Micro-osteoperforation for enhancement of orthodontic movement: A mechanical analysis using the finite element method.

BACKGROUND: Micro-osteoperforation is a minimally invasive technique aimed at accelerating tooth movement. The goal of this novel experimental study was to assess tooth movement and stress distribution produced by the force of orthodontic movement on the tooth structure, periodontal ligament, and maxillary bone structure, with and without micro-osteoperforation, using the finite element method. MATERIALS AND METHODS: Cone-beam computed tomography was used to obtain a virtual model of the maxilla and simulate the extraction of right and left first premolars. Three micro-osteoperforations (1.5 x 5 mm) were made in the hemiarch on the distal and mesial surfaces of upper canines, according to the power tip geometry of the Propel device (Propel Orthodontics, Ossining, New York, USA). An isotropic model of the maxilla was fabricated according to the finite element method by insertion of mechanical properties of the tooth structures, with orthodontic force (1.5 N) simulation in the distal movement on the upper canine of a hemiarch. RESULTS: Initial movement was larger when micro-osteoperforations were performed on the dental crown (24%) and on the periodontal ligament (29%). In addition, stress distribution was higher on the bone structure (31%) when micro-osteoperforations were used. CONCLUSIONS: Micro-osteoperforations considerably increased the movement of both the dental crown and periodontal ligament, which highlights their importance in the improvement of orthodontic movement, as well as in stress distribution across the bone structure. Important stress absorption regions were identified within micro-osteoperforations.

Influence of respiratory allergy and restless sleep on definite sleep bruxism: a cross-sectional clinical study.

OBJECTIVE: This cross-sectional clinical study evaluated the associations between sociodemographic, occupational, clinical conditions, psychological and sleep quality variables on definite sleep bruxism (SB). METHODS: All records obtained from adults (aged 20-60 years) and the elderly (aged >60 years) who had undergone polysomnography (PSG) at a private medical outpatients' clinic from July 2017 to February 2018 were reviewed. Data from a questionnaire, based on the criteria of the American Academy of Sleep Medicine (AASM), were also gathered. Definite SB data pattern distribution was analyzed, and multivariate Poisson regression with robust variance was used to assess the associations between definite SB diagnosis, determined via PSG recordings, and the independent variables. A significance level of 5% was adopted. RESULTS: A total of 240 individuals were included in the study and the SB prevalence was 7.08% (n = 17). The adjusted Poisson regression analysis revealed association between definitive SB and individuals with respiratory allergy (PR = 3.63; 95% CI:1.01-13; P = 0.047) and restless sleep (PR = 2.97; 95% CI:1.04-8.50; P = 0.042). CONCLUSION: This study found associations between definite SB and clinical conditions (respiratory allergy) and sleep behavior (restless sleep). Knowledge regarding factors associated with definite SB can contribute to decision making in the clinical setting and management strategies involving a multidisciplinary approach.

Comparison of maxillomandibular asymmetries in adult patients presenting different sagittal jaw relationships.

OBJECTIVE: The present study aims at using cone beam computed tomography (CBCT) to analyze the maxillomandibular characteristics present in adults with mandibular asymmetries and different sagittal jaw relationships. METHODS: 360 patients were selected and divided into three groups (Class I, Class II, and Class III), with 120 individuals per group. The groups were then subdivided according to the intensity of lateral deviation of the gnathion point, into: 1) relative symmetry, 2) moderate asymmetry, and 3) severe asymmetry. Three planes of reference were established in the CBCT images and several measurements were taken to compare the bilateral skeletal differences between the intensities of asymmetry for the different sagittal jaw relationships. RESULTS: When the groups were compared by the intensity of asymmetry, significant differences among patients with relative symmetry and moderate to severe asymmetry were found. This was especially noticed for severe asymmetry, suggesting that the deviation of the chin did not constitute the only morphological alteration for these patients, especially because a series of measurements showed significant bilateral differences. When comparing sagittal jaw relationships, the only significant finding was the vertical positioning of the gonion between Class II and III patients with severe asymmetry. CONCLUSIONS: When comparing the three sagittal jaw relationships with the same intensity of asymmetry, most maxillofacial aspects were quite similar. The only difference was found for patients with severe asymmetry, as the individuals with Class II showed greater bilateral difference in the vertical positioning of the gonion, when compared to patients with Class III.

