Validación y Comparación de un Nuevo Método para Predecir el Ancho Mesiodistal de Caninos y Premolares no Erupcionados en una Población Chilena de la Región de Valparaíso, Chile

Uno de los principales problemas durante la dentición mixta es la determinación de la futura discrepancia entre tamaño dentario y el espacio disponible. Para predecir el ancho mesiodistal de los dientes permanentes no erupcionados se han introducido diferentes métodos de análisis. Objetivo: El propósito de este estudio fue comparar el método Tanaka-Johnston con una nueva ecuación de regresión para predecir el ancho mesiodistal de caninos y premolares permanentes no erupcionados en una población de la región de Valparaíso, Chile. Material y método: Este estudio fue realizado en la Facultad de Odontología de la Universidad de Valparaíso, desde octubre de 2022 a junio de 2023 (8 meses), la muestra estuvo compuesta por 202 modelos de estudio del departamento de ortodoncia (91 hombres y 111 mujeres) en el rango de edad de 11 -20 años. Resultados: Se demostró que el método elaborado por Lara-Sandoval presenta mayor fiabilidad respecto a las medidas mesiodistales reales de los pacientes (ICC 0,773 para maxilar y 0,762 para mandíbula), en comparación con el método de Tanaka-Johnston (ICC 0,665 para maxilar y 0,623 para mandíbula). No existen diferencias significativas entre los valores reales y el método de Lara-Sandoval. Conclusión: El método de Lara-Sandoval es mejor que el propuesto por Tanaka-Johnston para determinar el ancho mesiodistal de caninos y premolares para esta muestra. Es necesario validar este método en otras regiones del país para ser utilizado con mayor seguridad que el ya existente como método estándar nacional.

One of the main orthodontic problems in mixed dentition is the determination of future tooth and size arch discrepancy. In order to predict the mesiodistal widths of unerupted permanent teeth different methods of analyses have been introduced. The aim of this study is to compare the Tanaka-Johnston analysis with a new regressive equation to predict the mesiodistal width of unerupted permanent canines and premolars in a Chilean population sample, from Valparaíso region. This study was conducted at the Universidad de Valparaíso Dental Faculty, from october 2022 to june 2023 (8 months), and the sample comprised historical dental casts from 202 patients (91 boys and 111 girls) in the age range of 11-20 from the orthodontics department. All the patients are from the Valparaíso region, Chile. The results show that the predictions of the new regressive equation method are closer to the actual mesiodistal measurements of the patients (ICC 0,773 for maxilla and 0,762 for mandible), compared to the Tanaka- Johnston method (ICC 0,665 for maxilla and 0,623 for mandible). There are no significant differences between the real values and the Lara-Sandoval method. Lara-Sandoval method is better than the one proposed by Tanaka-Johnston to determine the mesiodistal width of canines and premolars in this sample population. It is necessary to validate this method in other regions of the country to be used with greater security than the ones that already exists as a national standard method.

Odontometria eletrônica em dentes decíduos: revisão de literatura e relato de caso / Eletronic working length determination in primary tooth: review of literature and case report

Objetivo: Realizar uma revisão dos principais artigos encontra-dos na literatura acerca do uso dos Localizadores Eletrônicos Foraminais (LEF) em dentes decíduos e representar através de um relato de caso clínico, a importância do uso destes dispositivos durante o tratamento endodôntico em dentes decíduos. Revisão da literatura: Foi realizada uma busca nas principais bases de dados, e selecionados 13 artigos consi-derados mais relevantes. Todos os estudos mostraram que a determinação da odontometria em dentes decíduos utilizando o LEF é bastante segura e com boa acurácia, podendo ser utilizado o localizador para esta finalidade. Relato do caso:No caso clínico apresentado, o uso do LEF foi fundamental para a obtenção de uma odontometria precisa, além da diminuição do tempo de cadeira e identificar reabsorções não detectáveis radiograficamente. O caso foi conduzido em duas sessões, onde na primeira foi realizada a cirurgia de acesso, odontometria eletrônica, preparo manual dos canais e utilização de medicação intracanal de hidróxido de cálcio. Na segunda sessão foi removida a medicação intracanal e os canais foram obturados utilizando pasta iodoformada. Discussão: O uso do LEF no tratamento endodôntico de dentes decíduos tem se mostrado uma ferramenta segura e eficiente, tendo melhor performance na determinação do comprimento de trabalho quando comparado a outros métodos. Conclusão: De acordo com os estudos apresen-tados na revisão de literatura e o caso clínico apresentado, pudemos constatar que o uso do LEF contribui positivamente ao tratamento, principalmente quanto ao ganho de tempo e determinação confiável e segura do comprimento de trabalho.

