Robert J Lee1, Won Moon2, Christine Hong3. 1. Division of Orthodontics, University of California at San Francisco, San Francisco, Calif. 2. Section of Orthodontics, University of California at Los Angeles, Los Angeles, Calif. 3. Section of Orthodontics, University of California at Los Angeles, Los Angeles, Calif. Electronic address: chong@dentistry.ucla.edu.
Abstract
INTRODUCTION: Bone-borne palatal expansion relies on mini-implant stability for successful orthopedic expansion. The large magnitude of applied force experienced by mini-implants during bone-borne expansion may lead to high failure rates. Use of bicortical mini-implant anchorage rather than monocortical anchorage may improve mini-implant stability. The aims of this study were to analyze and compare the effects of bicortical and monocortical anchorages on stress distribution and displacement during bone-borne palatal expansion using finite element analysis. METHODS: Two skull models were constructed to represent expansion before and after midpalatal suture opening. Three clinical situations with varying mini-implant insertion depths were studied in each skull model: monocortical, 1-mm bicortical, and 2.5-mm bicortical. Finite element analysis simulations were performed for each clinical situation in both skull models. Von Mises stress distribution and transverse displacement were evaluated for all models. RESULTS: Peri-implant stress was greater in the monocortical anchorage model compared with both bicortical anchorage models. In addition, transverse displacement was greater and more parallel in the coronal plane for both bicortical models compared with the monocortical model. Minimal differences were observed between the 1-mm and the 2.5-mm bicortical models for both peri-implant stress and transverse displacement. CONCLUSIONS: Bicortical mini-implant anchorage results in improved mini-implant stability, decreased mini-implant deformation and fracture, more parallel expansion in the coronal plane, and increased expansion during bone-borne palatal expansion. However, the depth of bicortical mini-implant anchorage was not significant.
INTRODUCTION: Bone-borne palatal expansion relies on mini-implant stability for successful orthopedic expansion. The large magnitude of applied force experienced by mini-implants during bone-borne expansion may lead to high failure rates. Use of bicortical mini-implant anchorage rather than monocortical anchorage may improve mini-implant stability. The aims of this study were to analyze and compare the effects of bicortical and monocortical anchorages on stress distribution and displacement during bone-borne palatal expansion using finite element analysis. METHODS: Two skull models were constructed to represent expansion before and after midpalatal suture opening. Three clinical situations with varying mini-implant insertion depths were studied in each skull model: monocortical, 1-mm bicortical, and 2.5-mm bicortical. Finite element analysis simulations were performed for each clinical situation in both skull models. Von Mises stress distribution and transverse displacement were evaluated for all models. RESULTS: Peri-implant stress was greater in the monocortical anchorage model compared with both bicortical anchorage models. In addition, transverse displacement was greater and more parallel in the coronal plane for both bicortical models compared with the monocortical model. Minimal differences were observed between the 1-mm and the 2.5-mm bicortical models for both peri-implant stress and transverse displacement. CONCLUSIONS: Bicortical mini-implant anchorage results in improved mini-implant stability, decreased mini-implant deformation and fracture, more parallel expansion in the coronal plane, and increased expansion during bone-borne palatal expansion. However, the depth of bicortical mini-implant anchorage was not significant.
Authors: David Farnsworth; P Emile Rossouw; Richard F Ceen; Peter H Buschang Journal: Am J Orthod Dentofacial Orthop Date: 2011-04 Impact factor: 2.650
Authors: Brett J Garrett; Joseph M Caruso; Kitichai Rungcharassaeng; James R Farrage; Jay S Kim; Guy D Taylor Journal: Am J Orthod Dentofacial Orthop Date: 2008-07 Impact factor: 2.650
Authors: Won Moon; Kimberley W Wu; Matthew MacGinnis; Jay Sung; Howard Chu; George Youssef; Andre Machado Journal: Prog Orthod Date: 2015-06-04 Impact factor: 2.750
Authors: Marjorie Eguren; Anderson Holguin; Karla Diaz; Jose Vidalon; Carlos Linan; Camila Pacheco-Pereira; Manuel Oscar Lagravere Vich Journal: Dentomaxillofac Radiol Date: 2021-06-19 Impact factor: 2.419
Authors: Daniele Cantarella; Ramon Dominguez-Mompell; Sanjay M Mallya; Christoph Moschik; Hsin Chuan Pan; Joseph Miller; Won Moon Journal: Prog Orthod Date: 2017-11-01 Impact factor: 2.750