Variantes anatómicas del foramen mentoniano / Anatomical variants of the mental foramen

El foramen mentoniano es un hito anatómico en la cara externa del cuerpo mandibular del que emergen el nervio mentoniano y su paquete vascular. Podemos observar más forámenes, tanto en la cara externa como en la cara lingual de la mandíbula. Se denominará foramen mentoniano accesorio si se comprueba su continuidad con el conducto mentoniano o con el conducto dentario inferior, y se llamará foramen lingual lateral si se continúa con el conducto dentario inferior y emerge en la superficie lingual, distal a la zona de caninos. Se pueden presentar otras variantes anatómicas menos frecuentes como la agenesia uni o bilateral del foramen mentoniano y la presencia del foramen incisivo. La detección de las variantes anatómicas del foramen mentoniano es de gran importancia en el planeamiento de diversos tratamientos invasivos en la zona, para evitar disturbios sensoriales y accidentes vasculares.

The mental foramen is an anatomical landmark on the external face of the mandibular body from which the mental nerve and its vascular bundle emerge. We can observe more foramina, both on the external aspect and on the lingual aspect of the mandible. It will be called accessory mental foramen if its continuity with the mental canal or the lower dental canal is verified, and it will be called lateral lingual foramen if it continues with the lower dental canal and emerges on the lingual surface, distal to the canine area. Other less frequent anatomical variants may occur, such as unilateral or bilateral agenesis of the mental foramen and the presence of the incisive foramen. The detection of the anatomical variants of the mental foramen is of great importance in the planning of various invasive treatments in the area, to avoid sensory disturbances and vascular accidents.

Morphometric Evaluation of Mental Foramen of Dry Adult Human Mandibles of South Indian Population and Their Clinical Correlation

Introduction: Morphometric assessment of mental foramina (MF) of the mandible for its variable position is considered to be helpful for the surgeons and dentists for the localized surgical procedures and for the anesthetists to execute nerve block practices. Hence the objective of the present study is to establish the morphometric variability in the position of MF in terms of gender in the mandibles of Southern Indian origin with possible clinical implications. Methods: The shape, size, and location of MF were measured on both sides of the mandible (n=92). Location of MF was established by measuring the distance from MF to the [1] mental symphysis [2] alveolar crest, [3] the base of the mandible, and [4] posterior border of the ramus of the mandible. All the morphometric data were analyzed statistically with a significance level of p<0.05. Results: The higher incidence (58.7%) of rounded MF was recorded. There were no cases of MF anterior to the first pre-molar and below the 1st molar. Most of them (45.7%) were below the 2nd premolar. There was a significant association between gender and the position of the MF (p=0.011). But, no association between gender and side as well as the shape was noted. Significant associations were found between gender and the distance from mental foramen to the posterior border of the ramus and also to the alveolar crest. A significant association between the gender and the positions of the MF was noted. Conclusion: The variations observed from previous studies might be related to the feeding habits of different regions which may ultimately, affect the development of mandibles. Prior knowledge regarding the common positions of MF in local populations is helpful in effective nerve blocks and maxillofacial surgeries.

CBCT Evaluation of Unilateral Accessory Mental Foramina: Under Reported Anatomic Variant in Children

ABSTRACT: The following manuscript presents two paediatric cases with incidental finding of unilateral accessory mental foramina. Both the cases illustrate CBCT evaluation of a unilateral accessory foramina on the left side of the mandible, one of which, is a 12-year-old baby girl with pre-diagnosed medical history of precocious puberty and oral findings of supernumerary teeth and the other is an 8-year-old boy with oral bifurcation cyst. The not so frequent presence of additional foramina and canals in the mandible are frequently undervalued in clinical procedures and to our knowledge has not yet been reported in paediatric cases in the literature so far. In these case reports, authors attempt to document a rare and first of its type ever reported anatomic variant of mandible in paediatric patients in the whole literature.

RESUMEN: El manuscrito presenta dos casos pediátricos con hallazgo incidental de forámenes mentonianos accesorios unilaterales. Ambos casos se refieren a la evaluación CBCT de un foramen accesorio unilateral en el lado izquierdo de la mandíbula, uno de los cuales era una niña de 12 años con antecedentes medicos prediagnosticados de pubertad precoz y hallazgos orales de dientes supernumerarios y el otro un niño de 8 años con quiste de bifurcación bucal. La presencia no tan frecuente de forámenes y canales adicionales en la mandíbula se subestima con frecuencia en los procedimientos clínicos y, hasta donde sabemos, aún no se ha informado en casos pediátricos en la literatura hasta el momento. En esta serie de casos, los autores intentan documentar una variante anatómica rara y primera de su tipo de la mandíbula en pacientes pediátricos en toda la literatura.

Interexaminer agreement between two dental specialties for the detection of bifid mandibular canal and accessory mental foramen in cone-beam computed tomography / Concordancia inter-examinador entre dos especialidades odontológicas para la detección del canal mandibular bífido y foramen mental accesorio en tomografía computarizada de haz cónico

Introduction: The aim of this study was to assess the agreement between oral and maxillofacial radiologists (OMFR) and oral and maxillofacial surgeons (OMFS) for the detection of bifid mandibular canal (BMC) and accessory mental foramen (AMF) using cone-beam computed tomography (CBCT). Material and Methods: This retrospective study involved 22 examiners (11 OMFR and 11 OMFS) who independently assessed 30 CBCT volumes from patients (n = 60 hemi-mandibles) under preoperative radiographic evaluation for implant placement. The examiners scored the presence of BMC and AMF in each hemimandible. The interexaminer agreements were assessed using Fleiss' kappa statistics. Results: For intra-examiner agreement, 40% of the sample was reevaluated. The interexaminer agreement between OMFR and OMFS was slight (0.12) for the detection of BMC and fair (0.24) for AMF. The agreement among OMFR for detection of BMC was fair (0.22), and it was slight among OMFS (0.15). The agreement among OMFR for detection of AMF was substantial (0.61), and among OMFS it was fair (0.22). Agreements between OMFR and OMFS were slight for BMC and fair for AMF, independently of the years of experience. Intraexaminer agreement ranged from 60% to 90% among OMFR and from 55% to 90% among OMFS. Conclusion: A slight and a fair agreement between OMFR and OMFS was found for the detection of BMC and AMF, respectively. In general, OMFR obtained higher agreement among themselves, mainly for detection of AMF.