Aim: To review the main articles found in the literature on the use of Electronic Apex Locators (EAL) in deci-duous teeth, and to represent, through a clinical case report, the importance of using these devices during endodontic treatment in deciduous teeth. Review of literature: A search was performed in the main data-bases, and 13 articles considered most relevant were selected. All studies showed that the determination of odontometry in deciduous teeth using LEF is quite safe and with good accuracy, and the localizer can be used for this purpose. Case report: In the clinical case presented, the use of EAL was fundamental to obtain an accurate odontometry, besides the reduction of chair time and exposure to ionizing radiation. The case was conducted in two sessions, where in the first one the access surgery was performed, electronic odontometry, manual preparation of the canals and use of intracanal medication of calcium hydroxide. In the second session the intracanal medication was removed and the canals were filled using iodoform paste. Discussion: The use of LEF in the endodontic treatment of primary teeth has been shown to be a safe and efficient tool, with better permormance in determining the working length when compared to other methods. Conclusion: According to the studies presented in the literature review and the clinical case presented, we could verify that the use of LEF contributes positively to treatment, especially in terms of time gain and acurate determination of working length.

Concordância entre medida de comprimento de trabalho por radiografia e localizador eletrônico foraminal na dentição decídua: revisão integrativa / Agreement between work length measurement by radiography and electronic foraminal locator in the primary dentition: an integrative review

Introdução: O estabelecimento do comprimento de trabalho (CT) é uma etapa fundamental para o sucesso do tratamento endodôntico, principalmente na dentição decídua. O exame radiográfico é um dos principais meios de definir o CT. A mensuração desse comprimento também pode ser obtida por meio de dispositivos eletrônicos. Objetivo: Revisar a literatura acerca da concordância entre a medida de CT por radiografia e localizadores eletrônicos foraminais (LEFs) na dentição decídua. Metodologia: A busca bibliográfica foi realizada nas bases de dados PubMed, Cochrane Library e BVS, seguindo uma estratégia de combinação de palavras-chave, filtrando apenas pesquisas clínicas. A seleção dos artigos foi realizada em duas etapas: através da leitura dos títulos e resumos e, em seguida, por meio da obtenção e leitura dos artigos completos selecionados. Resultados: sete artigos foram selecionados, publicados entre 2011 e 2020. Todos foram analisados quanto à qualidade metodológica e à caracterização como tamanho da amostra, objetivo, metodologia, resultados e conclusão. Todos possuíam os dados necessários para contemplar o objetivo desta pesquisa. O uso dos LEFs mostrou-se tão preciso quanto o método radiográfico (n=6), e, em um estudo, o método eletrônico foi superior ao radiográfico para determinação do CT. Conclusão: O método eletrônico possui eficácia na determinação do CT durante o tratamento endodôntico de dentes decíduos sendo comparável ao radiográfico.

Introduction: To establish the working length (CT) is a fundamental step toward the suc-cess of endodontic treatment. Also, the radiographic examination is one of the most important means of determining CT. This length can also be measured by electronic devic-es. Objective: To review the literature on the agreement between the CT measurement by radiography and electronic foraminal locators (LEF) in the primary dentition. Methodology: A bibliographic search was performed on PubMed, Cochrane Library, and BVS, using a keyword combination strategy and filtering only clinical research. The selection of the articles occurred in two stages: by reading the titles and abstracts, and by obtaining and reading the selected full articles. Results: Seven articles, published between 2011 and 2020, were selected and analyzed for methodological quality and characterized for sample size, objectives, methodology, results, and conclusion. They had the essential data to contemplate the purpose of this research. The use of LEF proved to be as accurate as of the radiographic method (n=6), and in one study, the electronic method was superior to the radiographic method for determining TC. Conclusion: The electronic method is effective in determining the CT during the endodontic treatment of primary teeth and is comparable to the radiographic one.

Root canal length changes during mechanical preparation due to different cervical enlargement patterns

Abstract This study aimed to evaluate the root canal real length (RL) changes due to the mechanical instrumentation use with different flaring magnitudes. After access cavity, 60 mesial root canals of mandibular molars were randomly separated in three groups: Hyflex EDM (HF; #25/.12, #10/.05 e #25/~), Reciproc Blue (RB; R25), and MTwo (M2; #10/.04, #15/.05, #20/.06 e #25/.06). The RL was defined as the apical limit, and 2.5% sodium hypochlorite irrigating solution was chosen. After the access cavity (RL 1), cervical flaring (RL 2), and complete chemical-mechanical preparation (RL 3), the RL was evaluated. The RL was evaluated by a blind examiner with the aid of a microscope (16x) placing the endodontic file stop at the coronary reference. When comparing length measurements, the RL was shorter before instrumentation than that after instrumentation. A reduction of 0.65 mm (HF), 0.61 mm (RB), and 0.48 mm (M2) was observed. However, among groups, no statistical differences were found (p > 0.05). Under the conditions tested, it can be inferred that all mechanical systems provoked RL variations, which emphasizes the need for constant verification of the odontometry, mainly before root canal obturation.

