Avaliação da precisão de localização foraminal de um motor endodôntico integrado em diferentes velocidades de rotação / Evaluation of foraminal location accuracy of an integrated endodontic motor employed with different rotational speeds

Objetivo: avaliar a precisão do controle do limite apical de instrumentação do motor endodôntico SENSORY, acionado em três velocidades de rotação (300, 600 e 900 RPM) e função de parada automática apical (Auto Apical Stop - AAS). Material e métodos: sessenta pré-molares inferiores humanos unirradiculados tiveram seus acessos realizados e diâmetro foraminal padronizado em 300 µm. Os dentes foram aleatoriamente divididos em três grupos (n=20) e tiveram seus canais preparados instrumento Logic 30/05, acionado na velocidade predefinida e função AAS ajustada para a marca 0,0. Os instrumentos foram medidos em paquímetro digital e o comprimento real do canal foi aferido pelo método visual direto sob magnificação. Resultados: os valores absolutos dos erros médios e de precisão (±0,5 mm), obtidos foram respectivamente: 0,21 mm e 95% (300 RPM), 0,26 mm e 95% (600 RPM), 0,20 mm e 95% (900 RPM). Não houve diferença significativa entre os grupos (P>0,05). Conclusão: nas condições deste estudo, o uso da função de parada automática forneceu um controle adequado e preciso do limite apical durante a modelagem endodôntica em todas as velocidades testadas.

Objective: to evaluate the accuracy of the control of the apical limit of instrumentation of the SENSORY endodontic motor, activated at three rotation speeds (300, 600 and 900 RPM) and apical automatic stop function (Auto Apical Stop - AAS). Material and methods: Sixty single-rooted human mandibular premolars had their access performed and the foraminal diameter was standardized at 300 µm. The teeth were randomly divided into three groups (n=20) and had their canals prepared with a Logic 30/05 instrument, activated at the predefined speed and the AAS function set to the 0.0 mark. The instruments were measured using a digital caliper and the actual canal length was measured using the direct visual method under magnification. Results: the absolute values of mean and precision errors (±0.5 mm) obtained were respectively: 0.21 mm and 95% (300 RPM), 0.26 mm and 95% (600 RPM), 0.20 mm and 95% (900 RPM). There was no significant difference between groups (P>0.05). Conclusion: Under the conditions of this study, the use of the automatic stop function provided adequate and accurate control of the apical limit during endodontic shaping at all speeds tested.

Odontometria em molares inferiores: comparação entre radiografia convencional e digital / Odontometry in mandibular molars: a comparison between conventional and digital radiograph

Objetivo:Comparar os métodos radiográficos convencional e digital na Odontometria de molares inferiores. Materiais e Métodos: Foram selecionados 26 dentes e inseridos em recipientes com gesso e serragem para simular o osso alveolar. Após adequado acesso endodôntico, limas K#15 foram posicionadas nos canais mésio-vestibular e distal, 1mm aquém da patência foraminal (CT1). Foi construído um dispositivo em resina, onde fixou-se um medidor de ângulos padronizando a angulação horizontal em 20º para distal. O ângulo vertical foi 0º com distância foco-filme de 30 centímetros. Foi utilizado um aparelho de Rx de 70 KVp e 8 mA e exposição de 0,4 segundos. Para obtenção do CT radiográfico (CT2), posicionou-se o paquímetro na borda inferior do cursor até a ponta da lima. As mesmas medidas foram realizadas nas radiografias digitais obtidas com um sensor CMOS. A ferramenta "régua" foi utilizada determinando-se o CT digital (CT3). O teste de Correlação Intraclasse verificou concordâncias intragrupo e intergrupos e os testes Anova OneWay e Tukey (α = 0,05) foram usados para análise comparativa entre CT1, CT2 e CT3. Resultados: Tanto as medidas convencionais quanto as digitais apresentaram excelente concordância intragrupo (0,9842 e 0,9943, respectivamente). A concordância entre as mensurações para o CT digital foi maior em relação às medidas reais (0,8162) que as medidas do CT convencional (0,6761). A média e desvio padrão para CT1, CT2 e CT3 foram 18,4±1,4; 19,2±1,6 e 18,8±1,2mm, respectivamente. O teste de Tukey indicou diferença estatística entre CT1 e CT2 (p = 0,027); já entre CT1 e CT3 (p = 0,499) e entre CT2 e CT3 (p = 0,314) não houve diferenças significativas. Conclusão: As radiografias digitais propiciaram maior precisão na Odontometria de molares inferiores nas condições experimentais avaliadas.

