Fan Chun-xiang, Sun Rong, Wu Li-ping
Department of Stomatology, Shanghai Yueyang Hospital of Intergrated Chinese and Western Medicine, Shanghai 200437, China.
Shanghai Kou Qiang Yi Xue. 2009 Dec;18(6):592-5.
To evaluate the vertical changes in Class I patients treated with first premolar extraction and to compare these changes with those without extraction.
Each group had 25 cases.One group was treated with first premolar extraction and the other without extraction. Lateral cephalograms were taken both pretreatment and posttreatment. All the films were traced and measured. To determine the vertical dimension changes due to treatment and to compare differences between the 2 groups, paired and unpaired t tests were performed with SPSS 16.0 software package, respectively.
There was no significant difference in FH-MP, Yaxis, S-Go, S-Go/N-Me and ANS-Me/N-Me in both group after treatment. Both groups had increase in N-Me , but the change was comparatively greater in the extraction group. The extraction group showed more vertical movement of the mandibular first molars than the non-extraction group.Both groups showed mesial movement of the maxillary first molars and central incisors,but no significant difference was found.
Both groups have increase in linear vertical dimensions. The changes in vertical dimension is greater in the extraction group, but there is no further change in the mandibular plane angle.
评估拔除第一前磨牙治疗的安氏I类患者的垂直向变化，并将这些变化与未拔牙患者的变化进行比较。
每组25例。一组采用拔除第一前磨牙治疗，另一组未拔牙。治疗前和治疗后均拍摄头颅侧位片。对所有片子进行描记和测量。为确定治疗引起的垂直维度变化并比较两组之间的差异，分别使用SPSS 16.0软件包进行配对和非配对t检验。
治疗后两组的FH-MP、Y轴、S-Go、S-Go/N-Me和ANS-Me/N-Me均无显著差异。两组的N-Me均增加，但拔牙组的变化相对更大。拔牙组下颌第一磨牙的垂直移动比非拔牙组更多。两组上颌第一磨牙和中切牙均有近中移动，但未发现显著差异。
两组的线性垂直维度均增加。拔牙组垂直维度的变化更大，但下颌平面角无进一步变化。