Introducción: El objetivo de este estudio fue evaluar la con-cordancia entre los radiólogos orales y maxilofaciales (ROMF) y los cirujanos orales y maxilofaciales (COMF) para la detección del canal mandibular bífido (CMB) y el foramen mentoniano accesorio (FMA) mediante tomografía computarizada de haz cónico. CBCT). Material y Métodos: Este estudio retrospectivo involucró a 22 examinadores (11 ROMF y 11 COMF) que evaluaron de forma independiente 30 volúmenes CBCT de pacientes (n = 60 hemimandíbulas) bajo evaluación radiográfica preoperatoria para la colocación de implantes. Los examinadores puntu-aron la presencia de CMB y FMA en cada hemimandíbula. Los acuerdos entre examinadores se evaluaron utilizando las estadísticas kappa de Fleiss. Resultados: Por concordancia intraexaminador se reeva-luó el 40% de la muestra. El acuerdo entre examinadores entre ROMF y COMF fue ligero (0,12) para la detección de CMB y regular (0,24) para FMA. La concordancia entre ROMF para la detección de CMB fue regular (0,22) y leve entre COMF (0,15). El acuerdo entre ROMF para la detección de FMA fue sustancial (0,61), y entre COMF fue justo (0,22). Los acuerdos entre ROMF y COMF fueron leves para CMB y justos para FMA, independientemente de los años de experiencia. La concordancia entre examinadores varió del 60 % al 90 % entre ROMF y del 55 % al 90 % entre COMF. Conclusión: Se encontró un acuerdo leve y justo entre ROMF y COMF para la detección de CMB y FMA, respec-tivamente. En general, se obtuvo mayor acuerdo entre ROMF, principalmente para la detección de FMA.

A cone-beam computed tomography study to assess anterior loop and other anatomic variations in mental foramen area in an iranian population / Un estudio de tomografía computarizada de haz cónico para evaluar el asa anterior y otras variaciones anatómicas en el área del foramen mentoniano en una población iraní

Purpose: This study aimed to determine the prevalence and length of the anterior loop (AL) of the inferior alveolar nerve, and evaluate the emergence direction of the mental nerve and the location of mental foramen in a group of Iranian patients. Material and Methods: This study was carried out on CBCT scans of 150 patients (57 males and 93 females; mean age 40.8 ±14.33 years). The presence and extent of the AL was determined in reconstructed images. The emergence path of the mental nerve was classified into three groups: anteriorly directed emergence, right-angled pattern of emergence, and posteriorly directed emergence. The location of mental foramen relative to adjacent premolars was determined. Results: AL was identified in 14.7% of the cases with a mean length of 1.39± 0.91 mm (range 0.25 to 3.50 mm). No significant differences were observed in the prevalence and extent of the AL between genders (p>0.05). The right-angled pattern of emergence was more dominant (43.7%). The most prevalent location of mental foramen was between the first and second premolars (68.3%). There was no significant association between the presence of AL with the path of emergence of the mental nerve (p=0.627) or the location of the mental foramen (p= 0.10 0). Conclusion: The prevalence of anterior loop was relatively low in the present sample (14.7%) with a length range of 0.25 to 3.5 mm. Due to the importance of this anatomic variation in implant surgery, it is suggested to carefully assess CBCT images before the surgical procedure to avoid neurosensory complications.

Propósito: Este estudio tuvo como objetivo determinar la prevalencia y la longitud del loop anterior (LA) del nervio alveolar inferior, y evaluar la dirección de emergencia del nervio mentoniano y la ubicación del foramen mentoniano en un grupo de pacientes iraníes. Material y Métodos: Este estudio se llevó a cabo en exploraciones de tomografía computarizada de haz cónico de 150 pacientes (57 hombres y 93 mujeres; edad media 40,8 ± 14,33 años). La presencia y extensión de la LA se determinó en imágenes reconstruidas. La vía de emergencia del nervio mentoniano se clasificó en tres grupos: emergencia dirigida anteriormente, patrón de emergencia en ángulo recto y emergencia dirigida posteriormente. Se determinó la ubicación del foramen mentoniano en relación con los premolares adyacentes. Resultados: Se identificó LA en el 14,7% de los casos con una longitud media de 1,39± 0,91 mm (rango 0,25 mm a 3,50 mm). No se observaron diferencias significativas en la prevalencia y extensión de la AL entre sexos (p>0,05). El patrón de emergencia en ángulo recto fue más dominante (43,7%). La localización más prevalente del foramen men-toniano fue entre el primer y segundo premolar (68,3%). No hubo asociación significativa entre la presencia de AL con la vía de emergencia del nervio mentoniano (p=0,627) o la ubicación del foramen mentoniano p=0,100).Conclusión: La prevalencia de asa anterior fue rela-tivamente baja en la presente muestra (14,7%) con un rango de longitud de 0,25 mm a 3,5 mm. Debido a la importancia de esta variación anatómica en la cirugía de implantes, se sugiere evaluar cuidadosamente las imágenes de tomografía computarizada de haz cónico antes del procedimiento quirúrgico para evitar complicaciones neurosensoriales.

