Booij Johan Willem, Serafin Marco, Fastuca Rosamaria, Kuijpers-Jagtman Anne Marie, Caprioglio Alberto
Private Practice in Gorinchem, 4207 AC Gorinchem, The Netherlands.
Department of Biomedical Sciences for Health, University of Milan, 20133 Milan, Italy.
J Clin Med. 2022 Jun 2;11(11):3170. doi: 10.3390/jcm11113170.
The aim of the present retrospective study was evaluating skeletal, dental and soft tissue changes of two groups of Class II patients orthodontically treated with extractions of upper first premolars (U4 group) and upper first molars (U6 group). In total, 21 patient records (9M and 12F; mean age 12.5 ± 1.2 years) were selected for the U4 group, and 38 patient records (17M and 21F; mean age 13.2 ± 1.3 years) were recruited for the U6 group. Twenty cephalometric variables were analysed on standardised lateral cephalograms at baseline (T0) and at the end of orthodontic treatment (T1). Means and standard deviations (SDs) were calculated for both groups and increments were calculated. After revealing the normal distribution of data with the Shapiro-Wilk test, Student's -test was used to compare variables at T0 between groups. A paired -test was used to analyse changes between time points within each group, and Student's -test to compare differences between groups at T1. Both groups showed a significant increase in the distance among upper second molars and the vertical pterygoid line (PTV-maxillary second molar centroid U6 group: 6.66 ± 5.00 mm; U4 group: 3.66 ± 2.20 mm). Moreover, the distance of upper incisors to the palatal plane significantly increased (PP-maxillary incisor tip U6 group: 1.09 ± 1.52 mm; U4 group: 0.20 ± 2.00 mm; = 0.061). Significant changes were found for overjet (U6 group: -4.86 ± 1.62 mm; U4 group: -3.27 ± 1.90 mm; = 0.001). The distance between upper lip and esthetic plane showed a significantly reduction in both groups (ULip-E Plane U6 group: -2.98 ± 1.65 mm; U4 group: -1.93 ± 1.57 mm). No statistically significant changes were found in sagittal or vertical skeletal values. The significantly larger reduction of upper lip protrusion and overjet in the U6 group compared to the U4 group suggests preferring molar extraction treatment for severe Class II with protrusive soft tissues' profile and increased overjet. Since no differences on vertical values were found, an increased SN^GoGn angle should not be considered a discriminating factor for choosing molar extraction treatment.
本回顾性研究的目的是评估两组安氏II类患者在拔除上颌第一前磨牙（U4组）和上颌第一磨牙（U6组）进行正畸治疗后的骨骼、牙齿和软组织变化。U4组共选取了21份患者记录（9名男性和12名女性；平均年龄12.5±1.2岁），U6组招募了38份患者记录（17名男性和21名女性；平均年龄13.2±1.3岁）。在基线（T0）和正畸治疗结束时（T1），对标准化的头颅侧位片上的20个头颅测量变量进行了分析。计算了两组的均值和标准差（SDs），并计算了增量。在用Shapiro-Wilk检验揭示数据的正态分布后，使用Student's t检验比较两组在T0时的变量。使用配对t检验分析每组内时间点之间的变化，使用Student's t检验比较两组在T1时的差异。两组上颌第二磨牙与翼突垂直线之间的距离均显著增加（U6组：翼突垂直线-上颌第二磨牙质心为6.66±5.00mm；U4组：3.66±2.20mm）。此外，上颌切牙至腭平面的距离显著增加（U6组：腭平面-上颌切牙切端为1.09±1.52mm；U4组：0.20±2.00mm；P = 0.061）。覆盖有显著变化（U6组：-4.86±1.62mm；U4组：-3.27±1.90mm；P = 0.001）。两组上唇与审美平面之间的距离均显著减小（U6组：上唇-审美平面为-2.98±1.65mm；U4组：-1.93±1.57mm）。矢状或垂直骨骼值未发现统计学上的显著变化。与U4组相比，U6组上唇前突和覆盖的减小显著更大，这表明对于软组织前突且覆盖增加的重度安氏II类患者，更倾向于采用磨牙拔除治疗。由于在垂直值上未发现差异，因此增加的SN^GoGn角不应被视为选择磨牙拔除治疗的鉴别因素。
