Mandibular incisive canal-related prevalence, morphometric parameters, and implant placement implications: a multicenter study of 847 CBCT scans

BACKGROUND: This study evaluated the epidemiological and morphological features of the mandibular incisive canal (MIC) using cone beam computed tomography (CBCT) in a significant sample of subjects in Brazil. MATERIAL AND METHODS: This retrospective, multicenter study assessed 847 CBCT scans performed at four oral imaging centers. The sample comprised CBCT images acquired from dentate individuals who presented at least from tooth 35 to tooth 45 in the anterior mandible region. Data regarding patient sex and age, and MIC linear measurements (length and diameter in mm), anatomical distances (to the alveolar, buccal and lingual cortexes, inferior border of the mandible, and adjacent teeth apexes), and location were obtained. RESULTS: The MIC was more prevalent in women (76.3% [p < 0.001]) between the fourth and sixth decades of life (p < 0.001). It was present bilaterally (p < 0.001) and exhibited a mean length of 7.7 mm (standard deviation [SD]=3.7 mm). Spearman correlation and logistic regression analysis revealed collinearity between age and linear measurements (p < 0.05). The mean distances varied from the initial to the final portion of the MIC, respectively, in relation to the buccal cortex (mean = 2.6 mm, SD = 1.27; mean=3.96 mm; SD =1 .43), to lingual cortex (mean=5.13 mm; SD=1.7; mean = 4.61 mm, SD = 1.65), and to the inferior mandibular border (mean = 9.32 mm, SD = 1.92; mean=8.76 mm, SD = 2.07 mm). The difference in the proximity of the MIC to the apex of the inferior lateral incisor was statistically significant (p < 0.05). CONCLUSIONS: Results of this study revealed a high prevalence of MIC with a bilateral pattern in women who were between the fourth and sixth decades of life. Both the distance between the MIC and the lingual cortex of the mandibular alveolar bone, and the diameter of the MIC, decreased as its trajectory assumed a more anterior position

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Morphometric study on single-root premolars in a European population sample: an update on lengths and diameters

External dental root morphology knowledge is fundamental for the implication in periodontal and implant dentistry branches. So far the literature available presents a few and not updated studies regarding this particular topic. The aim of this study is to investigate the morphometry of external gross anatomy of single-rooted premolars, focusing on length and tapering parameters. One hundred seventy four extracted teeth of European origin were used to measure the root length and diameter on the 4 radicular surfaces, starting from the cement- enamel junction to the root apex. Data were statistically analyzed with descriptive measures and any statistical significance (p value <0.05) was evaluated by means of T-student test. The length of the single-root mandibular and maxillary premolars resulted to be higher than those reported in literature. The data regarding the tapering showed a pronounced lowering of the diameter root from the middle point of the root. In addition, the single-rooted premolar showed to own an oval-shaped root characterized, in both arches, by a high variability, confirming the data reported in literature. The present morphometric study providing analytical data regarding the length, the tapering and the high variability of the single-root premolar highlights the need of an accurate knowledge of the root anatomy for a correct therapeutic approach in the daily clinical practice

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Evaluación forense comparativa del método odontológico de Carrea para estimar la talla real en cadáveres mexicanos / Forensic comparative evaluation of the dental method of Carrea to estimate real height in Mexican corpses