Comparison of maxillomandibular asymmetries in adult patients presenting different sagittal jaw relationships

ABSTRACT Objective: The present study aims at using cone beam computed tomography (CBCT) to analyze the maxillomandibular characteristics present in adults with mandibular asymmetries and different sagittal jaw relationships. Methods: 360 patients were selected and divided into three groups (Class I, Class II, and Class III), with 120 individuals per group. The groups were then subdivided according to the intensity of lateral deviation of the gnathion point, into: 1) relative symmetry, 2) moderate asymmetry, and 3) severe asymmetry. Three planes of reference were established in the CBCT images and several measurements were taken to compare the bilateral skeletal differences between the intensities of asymmetry for the different sagittal jaw relationships. Results: When the groups were compared by the intensity of asymmetry, significant differences among patients with relative symmetry and moderate to severe asymmetry were found. This was especially noticed for severe asymmetry, suggesting that the deviation of the chin did not constitute the only morphological alteration for these patients, especially because a series of measurements showed significant bilateral differences. When comparing sagittal jaw relationships, the only significant finding was the vertical positioning of the gonion between Class II and III patients with severe asymmetry. Conclusions: When comparing the three sagittal jaw relationships with the same intensity of asymmetry, most maxillofacial aspects were quite similar. The only difference was found for patients with severe asymmetry, as the individuals with Class II showed greater bilateral difference in the vertical positioning of the gonion, when compared to patients with Class III.

RESUMO Objetivo: o presente estudo teve como objetivo analisar, por meio de tomografia computadorizada de feixe cônico (TCFC), as características esqueléticas maxilomandibulares presentes em adultos com diferentes graus de assimetria mandibular e diferentes relações esqueléticas sagitais. Métodos: foram selecionados 360 pacientes, os quais foram divididos em três grupos, com 120 indivíduos cada (Classe I, Classe II e Classe III). Cada grupo foi, ainda, subdividido de acordo com a intensidade do desvio lateral do mento: 1) simetria relativa; 2) assimetria moderada; e 3) assimetria severa. Três planos de referência foram estabelecidos nas imagens de TCFC e várias medidas foram realizadas, sendo comparadas as diferenças esqueléticas bilaterais existentes entre os graus de assimetria em cada grupo, nas diferentes relações esqueléticas sagitais. Resultados: quando comparados os grupos pelos graus de assimetria, existiram diferenças significativas entre pacientes com simetria relativa e pacientes assimétricos, especialmente para a assimetria severa, sugerindo que o desvio do mento não constitui a única alteração morfológica para esses pacientes, especialmente porque uma série de medidas apresentou diferenças bilaterais significativas. Quando comparadas as relações sagitais entre si, não foram encontradas diferenças significativas, exceto para o posicionamento vertical do gônio entre as Classe II e III na assimetria severa. Conclusão: ao comparar a mesma intensidade de assimetria entre as diferentes relações esqueléticas sagitais, pouca diferença pôde ser observada. A única diferença encontrada foi em pacientes com assimetria severa, na qual os indivíduos com Classe II apresentaram maior diferença bilateral no posicionamento vertical do gônio, quando comparados àqueles com Classe III.

Three-dimensional evaluation of craniofacial characteristics related to mandibular asymmetries in skeletal Class I patients.

INTRODUCTION: Our objective was to analyze the characteristics that affect skeletal Class I adults with mandibular asymmetries using cone-beam computerized tomography. METHODS: The sample included cone-beam computerized tomography images of 120 subjects. Asymmetry was determined by the deviation of gnathion from the midsagittal plane and classified as relative symmetry, moderate asymmetry, or severe asymmetry. Maxillary and mandibular measurements were made, and the differences between the contralateral side and the deviated side were evaluated, as well as the differences between the categories of asymmetry. RESULTS: For patients with moderate asymmetry, there were significant differences between the contralateral and deviated sides for some measuments in the transverse and vertical planes. For those with severe asymmetry, statistically significant differences were found between the sides for all measurements, except for the measuments that evaluated the position of the mandibular condyle in the transverse and sagittal directions. Furthermore, a strong correlation was found in patients with severe asymmetry, between the deviation of the mandibular dental midline and the lateral displacement of gnathion. CONCLUSIONS: Patients with relative symmetry had a bilateral balance, whereas those with moderate and severe asymmetries showed several skeletal imbalances. A great deviation of the mandibular dental midline may indicate severe skeletal asymmetry in Class I adults.

