Root and root canal system morphology of maxillary first premolars in a Chilean subpopulation: a cone-beam Computed Tomography Study / Morfología radicular y del sistema de canales radiculares de los primeros premolares maxilares en una subpoblación chilena: un estudio de tomografía computarizada de haz de cono

SUMMARY: The maxillary first premolar (MFP) presents a highly variable and complex root morphology; it is also one of the teeth most likely to suffer vertical root fractures. The aim of this study was to describe the morphology of the root and root canal system of the MFP in a Chilean population using Cone-Beam Computed Tomography (CBCT). One hundred and twenty-one MFP were evaluated (60 left and 61 right), belonging to subjects of both sexes. Descriptive and statiscal analysis of the data was carried out, with a value of P < 0.05 being statistically significant. One root was observed in 71 % of teeth and two roots in 29 %; statistically significant differences were observed in the number of roots by sex (p<0.05). Two root canals were found in 69.5 % of teeth and one canal in 30.5 %. In terms of morphological classification, 41.3 % of cases were Vertucci Type IV. The proximal cementodentinal walls were the thinnest. The MFP presented a high degree of morphological variation in a Chilean subpopulation.

RESUMEN: El primer premolar maxilar (PPM) presenta una morfología radicular muy variable y compleja; también es uno de los dientes con mayor probabilidad de sufrir fracturas radiculares verticales. El objetivo de este estudio fue describir la morfología de la raíz y el sistema de conductos radiculares del PPM en una población chilena mediante tomografía computarizada de haz cónico (CBCT). Se evaluaron 121 PPM (60 izquierdas y 61 derechas), pertenecientes a sujetos de ambos sexos. Se realizó un análisis descriptivo y estadístico de los datos, siendo estadísticamente significativo un valor de P < 0,05. Se observó una raíz en el 71 % de los dientes y dos raíces en el 29 %; se observaron diferencias estadísticamente significativas en el número de raíces por sexo (p<0.05). Se encontraron dos conductos radiculares en el 69,5 % de los dientes y un conducto en el 30,5 %. En cuanto a la clasificación morfológica, el 41,3 % de los casos fueron Vertucci Tipo IV. Las paredes cementodentinales proximales fueron las más delgadas. El PPM presentó un alto grado de variación morfológica en una subpoblación chilena.

Morphological analysis of maxillary first premolars by cone beam computed tomography in a Chilean sub-population / Análisis morfológico de primeros premolares maxilares a través de tomografía computarizada de haz cónico en una subpoblación chilena

SUMMARY: The root canal system of the maxillary first premolar (MFP), present a high rate of variation, especially at apical level. This complicates the action of antiseptic solutions and endodontic instruments at this level. The object of this in vivo study was to analyse by Cone Beam Computed Tomography (CBCT) the radicular and canalicular morphology of MFP in a Chilean sub-population. We carried out a cross sectional, descriptive and observational in vivo study with CBCT examinations of 70 MFP, both left and right. The data were analysed using descriptive statistics (mean (M), standard deviation (SD), with a confidence interval of 95 %), and one-factor ANOVA was used to relate the sections observed. Tooth 1.4 presented one root in 64.86 % of cases and two roots in 35.15 %. Tooth 2.4 presented one root in 66.67 % of cases and two roots in 33.33 %. The frequency of one and two canals was observed to be 30 % and 70% respectively. The walls with the smallest cementodentinal thickness were the mesial (1.11±0.55) and distal (1.08±0.52). The thickest dentinal wall was the palatine (2.07±1.29), followed by the buccal (1.6±1.0). No statistical differences between males and females were found in the thickness of the root wall, nor in the location of the premolar in the maxilla (p>0.05). In conclusion, the root morphology of the MFP is highly variable. Care must be taken not to over-instrument the proximal walls to avoid perforations or fractures. CBCT has proved to be a useful and effective diagnostic tool for in vivo study of dental morphology.

RESUMEN: El sistema de canal radicular del primer premolar maxilar (MFP) presenta una alta tasa de variación, especialmente a nivel apical. Esto complica la acción de las soluciones antisépticas y los instrumentos endodónticos a este nivel. El objetivo de este estudio in vivo fue analizar mediante tomografía computarizada de haz cónico (CBCT) la morfología radicular y canalicular de la MFP en una subpoblación chilena. Realizamos un estudio transversal, descriptivo y observacional in vivo con exámenes CBCT de 70 MFP, tanto a la izquierda como a la derecha. Los datos se analizaron mediante estadística descriptiva (media (M), desviación estándar (DE), con un intervalo de confianza del 95 %) y se utilizó ANOVA de un factor para relacionar las secciones observadas. El diente 1.4 presentó una raíz en el 64,86% de los casos y dos raíces en el 35,15 %. El diente 2.4 presentó una raíz en el 66,67 % de los casos y dos raíces en el 33,33 %. Se observó que la frecuencia de uno y dos canales era del 30 % y 70%, respectivamente. Las paredes con el espesor cementodentinal más pequeño fueron mesial (1,11 ± 0,55) y distal (1,08 ± 0,52). La pared dentinaria más gruesa fue la palatina (2,07 ± 1,29), seguida de la vestibular (1,6 ± 1,0). No se encontraron diferencias estadísticas entre machos y hembras en el grosor de la pared de la raíz, ni en la ubicación del premolar en el maxilar (p> 0,05). En conclusión, la morfología de la raíz de la MFP es muy variable. Se debe tener cuidado de no sobre-instrumentar las paredes proximales para evitar perforaciones o fracturas. CBCT ha demostrado ser una herramienta de diagnóstico útil y efectiva para el estudio in vivo de la morfología dental.

