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Abstract：
BACKGROUND: The intrusion of maxillary anterior teeth is often required and there are various intrusion modes with mini-implants in clear aligner treatment. The objective of this study was to evaluate the effectiveness of maxillary anterior teeth intrusion with different intrusion modes, aiming to provide references for precise and safe intrusion movements in clinical practice.
METHODS: Cone-beam computed tomography and intraoral optical scanning data of a patient were collected. Finite element models of the maxilla, maxillary dentition, periodontal ligaments (PDLs), clear aligner (CA), attachments, and mini-implants were established. Different intrusion modes of the maxillary anterior teeth were simulated by changing the mini-implant site (between central incisors, between central and lateral incisor, between lateral incisor and canine), loading site (between central incisors, on central incisor, between central and lateral incisor, between lateral incisor and canine), and loading mode (labial loading and labiolingual loading). Ten conditions were generated and intrusive forces of 100 g were applied totally. Then displacement tendency of the maxillary anterior teeth and CA, and stress of the PDLs were analyzed.
RESULTS: For the central incisor under condition L14 and for the canine under conditions L11, L13, L23, and L33, the intrusion amount was negative. Under other conditions, the intrusion amount was positive. The labiolingual angulation of maxillary anterior teeth exhibited positive changes under all conditions, with greater changes under linguoincisal loading. The mesiodistal angulation of canine exhibited positive changes under labial loading, while negative changes under linguoincisal loading except for condition L14.
CONCLUSIONS: The intrusion amount, labiolingual and mesiodistal angulations of the maxillary anterior teeth were affected by the mini-implant site, loading site, and loading mode. Labial and linguoincisal loading may have opposite effects on the intrusion amount of maxillary anterior teeth and the mesiodistal angulation of canine. The labiolingual angulation of the maxillary incisors would increase under all intrusion modes, with greater increases under linguoincisal loading.
METHODS: Cone-beam computed tomography and intraoral optical scanning data of a patient were collected. Finite element models of the maxilla, maxillary dentition, periodontal ligaments (PDLs), clear aligner (CA), attachments, and mini-implants were established. Different intrusion modes of the maxillary anterior teeth were simulated by changing the mini-implant site (between central incisors, between central and lateral incisor, between lateral incisor and canine), loading site (between central incisors, on central incisor, between central and lateral incisor, between lateral incisor and canine), and loading mode (labial loading and labiolingual loading). Ten conditions were generated and intrusive forces of 100 g were applied totally. Then displacement tendency of the maxillary anterior teeth and CA, and stress of the PDLs were analyzed.
RESULTS: For the central incisor under condition L14 and for the canine under conditions L11, L13, L23, and L33, the intrusion amount was negative. Under other conditions, the intrusion amount was positive. The labiolingual angulation of maxillary anterior teeth exhibited positive changes under all conditions, with greater changes under linguoincisal loading. The mesiodistal angulation of canine exhibited positive changes under labial loading, while negative changes under linguoincisal loading except for condition L14.
CONCLUSIONS: The intrusion amount, labiolingual and mesiodistal angulations of the maxillary anterior teeth were affected by the mini-implant site, loading site, and loading mode. Labial and linguoincisal loading may have opposite effects on the intrusion amount of maxillary anterior teeth and the mesiodistal angulation of canine. The labiolingual angulation of the maxillary incisors would increase under all intrusion modes, with greater increases under linguoincisal loading.
摘要：
背景：通常需要侵入上颌前牙，并且在清晰的矫正器治疗中，使用微型植入物存在各种侵入模式。这项研究的目的是评估不同侵入方式的上颌前牙侵入的有效性，旨在为临床实践中精确、安全的侵入动作提供参考。
方法：收集患者的锥形束计算机断层扫描和口内光学扫描数据。上颌骨的有限元模型，上颌牙列,牙周韧带（PDL），清除对准器（CA），附件,建立了微型植入物。通过改变微型种植部位（在中央切牙之间，模拟了上颌前牙的不同侵入方式。在中切牙和侧切牙之间，在侧门牙和犬齿之间)，装载部位(中间切牙之间，在中切牙上,在中切牙和侧切牙之间，在侧门牙和犬齿之间)，和加载模式（唇加载和唇舌加载）。产生了十个条件，并总共施加了100g的侵入力。然后上颌前牙和CA的位移趋势，并对PDL的应力进行了分析。
结果：对于条件L14下的中切牙和条件L11，L13，L23和L33下的犬科动物，侵入量为阴性。在其他条件下,入侵量为正。在所有情况下，上颌前牙的唇舌角均表现出积极的变化，在舌体负重下有更大的变化。在唇负荷下，犬的中远侧角度表现出积极的变化，而除条件L14外，在舌骨负荷下出现负变化。
结论：入侵量，上颌前牙的唇舌和中远端角度受到微型植入部位的影响，装货地点,和加载模式。唇侧和舌侧负荷可能对上颌前牙的侵入量和犬的远端角度产生相反的影响。在所有侵入模式下，上颌切牙的唇舌角度都会增加，在舌尖负荷下增加更大。
方法：收集患者的锥形束计算机断层扫描和口内光学扫描数据。上颌骨的有限元模型，上颌牙列,牙周韧带（PDL），清除对准器（CA），附件,建立了微型植入物。通过改变微型种植部位（在中央切牙之间，模拟了上颌前牙的不同侵入方式。在中切牙和侧切牙之间，在侧门牙和犬齿之间)，装载部位(中间切牙之间，在中切牙上,在中切牙和侧切牙之间，在侧门牙和犬齿之间)，和加载模式（唇加载和唇舌加载）。产生了十个条件，并总共施加了100g的侵入力。然后上颌前牙和CA的位移趋势，并对PDL的应力进行了分析。
结果：对于条件L14下的中切牙和条件L11，L13，L23和L33下的犬科动物，侵入量为阴性。在其他条件下,入侵量为正。在所有情况下，上颌前牙的唇舌角均表现出积极的变化，在舌体负重下有更大的变化。在唇负荷下，犬的中远侧角度表现出积极的变化，而除条件L14外，在舌骨负荷下出现负变化。
结论：入侵量，上颌前牙的唇舌和中远端角度受到微型植入部位的影响，装货地点,和加载模式。唇侧和舌侧负荷可能对上颌前牙的侵入量和犬的远端角度产生相反的影响。在所有侵入模式下，上颌切牙的唇舌角度都会增加，在舌尖负荷下增加更大。
