Department of Orthodontics, Saint Louis University, St Louis, Mo; Department of Orthodontics, Universidade do Sul de Santa Catarina, Florianopolis, Santa Catarina, Brazil.
Department of Orthodontics, Universidade Luterana do Brasil, Canoas, Rio Grande do Sul, Brazil.
Am J Orthod Dentofacial Orthop. 2018 Jul;154(1):91-98. doi: 10.1016/j.ajodo.2017.10.031.
Our objective was to analyze the characteristics that affect skeletal Class I adults with mandibular asymmetries using cone-beam computerized tomography.
The sample included cone-beam computerized tomography images of 120 subjects. Asymmetry was determined by the deviation of gnathion from the midsagittal plane and classified as relative symmetry, moderate asymmetry, or severe asymmetry. Maxillary and mandibular measurements were made, and the differences between the contralateral side and the deviated side were evaluated, as well as the differences between the categories of asymmetry.
For patients with moderate asymmetry, there were significant differences between the contralateral and deviated sides for some measuments in the transverse and vertical planes. For those with severe asymmetry, statistically significant differences were found between the sides for all measurements, except for the measuments that evaluated the position of the mandibular condyle in the transverse and sagittal directions. Furthermore, a strong correlation was found in patients with severe asymmetry, between the deviation of the mandibular dental midline and the lateral displacement of gnathion.
Patients with relative symmetry had a bilateral balance, whereas those with moderate and severe asymmetries showed several skeletal imbalances. A great deviation of the mandibular dental midline may indicate severe skeletal asymmetry in Class I adults.
本研究旨在利用锥形束计算机断层扫描分析下颌骨不对称的成人骨性Ⅰ类中影响骨骼特征的因素。
该样本包括 120 例患者的锥形束计算机断层扫描图像。采用颏部与正中矢状面的偏距来确定不对称性，并将其分为相对对称、中度不对称或重度不对称。对上颌和下颌进行测量，并评估对侧与偏侧之间的差异，以及不同的不对称类别之间的差异。
对于中度不对称的患者，在横断和垂直平面上，一些测量值在对侧和偏侧之间存在显著差异。对于重度不对称的患者，所有测量值的两侧之间均存在统计学差异，除了评估髁突在横断和矢状方向上位置的测量值。此外，在重度不对称的患者中，下颌牙中线的偏距与颏部的侧向移位之间存在很强的相关性。
相对对称的患者具有双侧平衡，而中度和重度不对称的患者则存在多种骨骼不平衡。下颌牙中线的较大偏距可能表明成人骨性Ⅰ类中存在严重的骨骼不对称。
