Multidisciplinary approach to restore esthetics and function in a young patient with three consecutive impacted teeth: a case report with 18-month follow-up.

This case report describes the orthodontic treatment of an 11-year-old patient with three maxillary impacted teeth on the right side. Cone-beam computed tomography showed that these teeth were close together, with the lateral incisor in a lower position, followed by the central incisor, and the canine in a more apical position. Treatment included applying traction to these teeth. A transpalatal arch was used as an anchorage device, and surgical exposure of the lateral incisor was performed for traction with an elastic chain toward the hook welded to the 0.017 × 0.025-inch steel segmented arch. Subsequently, the central incisor was surgically exposed, elastic chains were used, along with a 0.016-inch steel arch with a box loop for correcting the tooth position. The canine spontaneously began to erupt, and a 0.017 × 0.025-inch TMA segmented arch with boot loop was used to control rotation and torque of the canine during its distalization. Once these three teeth were in the arch, treatment was finished in the usual manner. For esthetic improvement, gingivoplasty was performed in the maxillary arch. Eighteen-month follow-up showed that orthodontic treatment allowed preservation of the natural teeth, the contour of gingival support, and avoidance of prosthetic rehabilitation, reestablishing the patient's esthetics and function, with satisfactory stability.

Tratamento compensatório da má oclusão de Classe III assimétrica com arcos multiloop: estabilidade após 10 anos de tratamento / Compensatory treatment of asymmetric Class III occlusion with multiloop archwires: stability after 10 years of treatment

Resumo Este relato de caso clínico apresenta o tratamento não cirúrgico de uma paciente de 17 anos e 4 meses de idade, com má oclusão de Classe III, subdivisão direita, assimetria facial, desvio do mento para a direita, perfil reto, mordida anterior de topo, com prognatismo mandibular e mordida cruzada posterior unilateral. Foi realizado um tratamento compensatório com arcos multiloop para nivelamento lateral e sagital do plano oclusal, uma vez que o tratamento ortodôntico-cirúrgico não foi aceito pela paciente devido aos custos e riscos envolvidos. Adequados trespasses vertical e horizontal foram alcançados, além da relação de Classe I, com uma melhora aceitável da assimetria facial que permaneceu estável após 10 anos do tratamento ortodôntico (AU)

Abstract This clinical case report presents the non-surgical treatment of a 17 years and 4 months old female patient, with right subdivision, Class III malocclusion, facial asymmetry, chin deviation to the right, straight profile, top anterior bite, with mandibular prognathism, and unilateral posterior crossbite. A compensatory treatment was performed with multiloop archwires for lateral and sagittal leveling of the occlusal plane, since the orthodontic-surgical treatment was not accepted by the patient due to the cost and risks involved. Adequate overjet and overjet were achieved, in addition to a Class I relationship, with an acceptable improvement in facial asymmetry that remained stable after 10 years of orthodontic treatment. (AU)

External apical root resorption after orthodontic treatment: analysis in different chronological periods.

INTRODUCTION: External apical root resorption (EARR) is characterized by the definitive loss of tooth root structure, with a higher incidence in lateral and central maxillary incisors. OBJECTIVE: To identify, in different chronological periods, the incidence of EARR in the maxillary incisors (MI) of patients orthodontically treated with or without premolars extraction. METHODS: Periapical radiographs before and after orthodontic treatment of 1,304 MIs from 326 patients (205 women and 121 men) were evaluated for EARR, divided into five groups, according to the chronological period in which treatments were started: G90) from 1990 to 1994, G95) from 1995 to 1999, G00) from 2000 to 2004, G05) from 2005 to 2009, G10) from 2010 to 2015. The evaluation was performed in each group, in patients who underwent maxillary first premolars extraction and those who did not. For statistical analysis, Fisher's exact test was used, with a significance level of p < 0.05. The EARR was measured using the adapted Levander and Malmgren classification. RESULTS: Incidence of EARR was higher in MIs of patients treated with maxillary premolar extraction (p < 0.05) in two chronological periods (G00 and G10), also being influenced by orthodontic treatments with longer duration, and due to possible individual genetic factors. CONCLUSION: Even with the limitations of a retrospective study, the lack of a defined EARR pattern in the MIs at different chronological periods was larger in the experimental group, due to the sum of factors such as premolars extraction, prolonged orthodontic treatment, possible genetic characteristics, and root shape, without the influence of the sex and age.