The T-loop in details.

INTRODUCTION: The T-loop as designed by Burstone is a space closure spring used in the rational application of orthodontic biomechanics. Despite the diversity of studies, there is still no consensus on the optimal parametric characteristics for its conformation. OBJECTIVE: This study aimed at reviewing the literature on the force systems released by different conformations of the T-loop, according to the type of anchorage and the main characteristics and factors that influence them. RESULTS: Comparing the studies, the need for standardization was perceived in the methodology to shape the loops, regarding the variables that influence the force system. Most of the experimental studies with this loop do not report the vertical movement, nor the steps and angles that occur in the brackets. Clinical studies have obtained more variable results in relation to vertical acting forces, considering the influence of chewing. CONCLUSION: There is great potential for future studies with this type of loop, especially using nickel-titanium alloys, in order to achieve a pure translational movement without friction, with optimal and constant levels of force.

Mandibular asymmetries and associated factors in orthodontic and orthognathic surgery patients.

OBJECTIVES: To estimate the prevalence of mandibular asymmetries in orthodontic and orthognathic surgery patients and to investigate demographic and skeletal factors associated with this disharmony. MATERIALS AND METHODS: Cone-beam computed tomography images of 1178 individuals aged 19 through 60 years with complete dentitions were analyzed. Outcomes were classified as relative mandibular symmetry, moderate asymmetry, and severe asymmetry. Factors recorded included sex, age, side of mandibular deviation, sagittal jaw relationship, vertical skeletal pattern, angle of the cranial base, and maxillary asymmetry. Ordinal logistic regression was used to estimate simple and adjusted odds ratios (OR) for the individuals with moderate and severe mandibular asymmetry, as well as 95% confidence intervals. RESULTS: Prevalence values of 55.2%, 27.2%, and 17.6% were observed for relative mandibular symmetry, moderate asymmetry, and severe asymmetry, respectively. An independent association with the side of mandibular deviation and the presence of maxillary asymmetry was observed, both for subjects with moderate mandibular asymmetry (left side: OR = 1.50; 95% CI: 1.01-2.24 / maxillary asymmetry: OR = 2.07; 95% CI: 1.11-3.76) and for those with severe asymmetry (left side: OR = 2.09; 95% CI: 1.27-3.44 / maxillary asymmetry: OR = 4.93; 95% CI: 2.64-9.20). CONCLUSIONS: Moderate and severe mandibular asymmetries were present in 44.8% of the sample, being associated with the side of mandibular deviation and with maxillary asymmetry.

The T-loop in details

ABSTRACT Introduction: The T-loop as designed by Burstone is a space closure spring used in the rational application of orthodontic biomechanics. Despite the diversity of studies, there is still no consensus on the optimal parametric characteristics for its conformation. Objective: This study aimed at reviewing the literature on the force systems released by different conformations of the T-loop, according to the type of anchorage and the main characteristics and factors that influence them. Results: Comparing the studies, the need for standardization was perceived in the methodology to shape the loops, regarding the variables that influence the force system. Most of the experimental studies with this loop do not report the vertical movement, nor the steps and angles that occur in the brackets. Clinical studies have obtained more variable results in relation to vertical acting forces, considering the influence of chewing. Conclusion: There is great potential for future studies with this type of loop, especially using nickel-titanium alloys, in order to achieve a pure translational movement without friction, with optimal and constant levels of force.

RESUMO Introdução: a alça T preconizada por Burstone é um instrumento de fechamento de espaços utilizado na aplicação racional da biomecânica ortodôntica, dentro da técnica do arco segmentado. Apesar da diversidade de estudos, ainda não há consenso quanto às características paramétricas ótimas para a sua conformação. Objetivo: esse estudo teve como objetivo revisar a literatura sobre os sistemas de forças liberados por diferentes conformações da alça T, de acordo com o tipo de ancoragem necessária, salientando suas principais características e os fatores que as influenciam. Resultados: comparando-se os estudos, foi perceptível a necessidade de padronização da metodologia usada para conformar as alças, levando em consideração as variáveis que exercem influência no sistema de forças, de forma a se obter sistemas mais acurados, permitindo a realização de testes mais precisos e uma comparação mais eficaz dos estudos. A maioria dos estudos experimentais com esse tipo de alça não relata a movimentação vertical, nem os degraus e ângulos que ocorrem nos braquetes. Estudos clínicos obtiveram resultados menos rígidos em relação às forças verticais atuantes, levando em consideração a influência da mastigação. Conclusões: há grande potencial para futuros estudos com esse tipo de alça, especialmente utilizando ligas de níquel-titânio, para que se chegue cada vez mais perto de um movimento de translação puro e sem atrito, com níveis de força ótimos e constantes.

