Optimizing Anterior En Masse Retraction with Miniscrew Anchorage
Figure 4
(a) MSPA consists of three parts: vertical-hooked arm (red arrow), horizontal middle part (blue arrow), and distal straight end section inserted in auxiliary molar tube (green arrow). (b) Place 1st- and 3rd-order bends as required in middle horizontal section of MSPA so that it passively engages the slot of miniscrew with insertion of distal end section into auxiliary molar tube.