Dentoskeletal effects of the maxillary splint headgear in the early correction of Class II malocclusion / Effets dento-squelettiques de la force extra-orale sur gouttière maxillaire dans la correction précoce des malocclusions de classe II

Objective: To compare dentoskeletal changes produced by the maxillary splint headgear and cervical headgear appliance during the early phase of Class II treatment, specially the initial overjet and upper incisors position. Subjects and methods: In this retrospective study, 28 Class II patients treated with the maxillary splint headgear (maxillary splint headgear or MSG, mean age 10.1 ± 1.9 years) and 28 Class II patients treated with cervical headgear (cervical headgear group or CHG, mean age 9.5 ± 1.9 years) were evaluated before and after treatment. Statistical comparisons between the two groups for cephalometric measurements at T1 and for T2-T1 changes were performed by means of independent sample t tests. Results: The MSG showed a significantly greater reduction of the overjet in comparison to the CHG (-2.4 mm and -0.7 mm, respectively) and a significantly greater maxillary incisor uprighting (-1.8 mm and 0.4 mm, respectively). In the MSG, overjet correction was due mainly to mandibular advancement (3.5 mm), while the correction of molar relationship (3.9 mm) was 64% skeletal and 36% dentoalveolar. In the CHG, the overjet correction was also more skeletal, due to mandibular growth (1.8 mm), while correction of molar relationship (3.5 mm) was 63% dentoalveolar and 37% skeletal. Conclusions: Both groups showed favorable skeletal mandibular changes, which was more significant in the MSG. Regarding tooth movement, the maxillary splint headgear was more effective in uprighting upper incisors and reducing the overjet than cervical headgear appliance.

Objectif: L'objectif de cet article était de comparer les changements dento-squelettiques produits par la force extra-orale sur gouttière maxillaire et la force extra-orale cervicale pendant la phase précoce du traitement de classe II, en particulier au niveau du surplomb initial et de la position des incisives supérieures. Matériels et méthodes: Dans cette étude rétrospective, les cas de 28 patients en classe II traités avec la force extra-orale sur gouttière maxillaire (maxillary splint headgear ou MSG, âge moyen 10,1 ± 1,9 ans) et de 28 patients en classe II traités avec la force extra-orale à traction cervicale (cervical headgear group ou CHG, âge moyen 9,5 ± 1,9 ans) ont été étudiés avant et après le traitement. Les comparaisons statistiques entre les deux groupes pour les mesures céphalométriques à T1 et pour les changements entre T2 et T1 ont été effectuées au moyen de tests t d'échantillons indépendants. Résultats: Le MSG a montré une réduction significativement plus importante du surplomb par rapport au CHG (-2,4 mm et -0,7 mm, respectivement) et un redressement significativement plus important des incisives maxillaires (-1,8 mm et 0,4 mm, respectivement). Dans le MSG, la correction du surplomb était principalement due à l'avancement mandibulaire (3,5 mm), tandis que la correction de la relation molaire (3,9 mm) était à 64 % squelettique et à 36 % dento-alvéolaire. Dans le CHG, la correction du surplomb était également plus squelettique, en raison de la croissance mandibulaire (1,8 mm), tandis que la correction de la relation molaire (3,5 mm) était à 63 % dento-alvéolaire et à 37 % squelettique. Conclusions: Les deux groupes ont présenté des modifications squelettiques mandibulaires favorables, qui étaient plus significatives dans le groupe MSG. En ce qui concerne le mouvement des dents, la force extra-orale sur gouttière maxillaire était plus efficace pour redresser les incisives supérieures et réduire le surplomb que la force extra-orale cervicale.

Reliability of a digital system for models measurements in BBO grading: A pilot study.