Aplicabilidad del método de Moyers para la estimación del diámetro mesiodistal de caninos y premolares en pacientes de 12-18 años / Applicability of the Moyers method for the estimation of the mesiodistal diameter of canines and premolars in patients of 12-18 years old

Uno de los métodos más universales empleados para predecir el ancho mesiodistal de caninos y premolares no erupcionados es el diseñado por el Dr. Edison Moyers, quien tomando como referencia la población anglosajona creó tablas de percentiles para estimar dichos valores en maxilar y mandíbula. Durante la última década varios investigadores han descubierto que, al aplicarlo en diversas poblaciones, existen diferencias significativas entre las predicciones y los valores reales. En Cuba, el método de Moyers es muy utilizado al 50% de probabilidades para la predicción en ambos sexos, pero existen pocos reportes de estudios que validen su confiablidad y los que existen utilizan muestras pequeñas de pacientes. Es por ello por lo que el objetivo de esta investigación es determinar la aplicabilidad del método de Moyers al 50% de probabilidades para la estimación del diámetro mesiodistal de caninos y premolares en pacientes de 12-18 años. Se desarrolló un estudio descriptivo y transversal desde julio de 2019 hasta febrero de 2020 con una población de 125 pacientes, 62 del sexo femenino y 63 del masculino, de entre 12 y 18 años de Cuba. Se efectuaron las mediciones de los anchos mesiodistales de los incisivos inferiores, todos los caninos y premolares. Se realizaron distribuciones de frecuencia a las variables estudiadas y los resultados se presentaron en tablas estadísticas. Para comprobar la existencia de diferencias significativas se utilizó la prueba estadística t-Student. Los resultados principales obtenidos fueron que el método de Moyers tiende a subestimar los valores para el sexo femenino entre los 0,4-0,5 mm, y para el sexo masculino entre los 0,6-0,7 mm, siendo esta diferencia significativa para los hombres. Se concluye que el método de Moyers no puede ser aplicado en la población estudiada para la predicción del ancho mesiodistal de caninos y premolares

One of the most universal methods used to predict the mesiodistal width of non-erupted canines and premolars is the one designed by Dr. Edison Moyers, an American orthodontist who, taking the Anglo-Saxon population as a reference, created percentile tables to estimate these values in the maxilla and mandible. During the last decade, several researchers have discovered that, when applied to various populations, there are significant differences between predictions and actual values. In Cuba, it is widely used at a 50% probability for prediction in both sexes, but there are few reports of studies that validate its reliability and those that do exist use small samples of patients. For this reason, the objective of this research is to determine the applicability of the Moyers method at 50% probabilities for estimating the mesiodistal diameter of canines and premolars in patients 12-18 years of age. A descriptive and cross-sectional study was developed from July 2019 to February 2020 with a population of 125 patients, 62 females and 63 males, between 12 and 18 years old from Cuba. Measurements were made of the mesiodistal widths of the lower incisors, all the canines and premolars. Frequency distributions were made to the variables studied and the results were presented in statistical tables. To verify the existence of significant differences, the statistical t-Student test was used. The main results obtained were that the Moyers method tends to underestimate the values for the female sex between 0.4-0.5 mm, and for the male sex between 0.6 and 0.7 mm, this difference being significant for men. It is concluded that the Moyers method cannot be applied in the population studied for the prediction of the mesiodistal width of canines and premolars

Aplicabilidad del método Tanaka-Johnston para la estimación del diámetro mesiodistal de caninos y premolares en pacientes de 12-18 Años / Applicability of the Tanaka-Johnston method for the estimation of the mesiodistal diameter of canines and premolars in patients of 12-18 years old

El método Tanaka-Johnston es utilizado mundialmente para predecir el diámetro de caninos y premolares no erupcionados por la conveniencia de no necesitar tablas ni radiografías para su uso. Sin embargo, durante los últimos años investigadores de varios países han demostrado que al ser utilizado en una población diferente para la que fue diseñado, puede sobrestimar o subestimar los valores. En Cuba, donde el patrón facial de la población difiere del ideal para este método, ha sido muy empleado, pero prácticamente no existen estudios donde se valide la confiabilidad o exactitud de las predicciones de este. Por tanto, el objetivo de esta investigación es determinar la aplicabilidad del método Tanaka-Johnston para la estimación del diámetro mesiodistal de caninos y premolares en pacientes de 12-18 años. Se desarrolló un estudio descriptivo y transversal desde junio de 2019 hasta enero de 2020 con una población de 140 pacientes de ambos sexos de entre 12 y 18 años de Cuba. Se efectuaron las mediciones de los anchos mesiodistales de los incisivos inferiores, todos los caninos y premolares. Se realizaron distribuciones de frecuencia a las variables estudiadas y los resultados se presentaron en tablas estadísticas. Para comprobar la existencia de diferencias significativas se utilizó la prueba estadística t-Student. Los resultados principales obtenidos fueron que el método Tanaka-Johnston tiende a sobrestimar los valores para el sexo femenino y subestimarlos para el masculino, ambos entre los 0,2 y 0,3 mm, pero esta diferencia no resulta significativa. Se concluye que el método Tanaka-Johnston puede ser aplicado en la población estudiada para la predicción del ancho mesiodistal de caninos y premolares no erupcionados.

