Liu Ye, Ge Xiao-Lei, Zhang Shi-Long, Qin Yuan, Hou Yan, Lu Hai-Yan, Ma Wen-Sheng
Department of Orthodontics, School and Hospital of Stomatology, Hebei Medical University; Hebei Key Laboratory of Stomatology; Hebei Clinical Research Center for Oral Diseases. Shijiazhuang 050017, Hebei Province, China. E-mail:
Shanghai Kou Qiang Yi Xue. 2024 Apr;33(2):180-185.
To investigate the efficacy of a modified maxillary protraction appliance in patients of skeletal Class Ⅲ with crowding.
Forty patients with skeletal Class Ⅲ malocclusion were divided into two groups, with 20 patients in each group. The experimental group had molar in a neutral or distal relationship and applied a modified maxillary protraction appliance, while the control group had molar mesial relationship and applied a conventional maxillary protraction appliance. Lateral cephalometric radiographs were taken before and after treatment in both groups for comparison. SPSS 22.0 software package was used for data analysis.
The angle measurements taken before and after treatment showed a significant increase in SNA, ANB, SN-MP and U4-SN(P＜0.01), while SNB decreased(P＜0.01) in both groups. SN-OL changes were statistically different before and after treatment in the experimental group(P＜0.05). The sagittal measurements before and after treatment in both groups showed significant alterations in all(P＜0.05) but the length of the maxillary arch in both groups. For vertical measurements, U1-PP, L1-MP, U4-SN, U6-SN, and ANS-ME all increased (P＜0.05), while the changes of U4-PP and U6-PP in the two groups before and after treatment were statistically different(P＜0.05). Compared with the control group, the experimental group had a significantly increased maxillary arch length, a more remote location at U6, and a less variable molar relationship after treatment(P＜0.01). The two groups showed a variable amount of cephalometric measurements before and after treatment: the experimental group had a significant increase in maxillary arch length, a more remote position at U6, and a smaller change in molar relationship compared to the control group(P＜0.01).
The modified maxillary protraction appliance showed good results for maxillary protraction and pushing the molar distally in patients with skeletal Class Ⅲ with crowding at neutral or distal molar relationship.
探讨改良上颌前牵引矫治器对伴有牙列拥挤的骨性Ⅲ类错 患者的矫治效果。
将40例骨性Ⅲ类错 患者分为两组，每组20例。试验组磨牙关系为中性或远中，采用改良上颌前牵引矫治器；对照组磨牙关系为近中，采用传统上颌前牵引矫治器。两组均在治疗前后拍摄头颅侧位片进行对比。采用SPSS 22.0软件包进行数据分析。
两组治疗前后角度测量显示，SNA、ANB、SN-MP及U4-SN均显著增大（P＜0.01），SNB减小（P＜0.01）。试验组治疗前后SN-OL变化有统计学差异（P＜0.05）。两组治疗前后矢状向测量显示，除两组上颌牙弓长度外，其余均有显著改变（P＜0.05）。垂直向测量显示，U1-PP、L1-MP、U4-SN、U6-SN及ANS-ME均增大（P＜0.05），两组治疗前后U4-PP及U6-PP变化有统计学差异（P＜0.05）。与对照组相比，试验组治疗后上颌牙弓长度显著增加，U6位置更偏远，磨牙关系变化更小（P＜0.01）。两组治疗前后头颅测量指标变化量不同：试验组上颌牙弓长度显著增加，U6位置更偏远，与对照组相比磨牙关系变化更小（P＜0.01）。
改良上颌前牵引矫治器对伴有牙列拥挤、磨牙关系为中性或远中的骨性Ⅲ类错 患者的上颌前牵引及磨牙远移效果良好。