Morphometric studies of supraorbital foramen, infraorbital foramen and mental foramen in a thai population related with nerve blocks / Estudios morfométricos del foramen supraorbitario, foramen infraorbitario y foramen mental en una población tailandesa relacionados con bloqueos nerviosos

SUMMARY: The aim of this study was to study the anatomical landmarks and variations of supraorbital, infraorbital, and mental foramina. One hundred and sixty Thai dry skulls were randomly selected from the Forensic Osteology Research Center. The distances of the parameters were measured by using Vernier caliper. The supraorbital foramen could be found in a notch form 13.8 %, single supraorbital foramen accounted for 82.5 %, and supraorbital foramen with an accessory foramen represented 3.8 %. Single infraorbital foramen was found 90.0 %, and infraorbital foramen with an accessory foramen represented 10.0 %. Single mental foramen was observed 96.6 %, and the frequency of mental foramen with an accessory foramen was determined 3.4%. The majority of infraorbital foramina (48.0 %) was detected above the second premolar area. 19.0 % of the infraorbital foramina was seen in the region between the first premolar and the second premolar, and 22.8 % of the infraorbital foramina was located between the second premolar and the first molar. The infraorbital foramen is anatomically positioned above the first molar (10.2 %). The majority of mental foramina (53.5 %) can be identified below second premolar area. The region between the first premolar and the second premolar is the site for the mental foramen 26.0 % of the total variations. The region between the second premolar and the first molar is the site for the mental foramen 16.9 % of the total variations. The mental foramen is approximately situated below the first molar (3.6 %). The present study of anatomical variations of various foramina demonstrates a useful application in cosmetic and ophthalmic plastic surgery. The findings could improve the efficacy of the surgeons and accuracy for the indicated localization of these foramina during maxillofacial operations and local anesthetic procedures.

RESUMEN: El objetivo de este estudio fue estudiar los puntos de referencia anatómicos y las variaciones de los forámenes supraorbitario, infraorbitario y mental. Ciento sesenta cráneos secos tailandeses fueron seleccionados al azar del Centro de Investigación de Osteología Forense. Las distancias de los parámetros se midieron utilizando un calibre Vernier. El foramen supraorbitario se pudo encontrar en forma de muesca el 13,8 %, el foramen supraorbitario único representó el 82,5 % y el foramen supraorbitario con un foramen accesorio representó el 3,8 %. El foramen infraorbitario único se encontró en un 90,0 % y el foramen infraorbitario con un foramen accesorio representó el 10,0 %. Se observó foramen mental único 96,6 % y se determinó la frecuencia de foramen mental con foramen accesorio 3,4 %. La mayoría de los forámenes infraorbitarios (48,0 %) se detectaron por encima del área del segundo premolar. El 19,0 % de los forámenes infraorbitarios se observó en la región entre el primer premolar y el segundo premolar, y el 22,8 % de los forámenes infraorbitarios se ubicó entre el segundo premolar y el primer molar. El foramen infraorbitario se ubica anatómicamente por encima del primer molar (10,2 %). La mayoría de los forámenes mentales (53,5 %) se pudieron identificar inferior al área del segundo premolar. La región entre el primer premolar y el segundo premolar es el sitio del foramen mental 26,0 % de las variaciones totales. La región entre el segundo premolar y el primer molar es el sitio del foramen mental 16,9 % del total de variaciones. El foramen mental se sitúa aproximadamente por debajo del primer molar (3,6 %). El presente estudio de variaciones anatómicas de estos forámenes demuestra una aplicación útil en la cirugía plástica y oftálmica. Los hallazgos podrían mejorar la eficacia de los cirujanos y la precisión para la localización de estos forámenes durante las operaciones maxilofaciales y los procedimientos anestésicos locales.

Vestibular landmarks to minimize injury to the mental nerve during transoral endoscopic thyroidectomy-vestibular approach (TOETVA) procedure: an anatomical study / Puntos de referencia vestibulares para minimizar la lesión del nervio mentoniano durante el procemiento de abordaje vestibular de tiroidectomía endoscópica transoral (TOETVA): un estudio anatómico

SUMMARY: The aim of this study is to reveal the morphometry of the mental nerve to describe a safe zone for minimizing mental nerve damage during transoral endoscopic thyroidectomy-vestibular approach (TOETVA). This study was performed on 12 cadavers. Localization of mental foramen according to teeth, distances of buccogingival sulcus-lip (BG-L), mental foramen-midline (MF-Midline), mental foramen - buccogingival sulcus (MF - BG), commissure - branching point (Cm - Br), branching point - vertical projection of branching point on lower lip (Br - LVP), vertical projection of branching point on lower lip - commissure (LVP - Cm), commissure - midline (Cm - midline), angles of mental (AM), angular (AA) and labial branches (AL) and branching patterns were recorded. Type 1 was mostly found as branching pattern in this study (45.8 %). A new branching pattern (type 9) was found on one cadaver. Mental foramen was mostly located at level of second premolar teeth. According to morphometric results of this study; supero- lateral to course of angular branch and infero-medial to course of mental branch of mental nerve on lower lip after exiting the mental foramen were described as safe zones during surgery for preserving mental nerve and its branches.

RESUMEN: El objetivo de este estudio fue revelar la morfometría del nervio mental o mentoniano para describir una zona segura y de esta manera, minimizar el daño de este nervio durante la tiroidectomía endoscópica transoral-abordaje vestibular (TOETVA). Este estudio se realizó en 12 cadáveres. Se realizó la localización del foramen mentoniano según los dientes, distancias surco gingival-labio (BG-L), foramen mentoniano-línea mediana (MF-Midline), foramen mentoniano-surco gingival (MF-BG), comisura-punto de ramificación (Cm-Br), punto de bifurcación - pro- yección vertical del punto de bifurcación en el labio inferior (Br - LVP), proyección vertical del punto de bifurcación en el labio inferior - comisura (LVP - Cm), comisura - línea mediana (Cm - línea mediana), ángulos del mentón (AM). Se registraron ramos angulares (AA) y labiales (AL) y patrones de ramificación. El tipo 1 se encontró principalmente como patrón de ramificación en el 45,8 %. Se describe un nuevo patrón de ramificación (tipo 9) encontrado en un cadáver. El foramen mentoniano se localizaba mayoritariamente a nivel de los segundos premolares. Según los resultados morfométricos, supero-lateral al curso de la rama angular e infero-medial al curso de la rama mentoniana del nervio mentoniano en el labio inferior, después de salir del foramen mentoniano, se describieron las zonas seguras, para la cirugía y preservación del nervio mentoniano y de sus ramos.

