Division of Oral Biology and Medicine, School of Dentistry, Center for Health Science, University of California, 10833 Le Conte Avenue, Box 951668, Los Angeles, CA, 90095-1668, USA.
Division of Growth and Development, Section of Orthodontics, School of Dentistry, Center for Health Science, University of California, Room 63-082 CHS, 10833 Le Conte Avenue, Box 951668, Los Angeles, CA, 90095-1668, USA.
Prog Orthod. 2017 Nov 1;18(1):34. doi: 10.1186/s40510-017-0188-7.
Mini-implant-assisted rapid palatal expansion (MARPE) appliances have been developed with the aim to enhance the orthopedic effect induced by rapid maxillary expansion (RME). Maxillary Skeletal Expander (MSE) is a particular type of MARPE appliance characterized by the presence of four mini-implants positioned in the posterior part of the palate with bi-cortical engagement. The aim of the present study is to evaluate the MSE effects on the midpalatal and pterygopalatine sutures in late adolescents, using high-resolution CBCT. Specific aims are to define the magnitude and sagittal parallelism of midpalatal suture opening, to measure the extent of transverse asymmetry of split, and to illustrate the possibility of splitting the pterygopalatine suture.
Fifteen subjects (mean age of 17.2 years; range, 13.9-26.2 years) were treated with MSE. Pre- and post-treatment CBCT exams were taken and superimposed. A novel methodology based on three new reference planes was utilized to analyze the sutural changes. Parameters were compared from pre- to post-treatment and between genders non-parametrically using the Wilcoxon sign rank test. For the frequency of openings in the lower part of the pterygopalatine suture, the Fisher's exact test was used.
Regarding the magnitude of midpalatal suture opening, the split at anterior nasal spine (ANS) and at posterior nasal spine (PNS) was 4.8 and 4.3 mm, respectively. The amount of split at PNS was 90% of that at ANS, showing that the opening of the midpalatal suture was almost perfectly parallel antero-posteriorly. On average, one half of the anterior nasal spine (ANS) moved more than the contralateral one by 1.1 mm. Openings between the lateral and medial plates of the pterygoid process were detectable in 53% of the sutures (P < 0.05). No significant differences were found in the magnitude and frequency of suture opening between males and females. Correlation between age and suture opening was negligible (R range, 0.3-4.2%).
Midpalatal suture was successfully split by MSE in late adolescents, and the opening was almost perfectly parallel in a sagittal direction. Regarding the extent of transverse asymmetry of the split, on average one half of ANS moved more than the contralateral one by 1.1 mm. Pterygopalatine suture was split in its lower region by MSE, as the pyramidal process was pulled out from the pterygoid process. Patient gender and age had a negligible influence on suture opening for the age group considered in the study.
微型植入物辅助快速腭扩张（MARPE）器具的开发旨在增强快速上颌扩张（RME）引起的矫形效果。上颌扩弓器（MSE）是一种特殊类型的 MARPE 器具，其特点是在后腭部有四个微型植入物，采用双皮质结合。本研究的目的是使用高分辨率 CBCT 评估 MARPE 对上颌中缝和翼腭缝的影响。具体目标是定义中缝张开的幅度和矢状平行度，测量分裂的横向不对称程度，并说明分裂翼腭缝的可能性。
对 15 名受试者（平均年龄 17.2 岁；范围，13.9-26.2 岁）进行 MSE 治疗。拍摄治疗前后的 CBCT 检查并进行叠加。利用一种基于三个新参考平面的新方法来分析缝的变化。使用 Wilcoxon 符号秩检验对参数进行非参数比较，以比较治疗前后和性别之间的差异。对于翼腭缝下部开口的频率，使用 Fisher 确切检验。
就中缝张开的幅度而言，前鼻棘（ANS）和后鼻棘（PNS）的分裂分别为 4.8 和 4.3mm。PNS 的分裂量为 ANS 的 90%，表明中缝的张开几乎是完全前后平行的。平均而言，一半的前鼻棘（ANS）比对侧移动 1.1mm。53%的翼状突外侧和内侧板之间有开口（P<0.05）。男性和女性之间在缝的张开幅度和频率上没有发现显著差异。年龄与缝张开之间的相关性可以忽略不计（R 范围，0.3-4.2%）。
MSE 成功地在上颌骨晚期青少年中分裂了中缝，并且在矢状方向上的开口几乎是完全平行的。关于分裂的横向不对称程度，平均而言，一半的前鼻棘（ANS）比对侧移动 1.1mm。MSE 也将翼腭缝下部分开，因为尖牙从翼状突中被拔出。考虑到研究中的年龄组，患者性别和年龄对缝的张开影响可以忽略不计。
