Pirttiniemi P, Raustia A, Kantomaa T, Pyhtinen J
Institute of Dentistry, University of Oulu, Finland.
Eur J Orthod. 1991 Dec;13(6):441-5. doi: 10.1093/ejo/13.6.441.
Mandibular asymmetry in the frontal plane is a common finding, the left side of the mandible being more often the longer one, and a progressive trend for a more post-normal occlusion on the right side as compared to the left has been reported recently. The aim of the present work was to measure bicondylar asymmetry using computed tomography (CT) and to determine whether this is correlated with certain occlusal characteristics in young adults with no gross malformations. The subjects were 49 adults aged from 15 to 33 years, mean 24.2 years (SD 3.79 years). All of them had a complete or nearly complete dentition. The left condyle was found to be more anteriorly located on average and to be positioned closer to the skull base midline than the right condyle. The joint space between the condyle and the posterior wall of the glenoid fossa was larger on the left side. The asymmetry in bicondylar position correlated with the occlusal asymmetry. Subjects with lateral malocclusions showed a more asymmetric position of the condyles with respect to the posterior wall of the glenoid fossa. This may be of clinical importance and stresses the necessity for early correction of such malocclusions, as complete adaptation does not seem to occur in these cases.
下颌骨在额状面的不对称是常见现象，下颌骨左侧通常较长，且最近有报道称，与左侧相比，右侧存在向更后正常咬合发展的趋势。本研究的目的是使用计算机断层扫描（CT）测量双侧髁突不对称性，并确定其是否与无明显畸形的年轻成年人的某些咬合特征相关。研究对象为49名年龄在15至33岁之间的成年人，平均年龄24.2岁（标准差3.79岁）。他们均有完整或接近完整的牙列。结果发现，左侧髁突平均位置更靠前，且比右侧髁突更靠近颅底中线。左侧髁突与关节盂后缘之间的关节间隙更大。双侧髁突位置的不对称与咬合不对称相关。伴有侧方错牙合的受试者，其髁突相对于关节盂后缘的位置更不对称。这可能具有临床意义，并强调了早期矫正此类错牙合的必要性，因为在这些情况下似乎不会出现完全适应。