Objetivo. Determinar la efectividad del método odontológico de Carrea para estimar la talla real de cadáveres mexicanos. Material y métodos. Estudio analítico, correlacional y transversal en 2 poblaciones mexicanas cadavéricas. Muestra: 56 cadáveres, 32 de Veracruz y 24 del Distrito Federal. En cada cadáver se realizaron 4 mediciones morfométricas, de las cuales se obtuvieron 5 derivadas. Análisis estadístico: 1) se calcularon media y desviación estándar (DE); 2) para sexo, se utilizaron las pruebas t Student y de Levene para comparación de medias y DE; 3) para calcular la variabilidad entre muestras, se realizó un análisis de componentes principales; 4) las tallas real, mínima, máxima y promedio se compararon mediante un ANOVA unifactorial y 5) se realizó un análisis de correlación de Pearson entre las tallas real y mínima. Resultados. No se encontraron diferencias entre las 2 muestras de cadáveres estudiadas ni entre las tallas real y mínima en ninguno de los 2 grupos: Distrito Federal, talla real (172,08 ± 6,53 cm) y talla mínima (171,35 ± 7,81 cm) (p > 0,05); Veracruz, talla real (167,5 ± 5,77 cm) y talla mínima (166,50 ± 6,36 cm) (p > 0,05). Se obtuvo que la correlación entre la talla real y la mínima es adecuada tanto para la muestra del Distrito Federal (r = 0,79; p = 0,000) como para la de Veracruz (r = 0,82; p = 0,000), así como en conjunto (r = 0,83; p = 0,000). Conclusiones. El método odontológico de Carrea, utilizando la talla mínima como referencia, es un excelente estimador de la talla real en cadáveres mexicanos (AU)

Objective. Evaluate the usefulness of the dental method of Carrea to estimate the height in Mexican population. Material and methods. Analytical, correlational and cross-sectional study in 2 cadaveric Mexican populations. Sample: 56 bodies, 32 of Veracruz and 24 of the Federal District. In each corpse 4 morphometric measurements were performed, of which 5 derivatives were obtained. Statistical analysis: 1) mean and standard deviation (SD) was calculated; 2) for sex, t Student and Levene tests for comparison of means and SDs were used; 3) to calculate the variability between Federal District and Veracruz, principal component analysis was made; 4) the heights, real, minimum, average and maximum were compared by univariate ANOVA, and 5) a Pearson correlation analysis between actual and minimum heights was performed. Results. No differences were found between the 2 cadavers samples studied, neither between real and minimum height in either group: Federal District, real height (172.08 ± 6.53 cm.) and minimum height (171.35 ± 7.81 cm) (P>.05); Veracruz, real height (167.5 ± 5.77 cm) and minimum height (166.50 ± 6.36 cm) (P>.05), having that the correlation between real height and the minimum height is advisable for both samples, Federal District (r=.79, P=.000), Veracruz (r=.82, P=.000) and overall (r=.83, P=.000). Conclusions. The dental Carrea's method, using the minimum height reference, is an excellent estimate of the actual size in mexican corpses (AU)

Anatomical characteristics and visibility of mental foramen and accessory mental foramen: Panoramic radiography vs. cone beam CT

BACKGROUND: The mental foramen (MF) is a small foramen located in the anterolateral region of the mandible through which the mental nerve and vessels emerge. The knowledge on the anatomic characteristics and variations of MF is very important in surgical procedures involving that area. The aim of this study was two-fold: firstly, to analyze the anatomic characteristics of MF and the presence of accessory mental foramen (AMF) using CBCT and, secondly, to compare the capability of CBCT and PAN in terms of MF and AMF visualization, as well as influencing factors. MATERIAL AND METHODS: A sample of 344 CBCT scans was analyzed for presence and characteristics (i.e. diameter, area, shape, exit angle) of MF and AMF. Subsequently, corresponding PANs were analyzed to ascertain whether MF and AMF were visible. RESULTS: Out of the 344 patients, 344 (100%) MFs and 45 (13%) AMFs were observed on CBCT. Regarding gender, MF diameter and area, MF-MIB and MF-MSB distances, and exit angle were all significantly higher in males. Also, statistically significant differences were found in terms of age and dental status. Statistically significant differences in MF long and short diameters and MF area were found with respect to AMF presence (p=.021, p=.008, p=.021). Only 83.87% of the MFs and 45.83% of the AMFs identified on CBCT were also visible on PANs. MF diameter, shape, exit angle, and age had a significant influence on MF visualization on PAN (B=.43, p=.005; B=-.55, p=.020; B=.20, p=.008; B=.61, p=.005). CONCLUSIONS: PAN is not an adequate technique to properly identify MF and AMF. Diameter, shape, exit angle, and age are all factors influencing MF visualization on PAN images. For surgery involving the MF anatomical region, a preoperative radiological study with CBCT is of crucial importance to avoid complications

