{"title":"The six geometries revisited.","authors":"Austin Kang, Marino Musilli, Mauro Farella","doi":"10.4041/kjod.2020.50.5.356","DOIUrl":null,"url":null,"abstract":"<p><p>Forces and moments delivered by a straight wire connecting two orthodontic brackets are statically indeterminate and cannot be estimated using the classical equations of static equilibrium. To identify the mechanics of such two-bracket systems, Burstone and Koenig used the principles of linear beam theory to estimate the resulting force systems. In the original publication, however, it remains unclear how the force systems were calculated because no reference or computational details on the underlying principles have been provided. Using the moment carry-over principle and the relative angulation of the brackets, a formula was derived to calculate the relative moments of the two brackets. Because of the moment equilibrium, the vertical forces that exist as a forcecouple on the two brackets can also be calculated. The accuracy of the proposed approach can be validated using previously published empirical data.</p>","PeriodicalId":49934,"journal":{"name":"Korean Journal of Orthodontics","volume":"50 5","pages":"356-359"},"PeriodicalIF":1.9000,"publicationDate":"2020-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/a7/a7/KJOD-50-356.PMC7500568.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Korean Journal of Orthodontics","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.4041/kjod.2020.50.5.356","RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"Dentistry","Score":null,"Total":0}
引用次数: 0
Abstract
Forces and moments delivered by a straight wire connecting two orthodontic brackets are statically indeterminate and cannot be estimated using the classical equations of static equilibrium. To identify the mechanics of such two-bracket systems, Burstone and Koenig used the principles of linear beam theory to estimate the resulting force systems. In the original publication, however, it remains unclear how the force systems were calculated because no reference or computational details on the underlying principles have been provided. Using the moment carry-over principle and the relative angulation of the brackets, a formula was derived to calculate the relative moments of the two brackets. Because of the moment equilibrium, the vertical forces that exist as a forcecouple on the two brackets can also be calculated. The accuracy of the proposed approach can be validated using previously published empirical data.
期刊介绍:
The Korean Journal of Orthodontics (KJO) is an international, open access, peer reviewed journal published in January, March, May, July, September, and November each year. It was first launched in 1970 and, as the official scientific publication of Korean Association of Orthodontists, KJO aims to publish high quality clinical and scientific original research papers in all areas related to orthodontics and dentofacial orthopedics. Specifically, its interest focuses on evidence-based investigations of contemporary diagnostic procedures and treatment techniques, expanding to significant clinical reports of diverse treatment approaches.
The scope of KJO covers all areas of orthodontics and dentofacial orthopedics including successful diagnostic procedures and treatment planning, growth and development of the face and its clinical implications, appliance designs, biomechanics, TMJ disorders and adult treatment. Specifically, its latest interest focuses on skeletal anchorage devices, orthodontic appliance and biomaterials, 3 dimensional imaging techniques utilized for dentofacial diagnosis and treatment planning, and orthognathic surgery to correct skeletal disharmony in association of orthodontic treatment.