Exploring the impact of malocclusion and dentofacial anomalies on the occurrence of traumatic dental injuries in adolescents.

OBJECTIVE: To investigate the association between malocclusion/dentofacial anomalies and traumatic dental injuries (TDI) in adolescents. MATERIALS AND METHODS: The sample of this cross-sectional study comprised 509 adolescents aged 11 to 14 years enrolled at public schools in the city of Osório, southern Brazil. Parents answered a structured questionnaire addressing demographic and socioeconomic characteristics. An examiner who had undergone a training and calibration exercise recorded malocclusion/dentofacial anomalies (Dental Aesthetic Index, DAI), TDI (Andreasen), and dental caries (World Health Organisation). Statistical analyses (SPSS software) involved Poisson regression with robust variance. RESULTS: The prevalence of TDI was 11.6%, and the prevalence of defined, severe, and handicapping malocclusion was 24.0%, 21.6%, and 22.0%, respectively. The multivariate analysis demonstrated that the probability of TDI was approximately twofold higher among adolescents with severe malocclusion (prevalence ratio [PR] 2.22; 95% confidence interval [CI] 1.14-4.31) and handicapping malocclusion (PR 1.95; 95% CI 1.01-3.85) in comparison to those with normal occlusion or minor malocclusion. Defined malocclusion was not significantly associated with the outcome. Among the dentofacial anomalies evaluated, the probability of TDI was nearly twofold higher among adolescents with overjet greater than 3 mm (PR 1.96; 95% CI 1.14-3.37) and 2.2-fold higher among those with an abnormal molar relationship (PR 2.24; 95% CI 1.17-4.32), after controlling for confounding variables. CONCLUSIONS: Severe and handicapping malocclusion, accentuated overjet, and abnormal molar relationship were strongly associated with the occurrence of TDI. Future studies should investigate whether the treatment of these conditions can help reduce the occurrence of TDI in adolescents.

Contaminação de cones de papel absorvente e cones de guta percha utilizados em endodontia: avaliação "in vitro" / Contamination of absorbent of paper points and gutta percha points used in endodontics: Assessment "in vitro"

The endodontic treatment has as goals to seek the disinfection of the root canal. For this, endodontic instruments and materials must be free from microorganisms, since that they may contribute to the installation and or persistence of apical periodontitis after closing the canal. Although paper points and gutta percha are produced under aseptic conditions, they may be contaminated by such factors as aerosol and or physical aspects during storage as well as for handling, even when carefully removed from their packaging. In this context, the aim of this study was to evaluate the presence of microbial contamination of three commercial brands being the absorbent paper cones considered sterile and gutta-percha cones in non-sterile packaging, as provided by the manufacturer, and after placement to clinical use. Methodology: 120 cones were evaluated, 60 of absorbent paper and 60 gutta percha, both of the brands Dentsply Maillefer® sistema Protaper universal (Ballaigues, Suisse), VDW GmbH® sistema Mtwo (Bayerwaldstr, Munich, Alemanha) and Meta Biomed® (Cheongju-si, Chungbuk, Korea), divided into twelve groups (n = 10, each). For microbiological evaluation, these materials were subjected to testing for bacterial growth, as determined by the turbidity of the culture medium. Results: The results showed that none of the marks showed turbidity in sterilized and sealed packages, suggesting the absence of bacterial growth. However, after placement for clinical use, the gutta percha brand Meta Biomed® proved to be contaminated. Conclusion: It can be concluded that packaging as provided by the manufacturers for paper and gutta-percha cones showed no microbial contamination, being reliable, unlike to the opened packagings, justifying the use of a decontamination routine these cones prior to clinical use.