Frecuencia y caracterización de foramen mental accesorio en una población chilena mediante tomografía computarizada de haz cónico / Frequency and characterization of accessory mental foramen in a Chilean population using cone beam computed tomography

RESUMEN: En la práctica clínica odontológica, reconocer estructuras anatómicas es determinante en la planificación de distintos tratamientos que involucren algún riesgo. Uno de los exámenes complementarios recomendados para la planificación de diferentes tratamientos en odontología es la Tomografía Computarizada de Haz Cónico (CBCT). Con este examen, se pueden pesquisar variantes anatómicas como el Foramen Mental Accesorio (FMA), el cual es importante identificar para prevenir complicaciones. El objetivo de este trabajo fue determinar la frecuencia y caracterización de FMA en una población chilena adulta, de la ciudad de Valdivia, Chile. Este estudio es de tipo observacional descriptivo. Se revisaron 247 exploraciones de diferentes centros radiológicos de la ciudad de Valdivia, cumpliendo 143 con los criterios de selección. Este estudio fue aprobado por el Comité ético científico del Servicio de Salud de Valdivia. Se encontró presencia de FMA en el 17,48 % que corresponde a 25 pacientes de un total de 143, correspondiendo un 80 % al sexo femenino. El rango etario en que se encontró con mayor frecuencia correspondió a 18-39 años. La distancia promedio entre FMA y FM (Foramen Mental) fue de 5,76 mm, correspondiendo a 2 mm la distancia mínima y 11,5 mm la distancia máxima. La distancia promedio entre FMA y ápice dentario más cercano fue de 5,36 mm. La distancia mínima y máxima fueron de 0,8 mm y 10,2 mm respectivamente. El ápice radicular mayormente asociado al FMA correspondió al segundo premolar con una frecuencia de 60 % (n=15). Este estudio confirma la importancia de la correcta evaluación de la región mental ante procedimientos en la zona, la cual es vital para prevenir lesiones en relación a esta variante anatómica.

SUMMARY: The recognition of key anatomical structures is decisive to avoid complications in the dental clinical practice. Cone Beam Computed Tomography (CBCT) is a complementary exam recommended for the planning of different procedures in dentistry. With this exam, anatomical variants can be identified, such as the Accessory Mental Foramen (AMF). The objective of this work was to determine the frequency and characteristics of AMF in an adult Chilean population from the city of Valdivia, Chile. This is an observational study that included 247 CBCT exams from different radiological centers in Valdivia. According to the selection criteria, 143 CBCT exams were included. This study was approved by the Scientific Ethics Committee of the Valdivia Health Services. AMF was identified in 25 patients representing 17.48 %. From this result, 80 % were found in females. AMF was most frequently identified in patients from 18 to 39 years old. The average distance between AMF and Mental Foramen (MF) was 5.76 mm, which corresponds to 2 mm the minimum distance and 11.5 mm the maximum distance. The average distance between AMF and the nearest dental apex was 5.36 mm, and the minimum and maximum distance were 0.8 mm and 10.2 mm, respectively. The root apex of the second premolar was most frequently associated with the AMF, representing 60 % (n=15). This study confirms the importance of the correct evaluation of the mental region before initiating procedures in the area, which is vital to prevent injuries associated with this anatomical variant.

Assessment of the mental foramen location in a sample of Saudi Al Hasa, population using cone-beam computed tomography technology: a retrospective study / Evaluación de la ubicación del foramen mental en una muestra de población de Arabia Al Hasa, utilizando tecnología de tomografía computarizada de haz cónico: un estudio retrospectivo

Background: It is essential that the dentist understand the positional variations of the mental foramen to perform different types of dental procedures. This study was conducted to identify the position of the mental foramen among the Saudi population of Al Hasa. Material and Methods: According to the selection criteria of 200 CBCT images, 101 images were selected. The selected images were categorized into five groups with respect to patient age. Each image was evaluated from both sides of the mandible and then recorded in six classes (position I-VI) according to the horizontal position and three classes in the vertical position. Results: In the Saudi Al Hasa population, Type 4 (at the level of 2ndpremolar) was the most common location for mental foramen in the horizontal direction, on the right side (n= 41; 40.6%) and on the left side (n=44; 43.6%). Mental foramen was found in the vertical location, Type 3 (below the apex of 1st and 2nd premolars) was found in the right side (n= 54; 53.5%) and left side (n=56; 55.4%). The position of mental foramen is not constant and changes according to gender and ethnicity. This warrants dentists to evaluate patients individually. Conclusion: Even though the present study was done with a small sample of patients it provides a picture about approximate location of mental foramen among the target group of a population.

Antecedentes: Es esencial que el dentista comprenda las variaciones posicionales del agujero mentoniano para realizar diferentes tipos de procedimientos dentales. Este estudio se realizó para identificar la posición del foramen mental entre la población saudita de Alhasa. Material y Métodos: De acuerdo con los criterios de selección de 200 imágenes CBCT, se seleccionaron 101 imágenes. Las imágenes seleccionadas se categorizaron en cinco grupos con respecto a la edad del paciente. Cada imagen se evaluó desde ambos lados de la mandíbula y luego se registró en seis clases (posición I-VI) según la posición horizontal y tres clases en la posición vertical. Resultados: En la población saudita de Al Hasa, el tipo 4 (al nivel del segundo premolar) fue la ubicación más común para el foramen mental en la dirección horizontal, en el lado derecho (n = 41; 40,6%) y en el lado izquierdo (n = 44; 43,6%). El foramen mental se encontró en la ubicación vertical, el Tipo 3 (debajo del ápice del 1er y 2do premolares) se encontró en el lado derecho (n = 54; 53,5%) y el lado izquierdo (n = 56; 55,4%). La posición del foramen mental no es constante y cambia según el género y la etnia. Esto justifica que los dentistas evalúen a los pacientes individualmente. Conclusión: Aunque el presente estudio se realizó con una pequeña muestra de pacientes, proporciona una imagen sobre la ubicación aproximada del foramen mental entre el grupo objetivo de una población.

