|
上颌骨种植支抗的使用，避免了其他辅助口外支抗预备，如口外弓、头帽等，避免这些 辅助装置的使用引发一些外伤意外，如刺伤粘膜、牙龈、面颊甚至眼睛，也解决了支抗效果 145 依赖患者合作的问题，使矫治器的设计更简单，操作简化[16]。本研究选择临床常用的微种 植体植入部位—上颌第二前磨牙与第一磨牙牙根之间[17]，因该区颊侧皮质骨骨密度要高于 上颌其他区域[18]。 3.4 磨牙和种植支抗移动原因浅析 正畸治疗是当有持久的压力作用在牙齿上时，牙齿周围发生骨改建而引导牙齿移动[19]。 150 治疗前，牙齿虽有近中倾斜的移动趋势，但牙列在各种口周作用力的作用下维持平衡，当第 一前磨牙拔出后，该平衡打破，磨牙发生近中移动[20-22]。微种植体与骨直接接触形成的骨结 合是其作为正畸支抗的基础[23]。微种植体对前牙提供一个远中向的作用力，种植体必受到 近中向的反作用力，导致微种植体发生近中移动[24,25]。但微植体向近中移动，但却没有发生 松动，这点对于我们探索正畸牙移动机理也提供一点重要的启示，是否正畸牙齿移动的关键 155 在于牙槽骨，而并非牙周膜组织呢？我们将在后期的动物实验中进一步深入研究。 在正畸治疗中，支抗是控制牙齿移动的基础，也是贯穿于整个错颌矫治过程的一个重要 因素。选择微种植体作为支抗，希望矫治牙能按设计要求的方向和距离移动，而支抗种植体 并不发生移动[26]。所以，支抗种植体在承受正畸力后能否保持稳定，不移位或少移位是治 疗成功的关键。微种植支抗被许多学者和临床医生称之为“绝对支抗”，意味着支抗的零丧 160 失，然而，基于我们长期的研究发现，在正畸施力下，微种植钉发生移位并伴随磨牙的前移。 根据相关研究，第一磨牙和第二前磨牙间牙根间距离约为1.6～3.46mm,微种植体的直径约为 1.6mm，且治疗过程中，磨牙和种植钉移动速率不同，移位的种植钉可能发生松动脱落，甚 至可能压迫邻近的牙周膜、牙根及神经血管[27-29]。因此我们建议选择偏近中的位置植入微种 植支抗。 165 4 结论 本研究表明在种植支抗辅助正畸治疗中，微种植体和磨牙均发生了不同程度的近中移 动，选择偏近中的位点植入微种植体可能有利于种植支抗的稳定和组织安全。但我们的研究 是非常有限的，磨牙和微种植体移位的具体机制，移位的影响因素都将是我们今后的研究目 标。 170 [参考文献] (References) [1] Labanauskaite B,Jankauskas G,Vasiliauskas A,Haffar N.Implants for orthodontic anchorage[J].Meta-analysis Stomatologija 2005;7:128-32. [2] Garfinkle JS,Cunninghan LL Jr,Beeman CS,Kluemper GT,Hicks EP,Kim MO.Evalution of orthodontic 175 mini-implant anchorage in premolar extration therapy in adolescents.Am J Orthod Dentofacial Orthop 2008;133:642-53. [3] Zhu SJ,Zhou YH,Fu MK.Stability of upper molars with the appliancation of implant anchorage.Zhonghua Kou Qiang Yi Xue Za Zhi 2006;41:4-7. [4] Liou EJ,Pai BC,Lin JC.Do Miniscrews remain stationary under orthodontic forces?Am J Orthod Dentofacial 180 Orthop 2004;126:42-7. [5] Xun CL, Zeng XL, Wang X. Clinical application of miniscrew implant for maximum anchorage cases. Zhonghua Kou Qiang Yi Xue Za Zhi 2004;39:505-8. [6] Hsieh YD, Su CM, Yang YH, Fu E, Chen HL, Kung S. Evaluation on the movement of endosseous titanium implants under continuous orthodontic forces: an experimental study in the dog. Clin Oral Implants Res 185 2008;19:618-23. [7] Grauer D, Cevidanes LSH, Proffit WR. Working with DICOM craniofacial images. Am J Orthod Dentofacial Orthop 2009;136:460-70. [8] Gu Y, McNamara JA Jr. Cephalometric superimpositions. Angle Orthod 2008;78:967-76. Halazonetis DJ. From 2-dimensional cephalograms to 3-dimensional computed tomography scans. Am J Orthod 190 Dentofacial Orthop 2005;127:627-37. [9] Bruntz LQ, Palomo JM, Baden S, Hans MG. A comparison of scanned lateral cephalograms with corresponding original radiographs. Am J Orthod Dentofacial Orthop 2006;130: 340-8. [10] Ongkosuwito EM, Katsaros C, van¡¯t Hof MA, Bodegom JC, Kuijpers-Jagtman AM. The reproducibility of cephalometric measurements: a comparison of analogue and digital methods. Eur J Orthod 2002;24:655-65. 