Kinzinger Gero Stefan Michael, Hourfar Jan, Kober Cornelia, Lisson Jörg Alexander
Department of Orthodontics, Saarland University, Universitätskliniken 56, 66424, Homburg/Saar, Germany.
HAW Hamburg, Hamburg, Germany.
J Orofac Orthop. 2018 Mar;79(2):116-132. doi: 10.1007/s00056-018-0124-6. Epub 2018 Feb 20.
During therapy of distoclusion entailing a rigid, fixed orthodontic appliance, the mandibular fossa and condyle are ideally remodeled, while dentoalveolar effects occur through adaptive mechanisms. Adaptive processes, especially in the fossa region, have not been adequately investigated. Our magnetic resonance imaging (MRI) investigation aimed to assess the effects of therapy with a functional mandibular advancer (FMA) on mandibular fossa morphology.
We monitored via MRI the therapeutic course of 25 patients at three time points. Visual findings and metric assessments were carried out in the sagittal plane. Three-dimensional (3D) reconstructions of the joint structure of two exemplary patients were also made.
Visual examinations of the MRI slices at the three time points revealed no changes in fossa shape in any of the 50 temporomandibular joints. Lateral comparisons showed that the morphology of the fossae of all 25 patients was identical. Metric analysis demonstrated no significant alterations in width, depth, or in their ratio, not even laterally. Nine measurements of the distances between the porion, mandibular fossa, and articular eminence revealed no significant changes in total or on the left and right sides, or intralaterally.
The visual findings and metric analyses of parasagittal MRI slices did not indicate any morphological changes in the mandibular fossa or articular eminence in patients with distoclusion treated via a rigid, fixed orthodontic appliance. However, special reworking of the MRI data facilitated reconstruction of the surfaces of joint structures in 3D. This new method makes it possible to depict more accurately and noninvasively the adaptive mechanisms not ascertainable via metric methods and to assess them as 3D structures.
在采用刚性固定正畸矫治器治疗远中错合期间，下颌窝和髁突理想情况下会发生重塑，而牙槽骨效应则通过适应性机制产生。适应性过程，尤其是在窝区，尚未得到充分研究。我们的磁共振成像（MRI）研究旨在评估功能性下颌前导器（FMA）治疗对下颌窝形态的影响。
我们通过MRI在三个时间点监测了25例患者的治疗过程。在矢状面进行视觉观察和测量评估。还对两名典型患者的关节结构进行了三维（3D）重建。
在三个时间点对MRI切片进行的视觉检查显示，50个颞下颌关节中没有一个的窝形状发生变化。横向比较表明，所有25例患者的窝形态相同。测量分析表明，宽度、深度或其比值均无显著变化，甚至在横向也没有。对耳点、下颌窝和关节结节之间距离的九次测量显示，总体上或左右两侧以及内侧均无显著变化。
对矢状面MRI切片的视觉观察和测量分析表明，采用刚性固定正畸矫治器治疗的远中错合患者的下颌窝或关节结节没有任何形态变化。然而，对MRI数据的特殊处理有助于对关节结构表面进行3D重建。这种新方法能够更准确、无创地描绘通过测量方法无法确定的适应性机制，并将其作为3D结构进行评估。
