Orthodontic Research Research Articles

Cone beam computed tomography in orthodontics

A new revolution in three-dimensional radiologic advances in dentistry was introduced in the year 1998, as cone beam computed tomography (CBCT). Over the years, it has become an increasingly popular technique in orthodontic diagnosis, treatment planning, and research. This rise in its popularity has been facilitated by the relative advantages of three-dimensional (3D) over 2D radiography. CBCT imaging involves only a minimal increase in radiation dose relative to combined diagnostic modern digital panoramic and cephalometric imaging. A combination of volumetric reconstruction and multiplanar views can provide the orthodontic clinician with skeletal hard tissue, soft tissue, dentition, and airway information. Despite many suggested indications of CBCT, scientific evidence that its utilization improves diagnosis and treatment plans or outcomes has only recently begun to emerge. This article provides a comprehensive review of the application of CBCT in orthodontics. The current indications for CBCT in standard orthodontic diagnosis include impacted teeth, cleft lip, and palate and skeletal discrepancies requiring surgical intervention, root resorption, supernumerary teeth, temporomandibular joint (TMJ) pathology, facial asymmetry, temporary anchorage devices, root morphology and angulation; alveolar boundary conditions; maxillary transverse dimensions and maxillary expansion, and vertical malocclusion. Advanced CBCT software applications can be used to quantify airway space in the cases of obstructive sleep apnea, perform superimpositions to semiquantitatively visualize changes over the hard and soft tissues, including the TMJ and airway.

First recipient of the Lifetime Achievement Award for Orthodontic Research.

First recipient of the Lifetime Achievement Award for Orthodontic Research.

Bias from historical control groups used in orthodontic research: a meta-epidemiological study

The validity of meta-analysis is dependent upon the quality of included studies. Here, we investigated whether the design of untreated control groups (i.e. source and timing of data collection) influences the results of clinical trials in orthodontic research. This meta-epidemiological study used unrestricted literature searching for meta-analyses in orthodontics including clinical trials with untreated control groups. Differences in standardized mean differences (ΔSMD) and their 95% confidence intervals (CIs) were calculated according to the untreated control group through multivariable random-effects meta-regression controlling for nature of the interventional group and study sample size. Effects were pooled with random-effects synthesis, followed by mixed-effect subgroup and sensitivity analyses. Studies with historical control groups reported deflated treatment effects compared to studies with concurrent control groups (13 meta-analyses; ΔSMD = -0.31; 95% CI = -0.53, -0.10; P = 0.004). Significant differences were found according to the type of historical control group (based either on growth study or clinical archive; 11 meta-analyses; ΔSMD = 0.40; 95% CI = 0.21, 0.59; P < 0.001). The use of historical control groups in orthodontic clinical research was associated with deflation of treatment effects, which was independent from whether the interventional group was prospective or retrospective and from the study's sample size. Caution is warranted when interpreting clinical studies with historical untreated control groups or when interpreting systematic reviews that include such studies. PROSPERO (CRD42015024179). None.

Communicating orthodontic research via social media

I n this article, I am going to share my personal viewpoint and knowledge on how to communicate orthodontic research via social media. This is based upon many years experience of involvement with computers and recently writing a surprisingly successful orthodontic blog. Like many people, I have used the Internet extensively in my work as an academic orthodontist, it is recently that I have become aware and made use of social media in obtaining and disseminating research knowledge. This article is, therefore, not based on any science; it is only my personal experience and other low levels of evidence. I am not going to reference any sources in this article because they are all available using an electronic search. This is an article about contemporary communication, which while having few restraints has great importance when considered in the realm of orthodontic communications. It is also difficult to write an article on social media because knowledge of this field is closely associated with age. This is because the younger generation of orthodontists will have grown up with the rapid developments in social media. As a result, I shall set this article at the level of someone who has minimal experience of this continuously changing area. Finally, I will only discuss platforms with which I have experience. I will start with Twitter.