A cone-beam computed tomography study of the root and canal morphology of maxillary premolars / 口腔疾病防治

Objective @# To study root morphology, the incidence of three root canals and the root canal anatomy of maxillary premolars.@*Methods@#The cone-beam computed tomography (CBCT) data of 779 maxillary first premolars and 728 maxillary second premolars were collected from 412 patients in Zhuhai Stomatological Hospital. The root and canal morphology, incidence of three canals, bilateral symmetry and location of root canal bifurcation were analyzed. @*Results @#The incidence of three canals in the maxillary first premolars was 1.8% and that in the maxillary second premolars was 0.3%. The incidence of three canals in the maxillary first premolars was significantly higher than that in the maxillary second premolars (c2=8.304, P=0.004). The symmetrical ratio of the three-canal maxillary first premolar was 27.3%. There was no symmetrical three-canal maxillary second premolar. The anatomical morphology of the maxillary premolar can be single root, double root or trident root. Its internal root canal system is complex and diverse. There are seven kinds of Vertucci morphology: the first maxillary premolar is mainly Vertucci IV type, and the second maxillary premolar is mainly Vertucci I type. Most of the root canal bifurcations of the three-canal maxillary premolars were observed in the midthird or the cervical third of the root. All three-canal maxillary premolars had three independent apical foramens. @*Conclusion @#The root canal morphology of maxillary premolars is complex and changeable. CBCT plays an important role in the discovery of variation and extra root canals.

Maxillary first premolar with four canals: a case report / 华西口腔医学杂志

This article presented a case of discovering and diagnosing three roots with four canals of the maxillary first premolar. We found and located the extra root canal by clinical diagnosis, careful observation during the operation, and multiangle X-ray. We further confirmed the existence of the three roots with four canals with the help of cone-beam computed tomography. Finally, we verified the success of the high-quality root-canal therapy through root optical microscopy.

Número y disposición de los forámenes apicales en la superficie radicular de primeros premolares superiores / Number and arrangement of the apical foramen in root surface of maxillary first premolars

El primer premolar maxilar es considerado un diente con alta variación en su anatomía radicular y morfología de canales radiculares (Chaparro et al., 1999). Por esto, toma gran relevancia el conocimiento de su anatomía al realizar tratamientos endodónticos. El objetivo de éste estudio fue describir frecuencia de número y disposición de forámenes apicales en la región apical radicular en primeros premolares maxilares. Se utilizó microscopia óptica para estudiar en detalle la anatomía radicular apical de 141 raíces de primeros premolares maxilares unirradiculares (n=51) y birradiculares (n=49) de nacionalidad chilena; en donde se observó número de forámenes apicales mayores y accesorios (foraminas), ubicación del foramen mayor, y distancia de éste al ápice anatómico. En dientes unirradiculares se encontró una mayor frecuencia de uno o dos forámenes mayores, y un promedio de 2,5 foraminas accesorias por diente analizado. En dientes birradiculares se encontró una mayor frecuencia de un foramen mayor por raíz, y un promedio de 1,3 foraminas por raíz. Además, se encontró que la ubicación del foramen mayor fue más frecuente en las superficies mesial-distal-palatino en dientes unirradiculares, no encontrando diferencias significativas entre éstas superficies. En cambio en dientes birradiculares se observó que el foramen apical mayor en todas las superficies radiculares sin haber diferencias significativas entre ellas. La distancia promedio entre el foramen mayor y el ápice anatómico fue de 0,819 mm en uni y birradiculares. En conclusión los primeros premolares maxilares representativos de población chilena, presentan una anatomía apical variable y compleja, en cuanto al número de forámenes mayores, número de foraminas, y su ubicación.

The first maxillary premolar tooth has a high variation in its anatomy and morphology. Therefore, knowledge of its anatomy is important at the time of endodontic treatment. The purpose of this study was to describe frequency, number and arrangement of apical foramen in external root apical region in maxillary first premolar. We studied under microscopy (4x) of 141 root of first maxillary premolar single-rooted teeth (51) and double-rooted teeth (49) in Chilean population; where the number of major apical foramen and accessories (foraminas), major foramen location and distance from it to the anatomical apex was observed. In single-rooted teeth the emergence of one or two major foramen was found, averaging 2.5 foramina accessory. In double-rooted teeth the emergence of one foramen was observed with an average of 1.3 foraminas by root. It was established that there were no significant differences in the location of the major foramen between the mesial-distal-palatal surfaces in single-rooted teeth. In double-rooted teeth the major apical foramen was observed in all root surfaces without significant differences between them. The average distance between the major foramen and the anatomic apex foramen was 0.819 mm. In conclusion, the first premolars of Chilean population, have a changeable and complex apical anatomy, in relation to the number of foramina, the number of foramen and its location.

