[Study of bracket placement with the preadjusted appliance for extraction cases].
OBJECTIVE
To determine the bracket placement with the preadjusted appliance for extraction cases.


METHODS
Sixty finishing occlusions were chosen as Andrews stated at debonding. The placement of the incisor teeth bracket was in the middle of the clinical crown, and retention arch wire was straight wire without step bends. The measurement from the incisal or occlusal edges to the bracket center was the height of the placement of the bracket. In order to produce bracket placement chart, the values of measurements +0.5 mm and +1.0 mm were added for larger teeth, and -0.5 mm and -1.0 mm for smaller teeth.


RESULTS
The placement in the second bicuspid and first molar was different between extraction cases and nonextraction cases.


CONCLUSIONS
The bracket placement chart improves the accuracy of bracket placement with the preadjusted appliance for extraction cases.
Liu
D X
DX
The Affliated Stomatology Hospital of Shandong Medical University, Shandong 250012, China.
Wang
C L
CL
Yue
J R
JR
Zhang
X Y
XY