远中移动磨牙技术的研究进展

近年来不拔牙矫治重新得到正畸医生的重视,远中移动磨牙开拓间隙在临床上广泛应用,常用的推磨牙向远中方法有活动型、固定型、混合型以及近年来发展迅速的种植体支抗。本文对各种远中移动磨牙技术的进展进行综述。     

釉质瓷在人工种植牙中的应用

为探索人工种植牙上部结构修复新途径，对４０例人工植牙患者采用釉质瓷冠修复，一年后，复查成功率９５％，与金属烤瓷相比，釉质瓷具操作简便，，负荷轻，硬度适中等优点，尤其适用于牙槽嵴吸收严重，种植体支持力不足患者。     

人工耳蜗植入电极分布频带不同排列模式对语言识别能力的影响

目的通过测试电子耳蜗植入患者电极分布频带颠倒排列前后声音识别的变化,探讨电极分布频带排列模式对声音识别能力的影响。方法15名电子耳蜗植入患者,分别依次测试电极分布频带颠倒排列前后对铃声（代表高频）和鼓声（代表低频）两种不同声音的识别能力,记录并分析结果。结果在电极分布频带按低频对应蜗尖、高频对应蜗底的正常顺序排列时,均能准确识别出铃声和鼓声。在电极分布频带颠倒排列后,13名受试者将铃声和鼓声均识别为鼓声,另2名则将铃声识别为鼓声,而将鼓声识别为铃声。结论电子耳蜗电极分布频带排列模式改变可以影响电子耳蜗植入患者对声音的识别能力。     

Finite element analysis of customized implant in mandibular reconstruction after tumor resection with and without using customized surgical osteotomy guide

Objectives

The aim of this work was to compare different 12 cases (3 patients * 4 cases = 12 cases) with varying gaps between implant and bone by analyzing the effect of these gaps on implant and screws using FEM.

Methods

In each patient's case 1 using CSOG and in case 2, 3, and 4 without using CSOG tumor cutting was done. Hence in each patient zero gaps at case 1 and overcutting at case 2, 3, and 4 have obtained at different locations.

Results

FEM results reveal that in each patient's case 4 (maximum gap) was more susceptible to loosening of the screws due to higher strains (37%) and implant failure due to higher stress (28%) concentration under the same loading conditions when compared with case 1 (zero gap).

Conclusions

The study reveals that mandibular reconstruction with implant placement using CSOG can significantly enhance the stability and safety of the implant.     

Validation of a Novel Surgical Data Capturing System Following Total Hip Arthroplasty

Background

The OrthoMiDaS (Orthopedic Minimal Data Set) Episode of Care (OME) database was developed in an effort to advance orthopedic outcome measurements on a national scale. This study was designed to evaluate if the OME data capture system would increase the quality of data collected in the context of primary and revision total hip arthroplasty (THA) compared to conventional operative notes.

Dose-Dependent Resorption of Allograft by rhBMP-2 Uncompensated by New Bone Formation—A Canine Study With Implants and Zoledronate

Background

Impacted bone allograft is used to restore lost bone in total joint arthroplasties. Bone morphogenetic proteins (BMPs) can induce new bone formation to improve allograft incorporation, but they simultaneously invoke a seemingly dose-dependent allograft resorption mediated by osteoclasts. Bisphosphonates effectively inhibit osteoclast activity. Predicting allograft resorption when augmented with bone morphogenetic protein 2 (BMP-2), we intended to investigate whether a balanced bone metabolism was achievable within a range of BMP-2 doses with systemic zoledronate treatment.

Heterotopic Implantation of Decellularized Pulmonary Artery Homografts In A Rodent Model: Technique Description and Preliminary Report

Purpose: Despite a substantial amount of literature on tissue-guided regeneration, decellularization process, repopulation time points and stem cell turnover, more in-depth study on the argument is required. Currently, there are plenty of reports involving large animals, as well as clinical studies facing cardiac repair with decellularized homografts, but no exhaustive rodent models are described. The purpose of this study was to develop such a model in rats; preliminary results are also herein reported. Material and Methods: Fresh or decellularized pulmonary homografts from wild type rats were implanted in the abdominal aorta of green fluorescent protein positive rats. Three experimental groups were build up: sham, fresh homograft recipients and decellularized homograft recipients. The homograft decellularization process was performed with three cycles of detergent-enzymatic treatment protocol. Surgical technique of pulmonary homograft implantation and postoperative ultrasonographic evaluation were also reported; gross, histology and immunohistochemistry analysis on unimplanted and postoperative homografts were also carried out. Results: The median total recipient operating time was 148 minutes, with a surgical success rate of 82%. The decellularization protocol resulted effective and showed a complete decellularization with intact extracellular matrix. At 15 days from surgery, the implanted decellularized pulmonary homografts exhibited cell repopulation in the outer media wall and partial endothelial lining in absence of rejection. Conclusions: Our technique is a feasible and reproducible model that can be fundamental for building a valid study for further exploitation on the field. Even in a short-term follow up, the decellularized pulmonary homografts showed autologous repopulation in absence of rejection.     

Additive manufactured push‐fit implant fixation with screw‐strength pull out

Additive manufacturing offers exciting new possibilities for improving long‐term metallic implant fixation in bone through enabling open porous structures for bony ingrowth. The aim of this research was to investigate how the technology could also improve initial fixation, a precursor to successful long‐term fixation. A new barbed fixation mechanism, relying on flexible struts was proposed and manufactured as a push‐fit peg. The technology was optimized using a synthetic bone model and compared with conventional press‐fit peg controls tested over a range of interference fits. Optimum designs, achieving maximum pull‐out force, were subsequently tested in a cadaveric femoral condyle model. The barbed fixation surface provided more than double the pull‐out force for less than a third of the insertion force compared to the best performing conventional press‐fit peg (p < 0.001). Indeed, it provided screw‐strength pull out from a push‐fit device (1,124 ± 146 N). This step change in implant fixation potential offers new capabilities for low profile, minimally invasive implant design, while providing new options to simplify surgery, allowing for one‐piece push‐fit components with high levels of initial stability. © 2017 The Authors. Journal of Orthopaedic Research® Published by Wiley Periodicals, Inc. on behalf of the Orthopaedic Research Society. J Orthop Res 36:1508–1518, 2018.