O tratamento endodôntico tem como objetivo promover a desinfecção do canal radicular. Para isso, instrumentos e materiais devem estar livres de microrganismos, visto que poderão contribuir para a instalação e/ou persistência de lesões perirradiculares após o fechamento do canal. Apesar dos cones de papel e de guta-percha serem produzidos em condições assépticas, eles podem ser contaminados por fatores como aerossóis e/ou aspectos físicos durante sua armazenagem, bem como pelo manuseio, mesmo quando removidos cuidadosamente de suas embalagens. Neste contexto, o objetivo deste estudo foi avaliar a presença de contaminação microbiana de três marcas comerciais tanto de cones de papel absorvente consideradas estéreis, quanto de cones de guta-percha, em embalagens não estéreis, conforme disponibilizadas pelo fabricante, bem como após a colocação para uso clínico. Metodologia: Foram avaliados 120 cones, sendo 60 de papel absorvente e 60 de guta percha, ambos das marcas Dentsply Maillefer® sistema Protaper universal (Ballaigues, Suisse), VDW GmbH® sistema Mtwo (Bayerwaldstr, Munich, Alemanha) e Meta Biomed® (Cheongju-si, Chungbuk, Korea), divididos em doze grupos (n=10, cada). Para avaliação microbiológica, esses materiais foram submetidos a testes para detecção do crescimento bacteriano, determinado através do turvamento do meio de cultura. Resultados: Os dados mostraram que nenhuma das marcas, conforme disponibilizadas pelo fabricante, apresentou turvamento nas embalagens estéreis ou não estéreis, sugerindo ausência de crescimento bacteriano. Já para as embalagens após colocação para uso clínico, os cones de guta percha da marca Meta Biomed® mostraram-se contaminados. Pode-se concluir que as embalagens conforme disponibilizadas pelos fabricantes, tanto para cones de papel quanto gutapercha, mostraram-se isentas de contaminação e, portanto, confiáveis, diferente das embalagens abertas e colocadas para uso clínico, justificando a utilização de uma rotina de descontaminação desses cones antes da sua utilização clínica.

Prevalence and Associated Factors of Mandibular Asymmetry in an Adult Population.

BACKGROUND: This study aimed to estimate the prevalence of mandibular asymmetry and investigate some associated factors. METHODS: Tomographic images of 952 individuals aged from 18 to 75 years old were analyzed. The investigated outcome was mandibular asymmetry. The explanatory variables included gender, age, absence of posterior teeth, and sagittal jaw relationship of the individuals. Statistical analyses included the chi-squared and the Poisson regression with robust variance. RESULTS: Mandibular asymmetry was present in 17.4% of the sample (95% confidence interval 15.2-20.0). In the bivariate analysis, there was an association between the variables age and sagittal jaw relationship with mandibular asymmetry (P = 0.026 and P = 0.018, respectively). However, in the adjusted regression model, the association with age was not maintained, occurring only an association between sagittal jaw relationship and mandibular asymmetry (P = 0.045), with significant difference between individuals with skeletal Class II and skeletal Class III (P = 0.013). CONCLUSION: Mandibular asymmetry was not independently associated with sex, age, or absence of posterior teeth. The only verified independent association was between mandibular asymmetry and sagittal jaw relationship.

Maxillofacial Features Related to Mandibular Asymmetries in Skeletal Class III Patients.

PURPOSE: To analyze components related to different degrees of mandibular asymmetry in adults with skeletal Class III using cone-beam computed tomographic (CBCT) images. MATERIALS AND METHODS: CBCT images from 138 patients were analyzed. Asymmetry was determined by the deviation of the gnathion point in relation to the midsagittal plane and classified as relative symmetry, moderate mandibular asymmetry, or severe mandibular asymmetry. Several maxillary and mandibular measurements were used to compare different degrees of mandibular asymmetry and the difference between measurements of the contralateral and deviated sides. RESULTS: For patients with moderate and severe mandibular asymmetry, there were statistically relevant differences between bilateral measurements of the sagittal position of the condylar heads, the transverse and sagittal positioning of the gonion, ramus height, and mandibular body length, the transverse and vertical positioning of the jugale point, including a vertical positioning of the gonion only for severe asymmetry. In patients with severe mandibular asymmetry, there was a highly relevant correlation of gnathion lateral displacement with lower dental midline displacement and with the difference in height of the mandibular rami between the deviated and contralateral sides. CONCLUSION: In patients with skeletal Class III, not only lateral displacement of the menton but also a series of morphologic changes differed markedly for each degree of mandibular asymmetry.

