Ioi Hideki, Nakata Shunsuke, Nakasima Akihiko, Counts Amy L
Department of Orthodontics, Faculty of Dentistry, Kyushu University, Higashi-ku, Fukuoka, Japan.
Eur J Orthod. 2007 Oct;29(5):493-9. doi: 10.1093/ejo/cjm059.
The aims of this study were to determine Japanese cephalometric norms in the antero-posterior and vertical dimension, and to test the hypothesis that there are racial differences in cephalometric measurements between Japanese and Caucasian norms. Radiographs were obtained from 25 healthy Japanese males (aged 25.1 +/- 2.7 years) and 24 healthy Japanese females (aged 23.6 +/- 1.3 years). Inclusion criteria were an ANB angle between 2 and 5 degrees, a normal occlusion with minor or no crowding, all teeth present except third molars, no previous orthodontic treatment, and no prosthetic replacement of teeth. Two angular and five linear measurements were constructed for the skeletal hard tissue analysis, one angular and six linear measurements for the dental hard tissue analysis, and two angular and seven linear measurements for the soft tissue analysis. The mean and standard deviations for the hard and soft tissue measurements were determined for each gender. Unpaired t-tests were used to determine the mean differences for each cephalometric measurement between the Japanese and the Caucasians. In the antero-posterior dimension, the Japanese subjects had a significantly more retruded chin position (P < 0.001), typically protruding mandibular incisors, and protruded lip positions compared with the Caucasian norms. In the vertical dimension, the Japanese had a significantly steeper mandibular plane (P < 0.01). The Japanese females had a significantly larger lower face height and increased dental height (P < 0.001). The results of this study suggest that these cephalometric measurements might be helpful to formulate treatment plans for Japanese patients.
本研究的目的是确定日本人群在前后向和垂直方向的头影测量标准，并检验日本人和高加索人头影测量存在种族差异这一假设。对25名健康日本男性（年龄25.1±2.7岁）和24名健康日本女性（年龄23.6±1.3岁）进行了X线片拍摄。纳入标准为ANB角在2至5度之间、咬合正常且轻微拥挤或无拥挤、除第三磨牙外所有牙齿均存在、既往未接受正畸治疗且无牙齿修复。构建了两个角度和五个线性测量用于骨骼硬组织分析，一个角度和六个线性测量用于牙齿硬组织分析，两个角度和七个线性测量用于软组织分析。确定了每种性别的硬组织和软组织测量的平均值和标准差。采用非配对t检验确定日本人和高加索人在每项头影测量上的平均差异。在前后向维度上，与高加索标准相比日本受试者的下巴位置明显后缩（P<0.001），下颌切牙通常前突，唇部位置前突。在垂直维度上，日本人的下颌平面明显更陡（P<0.01）。日本女性的下脸高度明显更大且牙高度增加（P<0.001）。本研究结果表明，这些头影测量可能有助于为日本患者制定治疗计划。
