Hellsing E, Hellsing G, Eliasson S
Karolinska Institutet, Department of Orthodontics, Faculty of Odontology, Huddinge, Sweden.
Am J Orthod Dentofacial Orthop. 1996 Jul;110(1):61-8. doi: 10.1016/s0889-5406(96)70088-4.
Orthodontic treatment of eight overbite cases with a maxillary fixed lingual arch appliance with anterior biteplane involved a reduction in overbite of 4 to 7 mm between the upper and the lower front teeth and a first molar separation of 2 to 4 mm. After a treatment period of 3.5 to 5 months, occlusal contact between the upper and the lower molars was established. The appliance was then removed, and permanent overbite reduction was secured with an edgewise appliance. With the subtraction technique, 15 temporomandibular joints were radiographically investigated in the retruded position for change of condylar position on the glenoid fossa before and directly after insertion of the appliance, as well as after achieved molar contact. All condyles changed position directly after the bite opening, indicating that pure rotation did not occur. The direction of movement varied not only between subjects but also between the two condyles of each subject. With one exception, none or very small further positional changes occurred during treatment. No imaged signs of hard structure remodeling were observed. It may be concluded that other factors than change of condylar position must be responsible for the therapeutic effect of the bite-opening appliance that has been demonstrated in an earlier study.
使用带有前牙咬合平面的上颌固定舌弓矫治器对8例深覆合病例进行正畸治疗，上下前牙之间的覆合减少了4至7毫米，第一磨牙分开了2至4毫米。经过3.5至5个月的治疗期后，上下磨牙之间建立了咬合接触。然后取下矫治器，使用方丝弓矫治器确保覆合永久性降低。采用减法技术，对15个颞下颌关节在矫治器插入前、插入后即刻以及磨牙接触后在后退位进行影像学研究，观察髁突在关节窝上的位置变化。所有髁突在开口咬合后即刻都改变了位置，表明并非单纯旋转。运动方向不仅在个体之间不同，而且在每个个体的两个髁突之间也不同。除一例例外，治疗期间没有或仅有非常小的进一步位置变化。未观察到硬组织重塑的影像学迹象。可以得出结论，在早期研究中已证明的开口咬合矫治器的治疗效果，其原因肯定不是髁突位置的改变，而是其他因素。