Cone beam- computed tomography as an indispensable tool in the management of radiculous premolar: a case report

Background: Internal anatomy of maxillary first premolars is particularly multifaceted on account of the variation in number of roots and canal configuration. Maxillary first premolars with 3 roots are called as small molar or "radiculous" because of their similar anatomy to the maxillary first molars. The most demanding step in endodontic treatment is identification and proper access to pulp canals of certain teeth with atypical canal configurations. Methods of identification of such premolars can be by various aides. Case Presentation: The present case describes the application of Cone Beam-Computed Tomography in the diagnosis of extra root with extra canal in a three rooted maxillary right first premolar. Conclusions: Proper knowledge of the anatomical variations is a must for an endodontist to make a treatment successful. Utilizing the latest technology along with the traditional concepts can surely rule out the inaccuracy in the treatment involved in such cases.

Maxillary first premolar with 3 root on both sides of a subjet:case report / 实用口腔医学杂志

The maxillary first premolar is a transitional tooth between incisors and molars. Most maxillary first premolars have 2 root canals. However, the bilateral maxillary first premolar with 3 roots and 3 canals has not been described. This article reports a rare case:The bilateral maxillary first premolar with 3 roots and 3 canals.

Three-rooted unilateral maxillary first premolar diagnosed by CBCT:A case report / 实用口腔医学杂志

Most of the maxillary first premolar are single-rooted,there are also two-rooted and three-rooted ones.A case of three-rooted maxillary first premolar was diagnosed by CBCT.CBCT has the advantage in the observation of the variation root number,root canal bending and the variation of root canal morphology.

Caracterización morfométrica del reborde anterior de la maxila mediante tomografía computarizada cone-beam / Morphometric characterization of anterior maxillary alveolar ridge by cone-beam computed tomography

Las imágenes obtenidas por Tomografía Computarizada Cone-Beam (TCCB) permiten determinar las relaciones de estructuras anatómicas tridimensionalmente y superar limitaciones de la radiografía convencional. El objetivo de este estudio fue describir las características morfométricas de la zona anterior del maxilar y su relación con los dientes canino y premolares mediante exámenes de TCCB. Se realizó un estudio descriptivo sobre 50 imágenes de TCCB siguiendo una sistemática de observación tridimensional se ubicaron puntos anatómicos entre dientes y paredes del seno maxilar, y se trazaron tangentes para su medición. Se calculo la Media y DE para cada parámetro, y la normalidad de la distribución se comprobó mediante la prueba de Kolmogorov-Smirnov. Los datos fueron comparados con la prueba ANOVA, con una valor p < 0,05 como significativo. El análisis de la relación entre los dientes y la pared anterior del seno maxilar, mostró que en un 80% de los casos se relacionó con el canino y 20% con el primer premolar. La menor altura entre el reborde alveolar y la pared inferior del seno maxilar se observó a nivel del segundo premolar con 13,54±0,30 mm en el lado derecho y 14,65± 0,30 mm en el izquierdo. Se registraron diferencias significativas en relación a las mediciones morfométricas y la variable rango etáreo. Los datos obtenidos en este estudio complementan las características morfométricas de la zona anterior del maxilar, lo que permite ejecutar tratamientos de implantes bajo una base morfológica científica y minimizando al máximo los riesgos de fracaso o daño a las estructuras anatómicas relacionadas.

The images obtained by Cone -Beam Computed Tomography (CBCT) allow the determination of three-dimensional relationships of anatomical structures and overcome limitations of conventional radiography. The aim of this study was to describe the morphometric characteristics of the anterior maxilla and its relation to canine and premolars by CBCT exams. A descriptive study on 50 CBCT images was made, following a systematic observation of three-dimensional anatomical points between teeth and maxillary sinus walls, they were located and plotted tangent for measurement. The Mean and SD was calculated for each parameter, and the normality of distribution was tested by Kolmogorov -Smirnov test. Data were compared by ANOVA test, with a p value <0.05 as significant. The analysis of the relationship between the teeth and the anterior wall of the maxillary sinus, showed that in 80% of cases are associated with the canine and in 20% to first molar. The lower height between the alveolar ridge and the inferior wall of the maxillary sinus was observed at the second premolar with 13.54±0.30 mm on the right side and 14.65±0.30 mm on the left. Significant differences were recorded in relation to morphometric measurements and age range variable. The data obtained in this study complement the morphometric characteristics of the anterior maxilla, allowing implant treatments in a scientific morphological basis and minimizing the level of risk of failure or damage to the anatomical structures related.