Objective: To compare conventional and digital radiographic methods in Odontometry of lower molars. Materials and Methods:Twenty-six teeth were selected and inserted into containers with plaster and sawdust to simulate the alveolar bone. After adequate endodontic access, K#15 files were positioned in the mesiobuccal and distal canals, 1 mm below the foraminal patency (CT1).A resin device was constructed, where an angle gauge was fixed, standardizing the horizontal angulation at 20º distally. The vertical angle was 0º with a focus-film distance of 30 cm. An Rx device of 70 KVp and 8 mA, with an exposure time of 0.4 seconds, was used. To obtain the radiographic CT (CT2), the caliper was positioned on the lower edge of the cursor up to the tip of the file. The same measurements were performed on digital radiographs, obtained with a CMOS sensor. The "ruler" tool was used to determine the digital CT (CT3). The Intra-Class Correlation test was used to verify intra-group and intergroup agreements, and the Anova One-way and Tukey tests (α = 0.05) were used for comparative analysis between CT1, CT2, and CT3. Results: Both conventional and digital measurements had excellent intra-group agreement (0.9842 and 0.9943, respectively). The agreement between measurements for digital CT was greater in relation to real measurements (0.8162) than conventional CT measurements (0.6761). The mean and standard deviation for CT1, CT2, and CT3 were 18.4±1.4; 19.2±1.6; and 18.8±1.2, respectively. The Tukey test indicated a statistical difference between CT1 and CT2 (p = 0.027); Between CT1 and CT3 (p = 0.499) and between CT2 and CT3 (p = 0.314) no significant differences were observed. Conclusion:Digital radiographs provided greater precision in the odontometry of lower molars according to the experimental conditions evaluated in this study.

Frecuencia y tipología del segundo conducto mesiovestibular en primeros molares superiores / Frequency and typology of the second mesiobuccal canal in maxillary first molars

Objetivos: Evaluar mediante microscopia quirúrgica la presencia del segundo conducto mesiovestibular (MV2) en el piso de la cámara pulpar de los primeros molares superiores, determinar su abordabilidad, establecer el calibre de lima que llegó al tercio apical y tipificar radiovisiográficamente su morfología se-gún la clasificación de Weine. Materiales y métodos: Se utilizaron 48 primeros molares superiores huma-nos extraídos. Sé tomaron radiovisografías preope-ratorias (Carestream 5200) en sentido orto radial y mesio-distal. Se realizó apertura y se localizó entra-da del MV2 con microscopio quirúrgico (Newton MEC XXI, Argentina) a 16 x. Se cateterizó MV1 y MV2 con limas tipo K #10 y #15 (Dentsply Maillefer). Se cortó raíz distovestibular para mejorar visualización ra-diovisográfica. Se tomó conductometria en sentido mesio-distal para establecer la tipología. Se compa-raron frecuencias y porcentajes mediante test de Chi-cuadrado con corrección de Yates, prueba exac-ta de Fisher y test z para diferencia de proporcio-nes. Se calcularon intervalos de confianza 95% para porcentajes mediante método score de Wilson. Re-sultados: El 54% (26 casos) presentó MV2. De los 26 MV2, el 77% (20 casos) fueron abordables, porcen-taje significativamente mayor al 23% no abordable (z=3,62; P<0,05). Al hacer cateterismo, hubo asocia-ción significativa entre tipo de conducto (MV1 y MV2) y calibre de lima que llegó al tercio apical (Chi-cua-drado=29,12; gl=1; P<0,05). La tipología I (58%) fue significativamente mayor que las tipologías II (21%) y III (21%) (P<0,05 para ambas comparaciones). Con-clusión: El alto porcentaje de piezas que presentó MV2 evidencia la importancia clínica de detectarlo y tratarlo correctamente. Dado el alto porcentaje de piezas donde fue abordable, se concluye que el clíni-co debe tener conocimiento, destreza y la tecnología necesaria para poder abordarlo. Si bien la tipología I (58%) fue la más encontrada, cuando el MV2 termina en foramen independiente (tipo III), su omisión puede conducir al fracaso del tratamiento (AU))

