Department of Oral and Maxillofacial Radiology, Faculty of Dentistry, Erciyes University, Kayseri, Turkey.
Department of Orthodontics, Faculty of Dentistry, Erciyes University, Kayseri, Turkey.
Eur J Orthod. 2022 Mar 30;44(2):125-133. doi: 10.1093/ejo/cjab048.
This controlled study aimed to evaluate the effects of Herbst therapy on the trabecular structure of the condyle and angulus mandible using fractal dimension analysis (FD-A) accompanied by skeletal cephalometric changes.
The panoramic and cephalometric radiographs of 30 patients with skeletal Class II malocclusion treated with the Herbst appliance (C II-H group, mean age: 15.23 ± 1.08), 30 patients with skeletal Class II malocclusion that received fixed orthodontic treatment (C II-C group, mean age: 15.73 ± 1.38), and 30 patients with skeletal Class I malocclusion (C I-C group, mean age: 15.90 ± 1.30) were selected. FD-A was performed on the superoposterior region (C-SP) and centre of the condyles (C-C) and the mandibular angulus (Ang) on the panoramic radiographs taken at the pretreatment (T0), intermediate stage of treatment (T1), and posttreatment (T2) timepoints just like cephalometric analysis.
Herbst therapy provided a statistically significant increase in SNB, ANS-Me, Na-Me, S-Go, Co-Gn and a decrease in ANB and overjet (P < 0.05). All skeletal changes remained stable during the fixed appliance treatment after Herbst. The FD values in C-C increased (P < 0.05), and C-SP values decreased (P < 0.05) during Herbst therapy, while after removal of the Herbst appliance, no significant change was observed despite an increase in C-SP. The Ang value did not change during Herbst treatment, but then increased significantly (P < 0.05). There was no significant change in the FD values of the C I-C and C II-C groups at any stage of treatment. The C-C and C-SP changes at T1-T0 period, C-SP and Ang changes at T2-T1 period, and C-C, C-SP, and Ang values at T2-T0 period were found higher in C II-H group compared with the C II-C group significantly (P < 0.05).
Herbst therapy changed the trabecular structure of the condyles in different directions at the superoposterior and central regions of the condyles, while the structural complexity of the angulus mandible, which did not change during the Herbst treatment, increased during the fixed orthodontic treatment after Herbst.
本对照研究旨在通过分形维数分析（FD-A）结合骨骼头颅侧位片评估 Herbst 治疗对髁突和下颌角小梁结构的影响。
选择 30 例骨性 II 类错颌患者（C II-H 组，平均年龄 15.23 ± 1.08 岁），使用 Herbst 矫治器治疗；30 例骨性 II 类错颌患者（C II-C 组，平均年龄 15.73 ± 1.38 岁）接受固定正畸治疗；30 例骨性 I 类错颌患者（C I-C 组，平均年龄 15.90 ± 1.30 岁）作为对照组。在治疗前（T0）、治疗中期（T1）和治疗后（T2），对全景片上的上后区（C-SP）和髁突中心（C-C）以及下颌角（Ang）进行 FD-A 分析，同时进行头颅侧位片的分析。
Herbst 治疗可显著增加 SNB、ANS-Me、Na-Me、S-Go、Co-Gn，减少 ANB 和覆颌（P<0.05）。 Herbst 治疗后，所有骨骼变化在固定矫治器治疗期间均保持稳定。在 Herbst 治疗期间，C-C 的 FD 值增加（P<0.05），C-SP 值减少（P<0.05），而在 Herbst 矫治器去除后，尽管 C-SP 值增加，但未观察到明显变化。在 Herbst 治疗期间，Ang 值没有变化，但随后显著增加（P<0.05）。在治疗的任何阶段，C I-C 和 C II-C 组的 FD 值均无显著变化。在 T1-T0 期间，C-C 和 C-SP 的变化，在 T2-T1 期间，C-SP 和 Ang 的变化，以及在 T2-T0 期间，C-C、C-SP 和 Ang 值在 C II-H 组与 C II-C 组相比均显著更高（P<0.05）。
Herbst 治疗改变了髁突上后区和中央区的小梁结构，而在下颌角，治疗期间结构复杂性没有改变，在 Herbst 治疗后的固定正畸治疗期间增加。