INTRODUCTION: Currently, no method is considered effective for the evaluation of digital models in the Certification Examination of the Brazilian Board of Orthodontics (BBO), considering the parameters of the currently used manual method. OBJECTIVE: Thus, the aim of this study is to verify the reliability of an evaluation method for digital models that could be used in the BBO exam, compared to the gold standard. METHODS: Measurements were performed by five previously calibrated examiners. Samples of ten sets of plaster models of the final phase of orthodontic treatment were measured using a manual method (Objective Grading System, OGS). These models were digitized using a 3D scanner and exported to Geomagic Qualify software, in which the measurements were made with the proposed digital method. These measurements were repeated using five models, after fifteen days. The intra-examiner performance with this method was analyzed with a paired t-test, whereas the inter-examiner analysis was carried out with analysis of variance and Tukey's test. To compare the manual and digital methods, a paired t-test and Pearson's correlation analysis were performed. RESULTS: A statistically significant difference was found. The results showed that, when compared to the manual method, the digital method was effective in measuring the OGS in four of the seven variables studied: Marginal Ridge, Overjet, Occlusal Contact, and Interproximal Contact. The variables Alignment, BL inclination, and Occlusal Relationship showed a great amount of dispersion in the findings. CONCLUSION: Further studies are needed to develop an adequate digital methodology that can be used for all OGS variables.

External apical root resorption after orthodontic treatment: analysis in different chronological periods

ABSTRACT Introduction: External apical root resorption (EARR) is characterized by the definitive loss of tooth root structure, with a higher incidence in lateral and central maxillary incisors. Objective: To identify, in different chronological periods, the incidence of EARR in the maxillary incisors (MI) of patients orthodontically treated with or without premolars extraction. Methods: Periapical radiographs before and after orthodontic treatment of 1,304 MIs from 326 patients (205 women and 121 men) were evaluated for EARR, divided into five groups, according to the chronological period in which treatments were started: G90) from 1990 to 1994, G95) from 1995 to 1999, G00) from 2000 to 2004, G05) from 2005 to 2009, G10) from 2010 to 2015. The evaluation was performed in each group, in patients who underwent maxillary first premolars extraction and those who did not. For statistical analysis, Fisher's exact test was used, with a significance level of p < 0.05. The EARR was measured using the adapted Levander and Malmgren classification. Results: Incidence of EARR was higher in MIs of patients treated with maxillary premolar extraction (p < 0.05) in two chronological periods (G00 and G10), also being influenced by orthodontic treatments with longer duration, and due to possible individual genetic factors. Conclusion: Even with the limitations of a retrospective study, the lack of a defined EARR pattern in the MIs at different chronological periods was larger in the experimental group, due to the sum of factors such as premolars extraction, prolonged orthodontic treatment, possible genetic characteristics, and root shape, without the influence of the sex and age.

RESUMO Introdução: A reabsorção radicular apical externa (RRAE) é caracterizada pela perda definitiva da estrutura dentária na região radicular, com maior incidência em incisivos centrais e laterais superiores. Objetivo: Identificar, em diferentes períodos cronológicos, a incidência de RRAE em incisivos superiores (IS) de pacientes tratados ortodonticamente com e sem extração de pré-molares. Métodos: Por meio de radiografias periapicais antes e após o tratamento ortodôntico, 1.304 IS de 326 pacientes (205 mulheres e 121 homens) foram avaliados quanto à RRAE, divididos em cinco grupos, de acordo com o período cronológico em que os tratamentos foram iniciados: G90) de 1990 a 1994; G95) de 1995 a 1999; G00) de 2000 a 2004; G05) de 2005 a 2009; e G10) de 2010 a 2015. Em cada grupo, foi realizada avaliação nos pacientes submetidos à extração dos primeiros pré-molares superiores e nos que não foram. Para análise estatística, foi utilizado o teste exato de Fisher, com p< 0,05; a RRAE foi mensurada por meio da classificação de Levander e Malmgren modificada. Resultados: A incidência da RRAE foi maior em IS de pacientes tratados com extrações de pré-molares (p< 0,05) em dois períodos cronológicos (G00 e G10), além de ter sido influenciada por tratamentos ortodônticos de maior duração e por possíveis fatores genéticos individuais. Conclusão: Mesmo com as limitações de um estudo retrospectivo, a ausência de um padrão definido de RRAE nos IS nos diferentes períodos cronológicos foi maior no grupo experimental, devido à soma de fatores, como extração de pré-molares, tratamento ortodôntico prolongado, possíveis características genéticas e morfologia radicular, sem influência do sexo e da idade.

