Arnold T G, Anderson G C, Liljemark W F
Department of Preventive Sciences, School of Dentistry, University of Minnesota, Minneapolis.
Am J Orthod Dentofacial Orthop. 1994 Sep;106(3):250-6. doi: 10.1016/S0889-5406(94)70044-3.
The submental-vertical (S-V) radiograph has become popular in the assessment of craniofacial asymmetry because of ease in identifying reliable midline reference structures. To date, no standards of asymmetry that use the S-V projection have been reported. Submental-vertical radiographs were obtained on 44 adults. Subjects were excluded if previous orthodontic treatment or temporomandibular joint symptoms were reported. With the use of a system of asymmetry analysis developed by Ritucci and Burstone, asymmetry was reported for cranial base, zygomaxillary complex, and mandibular structures. Mean and standard deviations were used to report the asymmetry values across 23 pairs of anatomic landmarks. The data showed that asymmetry is present to some degree in all landmarks and patients. Further, strong asymmetry associations existed between landmarks within patients, with most high positive correlation coefficient values found between regionally or geometrically related points. A refined version of the asymmetric analysis was presented that included easily identified and clinically relevant points. This system is more feasible for the orthodontic clinician.
颏下垂直位（S-V）X线片因易于识别可靠的中线参考结构，在颅面部不对称评估中已变得很常用。迄今为止，尚未有使用S-V投照的不对称标准报告。对44名成年人拍摄了颏下垂直位X线片。如果报告有既往正畸治疗史或颞下颌关节症状，则将受试者排除。使用Ritucci和Burstone开发的不对称分析系统，报告了颅底、颧上颌复合体和下颌结构的不对称情况。使用均值和标准差报告了23对解剖标志点的不对称值。数据表明，所有标志点和患者均存在一定程度的不对称。此外，患者体内标志点之间存在很强的不对称相关性，在区域或几何相关点之间发现的大多数相关系数值为高度正相关。提出了一种改进版的不对称分析方法，其中包括易于识别且与临床相关的点。该系统对正畸临床医生而言更可行。
