Three-dimensional assessment of virtual clear aligner attachment removal: A prospective clinical study.

INTRODUCTION: In digital dentistry, virtual attachment removal (VAR) optimizes clear aligner therapy by enhancing efficiency for refinements and enabling prefabricated retainer production through the removal of attachments from a digital scan before the clinical removal of clear aligner attachments. This prospective clinical study aimed to evaluate the accuracy of VAR in the maxillary arch. METHODS: A total of 110 teeth were analyzed from a sample of 54 maxillary scans from 25 subjects. Models with attachments were virtually debonded using Meshmixer (Autodesk, San Rafael, Calif) and superimposed over the control group in MeshLab. Vector Analysis Module (Canfield Scientific, Fairfield, NJ) was used to calculate and analyze 3-dimensional Euclidean distances on the buccal surfaces between the superimposed models. Statistical analysis was performed using SPSS (version 23.0, IBM, Armonk, NY). The Shapiro-Wilkes (α = 0.05) test determined a nonnormal distribution of results. The Kruskal-Wallis (α = 0.05) was used to determine differences between different tooth types and the number of attachments. RESULTS: The VAR protocol showed no statistical differences in the root mean square between different tooth segments with an overall tendency for inadequate attachment removal. No difference between the groups was found regarding the number of attachments when used as a main factor. CONCLUSIONS: The VAR technique is precise enough for the fabrication of retainers from printed dental models in a clinical setting and is not affected by the number of attachments on the tooth.

International investigation on temporary anchorage device use: A survey of orthodontists.

BACKGROUND: This study investigates characteristics of temporary anchorage devices (TADs) use by surveying a sample of international orthodontists. Furthermore, the survey investigates the stability, insertion technique, and failure rate of TADs and professionals' experience in residency, and it also attempts to establish guidelines for its use in everyday practice. METHODS: A 19-question survey was sent to orthodontists worldwide asking opinion-based, case-specific, and placement technique questions regarding TADs. Results were collected from 251 survey respondents. The country/regions of practice and length of time practicing orthodontics were the independent variables. RESULTS: Survey respondents indicated that most orthodontists rarely or sporadically use TADs. Significant differences were also found for TAD utilization purposes, sizes, and placement techniques among different countries/regions and for failure rates (1 or more of the last 6 TADs placed failed-61.6%). A significant difference was found in how many TADs orthodontists placed in residency versus private practice (56% vs. 15%) in relation to how long they have been practicing, but it did not greatly affect the frequency of use, mechanics, or placement technique. CONCLUSIONS: The frequency of TAD use is similar in many different countries and among different age groups. Although the collected responses suggested significant differences among respondents from different countries, the variability of results for TAD use worldwide prevent the establishment of clear guidelines.

Smart Flexible 3D Sensor for Monitoring Orthodontics Forces: Prototype Design and Proof of Principle Experiment.

There is a critical need for an accurate device for orthodontists to know the magnitude of forces exerted on the tooth by the orthodontic brackets. Here, we propose a new orthodontic force measurement principle to detect the deformation of the elastic semi-sphere sensor. Specifically, we aimed to detail technical issues and the feasibility of the sensor performance attached to the inner surface of the orthodontic aligner or on the tooth surface. Accurate force tracking is important for the optimal decision of aligner replacement and cost reduction. A finite element (FE) model of the semi-sphere sensor was developed, and the relationship between the force and the contact area change was investigated. The prototype was manufactured, and the force detection performance was experimentally verified. In the experiment, the semi-sphere sensor was manufactured using thermoplastic polymer, and a high-precision mold sized 3 mm in diameter. The change in the contact area in the semi-sphere sensor was captured using a portable microscope. Further development is justified, and future implementation of the proposed sensor would be an array of multiple semi-sphere sensors in different locations for directional orthodontic force detection.

Generational perspectives of orthodontists in the U.S. and Canada: A survey study.