Objectives: To evaluate by surgical microscopy the presence of second mesiobuccal canal (MB2) in the pulp chamber floor of the maxillary first molars, determine its approachability, establish the caliber of the file that reached the apical third, and radiographically typify its morphology according to Weine ́s classification. Materials and methods: 48 extracted human maxillary first molars were used. Preoperative radiovisographies (Carestream 5200) were taken in ortho-radial and mesio-distal direction. Coronal access was made and the entrance of MB2 was located with a surgical microscope (Newton MEC XXI, Argentina) at 16x. MB1 and MB2 were catheterized with K files #10 and #15 (Dentsply Maillefer). Distobuccal root was cut to improve radiovisographic visualization. Conductometry was taken in mesio-distal direction to establish the typology. Frequencies and percentages were compared using Chi-square test with Yates correction, Fisher's exact test and z test for difference in proportions. 95% confidence intervals were calculated for percentages using Wilson score method. Results: 54% (26 cases) presented MB2. Of the 26 MB2, 77% (20 cases) were approachable, a significantly higher percentage than those not approachable (z=3.62; P<0.05). When performing catheterization, there was a significant association between type of canal (MB1 and MB2) and file caliber that reached the apical third (Chi-square=29.12; df=1; P<0.05). Typology I (58%) was significantly higher than typologies II (21%) and III (21%) (P<0.05 for both comparisons). Conclusion: The high percentage of specimens that showed MB2 evidence the clinical importance of detecting and treating it correctly. Given the percentage of pieces where it was approachable (77%), it is concluded that the clinician must have the knowledge, skill and necessary technology to be able to approach it. Although typology I (58%) was the most found, when MB2 ends an independent foramen (type III), its omission can lead to treatment failure (AU)

Accuracy of Working Length Determination - Electronic Apex Locator Versus Cone Beam Computed Tomography

ABSTRACT Objective: To compare the accuracy of working length determination between cone beam computed tomography (CBCT) and electronic apex locator by measuring the actual working length of teeth. Material and Methods: A total of 150 single-rooted tooth assessed by radiograph undergoing root canal therapy were selected. The process was repeated to obtain a buccolingual and mesiodistal section of all teeth. The measurement line was considered from the reference occlusal plane following the center of the canal to the terminus. All information regarding the accuracy of cone-beam computed tomography and apex locator was noted in a pre-designed proforma. Results: CBCT consistently demonstrated high accuracy across all tooth types in both jaws. The electronic apex locator exhibited varying precision, with greater accuracy observed in the mandible. Statistical analyses revealed significant differences in electronic apex locator accuracy among tooth types in the maxilla (p=0.042), emphasizing the importance of specific clinical considerations. Conclusion: Cone beam computed tomography emerges as a reliable diagnostic tool for accurate working length determination, especially in complex cases, while the electronic apex locator remains valuable with careful consideration of potential variations in accuracy. An individualized approach, considering tooth type, jaw location, and clinical context, is crucial for precise working length determination in endodontic practice.

Factores etiopatogénicos de maloclusión. Parte II: el factor dentario en la organización de la oclusión / Etiopathogenic factors of malocclusion. Part II: the dental effect in occlusal organization

El objetivo de esta publicación es continuar con el tema desarrollado en la primera parte, donde se esbozaron aspectos generales de la organización de la oclusión, como introducción al estudio de la etiopa- togenia de las maloclusiones, con el factor dentario como aspecto central. Probablemente es el que com- parte mayor presencia en maloclusiones, donde el factor principal es de otro origen, es decir, esqueletal o neuromuscular. Se expondrá, a continuación, la condición del espacio en los arcos dentarios, sea por exceso o defecto de material dentario, sea por pérdida de perímetro del arco dentario, en cuanto al diagnóstico y a conductas preventivas. La parte III se centrará en alteraciones de erupción dentaria (AU)

