In vitro study examines posterior torque impact on 3D mechanics of anterior teeth in clear aligner treatment

BMC Oral Health

Table 1 Study protocol

Research group	Amount of mandibular 3–3 inward retraction (mm)	Amount of mandibular first premolar torque(°)	Amount of mandibular first molar torque(°)	Amount of mandibular second molar torque(°)
A1	0	-22	-30	-35
A2	0	-17	-25	-30
A3	0	-27	-35	-40
A4	0	-32	-40	-45
B1	0.25	-22	-30	-35
B2	0.25	-17	-25	-30
B3	0.25	-27	-35	-40
B4	0.25	-32	-40	-45

Group A1: no activation, posterior teeth in Andrews’ standard torque group; Group A2: no activation, posterior teeth increased by 5°crown-buccal to torque group; Group A3: no activation, posterior teeth increased by 5°crown-lingual to torque group; Group A4: no activation, posterior teeth increased by 10° crown-lingual to torque group; Group B1: anterior teeth inwardly retracted by 0.25 mm, posterior teeth in Andrews' standard torque group; Group B2: anterior teeth with 0.25 mm of internal retraction and posterior teeth with 5°crown buccal to buccal torque group; Group B3: anterior teeth with 0.25 mm of internal retraction and posterior teeth with 5°crown lingual to buccal torque group; Group B4: anterior teeth with 0.25 mm of internal retraction and posterior teeth with 10°crown lingual to buccal torque group

ISSN: 1472-6831