Retromolar canal diagnosed by cone-beam computed tomography and its influence in inferior alveolar nerve block / Canal retromolar diagnosticado por tomografía computarizada de haz cónico y su influencia en el bloqueo del nervio alveolar inferior

The aim of this study was to observed the anesthetic efficacy of the alveolar nerve block on nine patients that CBCT diagnosed unilateral retromolar canal on a double-blind, split-mouth approach. The assessments of patient response to thermal (pulp vitality test) and pressure (compression of soft tissue) stimuli were carried out before and 5 minutes after the inferior alveolar nerve block procedure, using both visual analog scale (VAS) and Mc Gill pain questionnaires (McG). The mean percentage of patient response decreased after alveolar nerve block, according to both VAS and McG, and was statistically similar among hemi mandibles with and without retromolar canal (Wilcoxon>0.05); however, those without retromolar canal presented greater reduction in patient response in 6 out of 9 cases. Therefore, the retromolar canal is not a determinant factor of inferior alveolar nerve block failure.

El objetivo de este estudio fue observar la eficacia anestésica del bloqueo del nervio alveolar en nueve pacientes que CBCT diagnosticó canal retromolar unilateral en un abordaje de boca dividida doble ciego. Las evaluaciones de la respuesta del paciente a los estímulos térmicos (prueba de vitalidad pulpar) y de presión (compresión de los tejidos blandos) se realizaron antes y 5 minutos después del procedimiento de bloqueo del nervio alveolar inferior, utilizando tanto la escala analógica visual (VAS) como los cuestionarios de dolor de Mc Gill ( McG). El porcentaje medio de respuesta de los pacientes disminuyó tras el bloqueo del nervio alveolar, según EVA y McG, y fue estadísticamente similar entre hemimandíbulas con y sin canal retromolar (Wilcoxon>0,05); sin embargo, aquellos sin canal retromolar presentaron mayor reducción en la respuesta del paciente en 6 de 9 casos. Por lo tanto, el canal retromolar no es un factor determinante del fracaso del bloqueo del nervio alveolar inferior.

Assessment of root canal anatomy of maxillary and mandibular canine teeth: a cone-beam computed tomography study / Evaluación de la anatomía del canal radicular de caninos maxilares y mandibulares: un estudio de tomografía computarizada de haz cónico

Abstract To investigate the root canal anatomy of permanent maxillary and mandibular canines in a Turkish subpopulation using cone beam computed tomography (CBCT). Retrospective CBCT data of 300 patients admitted to our clinic between 2016 and 2018 were screened and evaluated. A total of 235 patients, 100 males and 135 females, aged 14-76 years (mean age 37.27±13.40) were included in this study. A total of 191 (44,8%) maxillary canine teeth and 235 (55,2%) mandibular canine teeth were examined. The number of roots and root canal morphology according to Vertucci's classification, the presence of accessory canals, and the position of the apical foramen of the root were analyzed. The effect of gender and age on the incidence of root canal morphology was also investigated. The majority of the teeth had a Type I canal configuration in both maxillary canines (100%) and mandibular canines (92,8%). In the mandibular canines the other canal patterns found were Type III (6,8%), and Type II (0,4%). Apical foramen was centrally positioned in the majority of the teeth, 70,2% and 66,8% in maxillary and mandibular canines, respectively. The occurrence of two roots in mandibular canines was 3,8% and the root canal separation was found 53,8% and 46,2% in the middle and cervical third of the root, respectively. No significant statistical difference was observed effect of gender and age on the incidence of the root canal morphology and the position of the apical foramen. Due to the diverse morphology and the potential presence of a second canal for canine teeth among the Turkish subpopulation, dentists should perform endodontic treatments with greater care. CBCT is an accurate tool for the morphological assessment of the root canals.