The objective of this publication is to continue with the theme developed in the first part, where general aspects of the organization of the occlusion were outlined, as an introduction to the study of the etiopathogenesis of malocclusions, with the dental factor as a central aspect. It is probably the one that shares the greatest presence in malocclusions where the main factor is of another origin, that is, skeletal or neuromuscular. Next, the condition of the space in the dental arches will be exposed, whether due to excess or defect of dental material or loss of perimeter of the dental arch, in terms of diagnosis and preventive behaviors. Part III will focus on dental eruption disorders (AU)

3D Bitemark Analysis in Forensic Odontology Utilizing a Smartphone Camera and Open-Source Monoscopic Photogrammetry Surface Scanning

Abstract Bitemark analysis is a challenging procedure in the field of criminal case investigation. The unique characteristics of dentition are used to find the best match between the existing patterned injury and the suspected perpetrator in bitemark identification. Bitemark analysis accuracy can be influenced by various factors, including biting pressure, tooth morphology, skin elasticity, dental cast duplication, timing, and image quality. This review article discusses the potential of a smartphone camera as an alternative method for 3D bitemark analysis. Bitemark evidence on human skin and food should be immediately recorded or duplicated to retrieve long-lasting proof, allowing for a sufficient examination period. Various studies utilizing two-dimensional (2D) and three-dimensional (3D) technologies have been developed to obtain an adequate bitemark analysis. 3D imaging technology provides accurate and precise analysis. However, the currently available method using an intraoral scanner (IOS) requires high-cost specialized equipment and a well-trained operator. The numerous advantages of monoscopic photogrammetry may lead to a novel method of 3D bitemark analysis in forensic odontology. Smartphone cameras and monoscopic photogrammetry methodology could lead to a novel method of 3D bitemark analysis with an efficient cost and readily available equipment.

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.

Esthetic proportions of maxillary anterior tooth among 300 normal occlusion college students in Shanxi province / 中华口腔医学杂志

Objective: To explore the relationship between the width ratios of maxillary anterior teeth, the width/height ratios of maxillary central incisor and the esthetic proportions among individual normal occlusion, and to provide reference for the esthetic design of anterior teeth. Methods: A total of 300 Shanxi Medical University students who were residents from Shanxi province with normal occlusion (110 males, 190 females, aged 18-30 years) were recruited in this study from October 2020 to March 2021. Standardized digital photographs of the maxillary anterior tooth in natural head position were obtained, the perceived width of the maxillary anterior teeth (maxillary central incisors, lateral incisors and canines) on the left and right sides and height of maxillary central incisor were measured on the standardized digital photographs, then the width ratios of adjacent maxillary anterior teeth including the lateral incisor/central incisor width ratio (LI∶CI), the canine/lateral incisor width ratio (C∶LI), and the width/height ratios (W/H ratio) of the maxillary central incisor were calculated. The independent sample t test was used to compare the sex differences of each measurement project, Single sample t test was used to compare the difference of adjacent maxillary anterior teeth width ratios with golden proportion (0.618 and 0.618), Preston proportion (0.66 and 0.84), the recurring esthetic dental (RED) proportion (0.70 and 0.70). The percentage of anterior tooth width/intercanine width was calculated, the number and proportion of teeth conforming to golden percentage (25%, 15%, 10%)±1% or modified golden percentage (22.5%, 15.0%, 12.5%)±1% were calculated. The number and proportion of width/height ratio of maxillary central incisor ranged from 0.75 to 0.85 was counted. Results: The widths of maxillary central incisor, lateral incisor and canine were (8.50±0.52), (6.23±0.53) and (5.18±0.55) mm, respectively, the corresponding tooth of male [(8.74±0.49), (6.37±0.52), (5.41±0.47) mm] was significantly higher than that of female [(8.37±0.50), (6.15±0.52), (5.04±0.54) mm] (t=6.40, 3.55, 6.23,P<0.05). The width ratio of maxillary lateral incisor/central incisor was 0.73±0.05, and there was no significant difference between genders (t=-1.06, P>0.05). The width ratio of canine/lateral incisor was 0.84±0.10, and it was significantly higher in male (0.85±0.10) than in female (0.82±0.10) (t=2.42, P<0.05). Two width ratios of maxillary anterior teeth were significantly different from golden proportion and the RED proportion (t=38.50, 35.74, 11.48, 22.20, P<0.05). The lateral incisor/central incisor was significantly different from that of Preston proportion (t=24.66, P<0.05), while the canine/lateral incisor was not significantly different from that of Preston proportion (t=-0.92, P>0.05). In this study, a total of 0% (0/600) of central incisors, 63.0% (378/600) of lateral incisors and 5.8% (35/600) of canines met the golden percentage±1%. There were 42.8% (257/600) of central incisors, 63.0% (378/600) of lateral incisors and 56.7% (340/600) of canines met the modified golden percentage±1%. The width/height ratio of maxillary central incisors was 0.86±0.08, and there was no significant difference between genders (t=-0.88, P>0.05). Only 36.3% (218/600) of the subjects in this study ranged from 0.75 to 0.85. Conclusions: Gender differences should be considered in the esthetic design of anterior teeth; for the width ratios of maxillary anterior teeth, the golden proportion, the RED proportion and golden percentage do not accord with the natural tooth morphological characteristics of Shanxi nationality college students in normal occlusion. Preston proportion and modified golden percentage are of more reference value. The width/height ratio of maxillary central incisors is different from 0.75-0.85.