INTRODUCTION: The objectives of this study were to identify differences between generations of orthodontists in the United States and to evaluate the perspective of each generation on widely debated topics in orthodontics. METHODS: A 22-item Institutional Review Board-approved survey was randomly distributed to orthodontists in the United States and Canada. Participants were asked questions about the use of technology, the future of clear aligner therapy, orthodontic education, student debt, marketing, and corporate orthodontics, among other topics. RESULTS: Significant increase in female orthodontists over generations and a decrease in orthodontic educators were found (P <0.001). Among generations, differences were found regarding the amount of student debt, use of specific diagnostic tools, marketing preferences, and their opinion on the future of clear aligner therapy. Most of the silent generation did not have student debt, whereas millennials reported paying off their debt in 1 year to >20 years and being most heavily burdened by student debt. Younger generations appeared more likely to use cone-beam computed tomography and intraoral imaging, whereas older generations preferred traditional diagnostic tools such as hand-wrist radiographs and alginate impressions. Most of the silent generation indicated not marketing their practices, whereas millennials rely heavily on social media and e-mails for marketing. CONCLUSIONS: Clear distinctions exist between different generations of orthodontists. Issues such as increasing student debt load and a decrease in orthodontic educators over generations should be addressed to preserve the future of the orthodontic specialty.

Tooth loss and craniofacial factors associated with changes in mandibular condylar morphology.

Objective: To investigate the association between tooth loss and craniofacial factors with changes in mandibular condylar morphology. Methods: A total of 123 patients participated in this cross-sectional study. The mandibular condylar morphology was evaluated using digital panoramic radiography. The exposure variables included gender, age group, molar relationship, facial growth pattern, facial asymmetry, dental midline, posterior crossbite, presence of fixed dental prosthesis, and tooth loss. Results: Unilateral and bilateral mandibular condyle structural alterations were found in 20.3% and 28.5% of the sample, respectively. After the adjustment analysis, posterior crossbite (adjusted OR = 3.34, 95% CI = 1.23-9.06) and tooth loss (adjusted OR = 4.08, 95% CI = 1.72-9.64) were associated with the outcome. The tooth type associated with mandibular condyle structural alterations were premolars and upper molars. Conclusion: The findings suggest that posterior crossbite and tooth loss are associated with mandibular condyle structural alterations.

Immunohistochemical analysis of IL-1 Receptor 1 in the discs of patients with temporomandibular joint dysfunction.

Objective Temporomandibular joint dysfunction (TMD) may affect a patient's quality of life, and one of the etiologies can be anterior disc displacement with reduction (ADDwR) and anterior disc displacement without reduction (ADDWoR). Interleukin 1 Receptor 1 (IL-1R1) is a membrane receptor that plays an important role on initiating immune and inflammatory response by binding the agonists ligands of IL-1 alpha and IL-1 beta. Therefore, the aim of this study was to evaluate, through immunohistochemical analysis, the association of IL-1R1 with TMD. Methods Thirty-nine human disc samples were collected and composed three different groups: ADDwR (n = 19), ADDwoR (n = 12), and control group (n = 8). The samples were immunostained with IL-1R1 antibody and evaluated on both quantity and intensity of staining. Results There was a statistically significant difference (p < 0.05) between the control and test groups for both quantity and intensity of staining. Conclusion IL1-R1 was associated with ADDwR and ADDwoR in TMD discs of humans.

Immunohistochemical expression of TLR-4 in temporomandibular joint dysfunction.

Objective Toll-like receptor 4 (TLR-4) is a transmembrane protein involved in the innate immune system and has been implicated in the pathogenesis of temporomandibular joint dysfunction (TMD). The purpose of this study was to histologically examine the level of expression of TLR-4 relative to severity of TMD. Methods Thirty-one human TMJ disc samples were immunostained for TLR-4 and evaluated for intensity of stain. Among the samples, 8 were control samples, 16 were from patients with anterior disc displacement with reduction (ADDwR), and 7 were from patients with anterior disc displacement without reduction (ADDwoR). Results There was no statistically significant difference in intensity of stain between groupings (p = 0.673). Conclusions The results indicate a negative correlation between TMD and the expression of TLR-4.

Class II Division 2 Subdivision Malocclusion in an Adult Patient treated with the Forsus Fatigue-resistant Device placed Unilaterally.