Is there an association between skeletal asymmetry and tooth absence?

INTRODUCTION: Facial skeletal asymmetry is commonly found in humans and its main characteristic is menton deviation. The literature suggests that occlusal and masticatory problems arising from tooth absence could be related to the development of such asymmetries. OBJECTIVE: The aim of this cross-sectional study was to estimate the prevalence of mandibular skeletal asymmetries and to investigate its association with posterior tooth absences. METHODS: Tomographic images of 952 individuals aged from 18 to 75 years old were used. Asymmetry was the analyzed outcome, and it was categorized into three groups according to gnathion displacement in relation to the midsagittal plane (relative symmetry, moderate asymmetry, and severe asymmetry). Patients were sorted by the presence of all posterior teeth, unilateral posterior tooth absence, or bilateral posterior tooth absence. Chi-square test with a significance level of 5% was used to verify the association between posterior tooth absence and asymmetry. RESULTS: Results show relative symmetry present in 55.3% of the sample, as well as the prevalence of 27.3% for moderate mandibular asymmetry and 17.4% for severe asymmetry. Moderate and severe mandibular asymmetries occurred in a higher proportion in patients with unilateral posterior tooth absence. However, there was no statistically significant difference between the analyzed groups (p = 0.691). CONCLUSIONS: In this study, mandibular asymmetries did not present any association with the absence of teeth on the posterior area of the arch.

Is there an association between skeletal asymmetry and tooth absence?

ABSTRACT Introduction: Facial skeletal asymmetry is commonly found in humans and its main characteristic is menton deviation. The literature suggests that occlusal and masticatory problems arising from tooth absence could be related to the development of such asymmetries. Objective: The aim of this cross-sectional study was to estimate the prevalence of mandibular skeletal asymmetries and to investigate its association with posterior tooth absences. Methods: Tomographic images of 952 individuals aged from 18 to 75 years old were used. Asymmetry was the analyzed outcome, and it was categorized into three groups according to gnathion displacement in relation to the midsagittal plane (relative symmetry, moderate asymmetry, and severe asymmetry). Patients were sorted by the presence of all posterior teeth, unilateral posterior tooth absence, or bilateral posterior tooth absence. Chi-square test with a significance level of 5% was used to verify the association between posterior tooth absence and asymmetry. Results: Results show relative symmetry present in 55.3% of the sample, as well as the prevalence of 27.3% for moderate mandibular asymmetry and 17.4% for severe asymmetry. Moderate and severe mandibular asymmetries occurred in a higher proportion in patients with unilateral posterior tooth absence. However, there was no statistically significant difference between the analyzed groups (p = 0.691). Conclusions: In this study, mandibular asymmetries did not present any association with the absence of teeth on the posterior area of the arch.

RESUMO Introdução: a assimetria esquelética facial é comum em humanos, sendo o desvio do mento sua principal característica. É sugerido, na literatura, que problemas oclusais e mastigatórios advindos das ausências dentárias teriam relação com o desenvolvimento dessas assimetrias. Objetivo: o objetivo deste estudo transversal foi estimar a prevalência de assimetrias esqueléticas mandibulares e investigar sua associação com as ausências dentárias posteriores. Métodos: foram utilizadas imagens tomográficas de 952 indivíduos, com idade entre 18 e 75 anos. A assimetria foi o desfecho analisado, sendo categorizada em três grupos, de acordo com o desvio do gnátio em relação ao plano sagital mediano: simetria relativa, assimetria moderada e assimetria severa. Os indivíduos foram agrupados segundo a presença de todos os dentes posteriores, ausência dentária posterior unilateral ou ausência dentária posterior bilateral. Para verificar a associação entre a ausência dentária posterior e a assimetria, foi utilizado o teste Χ2, ao nível de significância de 5%. Resultados: os resultados mostraram que a simetria relativa esteve presente em 55,3% da amostra, bem como uma prevalência de 27,3% para a assimetria mandibular moderada e 17,4% para assimetria severa. As assimetrias mandibulares moderada e severa ocorreram em maior proporção nos indivíduos com ausência dentária posterior unilateral; entretanto, não houve diferença estatisticamente significativa entre os grupos (p = 0,691). Conclusões: nesse estudo, as assimetrias mandibulares em adultos não apresentaram associação com a ausência de dentes na região posterior da arcada dentária.

