PDF(Pubmed)
Abstract：
UNASSIGNED: The objective of this study was to investigate the biomechanical effects of different tooth movement patterns and aligner thicknesses on teeth and periodontal tissues during maxillary arch expansion with clear aligners, to facilitate more precise and efficient clinical orthodontic treatments.
UNASSIGNED: Three-dimensional models including teeth, maxilla, periodontal ligament, and aligner were constructed and subjected to finite element analysis. Tooth displacement trends and periodontal ligament stresses were measured for seven tooth displacement patterns (divided into three categories including overall movement of premolars and molars with gradually increasing molar expansion in each step; distributed movement of premolars and molars; and alternating movement between premolars and molars at intervals) and two aligner thicknesses (0.5 mm and 0.75 mm) during maxillary arch expansion with clear aligners.
UNASSIGNED: When expanding the maxillary arch with clear aligners, the effective expansion of the target teeth mainly showed a tilting movement trend. Increasing the amount of molar expansion increased the buccal displacement of the first molar but decreased the buccal displacement of the premolars. The mean buccal displacement of the target teeth was greater in the posterior teeth interval alternating movement group (0.026 mm) than in the premolar/molar distributed movement group (0.016 mm) and the overall movement group (0.015 mm). Increasing aligner thickness resulted in greater buccal displacement of the crowns and increased stress on the periodontal ligaments.
UNASSIGNED: Increasing the amount of molar expansion reduces the efficiency of premolar expansion. Alternating movement of premolars and molars at intervals achieves a higher arch expansion efficiency, but attention should be paid to the anchorage of adjacent teeth. Increasing the thickness of the aligner increases the expansion efficiency but may also increase the burden on the periodontal tissues.
UNASSIGNED: Three-dimensional models including teeth, maxilla, periodontal ligament, and aligner were constructed and subjected to finite element analysis. Tooth displacement trends and periodontal ligament stresses were measured for seven tooth displacement patterns (divided into three categories including overall movement of premolars and molars with gradually increasing molar expansion in each step; distributed movement of premolars and molars; and alternating movement between premolars and molars at intervals) and two aligner thicknesses (0.5 mm and 0.75 mm) during maxillary arch expansion with clear aligners.
UNASSIGNED: When expanding the maxillary arch with clear aligners, the effective expansion of the target teeth mainly showed a tilting movement trend. Increasing the amount of molar expansion increased the buccal displacement of the first molar but decreased the buccal displacement of the premolars. The mean buccal displacement of the target teeth was greater in the posterior teeth interval alternating movement group (0.026 mm) than in the premolar/molar distributed movement group (0.016 mm) and the overall movement group (0.015 mm). Increasing aligner thickness resulted in greater buccal displacement of the crowns and increased stress on the periodontal ligaments.
UNASSIGNED: Increasing the amount of molar expansion reduces the efficiency of premolar expansion. Alternating movement of premolars and molars at intervals achieves a higher arch expansion efficiency, but attention should be paid to the anchorage of adjacent teeth. Increasing the thickness of the aligner increases the expansion efficiency but may also increase the burden on the periodontal tissues.
摘要：
■这项研究的目的是研究使用清晰的矫正器在上颌弓扩张过程中不同的牙齿移动方式和矫正器厚度对牙齿和牙周组织的生物力学影响，以促进更精确和有效的临床正畸治疗。
■包括牙齿的三维模型，上颌骨,牙周膜,和对准器进行了构造和有限元分析。测量了7种牙齿位移模式的牙齿位移趋势和牙周膜应力（分为三类，包括前磨牙和磨牙的整体运动，每个步骤中磨牙的扩张逐渐增加；前磨牙和磨牙的分布运动；以及前磨牙和磨牙之间间隔交替运动）和两个矫正器厚度（0.5mm和0.75mm）。
■用清晰的矫正器扩张上颌弓时，目标牙齿的有效扩张主要表现为倾斜运动趋势。增加磨牙膨胀的量增加了第一磨牙的颊位移，但减少了前磨牙的颊位移。后牙间隔交替运动组（0.026mm）的目标牙齿平均颊位移大于前磨牙/磨牙分布运动组（0.016mm）和整体运动组（0.015mm）。矫正器厚度的增加会导致牙冠的口腔位移更大，并增加牙周韧带的应力。
■增加摩尔膨胀的量会降低前摩尔膨胀的效率。前磨牙和磨牙间隔交替运动可实现更高的牙弓扩张效率，但应注意相邻牙齿的锚固。增加矫正器的厚度会增加膨胀效率，但也会增加牙周组织的负担。
■包括牙齿的三维模型，上颌骨,牙周膜,和对准器进行了构造和有限元分析。测量了7种牙齿位移模式的牙齿位移趋势和牙周膜应力（分为三类，包括前磨牙和磨牙的整体运动，每个步骤中磨牙的扩张逐渐增加；前磨牙和磨牙的分布运动；以及前磨牙和磨牙之间间隔交替运动）和两个矫正器厚度（0.5mm和0.75mm）。
■用清晰的矫正器扩张上颌弓时，目标牙齿的有效扩张主要表现为倾斜运动趋势。增加磨牙膨胀的量增加了第一磨牙的颊位移，但减少了前磨牙的颊位移。后牙间隔交替运动组（0.026mm）的目标牙齿平均颊位移大于前磨牙/磨牙分布运动组（0.016mm）和整体运动组（0.015mm）。矫正器厚度的增加会导致牙冠的口腔位移更大，并增加牙周韧带的应力。
■增加摩尔膨胀的量会降低前摩尔膨胀的效率。前磨牙和磨牙间隔交替运动可实现更高的牙弓扩张效率，但应注意相邻牙齿的锚固。增加矫正器的厚度会增加膨胀效率，但也会增加牙周组织的负担。