A CBCT aided assessment for the location of mental foramen and the emergence pattern of mental nerve in different dentition status of the Saudi Arabian population / Avaliação auxiliada por CBCT para a localização do forame mentual e o padrão de emergência do nervo mentual em diferentes estados de dentição da população da Arábia Saudita

Objective: The anatomy of mental foramen (MF) is a noteworthy landmark during any surgical procedures in the inter-foraminal region. Thus, the study aims at evaluating the location of MF and the emergence pattern of MN in three status of dentition in Saudi Arabian population. Material and Methods: In a prospective study, we have analyzed 240 cone beam computed tomography (CBCT) for the location of MF and the emergence pattern of MN. The study comprising three groups, namely dentulous, partially edentulous and edentulous, each having eighty CBCT scans. We presented the data in percentages. The chi-square and McNemar's test were used for testing association and pair-wise analysis, respectively. Results: The most common location of MF was below the apex of the second premolar irrespective of dentition status, with 54.2% in right and 60% in the left side of the jaw. Among the dentition status, left side of the mandible has shown significant variation for the location of MF, whereas gender and age showed variation in the right side. Anterior loop (AL) (Type-III) the emergence pattern of MN was the highest in all dentition status, with 51.7% in right and 53.8% on the left side. The variation in the emergence pattern of MN in terms of gender and side of the jaw was statistically significant. Conclusion: In the Saudi Arabian population, the apex of second premolar and type III/AL was the most prevalent location of MF and the emergence pattern of MN, respectively (AU)

Introdução: Objetivo: A anatomia do forame mentual (FM) é de grande importância durante qualquer procedimento cirúrgico na região inter-foraminal. Por tanto, como objetivo o estudo visa avaliar a localização do FM e o padrão de emergência do NM em três estados de dentição na população da Arábia Saudita. Material e Métodos: Em um estudo prospectivo, analisamos 240 tomografias computadorizadas de feixe cônico (TCFC) para a localização do FM e o padrão de emergência de NM. O estudo compreendeu três grupos, a saber, dentados, parcialmente edêntulos e edêntulos, cada um com oitenta imagens de TCFC. Apresentamos os dados em porcentagens. O teste do Qui-quadrado e o teste de McNemar foram usados para testar associação e análise de pares, respectivamente. Resultados: A localização mais comum do FM foi abaixo do ápice do segundo pré-molar independente do estado da dentição, com 54,2% no lado direito e 60% no lado esquerdo da mandíbula. Dentre as condições da dentição, o lado esquerdo da mandíbula apresentou variação significativa para a localização dos FM, enquanto o sexo e a idade mostraram variação no lado direito. O padrão de emergência (Tipo III) da alça anterior (AL) do NM foi o mais alto em todos os estados de dentição, com 51,7% no lado direito e 53,8% no lado esquerdo. A variação no padrão de emergência de NM em termos de gênero e lado da mandíbula foi estatisticamente significativa. Conclusão: Na população da Arábia Saudita, o ápice do segundo pré-molar e tipo III / AL foi a localização mais prevalente de FM e o padrão de emergência de NM, respectivamente. (AU)

Prevalence and morphometric analysis of double mental foramen and double mandibular foramen from digital panoramic radiographs / Prevalencia y análisis morfométrico de foramen mental y foramen mandibular dobles a través de radiografías panorámicas digitales

The morphological variations of the mental foramen (MF) and mandibular foramen (MBF) have been studied for several years, and the prevalence and morphometric characteristics of double and triple foramina have been reported. The objective of this study was to establish the prevalence of variations in the MF and MBF, and to carry out a morphometric analysis of a Chilean population using digital panoramic radiographs. The study included 927 radiographs; the observed prevalence of double MF was 2.58 %, while the prevalence of double MBF was 1.51 %. No cases of triple foramina were found. In men, double MF was found more frequently in the left hemiarch (64.28 % of cases), while in women it was more frequent in the right hemiarch (80 %). Double MBF was found more frequently in the right hemiarch in women (80 % of cases), while the distribution between left and right in men was even. The mean area, width and height of the double MF were 5.46 mm2, 2.77 mm and 2.57 mm respectively. The means of the same morphometric measurements in double MBF were 6.37 mm2, 2.27 mm and 3.19 mm respectively. In both foramina, statistically significant differences were only found between the height of the foramen and the age of the subjects, with the observation that the greater the subject's age, the smaller the height. Dental surgeons must take these anatomical variants into consideration in clinical and surgical actions; timely diagnosis by radiograph is important to avoid possible complications.

Las variaciones morfológicas del foramen mental (FM) y mandibular (FMB) han sido estudiadas durante varios años, reportándose su prevalencia y las características morfométricas de forámenes dobles y triples. El objetivo de este estudio fue establecer la prevalencia de variaciones de los FM y FMB y realizar un análisis morfométrico a través de radiografías panorámicas digitales de una muestra de población chilena. En el estudio se incluyeron 927 radiografías y se observó una prevalencia de FM doble de 2,58 %, mientras que la prevalencia de FMB doble fue de 1,51 %. No se encontraron casos de forámenes triples. En hombres, el FM doble se encontró mayoritariamente en la hemiarcada izquierda (64,28 % de los casos), mientras que en mujeres fue en la hemiarcada derecha (80% de los casos). Para el caso de los FMB dobles, en mujeres se presentó mayoritariamente en la hemiarcada derecha (80 % de los casos), mientras que en hombres fue equitativo en ambos lados. El promedio del área, ancho y alto de los FM dobles fue de 5,46 mm2, 2,77 mm y 2,57 mm, respectivamente. Asimismo, los promedios de estas medidas morfométricas para el FMB doble fueron 6,37 mm2, 2,27 mm y 3,19 mm, respectivamente. Para ambos forámenes sólo se encontraron diferencias estadísticamente significativas entre el alto y la edad de los sujetos, observando que, a mayor edad menor era el alto del foramen. Los cirujanos dentistas deben tener en consideración estas variantes anatómicas para la realización de distintas acciones clínicas y quirúrgicas, su diagnóstico radiográfico oportuno es importante para prevenir posibles complicaciones.