Resumen Investigar la anatomía del conducto radicular de los caninos maxilares y mandibulares permanentes en una subpoblación turca utilizando la tomografía computarizada de haz cónico (CBCT). Se examinaron y evaluaron los datos CBCT retrospectivos de 300 pacientes ingresados en nuestra clínica entre 2016 y 2018. Un total de 235 pacientes, 100 hombres y 135 mujeres, de entre 14 y 76 años (edad media de 37,27±13,40) fueron incluidos en este estudio. Se examinaron un total de 191 (44,8%) dientes caninos maxilares y 235 (55,2%) dientes caninos mandibulares. Se analizó el número de raíces y la morfología del conducto radicular según la clasificación de Vertucci, la presencia de conductos accesorios y la posición del foramen apical de la raíz. También se investigó el efecto del sexo y la edad en la incidencia de la morfología del conducto radicular. La mayoría de los dientes tenían una configuración de conductos de tipo I tanto en los caninos maxilares (100%) como en los caninos mandibulares (92,8%). En los caninos mandibulares los otros patrones de conductos encontrados fueron el Tipo III (6,8%) y el Tipo II (0,4%). El foramen apical estaba situado en posición central en la mayoría de los dientes, 70,2% y 66,8% en los caninos maxilares y mandibulares, respectivamente. La ocurrencia de dos raíces en los caninos mandibulares es del 3,8% y la separación del conducto radicular se encontró en el tercio medio y cervical de la raíz en el 53,8% y el 46,2%, respectivamente. No se observó ninguna diferencia estadística significativa en el efecto del sexo y la edad sobre la incidencia de la morfología del conducto radicular y la posición del foramen apical. Debido a la diversa morfología y a la posible presencia de un segundo conducto en los dientes caninos entre la subpoblación turca, los odontólogos deberían realizar los tratamientos endodónticos con mayor cuidado. La CBCT es una herramienta precisa para la evaluación morfológica de los conductos radiculares.

Panoramic radiography and cone-beam computed tomography to measure distances between root apexes and anatomical structures / Radiografía panorámica y tomografía computarizada de haz cónico para medir distancias entre ápices radiculares y estructuras anatómicas

Aim: To compare the accuracy of the panoramic radiography with cone-beam computed tomography (CBCT) scans in measuring the distances between root apexes and the adjacent anatomical structures including the maxillary sinus and the mandibular canal. Material and Methods: A total of 200 CBCT scans (100 maxillary and 100 mandibular) from patients who also had corresponding panoramic radiography were selected. Linear measurements (in mm) presenting centralized image were made between the apexes of the maxillary teeth and the inferior wall of the maxillary sinus, and between the apexes of the mandibular teeth and the superior border of the mandibular canal by using specific software for panoramic radiography and the measurements on the coronal sections in CBCT scans. Data were submitted to inferential statistical analysis and Student's t-test for comparison between measurements. Results: CBCT scans were significantly more accurate than panoramic radiography to measure the distances between the apexes of the maxillary teeth and the inferior wall of the maxillary sinus (p<0.05) and between the apexes of the mandibular teeth and the superior border of the mandibular canal or mental foramen (p<0.05). Conclusion: CBCT scans present more accurate measurements than panoramic radiography.

Objetivo: Comparar la precisión de la radiografía panorámica con las exploraciones de la tomografía computarizada dental de haz en cónico (CBCT) para medir las distancias entre los vértices radiculares y las estructuras anatómicas adyacentes, incluidos el seno maxilar y el canal mandibular. Material y Métodos: Se seleccionaron un total de 200 tomografías CBCT (100 maxilares y 100 mandibulares) de pacientes que además tenían la correspondiente radiografía panorámica. Se realizaron mediciones lineales (en mm) que presentaban imagen centralizada entre los ápices de los dientes maxilares y la pared inferior del seno maxilar, y entre los ápices de los dientes mandibulares y el borde superior del canal mandibular mediante software específico para radiografía panorámica. y las mediciones en las secciones coronales en escaneos CBCT. Los datos se sometieron a análisis estadístico inferencial y prueba t de Student para comparación entre mediciones. Resultados: Las exploraciones CBCT fueron significativamente más precisas que la radiografía panorámica para medir las distancias entre los ápices de los dientes maxilares y la pared inferior del seno maxilar (p<0,05) y entre los ápices de los dientes mandibulares y el borde superior de los dientes mandibulares. canal o agujero mentoniano (p<0.05). Conclusión: Las exploraciones CBCT presentan mediciones más precisas que la radiografía panorámica.

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.