Cone beam computed tomography in orthodontics: Indications, insights, and innovations

Cone Beam Computed Tomography in Orthodontics: Indications, Insights, and Innovations provides a detailed and comprehensive look at one such area. It is a timely contribution to the literature on CBCT and will be of considerable interest to orthodontists, orthodontic researchers, and residents who are studying the use of this technology.The book covers 4 areas of the use of CBCT imaging in orthodontics: technology assessment and enhancement, protocols and principles for CBCT in orthodontics, diagnosis and treatment planning, and clinical applications and treatment outcomes.With leading experts contributing to the book, each of the 23 chapters examines 1 aspect of the use of CBCT in orthodontics, including concepts and characteristics, perspectives on radiation risk, selection criteria, medicolegal implications, protocols for its use, how to interpret the scans, detection of incidental findings, 3-dimensional diagnosis and treatment planning, temporomandibular joint and airway applications, assessment of impacted teeth and root positions, use of CBCT for orthognathic surgery treatment planning, and other clinical applications.The book comes with 2 DVDs, which provide 15 hours of video presentations from the 39th Annual Moyers Symposium and the 38th Annual International Conference on Craniofacial Research. The videos are well made and worth watching.As CBCT technology develops, so will attitudes concerning its use, which presently run from considerable interest to little faith. This book is so structured that it might easily go to several editions, with chapters revised or removed as the technology changes.Some manufacturers of CBCT units are advising clinicians to acquire CBCT images for their initial, progress, and final records. Although some clinicians have followed this advice, others have questioned whether CBCT, because of its radiation dose and cost, benefits patients by improving treatment outcomes.One of the more problematic aspects of CBCT is that the units vary considerably. They differ in major characteristics, such as effective radiation dose, image detector, scan time, patient positioning, and field of view. They also come with different operating softwares and footprints. Such differences are not typically seen in other dental and medical imaging techniques, but there is no reason to believe that manufacturers are likely to standardize CBCT machines anytime soon.Therefore, it behooves whoever uses CBCT to understand this technique to ensure effective and meaningful implementation. This text provides a great resource to help with understanding of several aspects of CBCT in orthodontic practice and research. Cone Beam Computed Tomography in Orthodontics: Indications, Insights, and Innovations provides a detailed and comprehensive look at one such area. It is a timely contribution to the literature on CBCT and will be of considerable interest to orthodontists, orthodontic researchers, and residents who are studying the use of this technology. The book covers 4 areas of the use of CBCT imaging in orthodontics: technology assessment and enhancement, protocols and principles for CBCT in orthodontics, diagnosis and treatment planning, and clinical applications and treatment outcomes. With leading experts contributing to the book, each of the 23 chapters examines 1 aspect of the use of CBCT in orthodontics, including concepts and characteristics, perspectives on radiation risk, selection criteria, medicolegal implications, protocols for its use, how to interpret the scans, detection of incidental findings, 3-dimensional diagnosis and treatment planning, temporomandibular joint and airway applications, assessment of impacted teeth and root positions, use of CBCT for orthognathic surgery treatment planning, and other clinical applications. The book comes with 2 DVDs, which provide 15 hours of video presentations from the 39th Annual Moyers Symposium and the 38th Annual International Conference on Craniofacial Research. The videos are well made and worth watching. As CBCT technology develops, so will attitudes concerning its use, which presently run from considerable interest to little faith. This book is so structured that it might easily go to several editions, with chapters revised or removed as the technology changes. Some manufacturers of CBCT units are advising clinicians to acquire CBCT images for their initial, progress, and final records. Although some clinicians have followed this advice, others have questioned whether CBCT, because of its radiation dose and cost, benefits patients by improving treatment outcomes. One of the more problematic aspects of CBCT is that the units vary considerably. They differ in major characteristics, such as effective radiation dose, image detector, scan time, patient positioning, and field of view. They also come with different operating softwares and footprints. Such differences are not typically seen in other dental and medical imaging techniques, but there is no reason to believe that manufacturers are likely to standardize CBCT machines anytime soon. Therefore, it behooves whoever uses CBCT to understand this technique to ensure effective and meaningful implementation. This text provides a great resource to help with understanding of several aspects of CBCT in orthodontic practice and research.

Linear regression.

Linear regression.

Evolving concepts of heredity and genetics in orthodontics.

The field of genetics emerged from the study of heredity early in the 20th century. Since that time, genetics has progressed through a series of defined eras based on a number of major conceptual and technical advances. Orthodontics also progressed through a series of conceptual stages over the past 100 years based in part on the ongoing and often circular debate about the relative importance of heredity (nature) and the local environment (nurture) in the etiology and treatment of malocclusion and dentofacial deformities. During the past 20 years, significant advancements in understanding the genomic basis of craniofacial development and the gene variants associated with dentofacial deformities have resulted in a convergence of the principles and concepts in genetics and in orthodontics that will lead to significant advancement of orthodontic treatments. Fundamental concepts from genetics and applied translational research in orthodontics provide a foundation for a new emphasis on precision orthodontics, which will establish a modern genomic basis for major improvements in the treatment of malocclusion and dentofacial deformities as well as many other areas of concern to orthodontists through the assessment of gene variants on a patient-by-patient basis.