Treatment of Class II subdivision malocclusion is challenging, and orthodontists frequently struggle to determine the choice of treatment. Several treatment modalities have been proposed for correcting these types of malocclusion. Thus, the aim of this case report is to present dentoalveolar and facial outcomes achieved using an unilateral Forsus fatigue-resistant device combined with fixed appliances in an adult female patient presenting with Class II subdivision malocclusion. Treatment outcome was effective producing dental esthetics and functional positive stable results after 3-year, 2-month follow-up.

U.S. and Canadian Orthodontic Faculty Professional Satisfaction: A Survey Study.

The aims of this study were to evaluate U.S. and Canadian orthodontic faculty members' degree of job satisfaction and to assess the relationship between job satisfaction and factors such as full-time/part-time status, tenure status, age, and teaching training. This information is needed to set long-term goals for improving the recruitment and retention of full-time and part-time faculty. In August 2016, all members of the Council on Orthodontic Education Society of Educators and faculty members of the American Association of Orthodontists were invited via email to participate in a 34-question survey, which collected demographic data and asked respondents to report their degree of satisfaction on seven factors. Out of 645 individuals invited to participate, 133 completed all items on the survey (response rate 20.6%). The results showed that faculty time commitment, rank/position in the institution, and tenure status affected respondents' levels of satisfaction regarding quantity of clinical time, value placed on teaching by their institution and students, and leadership of their department chair. In the open-ended responses, increased compensation, more teaching time, and less administrative activity were the most frequent recommendations to improve satisfaction levels. About half (52%) of the respondents reported being satisfied with their financial compensation. Respondents whose institutions gave them training opportunities in teaching skills were 4.78 times more satisfied than those not given those opportunities. The results suggest that reduction of administrative workload, creation of meaningful faculty development programs, more feedback and sharing of information about requirements for promotion, and improvement of financial compensation could improve recruitment and retention of orthodontic educators.

Perceptions of chin asymmetries among dental professionals and laypersons.

INTRODUCTION: Previous studies have looked at a variety of dental and facial asymmetries and compared their detection by dental professionals with those of laypersons. However, few studies have analyzed the diagnosis and perception of chin asymmetries. In this study, we assessed whether dental professionals can recognize and diagnose facial asymmetries of the chin better than laypeople. METHODS: Chin asymmetries were analyzed through a series of edited frontal photographs of 2 subjects (male and female). The transverse position of the chin was digitally altered from 0° (no alteration) to 6° (most severe alteration). Participant responses were collected from laypersons (n = 64), nonorthodontist dentists (n = 58), and orthodontists (n = 145). Participants graded the photographs according to esthetic appeal using a visual analog scale. Statistical analysis produced diagnostic threshold levels for identifying chin asymmetries. RESULTS: Nonorthodontist dentists and orthodontists were better able to diagnose transverse chin asymmetry in the female subject at a lower threshold level of 2° of deviation, compared with laypersons at a 3° deviation. Orthodontists could diagnose transverse chin asymmetry in the male subject at a lower threshold level of 1° of deviation, compared with laypersons and nonorthodontist dentists at a 2° deviation. All 3 groups of raters graded very small or no chin asymmetries (1° and 0°) as more attractive, whereas high degrees of chin asymmetries (5° and 6°) were graded as most unattractive by all 3 groups. CONCLUSIONS: Transverse asymmetries of the chin influence the perception of facial attractiveness by laypersons, nonorthodontist dentists, and orthodontists. Subjects with small asymmetries are graded as most attractive, and subjects with large asymmetries are graded as least attractive. Orthodontists were the harshest graders, followed by the nonorthodontist dentists, whereas laypersons were the most lenient. The accuracy of diagnosing chin asymmetries varied among laypersons, nonorthodontist dentists, and orthodontists. Laypersons were the least accurate in diagnosing transverse chin asymmetries in a female subject, and they were just as accurate as nonorthodontist dentists when diagnosing this asymmetry in a male subject. Nonorthodontist dentists were just as accurate as orthodontists when diagnosing transverse chin asymmetries in a female subject, and orthodontists were the most accurate in diagnosing transverse chin asymmetries in a male subject.

Nonsurgical correction of a severe anterior open bite with mandibular molar intrusion using mini-implants and the multiloop edgewise archwire technique.