Análisis comparativo de la visualización del canal mandibular mediante tomografía computarizada cone beam en humanos / Comparative analysis of the visualization of the mandibular canal by cone beam computed tomography in humans

RESUMEN: Una de las estructuras de mayor interés en la región maxilofacial es el canal mandibular, donde su preservación optimiza el éxito de los procedimientos clínicos. Por su disposición al interior de la mandíbula, la visualización in vivo requiere el uso de técnicas radiográficas, entre las que destaca el Cone Beam CT (CBCT). El objetivo de este trabajo es comparar la visualización del canal mandibular humano mediante imágenes en CBCT con distintos observadores y programas de radiación. Mediante imágenes generadas con CBCT en mandíbulas secas con distintos programas de adquisición, se obtuvieron cortes coronales en los sectores anterior, medio y posterior del canal mandibular, con un total 240 mediciones, las que incluyeron dos tamaños de voxel y dos dosis de radiación distintos. Cada una de las imágenes fue evaluada por un Cirujano Dentista, Máster en Anatomía y Especialista en radiología Máxilofacial. Se obtuvieron porcentajes de visualización según observador para cada programa de adquisición de imágenes. La prueba de Q de Cochran arrojó diferencias entre los observadores (p0,05). El grado de experticia del observador influye en la visualización y su precisión. A su vez, utilizar un programa de adquisición de imagen con distinto voxel y/o dosis no afecta a la visualización, siendo esta dependiente de la anatomía propia de la estructura. Podría utilizarse un protocolo con menor radiación para el usuario cumpliendo con la premisa ALARA (As Low As Reasonably Achievable).

SUMMARY: One of the structures of greatest interest in the maxillofacial region is the mandibular canal, where its preservation optimizes the success of clinical procedures. Due to its disposition inside the mandible, in vivo visualization requires the use of radiographic techniques, among which the Cone Beam CT (CBCT) stands out. The objective of this work is to compare the visualization of the human mandibular canal by means of CBCT images with different observers and radiation programs. Using images generated with CBCT in dry mandibles with different acquisition programs, coronal slices were obtained in the anterior, middle and posterior sectors of the mandibular canal, with a total of 240 measurements, which included two voxel sizes and two doses different radiation sources. Each of the images was evaluated by a Dentist, an Anatomy Master's degree and a specialist in Oral & Maxillofacial Radiology. Percentages of visualization according to observer were obtained for each image acquisition program. The Cochran Q test yielded differences between the observers (p 0.05). The degree of expertise of the observer influences the visualization and its precision. In turn, using an image acquisition program with a different voxel/radiation dose not affect the visualization, since it depends on the anatomy of the structure itself. A protocol with less radiation could be used in patients complying with the ALARA ("As Low As Reasonably Achievable") premise.

Avaliação da prevalência e localização de canais mandibulares bífidos: um estudo em TCFC / Evaluation of the prevalence and location of bifid mandibular canals: a CBCT study

Objetivo: Investigar a prevalência e localização de canais mandibulares bífidos (CMB) por meio de tomografia computadorizada de feixe cônico (TCFC). Materiais e métodos: Três radiologistas odontológicos treinados e calibrados avaliaram individualmente 1254 exames tomográficos por meio do software I-Cat Vision (Imaging Sciences International®) e classificaram em quatro tipos distintos (Retromolar, Dental, Anteriorizado e Bucolingual). Os dados de frequência, coletados a partir de um formulário Access (Microsoft® Office), foram analisados por meio dos testes de Fischer e Friedman. O nível de significância estatística foi estabelecido em 5%. Resultados: CMBs foram encontrados em 276 casos (22%), sem predileção por gênero (P=0,186). Houve diferença estatisticamente significante entre os tipos (P=0,001). Discussão: O reconhecimento de um CMB é de grande relevância quando associado a procedimentos anestésicos e cirúrgicos na região posterior da mandíbula. Apesar de muitos estudos demostrarem que o CMB não é comumente visto, uma falha em sua identificação pode resultar em danos ao nervo alveolar inferior (NAI) ou em dificuldade na obtenção do bloqueio anestésico. Conclusão: O tipo mais frequente de CMB em ambos os gêneros, foi o retromolar (P=0,001), representando 18,5%, e visualizado com taxas de 47,1% nas mulheres e 52,9% nos homens. A frequência de CMBs analisada por meio da TCFC foi significativa na população avaliada e apresentou-se com diferentes configurações. Desta forma, sua investigação não deve ser negligenciada frente a procedimentos cirúrgicos que envolvam a região posterior da mandíbula.

