thread pitch variant in orthodontic mini-screws: a 3-d finite element analysis

نویسندگان

fatemeh mottaghi dastenaei

graduate ms student, school of mechanical engineering, isfahan university of technology, isfahan, iran mahdi moghimi zand

assistant professor, school of mechanical engineering, college of engineering, university of tehran, tehran, iran saeed noorolahian

assistant professor, school of mechanical engineering, college of engineering, university of tehran, tehran, iran

چکیده

orthodontic miniscrews are widely used as temporary anchorage devices to facilitate orthodontic movements. miniscrew loosening is a common problem, which usually occurs during the first two weeks of treatment. macrodesign can affect the stability of a miniscrew by changing its diameter, length, thread pitch, thread shape, tapering angle and so on. in this study, a 3-d finite element analysis was done to show the effect of thread pitch variant on the stress distribution pattern of the screw-cortical bone interface. while orthodontic forces were applied, stresses were usually concentrated at the first thread of the screw in contact with the cortical bone. the cortical bone provided a significant percentage of stability compared to the trabecular bone against orthodontic forces. therefore, spongy bone was removed from the finite element analysis. the changes of maximum von mises stresses were shown on the charts. the results showed that stresses decreased with decrease in thread pitch, but they increase when thread pitch becomes less than a certain value. the pattern of stress distribution differed when the stresses were increased. the results are beneficial for the design of an ergonomic dual miniscrew, with better properties than the commercially available miniscrews and based on the results, a new dual miniscrew is recommended.

برای دانلود باید عضویت طلایی داشته باشید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Thread Pitch Variant in Orthodontic Mini-screws: A 3-D Finite Element Analysis

Orthodontic miniscrews are widely used as temporary anchorage devices to facilitate orthodontic movements. Miniscrew loosening is a common problem, which usually occurs during the first two weeks of treatment. Macrodesign can affect the stability of a miniscrew by changing its diameter, length, thread pitch, thread shape, tapering angle and so on. In this study, a 3-D finite element analysis wa...

متن کامل

Mechanical influence of thread pitch on orthodontic mini-implant stability.

The aim of this study was to evaluate the effect of pitch distance on the primary stability (PS) of orthodontic mini-implants (MIs) in artificial bone. Twenty experimental MIs were allocated to two groups, according to their geometric design: G1 (30o X 0.6 mm) and G2 (45o X 0.8 mm), and inserted into artificial bone of different densities: D1 (0.32 g/cm3) and D2 (0.64 g/cm3). The maximum insert...

متن کامل

Accelerated Tooth Movement with Orthodontic Mini-Screws

This case report outlines the possibility of accelerated tooth movement with the combination of microosteoperforation and mini-screws. A 14-year-old male patient presented Class II malocclusion with maxillary incisor protrusion. Upper first premolars were extracted, and after leveling, accelerated canine distalization started. For pre- and postdistalization times, amount of distalization, perio...

متن کامل

Effect of bite force on orthodontic mini-implants in the molar region: Finite element analysis

OBJECTIVE To examine the effect of bite force on the displacement and stress distribution of orthodontic mini-implants (OMIs) in the molar region according to placement site, insertion angle, and loading direction. METHODS Five finite element models were created using micro-computed tomography (microCT) images of the maxilla and mandible. OMIs were placed at one maxillary and two mandibular p...

متن کامل

Successes and failures with orthodontic mini-screws: a retrospective clinical study of 95 mini-screw implantations

The use of mini-screws has increased broadly over the last ten years. Effectively, these implantable devices, greatly reduced in size and easy to set in place and to remove, have provided orthodontists with a low cost means of reinforcing anchorage for a pre-determined period of time. However, their success rate is far from satisfactory compared to the well-established implants used for tooth r...

متن کامل

finite element analysis of concrete structures using plasticdamage model in 3-d implementation

neither damage mechanics model nor elastoplastic constitutive law can solely describe the behavior of concrete satisfactorily. in fact, they both fail to represent proper unloading slopes during cyclic loading. to overcome the disadvantages of pure plastic models and pure damage approaches, the combined effects need to be considered. in this regard, various classes of plastic-damage models have...

متن کامل

منابع من

با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید


عنوان ژورنال:
journal of computational applied mechanics

جلد ۴۶، شماره ۲، صفحات ۲۵۷-۲۶۵

میزبانی شده توسط پلتفرم ابری doprax.com

copyright © 2015-2023