Li Na, Wang ChunJuan, Yang Min, Chen DingGen, Tang MingYuan, Li DaoKun, Qiu ShengLei, Chen Qi, Feng Yi
Silk Crossing Clinic, Affiliated Hospital of North Sichuan Medical College, Nanchong, China.
Department of Stomatology, North Sichuan Medical College, Nanchong, China.
Front Bioeng Biotechnol. 2024 Jun 25;12:1424319. doi: 10.3389/fbioe.2024.1424319. eCollection 2024.
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.
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.
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.
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.
本研究的目的是调查在使用透明矫治器进行上颌扩弓期间，不同牙齿移动模式和矫治器厚度对牙齿及牙周组织的生物力学影响，以促进更精确、高效的临床正畸治疗。
构建包括牙齿、上颌骨、牙周膜和矫治器的三维模型，并进行有限元分析。在使用透明矫治器进行上颌扩弓期间，测量了七种牙齿移动模式（分为三类，包括前磨牙和磨牙整体移动且每一步磨牙扩弓逐渐增加；前磨牙和磨牙分布移动；以及前磨牙和磨牙间隔交替移动）和两种矫治器厚度（0.5毫米和0.75毫米）时的牙齿位移趋势和牙周膜应力。
使用透明矫治器扩弓上颌时，目标牙齿的有效扩弓主要呈现倾斜移动趋势。增加磨牙扩弓量会增加第一磨牙的颊向位移，但会减少前磨牙的颊向位移。目标牙齿的平均颊向位移在磨牙间隔交替移动组（0.026毫米）中大于前磨牙/磨牙分布移动组（0.016毫米）和整体移动组（0.015毫米）。增加矫治器厚度会导致牙冠颊向位移更大，牙周膜应力增加。
增加磨牙扩弓量会降低前磨牙扩弓效率。前磨牙和磨牙间隔交替移动可实现更高的牙弓扩弓效率，但应注意相邻牙齿的支抗。增加矫治器厚度可提高扩弓效率，但也可能增加牙周组织的负担。