Reliability of a digital system for models measurements in BBO grading: A pilot study

ABSTRACT Introduction: Currently, no method is considered effective for the evaluation of digital models in the Certification Examination of the Brazilian Board of Orthodontics (BBO), considering the parameters of the currently used manual method. Objective: Thus, the aim of this study is to verify the reliability of an evaluation method for digital models that could be used in the BBO exam, compared to the gold standard. Methods: Measurements were performed by five previously calibrated examiners. Samples of ten sets of plaster models of the final phase of orthodontic treatment were measured using a manual method (Objective Grading System, OGS). These models were digitized using a 3D scanner and exported to Geomagic Qualify software, in which the measurements were made with the proposed digital method. These measurements were repeated using five models, after fifteen days. The intra-examiner performance with this method was analyzed with a paired t-test, whereas the inter-examiner analysis was carried out with analysis of variance and Tukey's test. To compare the manual and digital methods, a paired t-test and Pearson's correlation analysis were performed. Results: A statistically significant difference was found. The results showed that, when compared to the manual method, the digital method was effective in measuring the OGS in four of the seven variables studied: Marginal Ridge, Overjet, Occlusal Contact, and Interproximal Contact. The variables Alignment, BL inclination, and Occlusal Relationship showed a great amount of dispersion in the findings. Conclusion: Further studies are needed to develop an adequate digital methodology that can be used for all OGS variables.

RESUMO Introdução: Ainda não há um método considerado eficaz para análise dos modelos digitais no exame do Board Brasileiro de Ortodontia (BBO), considerando-se os parâmetros do método manual atual. Objetivo: Assim, o presente estudo objetiva verificar a confiabilidade de um método de avaliação em modelos digitais para o exame do BBO, comparando com o padrão-ouro. Métodos: As medições foram realizadas por 5 examinadores, previamente calibrados. A amostra de 10 pares de modelos de gesso da fase final do tratamento ortodôntico foi medida no método manual (Sistema Objetivo de Avaliação, SOA). Os modelos foram digitalizados por meio de um scanner 3D e exportados para o software Geomagic Qualify, onde foram feitas as medidas no método digital proposto. As medidas foram refeitas em 5 modelos após 15 dias. A análise intraexaminador desse método foi realizada por meio do teste t pareado; já a interexaminadores, feita com ANOVA e teste de Tukey, sendo encontrada diferença estatisticamente significativa. Para a comparação dos métodos manual e digital, foram utilizados o teste t pareado e a correlação de Pearson. Resultados: Uma diferença estatisticamente significativa foi encontrada. Os resultados mostraram que, comparada ao método manual, a metodologia digital mostrou-se eficaz para medição do SOA em quatro das sete variáveis estudadas: Margem interproximal, Sobressaliência, Contato oclusal e Contato interproximal. As variáveis Alinhamento, Inclinação V-L e Relação oclusal mostraram muita dispersão nos achados. Conclusão: Mais estudos são necessários para o desenvolvimento de uma metodologia digital adequada em todas as variáveis do SOA.

New highlights on effects of rapid palatal expansion on the skull base: a finite element analysis study.

OBJECTIVE: The objective of this study was to evaluate the effect of the rapid palatal expansion (RPE) on the pterygoid process (PP), spheno-occipital synchondrosis (SOS) and sella turcica (ST) in the skull of a patient with transversal maxillary collapse, and identify the distribution of mechanical stresses and displacement, by finite element analysis (FEA). METHODS: Cone-beam computed tomography (CBCT) was employed to examine the skull of a patient in this study. The patient was a 13-year-old boy, with Class II skeletal relationship due to transverse atresia and maxillary protrusion. The computer-aided design (CAD) geometry of skull was imported into the SimLab v. 13.1 software, to build the finite element mesh. For the simulation, a displacement of 1 mm, 3 mm and 5 mm in a transverse direction was defined at the midpalatal suture, thereby representing the RPE. For the analysis of results, maximum principal stress (MPS) and displacements were evaluated by identifying different nodes, which were represented by the points as per the areas of interest in the study. RESULTS: In MPS, the maximum tensile stress was found at point 2 (366.50 MPa) and point 3 (271.50 Mpa). The maximum compressive stress was found at point 8 (-5.84 Mpa). The higher displacements in the transversal plane and the lateral segment were located at point 1 (2.212 mm), point 2 (0.903 mm) and point 3 (0.238 mm). CONCLUSIONS: RPE has a direct effect on PP, SOS and ST in the Class II model skeletal relationship with a transversal maxillary collapse. PP supported a higher tensile stress and displacement.