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.

Effect of Materials For Interim Restoration on Estimation of Working Length Using Electronic Apex Locator: in vitro Study / Efecto de Materiales Para Restauración Intermedia sobre la Estimación de la Longitud de Trabajo Endodóntico Utilizando Localizador Electrónico de Foramen: Estudio in vitro

ABSTRACT: The aim of this in vitro study was to evaluate measurement accordance using an electronic apex locator for estimation of working length in endodontics when different restorative materials for interim crown restoration are utilized. For this study, 13 single-rooted premolars with endodontic occlusal access cavity were prepared. To establish the working length of each tooth, these were mounted in alginate and with the help of an electronic foramen locator and endodontic file K-file # 15, the working length was established. This length was later compared to the estimated working lengths using different intermediate restoration materials. These materials were: Superior Chemfil, Ketac ™ Molar Easymix and Filtek z350 resin. In the electronic measurements, an acceptable tolerance range of variation up to ± 0.5 mm was considered. Highest discrepancies were considered erroneous. For these measurements, central tendency and dispersion were analyzed. The Bland-Altman method was used, and the ANOVA test with a significance level of p <0,05 for statistic difference. Regarding measurements' acceptability and the type of interim restoration material utilized, 7 were acceptable, and 6 were unacceptable for ChemFil Superior, 12 were acceptable and 1 unacceptable for Ketac™ Molar Easymix, and 11 were acceptable and 2 were unacceptable for Filtek Z350 composite resin. The average difference between all electronic measurements was 0.29 (± 0.44). Chemfill Superior showed the most prominent variation between measurements 0.58 (± 0.45). When using an electronic apex locator, measurements showed statistically significant differences depending on the interim restoration material of choice (p<0.05). In conclusion, the measurement accordance using electronic apex locator to estimation the working length is higher, however the electronic estimation of working length can be significatively affected by the material chosen for interim temporary restoration.

RESUMEN: El objetivo de este estudio in vitro, fue evaluar la concordancia de las estimaciones de longitud de trabajo mediante localizador electrónico de foramen, utilizando diferentes materiales de restauración intermedia coronaria. Para tales fines fueron preparados 13 premolares uniradiculares con cavidad de acceso oclusal endodóntico. Para establecer la a longitud de trabajo de cada diente, estos fueron montados en alginato y con la ayuda de un localizador electrónico de foramen y lima de endodoncia K-file #15 fue establecida la longitud de trabajo. Esta longitud fue comparada posteriormente con las longitudes de trabajo estimadas utilizando diferentes materiales de restauración in- termedia. Estos materiales fueron: Chemfil superior, Ketac™ Molar Easymix y resina Filtek z350. En las mediciones electrónicas, se consideró un rango de tolerancia aceptable de variación hasta ± 0,5 mm. Las discrepancias mayores se consideraron erróneas. Se calcularon medidas de tendencia central y la dispersión. Se utilizó el método de Bland- Altman y la prueba ANOVA con un nivel de significancia de p <0,05. Con respecto a la aceptabilidad de las mediciones y el tipo de material de restauración intermedia, 7 fueron aceptables y 6 fueron inaceptables para ChemFil Superior, 12 fueron aceptables y 1 inaceptable para Ketac ™ Molar Easymix, y 11 fueron aceptables y 2 fueron inaceptables para el compuesto Filtek Z350 resina. La diferencia promedio entre todas las mediciones electrónicas fue de 0,29 (± 0,44). Chemfil Superior mostró la mayor variación entre medicio- nes 0,58 (± 0,45). Las mediciones mostraron diferencias estadísticamente significativas dependiendo del material de restauración intermedio elegido (p <0,05). En conclusión, la concordancia en la estimación de la longitud de trabajo usando localizador electrónico de foramen es alta, sin embargo, puede verse afectada significativamente por el material de obturación intermedio.