Donald Garth Woodside: A leader for orthodontic research and education in Canada.

Donald Garth Woodside: A leader for orthodontic research and education in Canada.

Shinjiro Takahashi and Fujio Miura: Leaders in orthodontic education and research in Japan.

Shinjiro Takahashi and Fujio Miura: Leaders in orthodontic education and research in Japan.

Smile because of Dr Robert Murray Ricketts.

Smile because of Dr Robert Murray Ricketts.

American Association of Orthodontists Foundation Craniofacial Growth Legacy Collection: Overview of a powerful tool for orthodontic research and teaching

This article reports on the current status of the American Association of Orthodontists Foundation (AAOF) Craniofacial Growth Legacy Collection--an AAOF-supported multi-institutional project that uses the Internet and cloud computing to collect and share craniofacial images and data for orthodontic research and education. The project gives investigators and clinicians all over the world online access to longitudinal information on craniofacial development in untreated children with malocclusions of various types. It also is a unique source of control samples for testing the validity of consensually accepted beliefs about the effects of orthodontic treatment or of failure to treat.

Randomized controlled trial: the gold standard or an unobtainable fallacy?

This article is the result of a debate at the European Journal of Orthodontics Open Session in 2013 in Reykjavik, Iceland. The aim of this article is to highlight some of the strengths and weakness of clinical orthodontic research, with particular emphasis on randomized controlled trials (RCT). The ultimate aim of improving clinical orthodontic research in general. This article is organized into two sections with arguments for and against RCTs. The backgrounds to evidence-based evaluation and the level or quality of evidence in trials are discussed. The article emphasises what makes high quality clinical research, and gives practical advice including examples of tips and potential pitfalls for those undertaking clinical research. The overriding message is constructive and it is hoped that the article serves as an aid in evaluating, designing, conducting, and reporting clinical research.

Charles J. Burstone, 1928-2015

Charles J. Burstone, 1928-2015

Scientific use of the finite element method in Orthodontics.

INTRODUCTION: The finite element method (FEM) is an engineering resource applied to calculate the stress and deformation of complex structures, and has been widely used in orthodontic research. With the advantage of being a non-invasive and accurate method that provides quantitative and detailed data on the physiological reactions possible to occur in tissues, applying the FEM can anticipate the visualization of these tissue responses through the observation of areas of stress created from applied orthodontic mechanics. OBJECTIVE: This article aims at reviewing and discussing the stages of the finite element method application and its applicability in Orthodontics. RESULTS: FEM is able to evaluate the stress distribution at the interface between periodontal ligament and alveolar bone, and the shifting trend in various types of tooth movement when using different types of orthodontic devices. Therefore, it is necessary to know specific software for this purpose. CONCLUSIONS: FEM is an important experimental method to answer questions about tooth movement, overcoming the disadvantages of other experimental methods.

Randomized and nonrandomized studies: Complementary or competing?

Both randomized and nonrandomized studies are integral to orthodontic research and practice because they permit evaluation of relationships between exposures and outcomes, allowing the efficacy, effectiveness, and safety of interventions to be assessed. These designs allow clinical decisions to be informed. Nonrandomized designs include nonrandomized clinical trials, cohort studies, case-control studies, cross-sectional studies, case series, and ecological studies. There is debate surrounding the optimal research design; however, both randomized and nonrandomized designs are important to build a broad, informative evidence base. The designs are therefore complementary, with unique advantages and limitations. The applicability of either approach hinges on the clinical question posed, the feasibility of studying it, and ethical considerations.

Do orthodontic research outcomes reflect patient values? A systematic review of randomized controlled trials involving children

The selection of appropriate outcomes is a fundamental part of the design of clinical trials. Orthodontic treatment aims to improve a person's dentofacial appearance, and research outcomes should therefore reflect the perspectives of both clinicians and patients. In this study, we aimed to identify which outcomes were measured in recent orthodontic trials and to explore whether any relevant outcome domains were underrepresented. Five electronic databases were searched to identify all randomized controlled trials of orthodontic treatment interventions in children published in the last 5 years. Abstracts and eligible full-text articles were screened independently and in duplicate by 2 reviewers. Outcome measures were identified and categorized into 6 predetermined outcome domains. The search identified 650 abstracts, of which 244 eligible articles were retrieved in full. One hundred thirty-three studies met the inclusion criteria and were included. Morphologic features of malocclusion were measured in 84 studies (63%); health resource utilization in 43 (32%); adverse effects of orthodontic treatment in 43 (32%); quality of life in 12 (9%); functional status in 10 (8%); and physical consequences of malocclusion in 3 (2%). There was no consistency in the outcomes selected among the trials to measure these domains. Most of the outcomes used in orthodontic research are concerned with measuring morphologic changes of treatment and do not reflect patient perspectives. Five of the 6 domains were infrequently evaluated, and outcomes were heterogenous. A core set of outcomes for clinical trials of orthodontic treatment interventions would help to overcome these issues.