Validación de un algoritmo para el cálculo de las dimensiones dentarias basado en el método de Bloise / Validation of an algorithm for calculation of tooth dimensions based on the method of Bloise

Introducción: Cuando se estudia material óseo procedente de excavaciones arqueológicas o restos aislados es frecuente que las condiciones de conservación sean deficientes, por lo que la reconstrucción antropométrica de los principales rasgos característicos no se puede observar. Este problema es aún mayor en los casos forenses, en los que en muchas ocasiones la identificación debe realizarse únicamente a través de piezas dentarias. Por este motivo, son necesarios métodos alternativos validados que permitan la identificación de un individuo a partir de elementos dentarios. Objetivo: Validar el algoritmo, basado en el método de Bloise, comparando las dimensiones características de una pieza dentaria de diámetro mesiodistal conocido, tomado como dato inicial para el cálculo, con las dimensiones calculadas de esa misma pieza dentaria. Materiales y métodos: Materiales: se desarrolló un algoritmo basado en el método de Bloise en Excell Versión 14.0. 2010 para calcular el tamaño de piezas dentarias a partir de una única pieza conocida. Las mediciones se realizaron utilizando un calibre digital, clase 2, con precisión de 0,01 mm, y un calibre dentario, clase 2, con precisión de 0,01 mm. Muestra: se realizaron 106 medidas dentarias, provenientes de cráneos y modelos de yeso, todos seleccionados de la Cátedra de Odontología Legal y Forense. Procedimiento experimental: se midió el diámetro medial de una pieza dentaria conocida y se calculó su dimensión usando el algoritmo de cálculo. Análisis de datos: los datos experimentales se compararon con los valores calculados por el algoritmo aplicando el método de Bland-Altman. Para una mayor precisión del algoritmo se determinó un factor de corrección a partir de los coeficientes de regresión lineal de Pearson (p <0,05). Finalmente, se compararon de nuevo los valores corregidos y los valores experimentales usando el método de Bland-Altman. Resultados: Aplicando el método de Bland-Altman entre los valores experimentales y los calculados sin corrección se observó una dispersión de hasta dos desviaciones estándar. Este problema fue corregido utilizando el factor de corrección determinado por los coeficientes de Pearson, esto es, Cor = (Cal - 0,0183)/0,9601. Esta corrección permitió disminuir las diferencias entre el valor experimental y el valor calculado por el algoritmo próximo a ±0,08mm (menor que una desviación estándar). Conclusión: El factor de corrección sugerido para el método de Bloise se acerca más a los datos dentarios medidos experimentalmente. A partir de esta corrección fue posible validar el algoritmo basado en el método de Bloise (AU)