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.

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.

Influence of different coronal preflaring protocols on electronic foramen locators precision

Abstract: The aim of this study was to evaluate the influence of different coronal preflaring protocols (absent, conservative and conventional) on the accuracy of Root ZX II, Raypex 6, and RomiApex A-15 electronic foramen locators (EFLs). Twenty mandibular molars with Vertucci's type IV mesial roots were subjected to endodontic exploration and foraminal patency confirmation. Under 16x magnification, its real lengths (RL) were measured and registered (RL1). The canals were then irrigated with 2.5% sodium hypochlorite and electronically measured (EM1) employing the alginate model; all measurements were performed in triplicate by a blind operator using adjusted endodontic hand-files introduced until the apex foramen. Coronal preflaring procedures were sequentially performed with #25/.06 (conservative) and #25/.12 (conventional) instruments; new RLs extents were performed after each coronal preparation protocol (RL2/RL3), as same as electronic measurements (EM2/EM3). The devices error (mm) was evaluated considering the difference between RLs and EMs at each preparation stage; their precision was stablished adopting ±0.5 mm as tolerance margin. The EFLs error significantly reduced after conventional coronal preflaring protocol (p<0.05), which not occur after the conservative one. The best precisions values were noted after conventional preparation as 90% (Root ZX II), 97.5% (Raypex 6), and 92.5% (RomiApex A-15). No significant differences were found in EFLs comparisons, regardless of the coronal protocol tested (p>0.05). Under the conditions tested it can be concluded that the EFLs evaluated were precise. Moreover, the preflaring protocols influences its accuracy's, where the less conservative one produced the best results.

Resumo O objetivo deste estudo foi avaliar a influência de diferentes protocolos de pré-alargamento cervical (ausente, conservador e convencional) na precisão dos localizadores eletrônicos foraminais (LEFs) Root ZX II, Raypex 6 e RomiApex A-15. Vinte molares inferiores com raízes mesiais do tipo IV de Vertucci foram submetidos à exploração endodôntica e confirmação da patência foraminal. Sob ampliação de 16x, seus comprimentos reais (CR) foram medidos e registrados (CR1). Os canais foram então irrigados com hipoclorito de sódio a 2,5% e medidos eletronicamente (ME1) utilizando o modelo em alginato; todas as medidas foram realizadas em triplicata por um operador cego, utilizando limas endodônticas ajustadas introduzidas até o forame apical. Os procedimentos de pré-alargamento cervical foram realizados sequencialmente com os instrumentos #25/.06 (conservador) e #25/.12 (convencional); novas determinações de CRs foram realizadas após cada protocolo de preparação cervical (CR2/CR3), da mesma forma que as medidas eletrônicas (ME2/ME3). O erro dos dispositivos (mm) foi avaliado considerando a diferença entre CRs e MEs em cada estágio de preparação; sua precisão foi estabelecida adotando ± 0,5 mm como margem de tolerância. O erro dos LEFs reduziu significativamente após o protocolo convencional de alargamento cervical (p<0,05), o que não ocorreu após o conservador. Os melhores valores de precisão foram observados após a preparação convencional como 90% (Root ZX II), 97,5% (Raypex 6) e 92,5% (RomiApex A-15). Não foram encontradas diferenças significantes nas comparações entre os LEFs, independentemente do protocolo cervical testado (p>0,05). Sob as condições testadas, pode-se concluir que os LEFs avaliados foram precisos. Além disso, os protocolos de alargamento influenciam sua precisão, onde o menos conservador produziu os melhores resultados.