The Tanaka-Johnston method is used worldwide to predict the diameter of canines and premolars not erupted for the convenience of not needing boards or x-rays for use. However, in recent years researchers from several countries have shown that when used in a different population for which it was designed, it can overestimate or underestimate the values. In Cuba, where the facial pattern of the population differs from the ideal for this method, it has been highly used, but there are very few studies where the reliability or accuracy of the predictions of the same is validated. Therefore, the objective of this research is to determine the applicability of the Tanaka-Johnston method for estimating the mesiodistal diameter of canines and premolars in patients aged 12-18 years. A descriptive and cross-cutting study was conducted from June 2019 to January 2020 with a population of 140 patients of both sexes between 12 and 18 years of age from Cuba. Measurements were made of the mesiodistal widths of the lower incisors, all canines, and premolars. Frequency distributions were made to the variables studied and the results were presented in statistical tables. The t-Student statistical test was used to verify significant differences. The main results obtained were that the Tanaka-Johnston method tends to overestimate the values for the female sex and underestimate them for the male, both between 0,2 and 0,3 mm, but this difference is not significant. It is concluded that the Tanaka-Johnston method can be applied in the population studied for the prediction of the mesiodistal width of unerupted canines and premolars.

Análise comparativa da precisão de medição dos localizadores apicais eletrônicos Romiapex a15® e Root zx mini®: um estudo in vitro / Comparative analysis of the measuring accuracy of the electronic apex locators Romiapex a15® and Root zx mini®: an in vitro study

Este estudo analisou a precisão de medição dos aparelhos ROMIAPEX A 15® e ROOT ZX MINI®, in vitro, comparativamente pelo método radiográfico e eletrônico no que diz respeito à precisão e confiabilidade na determinação do Comprimento Real de Trabalho (CRT) e Comprimento Real do Dente (CRD). Vinte dentes humanos (incisivos superiores e pré-molares superiores/inferiores) foram avalia das e seus CRD's e CRT's aferidos de forma direta por meio de lima tipo k nº 10 ou 15 (Dentsply Sirona, Ballaigues, Suíça), pelo método radiográfico e método eletrônico. Não foram verificadas diferenças significativas entre as medidas para CRD (p=0,003) e CRT (p=0,042) entre os métodos direto, radio gráfico e eletrônico. Ambos os métodos ficaram próximos da medida real, quando por vezes também definiram a mesma medida real. Os CRD's obtidos pelos métodos radiográfico e eletrônico foram sub metidos ao Teste t de Student (p<0,024) apontando relação estatística significativa para a verificação da odontometria, sugerindo que ambos os métodos são eficazes na determinação do comprimento real do dente quanto de trabalho. O método eletrônico apresentou eficácia satisfatória estatistica mente nos casos comparativamente aos outros métodos também avaliados. Os dados sugerem que os localizadores citados podem auxiliar as tomadas de decisões para determinação do CRD e CRT

This study analyzed the measurement accuracy of the ROMIAPEX A15® and ROOT ZX MINI® locators, in vitro, comparatively by the radiographic and electronic methods with regard to the precision and reliability in the determination of the Real Working Length (RWL) and Real Tooth Length (RTL). Twenty human teeth (upper incisors and upper/lower premolars) were evaluated it had the RTL and RWL measured through rasp k No 10/15 (Dentsply Sirona, Ballaigues, Switzerland) by radiographic and electronic methods. There were no significant differences between the measures for RTL (p = 0,003) and RWL (p = 0,042) for the methods. It means that both methods were very close to the real measure, when sometimes they also defined the same real measure. The RTL obtained by methods radiographic and electronic, were submitted to Student's t test (p <0,024), showed statistical significance in relation to the methods used for verification of odontometry, which means that both methods are effective to determine an actual length of the element and the length of actual work. The electronic method showed statistically satisfactory effectiveness in the cases compared to the other methods.The data suggest that these locators can assist decision making to determine RTL and RWL ... (AU)

Sexual dimorphism applying the mandibular canine index in a Brazilian sample: a pilot study

This research study aimed at applying the morphometric quantification of the canine index for sexual dimorphism in a Brazilian sample. This was an observational study and the convenience sample consisted of 90 adult participants (45 male subjects and 45 female subjects), aging from 18 to 35 years. With the aidof a digital caliper, the intraoral mesiodistal measurement of the permanent mandibular right canine (MD43) and the intercanine distance (IC) were taken by three examiners. The measurements were applied to the mandibular canine index formula to estimate sex based on the morphometric features of human canines. The applicability of this approach for sexual dimorphism was assessed based on the mandibular canine index (MCI) calculated by the formula. The MCI was higher in male than in female subjects. In the total sample, the MCI overall mean accuracy rate for sexual dimorphism was 52.22%. In male subjects, the MCI was able to properly differentiate sex in 82.22% of the sample, while in female subjects the accuracy rate decreased to 22.22%. These results call the attention to the careful use of MCI especially for Forensic Anthropology. In particular, the accuracy of the method was close to the random of a sample that contained both sexes. Thus, the MCI should not be used as the only tool for sexual dimorphism.