Dentoskeletal effects of the maxillary splint headgear in the early correction of Class II malocclusion.

BACKGROUND: To compare dentoskeletal changes produced by the maxillary splint headgear and cervical headgear appliance during the early phase of Class II treatment, specially the initial overjet and upper incisors position. SUBJECTS AND METHODS: In this retrospective study, 28 Class II patients treated with the maxillary splint headgear (MSG, mean age 10.1 ± 1.9 years) and 28 Class II patients treated with cervical headgear (CHG, mean age 9.5 ± 1.9 years) were evaluated before and after treatment. Statistical comparisons between the two groups for cephalometric measurements at T1 and for T2-T1 changes were performed by means of independent sample t tests. RESULTS: The MSG showed a significantly greater reduction of the overjet in comparison to the CHG (- 2.4 mm and - 0.7 mm, respectively) and a significantly greater maxillary incisor uprighting (- 1.8 mm and 0.4 mm, respectively). In the MSG, overjet correction was due mainly to mandibular advancement (3.5 mm), while the correction of molar relationship (3.9 mm) was 64% skeletal and 36% dentoalveolar. In the CHG, the overjet correction was also more skeletal, due to mandibular growth (1.8 mm), while correction of molar relationship (3.5 mm) was 63% dentoalveolar and 37% skeletal. CONCLUSIONS: Both groups showed favorable skeletal mandibular changes, which was more significant in the MSG. Regarding tooth movement, the maxillary splint headgear was more effective in uprighting upper incisors and reducing the overjet than cervical headgear appliance.

Miniscrew-Assisted Rapid Palatal Expansion (MARPE) ­ practical guide for planning and installation / Expansão maxilar apoiada em mini-implantes (MARPE) ­ guia prático para planejamento e instalação

Rapid maxillary expansion (RME) is an orthodontic treatment alternative that aims to increase the transverse direction of the maxilla by separating the median palatine suture (MPS). miniscrew-assisted rapid palatal expansion (MARPE) aims to enhance the orthopedic effects of RME through skeletal anchorage. Thus, the aim of this article is to provide a guide for MARPE planning in cone beam computed tomography (CBCT) and for installation of the expander device with this technique. In addition, a case report of a Caucasian male patient, 16 years and 3 months old with Class II malocclusion, division 1 right subdivision, posterior crossbite of the right side and atresic upper arch in the post-pubertal growth spurt phase will be presented. The patient was treated with MARPE for a period of 5 weeks, when overcorrection of crossbite, correction of maxillary atresia, opening of MPS and creation of a transient diastema between the upper incisors were achieved, evidencing the success of the MARPE technique in a post-pubertal growth spurt patient. (AU)

A Expansão Rápida da Maxila (ERM) é uma alternativa de tratamento ortodôntico que visa o aumento no sentido transversal da maxila, através da separação da sutura palatina mediana (SPM). A Expansão Maxilar Apoiada em Mini-implantes (MARPE, do inglês Miniscrew-Assisted Rapid Palatal Expansion) visa potencializar os efeitos ortopédicos da ERM através da ancoragem esquelética. Assim o objetivo deste artigo é fornecer um guia para planejamento da MARPE em tomografia computadorizada de feixe cônico (TCFC) e para instalação do aparelho expansor com essa técnica. Além disso será apresentado um relato de caso de um paciente do sexo masculino, 16 anos e 3 meses de idade, caucasiano, portador da má-oclusão de Classe II, 1ª divisão subdivisão direita, mordida cruzada posterior do lado direito e arcada superior atrésica, em fase de pós-surto de crescimento puberal. O paciente foi tratado com MARPE, por um período de 5 semanas, quando foi alcançada a sobrecorreção da mordida cruzada, correção da atresia maxilar, abertura da SPM e criação de um diastema transitório entre os incisivos superiores, evidenciando o sucesso da técnica MARPE em um paciente pós-surto de crescimento puberal.

Predisposing factors for external apical root resorption associated with orthodontic treatment.