Medidas de piezas dentarias para el posicionamiento correcto de brackets en una población latina (Argentina) / Measures for positioning teeth correct brackets in a Latin population (Argentina)

Introducción: El posicionamiento preciso de los brackets de ortodoncia en las diferentes situaciones clínicas es esencial. Para ello, se utiliza la tabla de McLaughlin-Bennett, realizada sobre una población anglosajona. Dada la gran variabilidad que puede existir en los diferentes grupos poblacionales, para estandarizar las medidas en la colocación de los brackets, sería necesario emprender un análisis de la población local y determinar cuáles serán las alturas de las coronas clínicas de todas las piezas dentarias para nuestra población. Materiales y método: Se estudiaron 200 modelos de estudio de individuos argentinos, caucásicos, de ambos sexos, con dentición permanente completa hasta el segundo molar inclusive, entre 13 y 25 años, que no recibieron tratamiento ortodóncico previo. Resultados: Las diferencias estadísticas existentes, con respecto a lo propuesto por McLaughlin y Bennett, en el maxilar superior fueron: altamente significativas (p = 0,0001) en el incisivo central, incisivo lateral y segundo molar; significativas en el canino (p = 0,0128) y en el primer molar (p = 0,018) y no significativas en el primer premolar (p = 0,239) y segundo premolar (p = 0,1741). En el maxilar inferior: altamente significativas (p = 0,0001) en el segundo molar y no significativas en el resto de las piezas dentarias. Conclusión: Los valores que se obtuvieron con el estudio, dada la variabilidad regional de la muestra, no coinciden con los valores que arroja la tabla de McLaughlin-Bennett, de origen anglosajón. Se sugiere la creación de una tabla acorde con las medidas de los pacientes locales(AU)

Accurate positioning of dental braces in different clinical situations is essential. To that end, it is used the chart developed by McLaughlin and Bennett, which was made in the Anglo-Saxon population. Due to the considerable variability among different population groups, an analysis of the local population would be necessary to be carried out in order to standardize the measurements for the positioning of braces and to determine the clinical crown height of teeth in our population. Two hundred Caucasian, Argentine male and female study models, aged between 13 and 25 with full permanent dentition, fully erupted second molars with no previous orthodontic treatment were studied. Existing statistical differences with regard to the guidelines proposed by McLaughlin and Bennett in the maxilla were: highly significant (p = 0.0001) for second molars, central and lateral incisors; significant for canines (p = 0.0128) and first molars (p = 0.018); and non-significant for first premolars (p = 0.239) and second premolars (p = 0.1741). In the mandible the differences were: highly significant (p = 0.0001) for second molars and non-significant for the other teeth. The values that were obtained in the study, given the regional variability of the sample, do not correspond to the values that are shown in the chart by McLaughlin and Bennett, of Anglo Saxon origin. It is suggested the creation of a new chart in line with the measurements of local patients(AU)

Determinación de la Longitud de Trabajo Mediante Localizador Electrónico de Foramen Apical y CBCT a Través del Software 3D Endo de Dentsply Sirona: Estudio Comparativo in vitro / Determination of Working Length Using Electronic Locator for Apex and CBCT with 3D Endo Dentsply Sirona Software: Comparative in vitro Study

RESUMEN: En la historia de la Endodoncia, se han utilizado distintos métodos para determinar la longitud de los canales radiculares, como sensación táctil y radiografías. Últimamente, han adquirido gran importancia los localizadores apicales electrónicos, por su gran precisión. Actualmente se ha incorporado el uso de imagenología con Cone Beam. Debido a que existen muchas formas de medir dicha longitud, es necesario ponerlos a prueba y ver si se asemejan a la técnica gold estándar definida en la literatura como el localizador electrónico de foramen apical. El propósito de esta investigación es determinar si existen diferencias estadísticamente significativas en la medida de la longitud de trabajo entre el localizador electrónico de foramen apical, y el uso de Cone Beam procesado con el software 3D endo de Dentsply Sirona. Para esto, se seleccionaron 30 premolares extraídos; se les tomó un Cone Beam para ser analizados con el software 3D endo y medir la longitud de trabajo. Una vez hecho esto, se realizó manualmente cavidad de acceso y se preparó el tercio cervical con fresas Gates Glidden 1 y 2; luego, los dientes fueron colocados en un modelo Pro Train, que asemejó las propiedades de los dientes en la cavidad oral, para permitir el uso del localizador electrónico de foramen y determinar la longitud de trabajo. Una vez obtenidos los datos, fueron comparados a través del Test de Proporciones (p=0.05 hipotético), dando como resultado p=0,2 lo que indica que no existen diferencias estadísticamente significativas en la medida de la longitud de trabajo entre ambos métodos.

