Graduate School of Clinical Dental Science, Catholic University of Korea, Seoul, Korea.
Department of Orthodontics, Section of Dentistry, Seoul National University Bundang Hospital, Seongnam, Korea.
Orthod Craniofac Res. 2021 Mar;24 Suppl 1:31-38. doi: 10.1111/ocr.12468. Epub 2021 Mar 2.
The purpose of this study was to evaluate the long-term position of erupted third molars after maxillary total arch distalization using modified C-palatal plates (MCPPs) in adolescents and to identify factors associated with these positions.
Sixty-two third molars (male: 20, female: 42) in Class II patients treated with MCPPs and thirty-nine teeth for the Control group (male: 22, female: 17).
Samples were analyzed using panoramic radiographs taken initially (T0), after treatment (T1) and after >3 years retention (T2). Third molars were classified as downward (Group A, N = 31; males: 12, females: 19) and upward (Group B, N = 31; males: 8, females: 23) based on their vertical position after treatment. Analysis of variance and multiple logistic regression analysis were performed.
The vertical position of the third molars of Group A, Group B, and the Control showed a 2.2, 3.5 and 2.7 mm downward movement at T2. However, there was no difference in the amount of third molar eruption among the groups. Regarding factors affecting the vertical distance of the third molar, Age, C8-OP, ∠8-OP and D7-T at the initial affected vertical position of the third molars after molar distalization (P < .05).
Group A and B showed no difference in the third molar eruption during retention after total arch distalization. This study suggests that it might be unnecessary to extract the developing third molar before molar distalization in Class II adolescents.
本研究旨在评估使用改良 C 型腭板(MCPP)远移上颌全弓后萌出第三磨牙的长期位置,并确定与这些位置相关的因素。
62 颗第三磨牙(男性 20 颗,女性 42 颗)为 II 类错颌患者,接受 MCPP 治疗;39 颗第三磨牙为对照组(男性 22 颗,女性 17 颗)。
使用初始(T0)、治疗后(T1)和 >3 年保持(T2)时拍摄的全景片分析样本。根据治疗后垂直位置将第三磨牙分为向下(A 组,N=31;男性 12 颗,女性 19 颗)和向上(B 组,N=31;男性 8 颗,女性 23 颗)。进行方差分析和多因素逻辑回归分析。
A 组、B 组和对照组第三磨牙的垂直位置在 T2 时分别有 2.2、3.5 和 2.7mm 的向下移动。然而,各组第三磨牙萌出量无差异。关于影响第三磨牙垂直距离的因素,年龄、C8-OP、∠8-OP 和 D7-T 在初始时影响远移后第三磨牙的垂直位置(P<0.05)。
A 组和 B 组在远移上颌全弓后保持期间第三磨牙萌出无差异。本研究表明,在 II 类错颌青少年中,远移磨牙前可能没有必要拔除发育中的第三磨牙。