OBJECTIVE: This study aimed to identify possible risk factors for external apical root resorption (EARR) in the maxillary incisors after orthodontic treatment. METHODS: The root length of 2,173 maxillary incisors was measured on periapical radiographs of 564 patients who received orthodontic treatment. The Kappa test was performed to evaluate intraexaminer and interexaminer reproducibility. Multiple binary logistic regression was used to determine the association between EARR and various factors. Odds ratios and 95% confidence intervals were reported. RESULTS: The risk of developing EARR was 70% higher in orthodontic treatment with maxillary premolar extraction (p = 0.004), 58% higher in patients with increased overjet (p = 0.012), 41% lower in two-phase orthodontic treatment (p = 0.037), and 33% lower in patients with deep bite (p = 0.039). The lateral incisors were 54% more likely to develop EARR (p < 0.001), dilacerated roots were 2.26 times more likely to develop EARR (p < 0.001), and for each additional millimeter of root length, the risk of EARR increased by 29% (p < 0.001). CONCLUSIONS: The potential risk factors for EARR after orthodontic treatment included treatment with maxillary premolar extraction, increased overjet at the beginning of treatment, and dilacerated roots.

Possíveis fatores de risco para reabsorção radicular apical externa após tratamento ortodôntico / Possible risk factors of external apical root resorption associated with orthodontic treatment

A reabsorção radicular apical externa (RRAE) é uma condição que reduz permanentemente o tamanho da raiz dentária e é observada com relativa frequência após o tratamento ortodôntico. O objetivo deste trabalho foi identificar possíveis fatores associados com a ocorrência da RRAE em pacientes submetidos ao tratamento ortodôntico (sexo, idade, raça, forma e tamanho da raiz, características da má oclusão, duração e tipo de tratamento ortodôntico). Para isto, foram selecionadas radiografias periapicais de 2173 incisivos centrais e laterais superiores de 564 pacientes em fase de contenção tratados com aparelhagem fixa em três diferentes instituições brasileiras (UERJ, PUC Minas e UFMG). As medições foram realizadas por 2 examinadores e foram considerados reabsorvidos os dentes que, ao final do tratamento ortodôntico, apresentaram RRAE maior do que 2 mm. Foi realizado o teste kappa para avaliar a reprodutibilidade intra e interexaminador. A associação entre RRAE e os fatores avaliados foi realizada através de regressão logística binária múltipla. Razão de chance (OR) e intervalo de confiança de 95% foram relatados. Foi observado que incisivos laterais apresentaram mais chances de apresentar RRAE maior que 2 mm (OR = 1,54; p = < 0,001), assim como transpasse horizontal aumentado (OR = 1,58; p = 0,012), tratamento com extrações (OR = 1,70; p = 0,004), raiz dilacerada (OR = 2,26; p = < 0,001) e raízes mais longas (OR = 1,29; p = < 0,001). Os pacientes menos propensos à RRAE foram aqueles que realizaram tratamento em 2 fases (OR = 0,59; p = 0,037), assim como pacientes portadores de sobremordida exagerada (OR = 0,67; p = 0,039). Portanto, a morfologia radicular e os fatores estudados por este trabalho relacionados com a quantidade de deslocamento radicular foram fatores de risco para RRAE após tratamento ortodôntico

External apical root resorption (EARR) is a condition that permanently reduce the size of dental root and it is found with a relative frequency after orthodontic treatment. The objective of this study was to evaluate possible factors associated with the occurrence of EARR in patients submitted to orthodontic treatment (gender, age, race, root morphology and length, characteristics of malocclusion, duration and type of orthodontic treatment). Periapical radiographs of 2173 upper lateral and central incisors were selected from 564 patients in retention period treated with fixed appliance at three brazilian centers (UERJ, PUC Minas and UFMG). Measurements were performed by 2 examiners and were considered resorbed teeth with EARR greater than 2 mm at the end of treatment. The kappa test was performed to evaluate intra- and inter-examiner reproducibility. The association between EARR and the factors evaluated was assessed using multiple binary logistic regression. Odds ratio (OR) and 95% confidence interval were reported. It was observed that lateral incisors were more prone to EARR greater than 2 mm (OR = 1,54; p = < 0,001), as well as increased overjet (OR = 1,58; p = 0,012), treatment with extractions (OR = 1,70; p = 0,004), dilacerated root (OR = 2,26; p = < 0,001) and longer roots (OR = 1,29; p = < 0,001). Treatment performed in 2 phases was less prone to EARR (OR = 0,59; p = 0,037), as well as increased overbite (OR = 0,67; p = 0,039). Therefore, root morphology and factors evaluated in this study related to the amount of root displacement were risk factors for EARR after orthodontic treatment

Three-dimensional evaluation of mandibular anterior dental crowding in digital dental casts.

