Assistant Professor, Department of Developmental Sciences/Orthodontics, Marquette University School of Dentistry, Milwaukee, Wisconsin..
Assistant Professor, Division of Orthodontics, University of Connecticut Health, Farmington, Connecticut.
J World Fed Orthod. 2021 Dec;10(4):144-154. doi: 10.1016/j.ejwf.2021.07.001. Epub 2021 Jul 29.
The objective of this study was to evaluate the short-term and long-term effects of tooth-anchored and bone-anchored maxillary expansion appliances on the condyle-fossa relationship, compared to those in a matched control group. Another objective of the study was to evaluate whether the amount of dental and skeletal expansion is correlated with the condyle-fossa relationship.
A total of 180 cone-beam computed tomography scans (CBCTs) for 60 subjects were analyzed for 3 groups: 1) bone-anchored maxillary expansion (BA; n = 20); 2) tooth-anchored maxillary expansion (TA; n = 21); and 3) controls (n = 19) at pretreatment, post-expansion (T2), and post-treatment (T3). The posterior joint space (PJS), superior joint space (SJS), anterior joint space, angle of mandibular condyle, distance of the condyle to the mid-sagittal plane, the inter-molar cuspal width, and the skeletal maxillary width (SMW) were measured for all 3 groups.
Both BA and TA led to a significant increase in inter-molar cuspal width, SMW, and TA led to a significant increase in PJS as compared to controls at T2. However, there was no significant difference in the joint spaces between the BA, TA, and control groups in the long term. Both the BA and TA groups showed a significant increase in SMW at T3 compared to the control group. Molar extrusion showed a weak correlation with PJS at T2 (r = 0.46) and T3 (r = 0.51), and a moderate correlation with SJS at T2 (r = 0.61) and T3 (r = 0.69).
TA led to a significant increase in PJS, compared to a control group, at T2, but there was no long-term difference in the condyle-fossa relationship among the BA, TA, and control groups. Molar extrusion showed moderate correlation with SJS and PJS.
本研究旨在评估牙锚式和骨锚式上颌扩张装置在短期内和长期对髁突-窝关系的影响，并与匹配的对照组进行比较。本研究的另一个目的是评估牙齿和骨骼扩张的量是否与髁突-窝关系相关。
共分析了 60 名受试者的 180 个锥形束计算机断层扫描（CBCT），分为 3 组：1）骨锚式上颌扩张（BA；n=20）；2）牙锚式上颌扩张（TA；n=21）；和 3）对照组（n=19），分别在治疗前（T1）、扩张后（T2）和治疗后（T3）进行测量。对所有 3 组进行了后关节间隙（PJS）、上关节间隙（SJS）、前关节间隙、下颌髁突角度、髁突到正中矢状面的距离、磨牙牙尖宽度和上颌骨骼宽度（SMW）的测量。
与对照组相比，BA 和 TA 在 T2 时均显著增加了磨牙牙尖宽度、SMW 和 TA 增加了 PJS。然而，在长期随访中，BA、TA 和对照组之间的关节间隙没有显著差异。与对照组相比，BA 和 TA 组在 T3 时 SMW 均显著增加。T2 时，磨牙伸长与 PJS 呈弱相关（r=0.46），T3 时呈中度相关（r=0.51），T2 时与 SJS 呈中度相关（r=0.61），T3 时呈中度相关（r=0.69）。
与对照组相比，TA 在 T2 时显著增加了 PJS，但在 BA、TA 和对照组之间，髁突-窝关系没有长期差异。磨牙伸长与 SJS 和 PJS 呈中度相关。
