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.

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.

CBCT assessment of bone thickness in maxillary and mandibular teeth: an anatomic study

Abstract The site of the sinus tract depends on the rate of resistance against abscess exudate drainage, bone morphology, and distance from the root apex to the outer cortical bone. Objective To assess apical bone thickness in buccal and palatal/lingual aspects of maxillary and mandibular teeth, using a high-resolution cone-beam computed tomography (CBCT) system. Methodology In total, 422 CBCT examinations were included in the study, resulting in a sample of 1400 teeth. The scans were acquired by PreXion 3D, with a high-resolution protocol. The bone thickness was taken as the distance between the center of the apical foramen and the buccal and lingual/palatal cortical bone. The quantitative variables were expressed as mean values±standard deviation. The independent samples were analyzed using the t-test or the Mann-Whitney test (p<0.05). Results The lowest mean value of bone thickness was observed in the buccal cortical bone of the upper canines (1.49 mm±0.86) and in the upper central incisors (1.59 mm±0.67). In premolar teeth, the lowest values were found in the buccal cortical bone of upper first premolars (1.13 mm±0.68). In the posterior teeth, the lowest values were found in the buccal cortical bone of upper first molars (1.98 mm±1.33). In the lower second molar region, the buccal cortical bone (8.36 mm±1.84) was thicker than the lingual cortical bone (2.95 mm±1.16) (p<0.05). Conclusions The lowest mean values of bone thickness are in the buccal cortical bone of the maxillary teeth. In the mandible, bone thickness is thinner in the buccal bone around the anterior and premolar teeth, and in the lingual aspect of mandibular molars. All these anatomic characteristics could make the occurrence of the sinus tract more susceptible in these specific regions of the maxillary and mandibular alveolar bone.

In-depth morphological evaluation of tooth anatomic lengths with root canal configurations using cone beam computed tomography in North American population

Abstract Objective This study aimed to assess the association between tooth size and root canal morphology by using CBCT analysis. Methodology In this retrospective study, tooth anatomic lengths (crown and root lengths, buccolingual and mesiodistal dimensions) of 384 patients were assessed and correlated with Vertucci's root canal morphology classification. Data was analyzed for gender-related differences using the independent sample t-test, ANOVA, and the Pearson's correlation for a possible relation between anatomic lengths and canal morphology. Results The maxillary first and second premolars showed a greater predilection for Type IV and II variants, respectively, while the mandibular first premolar showed a greater predilection for Type II canal system. The root canal system of the mandibular second premolar showed maximal diversity (47% Type I, 30% Type II, and 20% Type III). The dimensions were greater in men regardless of tooth type. The most significant relation (p<0.05) between the anatomic size and canal morphology was observed in the maxillary first premolars, followed by the mandibular canines (buccolingual dimension) and the lower second premolars (crown length). Negative correlations existed between the crown length and the patient's age for the anterior teeth and mandibular second premolar (r=−0.2, p<0.01). Conclusions The most common canal formation for anterior teeth was the Type I. The anatomic lengths had the strongest influence on the canal configuration of the maxillary first premolar, with Type IV being the most common root canal system. The mandibular second premolars showed maximal diversity in the canal classification terms and had a significant correlation with their crown lengths. Clinical Relevance The complex relationship between the canal morphology and anatomic tooth sizes need meticulous awareness and recognition during endodontic procedures, in conjunction with the demographic variabilities.

Accuracy of Cone Beam Computed Tomography in the Assessment of Mandibular Molar Furcation Defects

Abstract Objective: To evaluate the accuracy of cone-beam computed tomography (CBCT) in the assessment of mandibular molar furcation defects. Material and Methods: Thirty patients with furcation defects were selected, oral hygiene instructions, scaling, and root planing with ultrasonic devices and hand instruments and occlusal adjustments were performed. Pre-surgical clinical measurements were carried out at the buccal aspect of the selected mandibular molars. The horizontal furcation measurements were measured with a Nabers Probe starting at the furcation entrance to the greatest horizontal depth. The degree of furcation involvement was graded from 0 to III. Bone loss in the horizontal and vertical direction and the width of the furcation entrance were measured on CBCT and after reflecting the full-thickness flap and debridement of the defects. The data were analyzed using t-test and Pearson's correlation coefficient. Results: The width of furcation entrance in clinical method was 3.27 ± 0.77, while in CBCT method was 3.35 ± 0.71, clinically the vertical bone loss was 3.61±1.09, while in CBCT was 3.57 ± 1.15, horizontal bone loss in clinical method was 5.08 ± 2.21, while in CBCT was 5.11 ± 2.23. No significant difference between the two methods was noted, and a high correlation between the two methods was observed. With regards to the agreement between the two methods of assessment, the width of furcation entrance revealed a difference between the two methods by 0.08 ± 0.21, while vertical bone loss showed difference between the two methods by -0.04 ± 0.19, the horizontal bone loss showed a mean difference between the two methods by 0.03 ± 0.21. Conclusion: CBCT provided high accuracy for the furcation involvement detection and anatomy of surrounding periodontal tissues.