Effects of cone beam computed tomography measurement of maxillary anterior teeth on implant success and patient satisfaction of maxillary anterior teeth / 中国基层医药

Objective:To investigate the effects of cone beam computed tomography measurement of maxillary anterior teeth on implant success and patient satisfaction of maxillary anterior teeth.Methods:120 patients who underwent maxillary anterior teeth implantation in Hangzhou Dental Hospital from October 2017 to October 2019 were included in this study. They were randomly assigned to receive either conventional maxillary anterior teeth implantation (control group, n = 60) or cone beam computed tomography measurement of maxillary anterior teeth and maxillary anterior teeth implantation (study group, n = 60). The implant success rate was compared between the two groups. Alveolar bone thickness and ISQ value immediately, 3 and 12 months after implantation as well as patient satisfaction were compared between the two groups. Results:Implant success rate in the observation group was significantly higher than that in the control group [96.67% (58/60) vs. 85.00% (51/60), χ2 = 4.904, P < 0.05]. In the observation group, alveolar bone thickness at 3 and 12 months after implantation was (1.53 ± 0.05) mm and (1.78 ± 0.12) mm, respectively, which was significantly higher than that in the control group [(1.46 ± 0.04) mm, (1.64 ± 0.10) mm, t = 9.839, 8.066, both P < 0.001]. In the observation group, ISQ value at 3 and 12 months after implantation was (76.83 ± 5.49) and (82.91 ± 4.85), respectively, which was significantly higher than that in the control group [(67.81 ± 4.61), (74.18 ± 5.21), t = 11.324, 11.038, both P < 0.001). Total satisfaction rate in the observation group was significantly higher than that in the control group [95.00% (57/60) vs. 81.67% (49/60), χ2 = 5.175, P < 0.05]. Conclusion:Cone beam computed tomography measurement of maxillary anterior teeth can help increase implant success rate and patient satisfaction.

Accuracy of Root ZXII, E-PEX and FIND apex locators in teeth with vital pulp: an in vivo study

Abstract: This research evaluated, in vivo, the accuracy of three electronic apex locators - EALs (Root ZXII, E-PEX and FIND) in teeth with vital pulp submitted to biopulpectomy, preserving the periodontal stump. For this study, 90 single-rooted teeth with extraction indication were selected. After positive pulpal cold sensitivity test, pulp chamber access was performed. The cervical and middle thirds of root canals were instrumented with Reciproc R25, and the K#15 file was used as a standard instrument to determine working length, forming 2 groups: Constriction (insertion of the instrument until the apical constriction limit) and Foramen (insertion of the instrument until the foramen and then repositioning at constriction, without removing the file from the canal). The hand file was stabilized with a light-cured flow resin. After extraction, the samples were analyzed through microCT SkyScan 1272, with CTAN software, which evaluated the proximity between the tip of the file to the apical constriction, providing data for comparative analysis using Kruskal-Wallis and Dunn tests (p<0.05). There was a statistically significant difference in the abilities of the EALs to detect the apical constriction after reaching the foramen with Root ZX II showing higher accuracy (89%). However, there was no difference in the accuracy of the three EALs in detecting the apical constriction without reaching the foramen. Based on the present results, we conclude that EALs may show accurate measures in detecting apical constriction and foramen, even without damaging the periodontal stump in biopulpectomy.

Esthetic proportions of maxillary anterior teeth of 120 Chinese adults / 北京大学学报(医学版)

OBJECTIVE@#To analyze the esthetic proportions of maxillary anterior teeth in term of the apparent widths proportion of the adjacent teeth and width/height ratio of the clinical crown in 120 Chinese adults.@*METHODS@#Maxillary gypsum casts were obtained from the dental laboratories of stomatological hospitals in North China, Southeast China, and Southwest China, according to the inclusion criteria and exclusion criteria. Standardized digital photographs of each cast were recorded. The apparent widths and actual widths and heights of the central incisors, lateral incisors and canines were determined by ImageJ software for the calculation of apparent widths proportion of the adjacent teeth and width/height ratio of the clinical crown. The ideal apparent widths proportion (Golden proportion and Preston proportion) and width/height ratio (0.80) were tested. The gender, arch side, and regional differences were investigated.@*RESULTS@#The apparent widths proportion of the lateral/central incisor was 0.724±0.047, of the canine/lateral incisor was 0.814±0.092. The width/height ratio of the central incisor was 0.848±0.072, of the lateral incisor was 0.834±0.094, of the canine was 0.883±0.098. The esthetic proportions were different from the predicted ideal ratio (P < 0.001). The apparent widths proportion of lateral/central incisor was significantly larger in the right side than that in the left side (0.730± 0.044 vs. 0.718±0.050), and was significantly smaller in North China than that in Southwest China (0.711±0.051 vs. 0.731±0.044). The width/height ratio of the central incisor was significantly larger in the female than that in the male (0.855±0.074 vs. 0.835±0.068), and in the right side than that in the left side (0.855±0.073 vs. 0.842±0.072). The width/height ratio of the lateral incisor was significantly larger in the female than that in the male (0.843±0.097 vs. 0.817±0.084).@*CONCLUSION@#The apparent widths proportion of adjacent teeth and the width/height ratio of the clinical crown in Chinese adults are different from the foreigner's. The esthetic proportion parameters have significant population specificity, and the measurements cannot be generalized as well as it should be applied with caution.