Localización anatómica del foramen mentoniano mediante tomografía computarizada cone-beam en una población de Chile: estudio observacional / Anatomical localization of the mental foramen using cone-beam computed tomography in a population in Chile: observational study

La ubicación del foramen mentoniano (FM) varía desde el canino hasta el primer molar. La confirmación de la ubicación del FM es fundamental para evitar lesiones nerviosas durante procedimientos odontológicos. La distancia del FM al diente adyacente se puede evaluar mediante tomografía computarizada cone beam (CBCT) de forma segura y precisa. El objetivo fue determinar la distancia promedio entre la cortical superior del FM y el ápice dentario más cercano. Se realizó un estudio descriptivo que midió la distancia en milímetros (mm) desde FM al ápice dentario más cercano de 99 exploraciones CBCT. La medición se realizó en un corte que intercepta el FM y el ápice adyacente. Se evaluaron un total de 99 casos (72 mujeres/ 27 hombres), con una edad promedio de 34,7 años, (rango de 18-73 años). La distancia promedio se ubicó a 3,22 mm del ápice dentario más cercano al FM, la distancia mínima encontrada fue de 0,81 mm y la máxima de 6,99 mm. Se relaciona con el segundo premolar en un 79 % de los casos, y primer premolar en un 17 %. El FM se ubica cercano a la zona de premolares, su localización puede variar en relación a los ápices de estos dientes. Este estudio confirma la importancia de ser cautelosos durante los tratamientos endodónticos y/o quirúrgicos, para prevenir lesiones nerviosas en relación a esta estructura anatómica.

The location of the mental foramen (MF) varies from the canine to the first molar. The confirmation of the location of the MF is essential to avoid nerve injuries during dental procedures. The distance from the MF to the adjacent tooth can be assessed by cone beam computed tomography (CBCT) safely and accurately. The objective was to determine the average distance between the upper cortex of the MF and the nearest dental apex. A descriptive study was carried out, where the distance in millimeters (mm) from MF to the nearest dental apex was measured in 99 CBCT exploration. The measurement was realized in a slice that intercepts the MF and the adjacent apex. A total of 99 cases were evaluated (72 women / 27 men), with an average age of 34.7 years (range of 18-73 years). The average distance was located at 3.22 mm from the nearest dental apex to MF, the minimum distance found was 0.81 mm and the maximum was 6.99 mm. It is related to the second premolar in 79 % of cases, and first premolar in 17 %. The MF is located close to the premolar area, its location can vary considerably in relation to the apices of these teeth. This study confirms the importance of being cautious during endodontic and / or surgical treatments to prevent nerve injuries in relation to this anatomical structure.

The Shape, Size And Position Of Mental Foramen In Human Dried Mandible In The Kalaburagi Region

Introduction: The mental foramen is a funnel-like opening located on the anterolateral aspect of body of themandible which marks the termination of the mental canal. The orientation and position of the mental foramenis important in performing anesthetic block prior to clinical procedures in lower-anterior teeth and also topreserve the integrity of the mental nerve trunk in surgical interventions.Materials and Methods: A total of 100 adult dry human mandibles were collected from the department ofAnatomy, Khaja Banda Nawaz institute of medical sciences, Faculty of Medicine, Khaja Banda Nawaz University,Gulbarga, Karnataka. The size, shape and position of the right and left side of the mandible were recorded in mmby direct visual inspection and digital vernier calipers.Results: The parameters which were considered in the present study were size, shape and position of the mentalforamen. In the present study the common shape encountered was oval shape, and the common position wasbelow the Apex of 2nd PM which coincides with the study by AGARWAL & GUPTA.Discussion: Agarwal & Gupta et al studied on 100 mandibles in gujarat population. Mean H.D was 3.33mm onright side and 3.25mm on left side, mean V.D was 2.15mm on right side and 2.13mm on left side. The comparativestudy of the present study and the other authors is tabulated in the tables.Conclusion: The present study enlightens and assist the maxillofacial and dental surgeons about the importanceof size, shape and position of the mental foramen for nerve block. It also has impact on the studies donepreviously like Agarwal et all and others. Hence this knowledge can be used as a tool for the dental surgeons.

Características anatómicas del asa mandibular evaluada por tomografía computarizada de haz cónico / Anatomical characteristics of the mandibular loop evaluated by cone beam computed tomography

Introducción: El nervio dentario inferior es una estructura anatómica de la mandíbula, la cual presenta variaciones como el asa mandibular, ambas estructuras están relacionadas con iatrogenias con tratamientos como cirugías orales, regeneraciones óseas e implantes. El objetivo del presente estudio es evaluar las características del asa mandibular y el agujero mentoniano utilizando tomografía axial computarizada de haz cónico (CBCT) en pacientes del Postgrado de Periodoncia de la Universidad Autónoma de Nuevo León. Material y métodos: Se analizaron un total de 110 CBCT, de los cuales 61 entraron al estudio cumpliendo con los criterios de inclusión, se realizaron cortes transversales utilizando el software On Demand® para identifi car y medir el asa mandibular y localizar la posición del agujero mentoniano de ambos lados separando los grupos por género. Resultados: La prevalencia del asa mandibular fue de 32.8% de 61 CBCT que se analizaron, se observó más comúnmente en hombres y de manera bilateral, y cuando fue unilateral sólo se encontró en el lado derecho, la longitud promedio fue de 6 ± 1 mm. El agujero mentoniano se detectó en mayor porcentaje apical al segundo premolar inferior con un diámetro promedio de 3.5 ± 0.5 mm, alejándose de la raíz del diente adyacente en un promedio de 6 ± 1 mm y del borde de la mandíbula 12.5 mm ± 0.5 mm. Conclusión: Es de suma importancia identifi car las características anatómicas del asa mandibular y localizar la posición del agujero mentoniano durante la planifi cación del tratamiento para evitar complicaciones durante y después del acto quirúrgico (AU)