Introduction: When you study bone material from archaeological excavations or isolated remains, it is frequent that storage conditions are poor, so the anthropometric reconstruction of the main characteristic features cannot be observed. This problem is even greater in forensic cases in which, on many occasions, the identification must only be performed through tooth parts. For this reason, it is necessary to use validated alternative methods that allow the identification of an individual from dental fragmented remains. Goal: Validate the algorithm, based on the Bloise's method, by comparing the characteristic dimensions of a tooth in mesiodistal diameter known, taken as initial data for the calculation, with the calculated dimensions of the same tooth. Materials and methods: Software: an algorithm based on the Bloise's method in friendly Excel Version 14.0. 2010 was developed to calculate the size of the teeth from a single known piece. Instruments: the measurements were performed using a digital caliper, class 2, with 0.01 mm accuracy and a tooth gauge, class 2, with 0.01 mm accuracy. Subjects: were carried out 106 measures teeth, skulls and plaster models, were selected from Chair of Legal and Forensic Dentistry. Experimental procedure: a known tooth medial diameter was measured and its dimension was calculated using the algorithm. Analysis of data: the experimental data were compared with the values calculated by the algorithm using the method of Bland-Altman. For greater accuracy of the algorithm a correction factor was determined from the linear regression of Pearson coefficients (p <0.05). Finally, the corrected values and the experimental values were again compared using the method of Bland-Altman. Results: When the Bland-Altman's method was applied between the experimental and the calculated values without correction, it was observed a dispersion of up to two standard deviations. This problem was corrected using the correction factor determined by the Pearson coefficient, i.e. Cor = (Cal - 0.0183)/0.9601. This fix allowed to decrease the bias for differences of ±0.08 mm (less than one standard deviation) between the experimental value and the value obtained from the algorithm. Conclusion: Correction factors suggested to Bloise's method is closer to the dental data measured experimentally. From this correction, it was possible to validate the virtual simulator based on the Bloise's method (AU)

Nivelación 4x2: importancia sobre su aplicación en la dentición mixta y permanente / 4x2 levelling: considerations on its indication in the mixed and permanent dentition

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Evolución de las características de las arcadas dentarias en dos grupos de edad / Evolution of dental arches characteristics in two age groups

Introducción: Se comparan las características dimensionales de las arcadas dentarias entredos grupos de edades diferentes, adolescentes y adultos jóvenes, para analizar las variaciones asociadasa la edad, sexo y a la influencia del tratamiento ortodóncico. Material y método: Se utilizaron dosmuestras: 88 pares de modelos de escayola de adolescentes (edad media 14,05 años) y 65 de adultos(edad media 22,15 años). Se usó un método digital para la medición de los diámetros mesiodistales delos dientes, distancias intercaninas e intermolares, longitudes de las arcadas y se obtuvo el apiñamientodentario inferior. Para el análisis estadístico se agruparon las muestras de cada grupo de edad porsexos y por tratados/no tratados con ortodoncia. Resultados: Los diámetros mesiodistales de los chicoseran mayores a los de las chicas y los de los adolescentes mayores que los de los adultos, sobretodo en el sexo femenino. La distancia intercanina disminuyó con la edad en las chicas y la intermolarsuperior disminuyó en las chicas no tratadas, mientras que la inferior aumenta en los chicos. Ambaslongitudes de arcada tienden a disminuir en ambos sexos y sobre todo en los grupos de no tratados.Existó un aumento del apiñamiento inferior con la edad en ambos sexos en los individuos tratados.Conclusiones: La pérdida de material dentario con el paso de los años unido a una mayor pérdida delongitud de la arcada podría ser otro factor en el apiñamiento terciario. A su vez, el desplazamientodentario a mesial podría explicar la disminución de los diámetros transversales de caninos y molares,al ocupar una zona más estrecha del arco dentario

Introduction: Dimensional characteristics of dental arches between two groups of age, adolescentsand adults, are compared to analyze the variations associated with age, sex and influence oforthodontic treatment. Material and methods: Two samples of 88 pairs of stone models from adolescents(average age, 14.05 years) and 65 from adults (average age, 22.15 years) were selected. Aftercast scanning, a digital program was used to measure dental mesiodistal diameters, intercanine andintermolar widths, arch lengths and lower dental crowding. For the statistic analysis the samples ofeach age group were divided by sex and by the fact of having been treated or not with orthodontics.Results: The values of the mesiodistal diameters in males were greater than in females, and greater inadolescents than in adults, especially in females. The intercanine distance decreased with age in femalesand the maxillary intermolar distance decreased in untreated females, while the mandibular oneincreased in males. Both arch lengths decreased in both sexes, mainly in the untreated individuals. Thereis an increase of the anteroinferior dental crowding with age in both sexes in the treated group.Conclusions: The loss of dental material with age associated to a greater decrease of arch length couldbe another factor in the later crowding. Also the mesial displacement of the teeth to a narrower partof the arch could explain the decrease in the intercanine and intermolar widths