Relationship between the inner intercanthal distance and the mesiodistal dimension of maxillary anterior teeth in a peruvian population with facial harmony / Relación entre la distancia intercantal interna y la dimensión mesiodistal de dientes anterosuperiores en una población peruana con armonía facial

Objective: To determine the relationship between the inner intercanthal distance and the mesiodistal dimension of the maxillary anterior teeth in a Peruvian population with facial harmony. Material and Methods: A cross-sectional study on a sample of 75 Peruvian subjects with facial harmony, with ages ranging between 18 and 30 years, was conducted. The inner intercanthal distance and the mesiodistal dimension of maxillary anterior teeth of each subject were measured with a digital vernier caliper. The relationship was evaluated by simple linear regression analysis. Results: A statistically significant direct relationship was found between the dimension of the inner intercanthal distance with the mesiodistal width of the lateral incisors (p=0.040, R2=5.65%), canines (p=0.032, R2=6.17%), and the total mesiodistal sum of the six anterior teeth (p=0.040, R2=5.63%), but not with the central incisors (p=0.273, R2=1.64%). Conclusion: The inner intercanthal distance showed a direct relationship with the total mesiodistal linear dimension of the maxillary anterior teeth, with the mesiodistal dimensions of the lateral incisors and canines in a Peruvian population with facial harmony.

Determinar la relación entre la distancia intercantal interna y la dimensión mesiodistal de los dientes anterosuperiores en individuos peruanos con armonía facial. Material y métodos: Se realizó un estudio transversal en una muestra de 75 individuos peruanos con armonía facial entre 18 a 30 años. Se midió la distancia intercantal interna y la dimensión mesiodistal de dientes anterosuperiores de cada sujeto con un calibrador vernier digital. La relación fue evaluada mediante análisis de regresión lineal simple. Resultados: Se encontró relación directa estadísticamente significativa entre la dimensión de la distancia intercantal interna con el ancho mesiodistal de los incisivos laterales (p=0.040, R2=5.65%), caninos (p=0.032, R2=6.17%) y la suma total mesiodistal de los seis dientes anteriores (p=0.040, R2=5.63%), más no con los incisivos centrales (p=0.273, R2=1.64%). Conclusión: La distancia intercantal interna mostró relación directa con la dimensión lineal mesiodistal total de los dientes anterosuperiores, con las dimensiones mesiodistales de los incisivos laterales y de caninos en individuos peruanos con armonía facial.

Comparison of Two Different Non-Radiographic Mixed Dentition Analysis

Objective: To evaluate the applicability of two different non-radiographic mixed dentition analysis in school going children of Aligarh district, India. Material and Methods: Mesiodistal dimension was measured on the dental casts of 120 school going children with electronic digital vernier caliper. The following inclusion criteria were adopted: presence of all fully erupted permanent teeth; no congenital craniofacial anomalies; no previous history of orthodontic treatment; and presence of intact dentition with no proximal caries, restoration, or age related attrition. Predicted values of canines and premolars were obtained from Moyer's at 75th percentile and Tanaka and Johnston mixed dentition analysis. Descriptive statistics were used to calculate the mean and standard deviation. Paired observations were compared by t­test. The level of significance was at p<0.001. Results: The mean difference between the predicted and the actual value of canines and premolars using Moyer's probability table at 75th percentile and Tanaka and Johnston regression equation were statistically significant. No significant differences were found between Moyer's analysis 75th percentile and Tanaka and Johnston mixed dentition analysis in both arch and sexes. Conclusion: These two non-radiographic mixed dentition analysis overestimated the mesiodistal width of canines and premolars.

Vertical Cephalic Index, Dental Arch and Palatal Depth Measurement: A Study in Bataknese Children

Objective: To evaluate the cephalic indices among Bataknese school students. Material and Methods: An observational study was performed by measuring 95 Bataknese children aged 3-5 years using a purposive sampling technique. The vertical cephalic index was measured directly in children, while the dental arch and palatal depth were measured on maxillary impressions. Vertical cephalic index data were obtained by measuring the height and length of the child's head directly. Measurement was performed three times by three different people. Cephalic height was measured by a digital calipers by placing each edge of the calipers on the nasion and gnathion. Descriptive statistics were used to calculate the mean and standard deviation. Results: The analysis of height and cephalic length showed that the highest values were 9.28 cm and 18.13 cm, while the lowest were 7.43 cm and 13.43 cm, respectively. The means for Maxillary canine arch width and Maxillary molar arch width were 30.66 mm and 46.69 mm, respectively. For the Maxillary canine arch depth, the mean was 12.0 mm, while for the Maxillary molar arch depth was 28.65 mm. The palatal depth was 14.33. Conclusion: The majority of Bataknese children have a dolichocephalic head shape with a tapered maxillary dental arch and a narrow one.