Evidence of secular trends in a collection of historical craniofacial growth studies.

Although secular trends have been well documented in the craniofacial region, there is no evidence to suggest that these temporal changes exist in samples used for orthodontic research. The aim of this study is to determine the effect of secular trends on craniofacial growth in a series of longitudinal birth cohorts that are frequently used in orthodontic research. Cephalometric data from serial lateral headfilms of 138 adolescents (total of 1252 cephalograms) were collected from the Craniofacial Growth Legacy Collection, which includes nine historical growth studies that were mostly conducted throughout the past century. Mixed-effects linear models were used to test the effect of 'year of birth (yob)', 'age', and their interaction on six sagittal (SNA, SNB, ANB, S-N, Co-A, Co-Po) and two vertical (N-Me, ANS-Me) cephalometric measurements. Five of the eight cephalometric variables showed a significant (P ≤ 0.017) 'yob' effect, with four of these indicating an increase over time (SNA, ANB, S-N, Co-A) and one indicating a decrease (SNB). Highly significant (P < 0.001) interactions between 'age' and 'yob' were found for the measurements SNA, ANB, Co-A, and S-N. Some of the limitations of the present study include the use of a small, non-random sample of the original large-scale growth studies. Secular trends were found in the craniofacial growth records of the 138 participants derived from the longitudinal growth studies. These secular trends are likely to have important clinical implications for the findings of controlled clinical trials in orthodontics. More research is needed to establish the presence of secular trends in other historical collections.

The reliability of Little's Irregularity Index for the upper dental arch using three dimensional (3D) digital models

AimTo investigate the inter-examiner variability of contact point displacement measurements (used to calculate the overall Little's Irregularity Index (LII) score) from digital models of the maxillary arch by four independent examiners. MethodsMaxillary orthodontic pre-treatment study models of ten patients were scanned using the Lava(tm) Chairside Oral Scanner (LCOS) and 3D digital models were created using Creo® computer aided design (CAD) software. Four independent examiners measured the contact point displacements of the anterior maxillary teeth using the software. Measurements were recorded randomly on three separate occasions by the examiners and the measurements (n=600) obtained were analysed using correlation analyses and analyses of variance (ANOVA). ResultsLII contact point displacement measurements for the maxillary arch were reproducible for inter-examiner assessment when using the digital method and were highly correlated between examiner pairs for contact point displacement measurements >2mm. The digital measurement technique showed poor correlation for smaller contact point displacement measurements (<2mm) for repeated measurements. The coefficient of variation (CoV) of the digital contact point displacement measurements highlighted 348 of the 600 measurements differed by more than 20% of the mean compared with 516 of 600 for the same measurements performed using the conventional LII measurement technique. ConclusionsAlthough the inter-examiner variability of LII contact point displacement measurements on the maxillary arch was reduced using the digital compared with the conventional LII measurement methodology, neither method was considered appropriate for orthodontic research purposes particularly when measuring small contact point displacements.

Residents' journal review

Residents' journal review

Methodology for clinical research in Orthodontics, the assets of the beOrtho website

The rules applying to the "evidence-based" methodology strongly influenced the clinical research in orthodontics. However, the implementation of clinical studies requires rigour, important statistical and methodological knowledge, as well as a reliable environment in order to compile and store the data obtained from research. We developed the project "beOrtho.com" (based on orthodontic evidence) in order to fill up the gap between our desire to drive clinical research and the necessity of methodological rigour in the exploitation of its results. BeOrtho website was created to answer the issue of sample recruitment, data compilation and storage, while providing help for the methodological design of clinical studies. It allows the development and monitoring of clinical studies, as well as the creation of databases. On the other hand, we designed an evaluation grid for clinical studies which helps developing systematic reviews. In order to illustrate our point, we tested a research protocol evaluating the interest of the mandibular advancement in the framework of Class II treatment.