Valoración de los métodos de predicción de tamaños dentarios en dentición mixta / Assessment of the mixed dentition methods to predict unerupted teeth

Desde siempre, conocer el tamaño de los dientes no erupcionados, caninos y premolares, en dentición mixta, ha sido un claro reto en ortodoncia. El objetivo del presente trabajo es mostrar todos los métodos existentes en la bibliografía para realizar la predicción del tamaño de estos dientes, así como sus ventajas e inconvenientes. Estos métodos pueden clasificarse en 4 grandes grupos: los basados en ecuaciones de regresión; los basados en mediciones directas en radiografías; los que combinan elementos de los 2 anteriores, y otro método no clasificable en ninguno de los anteriores. Los métodos basados en ecuaciones de regresión son rápidos de realizar pero presentan coeficientes de correlación bajos y de poca fiabilidad; los que usan mediciones directas sobre radiografías periapicales presentan el problema de obtener imágenes distorsionadas en ocasiones, lo cual limita la exactitud de estas técnicas; los métodos combinados son los más fiables, aunque son los que más tiempo consumen y son más complejos de realizar. Por último, se presenta un método digital de gran fiabilidad y sencillo y rápido de realizar, no clasificable en ninguno de los grupos anteriores. Se trata de un método basado en la interpolación de tamaños de los dientes utilizando listas de tamaños dentarios y dientes de referencia ya erupcionados

The estimation of the size of unerupted permanent teeth, canines and premolars, in mixed dentition has always been considered an essential aspect in orthodontics. The aim of the present study is to show all the methods that have been developed to make these predictions and their advantages and disadvantages. Four main methods have been used to estimate the mesiodistal crown widths of unerupted canines and premolars: calculations from prediction equations and tables, direct measurements on radiographs, combination of radiographic measurements and prediction tables and other independent method. Methods with a regression equation that relate the widths of unerupted teeth to the widths of erupted teeth are easy and fast to use but not very reliable, methods of measuring unerupted teeth on radiographs depend on the quality of the x-ray films available for use and methods that combine regression equations and radiographs present great accuracy but are time consuming and difficult to use. Finally, we present a new digital computerized-aid method to predict the size of unerupted teeth in mixed dentition using several reference teeth already erupted and mesiodistal teeth tables

Maloclusión tratada con extracciones seriadas / Malocclusion treated with serial extractions

En este artículo se describe el caso clínico de un paciente de sexo femenino, de 9 años de edad. Al inicio del tratamiento presentaba un biotipo dolicofacial intenso, con una desviación de la línea media superior de 4 mm hacia la izquierda, con el 12 y el 22 lingualizados, con mordida cruzada funcional, desde el primer molar superior derecho hasta el incisivo lateral superior del mismo lado. Los procedimientos adoptados han incluido, además de la corrección de la mordida cruzada, la opción de un programa de extracciones seriadas, lo que posibilitó terminar el caso con una relación oclusal normal y estable entre las arcadas maxilar y mandibular y con los dientes en una relación ideal tanto transversal como sagitalmente. (AU)

Método de medición del índice de Bolton mediante digitalización de la arcada dentaria / Bolton tooth-size analyses measurement by a digital and computerized new method

El presente trabajo consiste en la puesta a punto de un método de medida que a través de una imagen digitalizada de la arcada dentaria y el correspondiente programa informático desarrollado por nosotros, permite de una forma rápida, sencilla y exacta, la medición de los tamaños mesiodistales de los dientes, así como el posterior cálculo del índice de Bolton.Este procedimiento, al que denominamos método digital, resulta igualmente sensible y más rápido de realizar que el método de medición tradicional. (AU)