Introduction: The inferior dental nerve is an anatomical structure of the mandible which presents variations such as the anterior loop, both structures are related to iatrogenies with treatments such as oral surgeries, bone regenerations and implants. The aim of the present study is to evaluate the characteristics of the anterior loop and the mental foramen using cone beam computed tomography (CBCT) in patients of the Graduate Periodontics Program, School of Dentistry, Universidad Autónoma de Nuevo León. Material and methods: 110 CBCT were analyzed of which 61 entered the study fulfi lling the inclusion criteria, cross sections were made using the On Demand® software to identify and measure the anterior loop and locate the position of the mental foramen both sides separating our groups by gender. Results: The prevalence of the anterior loop was 32.8% of 61 CBCT that were analyzed, it was found more commonly in men and bilaterally, and when it was unilateral only found on the right side, the average length was 6 ± 1 mm. The mental hole was found in greater percentage apical to the second lower premolar with an average diameter of 3.5 ± 0.5 mm, moving away from the root of the adjacent tooth by an average of 6 ± 1 mm and from the edge of the mandible 12.5 ± 0.5 mm. Conclusion: It is very important to locate these anatomical structures during treatment planning and avoid complications during and after the surgical act (AU)

Evaluation Of The Mental Foramen Position Using Digital Panoramic Radiographs In Selected Costal Population Of Andhra Pradesh

Introduction: Mental foramen is defined as the funnel-like opening in the lateral surface of the mandible at theterminus of the mental canal. The mental foramen is the termination of the mandibular canal in the mandible,transmits the inferior alveolar nerve and vessels. Accurate position of the mental foramen would help surgeonsin achieving successful anaesthesia to the terminal branches of the inferior alveolar nerve. The aim of the studywas to evaluate the most common radiographic position of mental foramen in costal population of AndhraPradesh.Materials and methods: A total of 250digital panoramic radiographs were collected between age of 16 and60yrs, which fulfil the inclusion criteria.Results: We observed that, in 40.4% of individuals mental foramen was in line with second premolar (position 4)followed by 27.8% between the first and second premolars (position 3), least common is position 1 in 4% of thepopulation. We also observed the mental foramen position to vary with gender and on right and left sides.Conclusion: The most common position of mental foramen is position 4. Gender and right and left side variationswere also observed in our study. surgeons should carefully identity mental foramen position in achievingsuccessful anaesthesia to the terminal branches of the inferior alveolar nervebefore going for the surgery of thelower jaw and floor of the mouth

Study Of Distribution Of Various Accessory Foramina In 100 Human Mandibles Of South India

Introduction: Any unnamed opening is termed as Accessory foramen. Mandible being the strongest bone of theskull is pervaded by many accessory foramina other than mandibular and mental foramen. In the present studyaccessory mandibular, mental, retromolar and lingual foramina are distinguished and clinical implications arediscussed. The presence of such foramina if not identified during clinical practice may cause complications.Hence our study is done to find out the incidence and distribution of various accessory foramina of mandibleamong South Indians.Materials and Methods: The study was done on 100 adult dry human mandibles of South Indian origin obtainedfrom first MBBS students. The location and distribution of various accessory foramina were carefully observed,noted and tabulated.Results: Accessory foramen was found in 93% of mandibles. Accessory lingual foramen was found in 93 mandibles,with supraspinous foramen in 84%, accessory mandibular foramen in 34%, accessory mental foramen in 12%and retromolar foramen in 6%.Conclusion: Presence of accessory foramina may cause failure of anaesthesia during inferior alveolar nerveblock and haemorrhage during mandibular reconstruction surgeries owing to the neurovascular structurespassing through these accessory foramina. The clinicians should be aware about the presence of such accessoryforamina during the procedures.

A Study on Position of the Mental Foramen in Children Using Panorama / 대한소아치과학회지

The purpose of this study was to investigate the changes of the position of the mental foramen according to age by using panorama of children with mixed and early permanent dentition. 180 panorama of 6 to 13-year-old boys and girls were analyzed and PiView(Infinitt, Korea) program was used.The horizontal position of the mental foramen was evaluated by the relative position of the teeth. The vertical position of the mental foramen was evaluated by the ratios between the distance from the center of the mental foramen to the inferior border of the mandible and the distance from to the alveolar crest to the inferior border of the mandible.The mental foramen was horizontally located in the anterior aspect of the second primary molar(premolar), and vertically slight below the half of mandibular body. As the age increased, it moved to the posterior and the downward and showed a significant correlation with age.

Implant-retained overdenture and o-ring attachments ­ case report / Overdenture retida por implantes e encaixes do tipo o'ring ­ relato de caso

The increase in life expectancy occurred along an increase in the demand of edentulous patients for a type of rehabilitation that provides higher masticatory efficiency. Thus, implant overdentures using the ball/o-ring and bar-clip attachment systems represent a muco-supported and implant-retained prosthetic type that allows greater security, stability, and aesthetics, besides presenting a lower cost and easier hygiene. The present study aims to report a clinical case of overdenture with the o-ring retention system. In this case, the patient complained of difficulties during mastication due to instability of the mandibular complete denture, sensitivity from the superficialization of the mental foramina, dissatisfaction with aesthetics, and successive dislocations of the mandibular condyle. After clinical and radiographic evaluation, the treatment proposed was the installation of two osseointegrated implants between the mental foramina and the o-ring attachment overdenture. This prosthetic rehabilitation presents a successful clinical follow-up of 24 months, confirming the effectiveness of the treatment applied. The patient was satisfied because the implant-retained prosthesis provided benefits related to aesthetics, comfort, phonation, and mastication. It is noted that the rehabilitation performed has solved the patient's initial complaints. After the clinical case and literature review, it is concluded that overdentures using the o-ring retention system are viable alternatives and provide adequate function and aesthetics, presenting integration with the stomatognathic system.

