120°Back to article page