This article reports the case of a 24-year-old man with a large anterior open bite, mild mandibular crowding, increased overjet, no passive lip sealing, and Angle Class I malocclusion. The treatment results were achieved by mandibular molar intrusion using 1.8 × 8.5-mm mini-implants (C-implants) inserted between the mandibular first and second molars bilaterally. A 2.5-mm molar intrusion and open-bite closure occurred within 8 months. The multiloop edgewise archwire technique helped to intrude the posterior teeth. Total treatment time was 20 months. Fifty months postretention records are also presented. The patient achieved a suitable occlusion and satisfactory facial esthetics at the end of treatment and at the 50-month retention check.

Expression of Interleukin-1 and temporomandibular disorder: Contemporary review of the literature.

OBJECTIVE: Temporomandibular disorders (TMD) are a group of conditions affecting the temporomandibular joint (TMJ), leading to jaw dysfunction, joint and muscle pain, and a decrease in quality of life. A communication network of pro- and anti-inflammatory mediators called cytokines maintains the homeostasis of the TMJ. This review will focus on the Interleukin (IL) family of cytokines, which have been quantified in TMJ synovial fluids in a variety of studies. IL-1α and IL-1ß have pro-inflammatory effects, while the endogenous receptor antagonist (IL-1RA) inhibits the pro-inflammatory effects of IL-1. METHODS: A literature search (2006-2016) to identify eligible studies was completed using the PubMed database. Studies identified used saline irrigation to quantify cytokine profiles in synovial fluid of healthy and/or dysfunctional joints. RESULTS: The initial search yielded 111 articles, 5 of which met the inclusion criteria after inter-reviewer discussion. CONCLUSIONS: Articles that compared IL-1 concentrations in TMD vs. control groups found significant differences.

Extrações ortodônticas de pré-molares e seus efeitos nas vias aéreas respiratórias superiores ­ revisão da literatura / Orthodontic premolar extractions and their effects on oropharyngeal airway ­ literature review

Extrações de pré-molares por indicação ortodôntica e seus efeitos nas vias aéreas respiratórias superiores (VARS) têm sido objeto de constante investigação e controvérsia nos últimos anos. O objetivo deste estudo é identificar, através de uma busca literária, as referências mais relevantes sobre o assunto. Utilizando as bases de dados PubMed (http://www.ncbi.nlm.nih.gov/pubmed), de Janeiro de 1966 a Junho e 2016, e Google Acadêmico (http://scholar.google.com), foi conduzida uma revisão de literatura. Seis indexadores (airway, pharynx, bicuspid, premolar, incisor retraction, e sleep apnea) foram utilizados. Somente os estudos clínicos em seres humanos que não apresentavam nenhum tipo de síndrome ou deficiência física foram incluídos. Uma pesquisa manual sobre a lista de referência bibliográfica de cada artigo selecionado foi adicionada. Potencialmente, vinte e oito artigos foram identificados e somente nove artigos atingiram os critérios propostos. Quatro artigos selecionados avaliaram as alterações em imagens 2D e cinco artigos em imagens 3D. Nenhum estudo clínico selecionado utilizou randomização. A quantidade de retração dos incisivos, bem como o tipo de avaliação (2D ou 3D), tiveram influências diferentes sobre as VARS. Pouca retração dos incisivos apresenta pouca ou nenhuma influência nas VARS. Concluiu-se que a extração de pré-molares não afeta as dimensões das VARS quando pequena retração dos incisivos é realizada. A falta de estudos clínicos randomizados e de avaliação da função respiratória como indicador de apneia obstrutiva do sono ­ AOS - (por exemplo, polissonografia) justificam inconsistências da literatura sobre possível relação entre extrações ortodônticas de pré-molares e VARS/AOS.(AU)

