【Yang Yeh】評論

摘錄自Profitt Ch14 Growth Modification in Class II, Open Bite/Deep Bite, and Multidimensional Problems p477In practice, it is difficult to analyze exactly where the center of resistance and center of rotation of the maxilla might be, but they are above the teeth and most likely above the premolar teeth. Directing the line of force closer to the center of resistance is another major reason for including an upward direction of pull for most children who have headgear force to the maxilla.就理解上，上顎Anchorage最大的就是臼齒再來犬齒，如果整個Arch連為一體Center of resisrance應該也會前移，所以選擇小臼齒也滿合理的（雖然課本的Headgear圖都為了簡化只標示molar）