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.

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.

Agreement Between Working Length Measurements in Primary Teeth Obtained by Radiographs or Apical Locators

Abstract Objective: To perform an in vivo evaluation on the agreement between measurements of working length obtained by conventional radiographic examinations and an apex locator in deciduous teeth with or without root resorption. Material and Methods: Nine canals of teeth from children ranging from 3 to 5 years old were selected. Endodontic access was performed with a spherical diamond tip, the pulp was removed with Kerr-type steel files, and the canal was irrigated with 1% sodium hypochlorite. A file, compatible with the channel gauge, was then used to measure the length of the root canal with the apex locator. Conventional radiographs were also performed and, using a millimeter endodontic ruler, the length of the canal was determined. The differences between the measurements obtained between the two methods were analyzed using the Student's t-test. Results: The mean canal length for conventional radiography was 9.83 mm and 9.67 mm for the apex locator. The results of this study did not show significant differences (p=0.641), independent of the presence or absence of physiological root resorption. Conclusion: The similarity in measurements obtained with X-ray or an apex locator indicates that it is not necessary to use X-rays as a complement to obtain the working length. The use of the apex locator can provide a quicker treatment, reducing the clinical time and stress of the child.

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.

Analysis of electronic apex locators in human teeth diagnosed with apical periodontitis

Abstract Electronic apex locators (EAL) have been used to establish the working length (WL) in root canal treatment. In teeth diagnosed with apical periodontitis, resorption of tooth apical structures can lead to difficulties to obtain an appropriate WL. The aim was to compare the capacity of three EAL's (Root ZX II, Raypex 6 and Endo-Eze Quill) to locate the tip of the K-file between 0 to -0.5 mm from the apical foramen (AF) on teeth diagnosed with asymptomatic apical periodontitis (AAP). Electronic working length was performed on 60 roots with AAP. A K-file #15 was inserted in the root canal until the apical foramen (AF) was located, and followed was re-adjusted to -0.5 mm through observation in EAL display. The K-file was fixed to the tooth with composite and teeth were extracted. The 4 apical millimeters were worn out until the K-file could be seen and were prepared and measured its distance to AF in a scanning electron microscope. Appropriate WL was when the tip of the K-file was located between 0 to -0.5 mm from AF. Results: Root ZX II showed significant difference (p<0.01) with the other two EALs. Root ZX II presented the better performance than Raypex 6 or Endo-Eze Quill in teeth with AAP.

Resumo Os localizadores eletrônicos apicais têm sido usados ​​para estabelecer o comprimento de trabalho no tratamento do canal radicular. Nos dentes diagnosticados com periodontite apical, a reabsorção das estruturas apicais dos dentes pode levar a dificuldades na obtenção de uma odontometria apropriada. Este estudo comparou três localizadores apicais (Root ZX II, Raypex 6 e Endo-Eze Quill) para localizar a ponta do instrumento K-file entre 0 a -0,5 mm do forame apical em dentes com diagnóstico de periodontite apical assintomática. O comprimento de trabalho eletrônico foi realizado em 60 dentes com periodontite apical assintomática. Uma lima K-file de número 15 foi inserida no canal radicular até a localização do forame apical, e seguida foi reajustada para -0,5 mm por meio de observação no visor do localizador eletrônico apical. A lima K-file foi fixada ao dente usando compósito, e a seguir os dentes foram extraídos. Os 4 milímetros apicais foram desgastados até que a lima K-file pudesse ser visualizada para as medidas de distância no forame apical por meio de microscópio eletrônico de varredura. O comprimento de trabalho apropriado foi determinado quando a ponta do instrumento estivesse localizada entre 0 a -0,5 mm do forame apical. O Root ZX II apresentou o melhor desempenho (p<0,01) que o Raypex 6 ou Endo-Eze Quill em dentes humanos com periodontite apical assintomática.