Premolar extractions, due to orthodontic treatment, and their effect on airways have been investigated frequently in the last few years and have shown inconsistencies. The current literature review aimed to show the best articles about the topic intending to clarify such inconsistencies. Two data base, PubMed (http://www.ncbi.nlm.nih.gov/pubmed), from January of 1966 to June of 2016, and Google Scholar (http://scholar.google.com) were used to access the literature. Six key words (airway, pharynx, bicuspid, premolar, incisor retraction, and sleep apnea) were used. Only clinical studies were selected. Studies with subjects presenting syndromes or physical deficiency were excluded. Checking the references from the potential studies also targeted to find articles of interest. Initially, 28 articles were selected but only nine met the stablished criteria. Four articles evaluated the changes using 2D images and five used 3D images. None of the studies was randomized. The amount of incisor retraction and the type of evaluation (2D or 3D) showed different influences on airway. Small retraction of the incisors had none or minor influence on airway. It was concluded that premolar extractions do not cause changes on airway dimensions when the incisors were slightly retracted. Lack of randomized clinical trials and the evaluation of breathing function as indicator of obstructive sleep apnea (i.e. polysomnography) justify inconsistencies in the literature relating orthodontic premolar extractions and airway. (AU)

Odontologia digital contemporânea - scanners intraorais digitais / Contemporary digital dentistry - intraoral digital scanners

Objetivo: O uso de scanners intraorais em Odontologia, visando à reprodutibilidade de dentes e arcadas dentárias, tem sido uma nova tendência na última década. As imagens obtidas são utilizadas principalmente em diagnóstico e planejamento de casos clínicos, mas podem também ser impressas, materializando-se em modelos e troqueis de acordo com a necessidade específica. Materiais e métodos: uma revisão de literatura foi conduzida, via PubMed e Google Acadêmico. Os artigos mais relevantes nas áreas relacionadas foram identificados. Dessa seleção, 30 artigos foram revisados e discutidos. Resultados: técnicas, equipamentos e marcas comerciais, com suas relativas vantagens e desvantagens, são apresentados à comunidade odontológica. Sob o ponto de vista técnico-científico, a acuidade e a precisão dos processos de escaneamento e impressão são as principais demandas e devem ser cuidadosamente testadas. Sob o ponto de vista clínico, a facilidade de cada operação, os requisitos necessários para que se realizem (por exemplo, uso de contraste), o tamanho e peso dos equipamentos (em especial da câmera intraoral), o processo de esterilização, o tempo de escaneamento e o conforto do paciente são os fatores mais relevantes. Do ponto de vista comercial, a disponibilidade dos equipamentos, seu preço e sua assistência técnica são as principais condições a serem consideradas pelos profissionais que pretendem aplicar o método de "moldagem virtual". Conclusão: os equipamentos avaliados apresentam claras vantagens e desvantagens, que precisam ser consideradas pelos compradores em potencial dessa tecnologia. Relevância clínica: este artigo visa informar profissionais da área de Odontologia sobre as principais características e limitações do escaneamento intraoral nas áreas de Ortodontia, Prótese, Implantodontia e Cirurgia Ortognática.(AU)

Introduction: the use of intraoral scanners for teeth and dental arches reproduction in dentistry has become a new trend in the last decade. The images acquired are used in diagnosis and treatment planning of clinical cases, but they can also be printed, materialized in dental casts and dies, depending on the specific needs. Materials and Methods: a review of the literature was conducted using PubMed and Google Scholars. Thirty articles were found to be the most relevant and selected to be included in this literature review. Results: techniques, equipment, and commercial brands, including their advantages and disadvantages, have been introduced to the dental community. From the technical-scientific point of view, the accuracy and precision of scanning and printing processes are the main demands, and must be carefully tested. From the clinical standpoint, easiness of operation, need of contrast agent (i.e, titanium dioxide powder), the size and weight of equipment wand, infection control, scanning time, and patient comfort are the most relevant factors. From the commercial point of view, equipment availability, price and available assistance are the main conditions to be considered by the professionals interested in the "virtual impression" method. Conclusion: apparatus es described in this literature review present clear advantages and disadvantages, which need to be taken into consideration by potential buyers of this technology. Clinical relevance: the article intents to inform dental professionals about the main features and limitations of the intraoral scanning in Orthodontics, Prosthodontics, Implantodontics and Oral Maxillofacial Surgery..(AU)

O desafio do tratamento ortodôntico do paciente com fenótipo facial hiperdivergente / The challenge of the orthodontic treatment of the hyperdivergent facial phenotype patient