INTRODUCTION:: Digital dental models provide a more accurate and comprehensive assessment of orthodontic cases. Although this technique is quite promising, there are few three-dimensional measurements methods described in the literature. OBJECTIVE:: The aim of this study was to propose a method for assessing the degree of mandibular anterior dental crowding in the three planes of space, using digital dental models. METHODS:: Thirty dental casts were selected and scanned by Maestro 3D Dental Scanner and imported by Geomagic Qualify 2013 software. The degree of crowding was calculated by two examiners, based on the Little's Irregularity Index, by means of the definition of axial, coronal and sagittal planes for each model. Intraexaminer analysis was performed with Dahlberg's Formula (DF) and Intraclass Correlation Coefficients (ICC), and interexaminer analysis was performed with ICC and paired t-test. RESULTS:: The ICC showed an excellent agreement (p < 0.05) for all measurements, except for the intraexaminer and interexaminer in the Z-axis, in which it was found a moderate agreement. The DF showed a satisfactory accuracy with all measurements showing less than 1 mm difference. The paired t-test showed statistical difference between the examiners in two measurements, although it was clinical irrelevant. CONCLUSION:: When comparing the three planes of space, the Z-axis showed the greatest variation in landmarks placement; however, overall, the present method seems precise and reproducible.

Three-dimensional evaluation of mandibular anterior dental crowding in digital dental casts

ABSTRACT Introduction: Digital dental models provide a more accurate and comprehensive assessment of orthodontic cases. Although this technique is quite promising, there are few three-dimensional measurements methods described in the literature. Objective: The aim of this study was to propose a method for assessing the degree of mandibular anterior dental crowding in the three planes of space, using digital dental models. Methods: Thirty dental casts were selected and scanned by Maestro 3D Dental Scanner and imported by Geomagic Qualify 2013 software. The degree of crowding was calculated by two examiners, based on the Little's Irregularity Index, by means of the definition of axial, coronal and sagittal planes for each model. Intraexaminer analysis was performed with Dahlberg's Formula (DF) and Intraclass Correlation Coefficients (ICC), and interexaminer analysis was performed with ICC and paired t-test. Results: The ICC showed an excellent agreement (p < 0.05) for all measurements, except for the intraexaminer and interexaminer in the Z-axis, in which it was found a moderate agreement. The DF showed a satisfactory accuracy with all measurements showing less than 1 mm difference. The paired t-test showed statistical difference between the examiners in two measurements, although it was clinical irrelevant. Conclusion: When comparing the three planes of space, the Z-axis showed the greatest variation in landmarks placement; however, overall, the present method seems precise and reproducible.

RESUMO Introdução: os modelos digitais fornecem uma avaliação mais precisa e abrangente dos casos ortodônticos. Embora essa técnica seja bastante promissora, existem poucos métodos de medição tridimensional descritos na literatura. Objetivo: o objetivo do presente estudo foi propor um método para avaliar o grau de apinhamento dentário anteroinferior, nos três planos do espaço, usando modelos digitais. Métodos: trinta modelos de gesso foram selecionados, escaneados pelo scanner Maestro Dental 3D e importados para o software Geomagic Qualify 2013. Dois examinadores calcularam o grau de apinhamento, com base no Índice de Irregularidade de Little, mediante a definição dos planos axial, coronal e sagital para cada modelo. A análise intraexaminador foi realizada por meio da fórmula de Dahlberg (FD) e do Coeficiente de Correlação Intraclasse (ICC), enquanto a análise interexaminadores foi realizada com o ICC e o teste t pareado. Resultados: o ICC mostrou um excelente grau de concordância (p< 0,05) para todas as medições, exceto para as avaliações intraexaminador e interexaminadores no eixo Z, onde foi encontrado um grau moderado. A FD mostrou uma precisão satisfatória, com todas as medidas apresentando diferença menor que 1 mm. O teste t pareado mostrou diferenças estatisticamente significativas entre os examinadores em duas medidas, apesar de terem sido clinicamente irrelevantes. Conclusão: ao se comparar os três planos do espaço, o eixo Z mostrou maior variação na marcação de pontos; no entanto, em geral, o presente método parece ser preciso e reprodutível.