195 [11] Cevidanes LH, Heymann G, Cornelis MA, DeClerck HJ, Tulloch JF. Superimposition of 3-dimensional cone-beam computed tomography models of growing patients. Am J Orthod Dentofacial Orthop 2009;136:94-9. [12] Harrell WE. 3D diagnosis and treatment planning in orthodontics. Semin Orthod 2009;15:35-41. [13] Park J, Cho HJ. Three-dimensional evaluation of interradicular spaces and cortical bone thickness for the placement and initial stability of microimplants in adults. Am J Orthod Dentofacial Orthop 2009;136:314.e1-12; 200 discussion 314-5. [14] Hill DLG, Batchelor PG, Holden MH, Hawkes DJ. Medical image registration. Phys Med Biol 2001;46:1-45. [15] Cevidanes LH, Bailey LJ, Tucker GR Jr, StynerMA,Mol A, Phillips CL, et al. Superimposition of 3D cone-beam CT models of orthognathic surgery patients. Dentomaxillofac Radiol 2005;34:369-75. [16] Turley PK, Kean C, Schur J, Stefanac J, Gray J, Hennes J, et al. Orthodontic force application to titanium 205 endosseous implants. Angle Orthod 1988;58:151-62. [17] Costa A, RaffainiM,Melsen B.Miniscrews as orthodontic anchorage: a preliminary report. Int J AdultOrthodOrthog Surg 1998;13:201-29. [18] Park HS, Bae SM, Kyung HM, Sung JH. Micro-implant anchorage for treatment of skeletal Class I bialveolar protrusion. J Clin Orthod 2001;35:417-22. 210 [19] Meikle MC. The tissue, cellular, and molecular regulation of orthodontic tooth movement: 100 years after Carl Sandstedt. Eur J Orthod 2006;28:221-40. [20] Melsen B. Tissue reaction to orthodontic tooth movement-a new paradigm. Eur J Orthod 2001;23:671-81. [21] Cattaneo PM, Dalstra M, Melsen B. Strains in periodontal ligament and alveolar bone associated with orthodontic tooth movement analyzed by finite element. Orthod Craniofac Res 2009;12:120-8. 215 [22] Thongudomporn U, Chongsuvivatwong V, Geater AF. The effect of maximum bite force on alveolar bone morphology. Orthod Craniofac Res 2009;12:1-8. [23] Vannet BV, Sabzevar MM, Wehrbein H, Asscherickx K. Osseointegration of miniscrews: a histomorphometric evaluation. Eur J Orthod 2007;29:437-42. [24] Zmudzki J, Walke W, Chladek W. Stresses present in bone surrounding dental implants in FEM model 220 experiments. JAMME 2008;27:71-4. [25] Lin D, Li Q, Li W, Swain M. Dental implant induced bone remodeling and associated algorithms. J Mech Behav Biomed Mater 2009; 2:410-32. [26] Miyawaki S, Koyama I, Inoue M, Mishima K, Sugahara T, Takano-Yamamoto T. Factors associated with the stability of titanium screws placed in the posterior region for orthodontic anchorage. Am J Orthod Dentofacial 225 Orthop 2003;124:373-8. [27] Miyawaki S, Koyama I, Inoue M, Mishima K, Sugahara T, Takano-Yamamoto T. Factors associated with the stability of titanium screws placed in the posterior region for orthodontic anchorage. Am J Orthod Dentofacial Orthop 2003;124:373-8. [28] Yano S, Motoyoshi M, Uemura M, Ono A, Shimizu N. Tapered orthodontic miniscrews induce bone-screw 230 cohesion following immediate loading. Eur J Orthod 2006;28:541-6. [29] Wang YC, Liou EJ. Comparison of the loading behavior of selfdrilling and predrilled miniscrews throughout orthodontic loading. Am J Orthod Dentofacial Orthop 2008;133:38-43. 学术论文网Tag：代写硕士论文 代写论文 代写MBA论文 代写博士论文 |