Com o aumento da expectativa de vida, houve também o aumento da procura dos pacientes edêntulos por uma forma reabilitadora que lhes proporcione maior eficiência mastigatória. Sendo assim, as sobredentaduras sobre implantes utilizando sistemas de encaixe bola/o'ring e barra-clip representam modalidade protética mucossuportada e implantorretida que possibilita maior segurança, estabilidade e estética, além de apresentarem menor custo e facilidade para higienização. O presente trabalho tem por objetivo relatar um caso clínico de overdenture que utiliza o sistema de retenção o'ring. Neste caso, a paciente queixava-se de dificuldades durante a mastigação devido à instabilidade da prótese total inferior, sensibilidade pela superficialização dos forames mentuais, insatisfação com a estética, além de sucessivas luxações do côndilo mandibular. Após avaliação clínica e radiográfica, o tratamento proposto foi a instalação de dois implantes osseointegráveis entre os forames mentuais e overdenture com encaixes do tipo o'ring. A reabilitação protética em questão apresenta um acompanhamento clínico bem sucedido de 24 meses, comprovando a eficácia do tratamento instituído. A paciente demonstrou estar satisfeita, pois a prótese implanto-retida possibilitou benefícios relacionados à estética, conforto, fonação e mastigação. Nota-se que a reabilitação realizada atendeu às queixas iniciais da paciente. Após a realização do caso clínico e revisão de literatura, conclui-se que overdentures que utilizam o sistema de retenção o'ring são alternativas viáveis e que promovem função e estética adequadas, integrando-se ao sistema estomatognático.

The mental foramen in dry human mandibles of adult South Africans: an anatomical study / El foramen mental en mandíbulas humanas secas de adultos sudafricanos: un estudio anatómico

The objective of the study was to investigate the position, position symmetry, shape and number of the mental foramen in a heterogeneous South African population. Knowledge of the precise position of MF in maxillofacial surgery is critical for an accurate local anaesthesia; and can provide a landmark in forensic or medico legal cases. Dry adult human mandibles (n = 325) were selected and classified by ancestry. The sample comprised male-to-female ratio of 1.2:1. Observations were made for the position, position symmetry, shape and number of the mental foramen. There was a substantial to perfect agreement (p < 0.001) for most observations, except for the shape of the MF on the right side of the mandible that had a fair agreement (K = 0.25; P > 0.05). PIV of the MF is shown as the most prevalent position. PIII and IV were commonly observed in males and females respectively. PII was commonly observed in the males of European descent, while PIII was observed in male African and Mixed descents and female European descents. There was no significant difference in the symmetric analysis of MF amongst male and female (p = 0.059) and between ancestry (p = 0.455). But also, an oval shape of MF was the most common across subpopulations and ancestries, with 2 (2 %) and 3 (0.46 %) of the AMFs present. This study is the first comprehensive description of the MF in the South African population, and could be very useful in forensic anthropology in the South Africa population.

El objetivo de este estudio fue investigar, en una población sudafricana heterogénea, la posición, simetría de posición, forma y número de forámenes mentales (FM). El conocimiento de la localización exacta del FM en la cirugía maxilofacial es crítico para una anestesia local precisa y puede proporcionar un punto de referencia en casos legales forenses o médicos. Se seleccionaron 325 mandíbulas humanas secas adultas y clasificadas por ascendencia. La muestra relación hombre-mujer fue de 1,2:1. Las observaciones fueron realizadas para la posición, simetría de la posición, forma y el número forámenes mentales. Se alcanzó la perfección de concordancia (p < 0,001) para la mayoría de las observaciones, a excepción de la forma intermedia en el lado derecho de la mandíbula el cual presentó un acuerdo justo (K = 0,25; p > 0,05). La PIV de la MF se muestra como la posición más prevalente. PIII y IV fueron observados comúnmente en hombres y mujeres, respectivamente. La PII se observó comúnmente en los varones de ascendencia europea, mientras que el PIII se observó en descendientes africanos y mixtos masculinos y descendientes femeninos europeos. No hubo diferencias significativas en el análisis simétrico del FM entre hombres y mujeres (p = 0,059) y entre ascendencia (p = 0,455). Una forma ovalada de FM fue la más común a través de subpoblaciones y ancestros, con 2 (2 %) y 3 (46 %) del con la presencia de un foramen mental accesorio. Este estudio es la primera descripción comprensiva del FM en la población sudafricana, y podría ser muy útil en antropología forense en la población de Sudáfrica.

Evaluation of incidence of mental nerve loop in Central India population using cone beam computed tomography

Anatomical literature has described the anterior loop being an extension of the mental nerve which is present anterior to the mental foramen while the caudal loop has been described as the distance between the lower border of the mental foramen and the lowest point of the mandibular canal. The knowledge and identification of the anterior and caudal loop of the mental nerve are important in surgical procedures performed around the mental foramen to avoid inadvertent damage to these vital structures resulting in postoperative complications. Aim: The present study was conducted to determine the incidence and measurement of mental nerve loop in the mandibular arches using cone beam computed tomography (CBCT). Settings and Design: A total of 200 CBCT images were retrieved and inspected for the presence of the mental nerve loop. The length of the anterior loop was measured by counting the number of consecutive contiguous vertical cross sections displaying two round hypodense images. This number was multiplied by the thickness of the slices. The caudal loop was measured as the distance between the lower border of the mental foramen and the lowest point of mandibular canal. Statistical Analysis Used: Shapiro–Wilk test and Mann–Whitney U-test were used. P < 0.05 was considered statistically significant. Results: 57.5% (n = 200 scans) presented with the anterior loop of the mental nerve with a mean length of 0.50 mm and 0.37 mm on the right side and left side, respectively. All the samples of CBCT scans taken were having caudal loop extension with a mean length of 3.53 mm. Conclusion: A considerable number of individuals (57.5%) in the present study presented with the anterior loop of the mental nerve. CBCT was found to be an effective imaging modality for the detection of anterior loop of the mental nerve.