Application of CBCT in the detection of gingival biotype of Han nationality youths in Shanghai / 上海交通大学学报（医学版）

Objective · To detect gingival thickness of the anterior teeth region of Han nationality youths in Shanghai by cone-beam computerized tomography (CBCT), and evaluate its clinical application feasibility and the gingival biotype. Methods · Firstly, gingival thickness in the same site (5 participators, 30 sites) was detected by bone sounding and CBCT respectively, and the data were compared. A total of 30 participators with healthy gingival were recruited to the study and examined by the CBCT, the gingival thickness of selected sites (330 sites) was assessed and compared. All the subjects were examined by the experienced doctors and classified into three groups, thick-type middle-type and thin-type. Gingival thickness range and the proportion of every type were obtained. All data analyses were performed using SPSS 13.0. Results · There was no statistical difference in the thickness of gingival measured by bone sounding and CBCT (P>0.05). The main gingival biotypes of Han nationality youths in Shanghai were thin-type and middle-type. The average gingival thickness of upper central incisors [(1.32±0.15) mm] was larger than those of upper lateral incisors [(1.07±0.16) mm,P=0.000] and upper canines [(1.08±0.18) mm, P=0.000]. Conclusion · CBCT is feasible for detecting gingival thickness. Gingival thickness of the upper central incisors is significantly larger than those of upper lateral incisors and upper canines. The main gingival biotype of Han nationality youths in Shanghai is middle-type, the proportion of thick-type is least.

Influence of the instrument used for cervical preflaring on the precision of 2 Eletronic Apex Locators / Influência do instrumento utilizado no preparo cervical na precisão de 2 localizadores apicais eletrônicos

ABSTRACT Objective: This study was aimed at evaluating the influence of cervical preflaring using LA-Axxes No. 1 bur (SybronEndo, Glendora, USA) or S1 and SX ProTaper files (Dentsply Maillefer, Ballaigues, Switzerland) on the accuracy of the Electronic Apex Locators (EALs): Root ZX mini (J. Morita Corporation, Tokyo, Japan), and Joypex 5 (Denjoy, Changsha, China). Methods: Thirty mandibular incisors were accessed, and the root canal length (RCL) was determined with a K-file #15, with the aid of a stereo microscope. Afterwards, the specimens were divided into 2 groups (n = 15) referring to the cervical preflaring with LA-Axxess or ProTaper files. The teeth were embedded in alginate and the RCL was determined by the EALs before and after preflaring. Data were classified into: accurate, if the difference in RCL measurement were ≤0.05 mm; and inaccurate, if the difference were >0.5 mm or beyond the RCL. Results: McNemar's test (α<0.05) was used to detect differences in the accuracy of the EALs before and after each preflaring with different instruments, and to detect difference in accuracy among devices. No differences were found concerning the accuracy of the EALs (P > 0.05) after the cervical preflaring, regardless of the used instrument. Conclusion: The preflaring procedure increased the number of accurate measurements for both EALs, with statistical difference for Joypex 5 when the preflaring was performed with LA-Axxess. However, after the cervical preflaring, the EALs showed similar accuracy, regardless of the used instrument.

RESUMO Objetivo: Avaliar a influência do preparo cervical utilizando a broca LA-Axxess nº 1 (SybronEndo, Glendora, EUA) ou os instrumentos ProTaper S1 e SX (Dentsply Maillefer, Ballaigues, Suíça) na precisão dos Localizadores Apicais Eletrônicos (LAEs): Root ZX mini (J. Morita Corporation, Tóquio, Japão) e Joypex 5 (Denjoy, Changsha, China). Métodos: Trinta incisivos inferiores foram acessados e o comprimento do canal radicular (CCR) determinado com uma lima K #15 com o auxílio de um estereomicroscópio. Em seguida, os dentes foram distribuídos em dois grupos (n=15) referentes ao preparo cervical com LA-Axxess ou instrumentos ProTaper. Os dentes foram incluídos em alginato e o CCR determinado pelos LAEs antes e após o preparo cervical. Os dados foram classificados em: precisos, se a diferença na medida do CCR era ≤ 0,05 mm; e imprecisos, se a diferença era >0,5 mm ou estava além do CCR. Resultados: O teste de McNemar (α<0.05) foi utilizado para detectar diferenças na precisão dos LAEs antes e após o preparo com os diversos instrumentos, e para detectar diferenças na precisão entre os aparelhos. Não foram identificadas diferenças na precisão entre os dois LAEs (P>0,05) após o preparo cervical, indiferente do instrumento utilizado. Conclusão: O preparo cervical aumentou o número de medições precisas dos LAEs, com diferença estatística para Joypex 5 após o uso da LA-Axxess, contudo os aparelhos apresentaram precisão similar após o preparo cervical, indiferente do instrumento utilizado.