Objetivo: o artigo visa informar aos profissionais da área de Ortodontia os desafios de se diagnosticare tratar pacientes que apresentem fenótipo facial hiperdivergente. Materiais e métodos: através de revisão sistemática da literatura, via PubMed e Google Acadêmico, identificou-se os melhores artigos, descritivos e experimentais, nas áreas relacionadas. Dessa seleção, 30 artigos foram revisados e discutidos. Resultados: embora a prevalência de fenótipos faciais hiperdivergentes na população dos EUA (por falta de dados referentes à população brasileira) seja bastante pequena, seu diagnóstico e tratamento são desafiadores. Os principais fatores causais envolvidos em seu desenvolvimento são:a) genéticos; b) epigenéticos e; c) ambientais. A postura mandibular tem um papel fundamental no estabelecimento deste tipo facial, e algumas características morfológicas são patognomônicas: a)excessiva altura facial anterior inferior; b) falta de altura facial posterior; c) ângulo goníaco aberto;d) rotação mandibular desfavorável; e) plano oclusal inclinado anteriormente para baixo; f) sínfisementoniana aumentada e fina e; g) ossos corticais mais delgados, tanto na maxila como na mandíbula.Além disso, esses indivíduos apresentam funções respiratória e mastigatória deficientes. Em geral, apresentam mordida aberta anterior e possivelmente mordida cruzada posterior. Conclusão: o estabelecimento do fenótipo facial hiperdivergente é complexo e multifatorial. A ocorrência de fenômenos morfofuncionais severos sequenciais é difícil de ser controlada ou revertida e as possibilidades terapêuticas são, na melhor das hipóteses, limitadas e ainda experimentais.

Goal: the goal of the paper is to inform orthodontic professionals about the challenges to diagnose and to treat patients presenting hyperdivergent facial phenotype. Materials and methods: a systematic review of the literature was conducted using PubMed and Google Academics, and the best descriptive and experimental studies in the related areas were identified. From the initial selection, 30 papers were revised and discussed. Results: although the prevalence of individuals presenting hyperdivergent facial phenotype in the USA population (since no Brazilian epidemiologic is available) is considerably low, diagnosis and treatment are challenging. The major causal factors involved in its development are: a)genetic; b) epigenetic and; c) environmental. The mandibular posture has a fundamental role in the establishment of such facial type, and some morphological features are pathognomonic: a) excessive inferior anterior facial height; b) lack of posterior facial height; c) increased goniac angle; d) un favorable mandibular rotation; e) occlusal plane anterior ly tilted down; f) higher and thinner mandibular symphysisand; g) thinner maxillary and mandibular cortical bones. Furthermore, these individuals present respiratory and masticatory functions deficiences. In general, they present anterior open bite and possibly posterior cross bite. Conclusion: settling of the hyperdivergent facial phenotype is complex and multifactorial. The occurrence of sequential severe morphofunctional phenomena is hardly controlledor reverted, while therapeutic options are limited and still experimental.

Maxillary lateral incisor agenesis and its relationship to overall tooth size.

STATEMENT OF PROBLEM: Agenesis of the maxillary lateral incisor has been linked to differences in the size of the remaining teeth. Thus, the mesiodistal space required for definitive esthetic restoration in patients with missing maxillary lateral incisors may be reduced. PURPOSE: The purpose of this study was to determine whether a tooth size discrepancy exists in orthodontic patients with agenesis of one or both maxillary lateral incisors. MATERIAL AND METHODS: Forty sets of dental casts from orthodontic patients (19 men and 21 women; mean 15.9 years of age; all of European origin) were collected. All casts had agenesis of one or both maxillary lateral incisors. Teeth were measured with a digital caliper at their greatest mesiodistal width and then compared with those of a control group matched for ethnicity, age, and sex. Four-factor ANOVA with repeated measures of 2 factors was used for statistical analysis (α=.05). RESULTS: Orthodontic patients with agenesis of one or both maxillary lateral incisors exhibited smaller than normal tooth size compared with the control group. The maxillary arch had a larger tooth size difference between the control and test groups than the mandibular arch (there was a significant Jaw × Group interaction [F=4.78, P=.032]). CONCLUSIONS: Agenesis of one or both maxillary lateral incisors is significantly associated with tooth size discrepancy, which may affect the space remaining for restoration of the remaining teeth.