PDF(Pubmed)
Abstract：
BACKGROUND: In this study, we sought to quantify the influence of vertical control assisted by a temporary anchorage device (TAD) on orthodontic treatment efficacy for skeletal class II patients with a hyperdivergent facial type and probe into the critical factors of profile improvement.
METHODS: A total of 36 adult patients with skeletal class II and a hyperdivergent facial type were included in this retrospective case-control study. To exclude the effect of sagittal anchorage reinforcement, the patients were divided into two groups: a maxillary maximum anchorage (MMA) group (N = 17), in which TADs were only used to help with anterior tooth retraction, and the MMA with vertical control (MMA + VC) group (N = 19), for which TADs were also used to intrude the maxillary molars and incisors. The treatment outcome was evaluated using dental, skeletal, and soft-tissue-related parameters via a cephalometric analysis and cast superimposition.
RESULTS: A significant decrease in ANB (P < 0.05 for both groups), the retraction and uprighting of the maxillary and mandibular incisors, and the retraction of protruded upper and lower lips were observed in both groups. Moreover, a significant intrusion of the maxillary molars was observed via the cephalometric analysis (- 1.56 ± 1.52 mm, P < 0.05) and cast superimposition (- 2.25 ± 1.03 mm, P < 0.05) of the MMA + VC group but not the MMA group, which resulted in a remarkable decrease in the mandibular plane angle (- 1.82 ± 1.38°, P < 0.05). The Z angle (15.25 ± 5.30°, P < 0.05) and Chin thickness (- 0.97 ± 0.45°, P < 0.05) also improved dramatically in the MMA + VC group, indicating a better profile and a relaxed mentalis. Multivariate regression showed that the improvement in the soft tissue was closely related to the counterclockwise rotation of the mandible plane (P < 0.05).
CONCLUSIONS: TAD-assisted vertical control can achieve intrusion of approximately 2 mm for the upper first molars and induce mandibular counterclockwise rotation of approximately 1.8°. Moreover, it is especially important for patients without sufficient retraction of the upper incisors or a satisfactory chin shape.
METHODS: A total of 36 adult patients with skeletal class II and a hyperdivergent facial type were included in this retrospective case-control study. To exclude the effect of sagittal anchorage reinforcement, the patients were divided into two groups: a maxillary maximum anchorage (MMA) group (N = 17), in which TADs were only used to help with anterior tooth retraction, and the MMA with vertical control (MMA + VC) group (N = 19), for which TADs were also used to intrude the maxillary molars and incisors. The treatment outcome was evaluated using dental, skeletal, and soft-tissue-related parameters via a cephalometric analysis and cast superimposition.
RESULTS: A significant decrease in ANB (P < 0.05 for both groups), the retraction and uprighting of the maxillary and mandibular incisors, and the retraction of protruded upper and lower lips were observed in both groups. Moreover, a significant intrusion of the maxillary molars was observed via the cephalometric analysis (- 1.56 ± 1.52 mm, P < 0.05) and cast superimposition (- 2.25 ± 1.03 mm, P < 0.05) of the MMA + VC group but not the MMA group, which resulted in a remarkable decrease in the mandibular plane angle (- 1.82 ± 1.38°, P < 0.05). The Z angle (15.25 ± 5.30°, P < 0.05) and Chin thickness (- 0.97 ± 0.45°, P < 0.05) also improved dramatically in the MMA + VC group, indicating a better profile and a relaxed mentalis. Multivariate regression showed that the improvement in the soft tissue was closely related to the counterclockwise rotation of the mandible plane (P < 0.05).
CONCLUSIONS: TAD-assisted vertical control can achieve intrusion of approximately 2 mm for the upper first molars and induce mandibular counterclockwise rotation of approximately 1.8°. Moreover, it is especially important for patients without sufficient retraction of the upper incisors or a satisfactory chin shape.
摘要：
背景：在这项研究中，我们试图量化临时锚固装置(TAD)辅助垂直控制对骨性II类面部类型过度发散患者正畸治疗效果的影响,并探讨轮廓改善的关键因素.
方法：这项回顾性病例对照研究共纳入了36例II类骨骼型和面部过度发散型的成年患者。为了排除矢状锚固加固的影响，患者分为两组：上颌最大支抗（MMA）组（N=17），其中TAD仅用于帮助前牙缩回，和垂直控制的MMA(MMA+VC)组(N=19)，TAD也用于侵入上颌磨牙和门牙。使用牙科评估治疗结果，骨骼，和软组织相关参数通过头颅测量分析和铸造叠加。
结果：ANB显着降低（两组P<0.05），上颌和下颌切牙的缩回和直立，观察两组上唇和下唇的退缩情况。此外，通过头颅测量分析观察到上颌磨牙的明显侵入（-1.56±1.52mm，P<0.05）和铸造叠加（-2.25±1.03mm，P<0.05)MMA+VC组而非MMA组,导致下颌平面角显着减小（-1.82±1.38°，P<0.05)。Z角(15.25±5.30°,P<0.05）和下巴厚度（-0.97±0.45°，P<0.05)在MMA+VC组中也有显著改善，表明更好的轮廓和放松的精神。多因素回归分析显示，软组织的改善与下颌骨平面的逆时针旋转密切相关（P<0.05）。
结论：TAD辅助的垂直控制可实现上第一磨牙约2mm的侵入，并诱导下颌逆时针旋转约1.8°。此外，对于上切牙没有足够回缩或下巴形状令人满意的患者尤其重要。
方法：这项回顾性病例对照研究共纳入了36例II类骨骼型和面部过度发散型的成年患者。为了排除矢状锚固加固的影响，患者分为两组：上颌最大支抗（MMA）组（N=17），其中TAD仅用于帮助前牙缩回，和垂直控制的MMA(MMA+VC)组(N=19)，TAD也用于侵入上颌磨牙和门牙。使用牙科评估治疗结果，骨骼，和软组织相关参数通过头颅测量分析和铸造叠加。
结果：ANB显着降低（两组P<0.05），上颌和下颌切牙的缩回和直立，观察两组上唇和下唇的退缩情况。此外，通过头颅测量分析观察到上颌磨牙的明显侵入（-1.56±1.52mm，P<0.05）和铸造叠加（-2.25±1.03mm，P<0.05)MMA+VC组而非MMA组,导致下颌平面角显着减小（-1.82±1.38°，P<0.05)。Z角(15.25±5.30°,P<0.05）和下巴厚度（-0.97±0.45°，P<0.05)在MMA+VC组中也有显著改善，表明更好的轮廓和放松的精神。多因素回归分析显示，软组织的改善与下颌骨平面的逆时针旋转密切相关（P<0.05）。
结论：TAD辅助的垂直控制可实现上第一磨牙约2mm的侵入，并诱导下颌逆时针旋转约1.8°。此外，对于上切牙没有足够回缩或下巴形状令人满意的患者尤其重要。