An interview with Hyeon-Shik Hwang.

It gives me great pleasure to interview Dr. Hyeon-Shik Hwang, an innovative orthodontist who has developed many creative techniques over his career. Dr. Hwang was born in Korea and received his DDS and PhD degrees from Yonsei University in Seoul. He is professor and chairman of the Department of Orthodontics at Chonnam National University School of Dentistry, Gwangju, Korea. Dr. Hwang, as a faculty at the university hospital, has maintained a successful clinical practice for more than 25 years. He has treated many adult patients focusing on esthetics and periodontal health and has developed many clinical techniques to improve the effectiveness and efficiency of treatment to the benefit of both the patient and practitioner. Dr. Hwang is also interested in the evaluation of facial asymmetry two- and three-dimensionally. As one of the early adopters of cone-beam volume imaging, he has given special emphasis on the management of surgical cases. He is married to Jung-Un Park with whom he has two sons. His favorite hobbies are photography and listening to music. When I was presented to him in a congress, it was a great pleasure meeting someone who I already admired for his singular work. Later on, his humbleness and knowledge made me marvel at him even more. I hope that all readers of Dental Press Journal of Orthodontics also enjoy the teachings from this brilliant Korean orthodontist! Guilherme Thiesen - interview coordinator.

Facial asymmetry: a current review.

The term "asymmetry" is used to make reference to dissimilarity between homologous elements, altering the balance between structures. Facial asymmetry is common in the overall population and is often presented subclinically. Nevertheless, on occasion, significant facial asymmetry results not only in functional, but also esthetic issues. Under these conditions, its etiology should be carefully investigated in order to achieve an adequate treatment plan. Facial asymmetry assessment comprises patient's first interview, extra- as well as intraoral clinical examination, and supplementary imaging examination. Subsequent asymmetry treatment depends on patient's age, the etiology of the condition and on the degree of disharmony, and might include from asymmetrical orthodontic mechanics to orthognathic surgery. Thus, the present study aims at addressing important aspects to be considered by the orthodontist reaching an accurate diagnosis and treatment plan of facial asymmetry, in addition to reporting treatment of some patients carriers of such challenging disharmony.

Facial asymmetry: a current review

Abstract The term "asymmetry" is used to make reference to dissimilarity between homologous elements, altering the balance between structures. Facial asymmetry is common in the overall population and is often presented subclinically. Nevertheless, on occasion, significant facial asymmetry results not only in functional, but also esthetic issues. Under these conditions, its etiology should be carefully investigated in order to achieve an adequate treatment plan. Facial asymmetry assessment comprises patient's first interview, extra- as well as intraoral clinical examination, and supplementary imaging examination. Subsequent asymmetry treatment depends on patient's age, the etiology of the condition and on the degree of disharmony, and might include from asymmetrical orthodontic mechanics to orthognathic surgery. Thus, the present study aims at addressing important aspects to be considered by the orthodontist reaching an accurate diagnosis and treatment plan of facial asymmetry, in addition to reporting treatment of some patients carriers of such challenging disharmony.

Resumo O termo assimetria é utilizado quando existe uma desigualdade entre as partes homólogas, afetando, assim, o equilíbrio entre as estruturas. A assimetria facial é comum na população, e muitas vezes se apresenta de forma subclínica. Entretanto, em alguns casos existe uma assimetria facial significativa que resulta tanto em problemas funcionais quanto estéticos. Nessas circunstâncias, a etiologia deve ser cuidadosamente investigada, para que seja possível elaborar um plano de tratamento adequado. A avaliação da assimetria facial é constituída por uma anamnese do paciente, exame clínico extra e intrabucal, além de exames complementares de imagem. O tratamento subsequente dessa assimetria depende da idade do paciente, etiologia e da magnitude da desarmonia, podendo envolver desde mecânicas ortodônticas assimétricas até a realização de cirurgia ortognática. Assim, o presente artigo busca abordar aspectos importantes para que o ortodontista possa realizar um adequado diagnóstico e plano de tratamento da assimetria facial, além de relatar o tratamento de alguns pacientes portadores dessa desafiadora desarmonia.