ABSTRACT: Various methods have been used in the history of endodontics, to determine the length of the root canals (working length), such as tactile sensation and X-rays. Recently, apical locators have acquired importance, due to their precision. The use of Cone Beam has now also been incorporated. Because there are many ways to measure this length, it is necessary to test them and see if they resemble the standard gold measurement technique defined in the literature as the electronic apex locators. The purpose of this research is to determine whether there are statistically significant differences in the working length between the electronic apex locators, and the use of Cone Beam processed with the Software 3D Endo by Dentsply Sirona. For this, 30 extracted pre-molars were selected, for Cone Beam tomography and 3D endo Software analysis, to measure the working length. Once this was carried out, cavity preparation was performed manually, and the cervical third approached with gates glidden drills 1 and 2. Subsequently, the teeth were placed in a Pro Train model, which resembled the properties of the teeth in the oral cavity, to allow the use of the electronic apex locators to determine the working length.Once the data were obtained, they were compared through the proportions Test (p = 0.05 hypothetical), resulting in p = 0.2, indicating that there are no statistically significant differences in the working length between the two methods.

Analysis of the relationship among maxillary anterior teeth width, anterior arch perimeter and anterior segment depth / 北京大学学报(医学版)

OBJECTIVE@#To analyze the relationship between the width of the maxillary anterior teeth and the anterior arch perimeter, to analyze the change rule of the width of the anterior teeth and the anterior arch perimeter, when altered the convexity of the anterior arch, with the width of the maxillary anterior arch keeping constant, and to provide a reliable basis for later digitized and personalized aesthetic analysis of front teeth.@*METHODS@#In the study, 61 front teeth complete and well-arranged models had been selected from the working models after the prostheses in Department of Prosthodontics, Peking University School and Hospital of Stomatology, including 22 male models and 39 female models. A photograph was taken from the occlusal surface of each model using the fixed magnification with a single lens reflex camera. The width of anterior teeth, the width of anterior arch and the convexity of anterior arch had been measured using the Photoshop software. The ratio of the width of the anterior teeth to the width of the anterior arch was calculated. Keeping the width of anterior arch unchanged, the layer free transformation function used to add or decrease the curvature of the anterior arch from 1-5 mm, each circumference of the anterior arch was measured. According to the proportion of their anterior teeth in the anterior arch perimeter, the width of each anterior teeth crown under different convexities of anterior arch was calculated. SPSS 23.0 was used to analyze the ratio of the width anterior teeth to the anterior arch perimeter and correlation between the convexity of the anterior arch and the width of the anterior teeth.@*RESULTS@#The percentages of the median length of the anterior arch in the central incisor, lateral incisor and canine were 36.2%±1.3%, 30.2%±1.5%, and 33.6%±1.4%, respectively. The proportions were normal distributions and not related to the perimeter of the anterior arch. When the width of the anterior arch was constant, there was a positive correlation between the convexity of anterior arch in the range of 5 mm and the width of anterior teeth or the front arch circumference. With each increase or decrease of 1 mm of the convexity of anterior arch, the width of the middle incisor increased or decreased by about 0.18 mm, the half circumference of the anterior arch increased or decreased by about 0.50 mm.@*CONCLUSION@#The width of the anterior teeth in the middle-distal direction remained stable in the anterior arch circumference. Within a certain range, when the width of the maxillary anterior arch remains unchanged, the width of the anterior teeth and the perimeter of the anterior teeth are positively correlated to the convexity of the anterior arch.

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.