Odontometric analysis of molars for sex determination

Aim: To investigate the existence of sexual dimorphism between the first and second permanentmolars. Methods: A cross-sectional, observational, blind study using comparative and statisticaldescriptive procedures. The sample included 50 pairs of plaster casts from undergraduate dentalstudents (25 men/25 women) from the Federal University of Paraíba, João Pessoa/PB, Brazil,aged 20-26 years. Odontometric measurements of first and second maxillary/mandibular, right/left permanent molars were performed. Mesiodistal (MD) and buccolingual/palatal (BL/BP) widthsand the distance between the lingual cusps of corresponding molars in opposite quadrants, weremeasured. The data were analyzed by Student’s t test and ANOVA with Bonferroni (p≤0.05).Results: The crowns of all first molars were statistically larger in men than in women (p<0.05).Maxillary and mandibular left second molars (#27 and #37) did not differ in their MD widths (p=0.66,p=0.75), whereas mandibular left and right second molars (#37 and #47) showed statisticallydifferent BL widths (p=0.007 and p=0.008). As to the distance between the lingual cusps, only thefirst left-to-right mandibular molars (#36-46) showed no sex dimorphism (p=0.107). Conclusions:Molars are larger in males than in females. Individually, first molars demonstrated higher evidenceof sex distinction than second molars.

Identification of gender using radiomorphometric measurements of canine by discriminant function analysis.

Purpose: Human teeth are the most stable and durable tissues in the body. Teeth can be identified even after complete decomposition, thus making them invaluable for identification of sex and age from fragmentary adult skeleton. This study aimed to compare the morphological and radiological measurements of canine and investigate its accuracy in sex determination. Materials and Methods: This study involved 60 males and 60 females between the age group of 20 and 30 years. Mesiodistal (MD) widths of mandibular left canines and mandibular inter‑canine distance (ICD) were measured and compared both clinically and on digital intraoral periapical and occlusal radiographs. Discriminant function analysis was carried out for gender determination. Discriminant equation and cutoff point were used in determining the gender and the percentage accuracy. Kappa statistics were carried out to assess intra‑observer agreement. Results: A definite statistically significant difference in the MD width and ICD was found between males and females. Clinical and radiological measurements were almost equally efficacious in gender determination with an accuracy of 55–75% in both males and females. When all the variables were used, the accuracy of gender determination increased substantially to 94%. k‑values suggested a high intra‑observer agreement. Conclusion: It can be concluded that both the clinical and radiographic measurements of MD width of canine and ICD are quick and easy methods for determining sex and in identification of an unknown individual with a substantial accuracy.

Accuracy of Root ZX mini and Raypex 6 in locating the apical foramen of molars: radiographic and microscopic evaluation

Introduction: The precise localization of the apical foramen and the odontometry determination is an important stage since it locates the apical limit for instrumentation and filling. Objective: To compare the accuracy of Root-ZX Mini and Raypex 6 in locating apical foramen in extracted molars. Material and methods: 80 mesial and buccal canals from 40 mandibular and maxillary human molars were used. A size #15 K-file was introduced to canal, until the locator indicated the apical foramen (red bar/line in both devices). With the file in position, it was re-adjusted for Root-ZX II Mini on the green bar and on the two yellow bars for Raypex 6. All the samples were measured from the tip of the file to the apical foramen with radiovisiograph and the Sidexis software. The apical third of the root was shaved until exposure of the file. The distance from the file tip to the most coronal border of the apical foramen was obtained and it was measured with a clinical microscope at 16-fold magnification. The measured lengths with the radiovisiograph and the clinical microscope were analyzed with the statistical Student's T-test. Results: The average length from the tip of the file to the apical foramen using Root-ZX Mini was 0.695 mm and 0.543 mm with Raypex 6. There was no significant difference. Conclusion: Two devices were accurate in locating apical foramen with an adequate level of reliability.

Association between Bolton discrepancy and Angle malocclusions

This study aimed to assess and compare the overall and anterior ratios of tooth size discrepancies in all Angle malocclusion groups. The following null hypothesis (H0) was tested: no difference between tooth size discrepancies (overall and anterior) would be observed among Angle malocclusion groups. The sample comprised of 711 pre-orthodontic treatment study casts of Brazilian patients with a mean age of 17.42 years selected from private practices in Brazil. The casts were divided into 3 groups according to the type of malocclusion: Class I (n = 321), Class II (n = 324), and Class III patients (n = 66). The measurement of the greatest mesiodistal width of the teeth was performed using a centesimal precision digital caliper directly on the study casts, from the distal surface of the left first molar to the distal surface of the right first molar. The overall and anterior ratios between the maxillary and mandibular teeth were evaluated using Bolton’s method. The following statistical tests were applied: chi-square, independent t-test, and one-way ANOVA. Results showed that all Angle malocclusions groups exhibited a ratio compatible with those recommended by Bolton. With respect to the overall and anterior ratios among the malocclusion groups, no statistically significant differences were found. The null hypothesis was accepted because the results showed no differences in the overall and anterior ratios of tooth size discrepancies among different Angle malocclusion groups.