Biomechanical Selection Of Mini-implant Diameter And Length In 4 Types Of Bone

Micro-implant anchorage for orthodontics has more advantages than the traditional anchorage. in recent years, micro-implant anchorage has been a huge development. It becomes more and more popular among patients . According to the ratio between the cortical bone and cancellous bone and the density of them, quality of the mandible is divided into four categories by Lekholm and Zarb. Previous design and studies about the diameter and length of Micro-implant anchorage focused on mechanical analysis on the part of mandible which is single implanted. However, due to the difference of the quality on each part of mandible, it is difficult to describe the mechanical analysis on different parts of the mandible completely, with the diameter and length of Micro-implant anchorage.In this study, with the application of the Pro / E and Ansys Workbench and other software in the field of mechanical engineering optimization, we can systematically optimize implant anchorage macrostructure parameters (such as implant anchorage diameter and length). And this study was also to make us a better understanding about the role and effect order of each implant anchorage macrostructure parameter in biomechanics transmission. At the same time, present study was designed to provide us the detailed implant anchorage diameter and length. This study may provides us a theoretical basis to Select the best length and diameter of Micro-implant anchorage for different type of bone . The results are as follows.1. With the application of the Adaptive assembly function of Pro / E software and Ansys Workbench, three dimensional finite element model of the local section of mandibular including micro- implant anchorage was Simulated. With high efficiency and scalability of this modeling approach, It can provide a technology platform for the analysis of biomechanics of Micro-implant anchorage in different type of bone.2. With the use of three-dimensional finite element method , we analyzed the micro-implant anchorage mechanical properties between diameter and length under different type of bone on the stress distribution, the results showed that: (1) Implant diameter plays a more important role than length in reducing maxilla stress and enhancing mini-implant stability in 4 types of bone.(2) Implant with a diameter 1.4 mm is more suitable for type I bone and type II bone; Implant with a length range of 5.0mm-11.0mm. Type III bone and type IV bone should be implanted with a diameter range of 1.0mm-1.8mm Micro- implant anchorage, the more coarse the better; the length range should be between 6.5mm-9.5mm by the basis of clinical need .