Aim: To investigate the prevalence and location of bifid mandibular canals (CMB) using cone beam computed to-mography (CBCT). Materials and methods: Three trained and calibrated dental radiologists individually evaluated 1254 CT scans using the I-Cat Vision software (Imaging Sciences International®) and classified them into four distinct types (Retromolar, Dental, Forward and Buco-lingual). Frequency data, collected from an Access form (Microsoft® Office), were analyzed using the Fischer and Friedman test. The level of statistical significance was set at 5%. Results: CMBs were found in 276 cases (22%), with no gender predilection (P = 0.186). There was a statistically significant difference between the types (P = 0.001). Dis-cussion: The recognition of a CMB is of great relevance when associated with anesthetic and surgical procedures in the posterior region of the mandible. Although many studies have shown that CMB is not commonly seen, a failure to identify it can result in damage to the lower alveolar nerve (NAI) or difficulty in obtaining anesthetic block. Conclusion: The most frequent type of CMB in both genders was retromolar (P = 0.001), representing 18.5%, and visualized with rates of 47.1% in women and 52.9% in men. The frequency of CMBs analyzed using the CBCT was significant in the population evaluated and presented in different configurations. Thus, its investigation should not be neglected in the face of surgical procedures that involve the posterior region of the mandible

Determinación de la morfología del canal incisivo mandibular mediante tomografía computarizada de haz cónico (CBCT) en población de Valdivia, Chile / Determination of mandibular incisor canal morphology by cone beam computed tomography (CBCT) in a population of Valdivia, Chile

RESUMEN: El canal incisivo mandibular (MIC) es un canal neural que contiene una de las ramas inferiores del nervio alveolar inferior, llamado nervio incisivo mandibular, que puede resultar dañado durante intervenciones quirúrgicas y causar complicaciones postoperatorias. Estudio descriptivo de corte transversal. Se identificó el MIC en la imagen transversal del canino en 83 hemiarcadas. Se registró edad, sexo, hemiarcada, longitudes desde reborde alveolar vestibular de canino a MIC, cortical lingual y vestibular de canino a MIC, base mandibular de canino a MIC y ubicación del MIC (tercio lingual, medio, vestibular). Medidas se registraron en milímetros. Se aplicó test T-student para muestras independientes para variables de longitud y Chi-cuadrado para ubicación espacial del MIC, en relación con grupo etario y sexo. Se evaluó el MIC en todas las muestras (100 %). El MIC fue encontrado mayormente en el tercio medio mandibular (p <0,05). La media desde el MIC a la cortical lingual es de 5,25 mm ? 1,42 mm (derecho) y 5,24 mm ? 1,18 mm (izquierdo). La media desde el MIC a la cortical vestibular fue de 4,42 mm ? 1,29 mm (derecho) y 4,53 mm ? 1,24mm (izquierdo). La media entre centro del canal y reborde alveolar vestibular fue 18,89 mm ? 2,68mm (derecho) y 18,20 mm ? 3,06 mm (izquierdo), media desde centro del MIC al margen basal fue de 9,77 mm ? 1,93 (derecho) y 10,12 mm ? 1,92 mm (izquierdo). Se encontró mayor distribución del MIC en el tercio medio mandibular. Se identificó el MIC en el 100 % de las muestras a través de CBCT por lo que su uso como examen complementario debe ser considerado al planificar cirugías en el sector anterior mandibular.

SUMMARY: The objective of the study was to determine the morphology of the mandibular incisive canal (MIC) and its location using cone beam computed tomography (CBCT) in the population of Valdivia, Chile. Descriptive cross-sectional study. MIC was identified in the canine cross image in 83 quadrants. Age, gender, quadrants, length from buccal alveolar ridge of canine to MIC, lingual and buccal cortical of canine to MIC, mandibular base of canine to MIC, and location of MIC (lingual, middle and buccal third) were recorded. Measurements were recorded in millimeters. Independent sample Student-T test was performed to determine length variables and Chi-square test was performed to determine spatial location of MIC, in relation to age group and gender. MIC was evaluated in all samples (100 %). MIC was found mainly in the mandibular third quadrant (p < 0.05). The mean from the MIC to the lingual cortex is 5.25 mm ? 1.42 mm (right) and 5.24 mm ? 1.18 mm (left). The mean from the MIC to the buccal cortex was 4.42 ? 1.29 mm (right) and 4.53 mm ? 1.24 mm (left). The mean between the center of the canal and the buccal alveolar ridge was 18.89 mm ? 2.68mm (right) and 18.20 mm ? 3.06 mm (left), the mean from the center of the MIC to the basal edge was 9.77 mm ? 1.93 (right) and 10.12 mm ? 1.92 mm (left). A greater distribution of MIC was found in the mandibular third quadrant. MIC was identified in 100 % of the samples through CBCT, therefore, its use as a complementary examination should be considered when planning surgeries in the anterior mandibular area.

The usage of the terms mandibular canal, inferior alveolar canal, and inferior dental canal in the academia: a bibliometric analysis / El uso de los términos canal mandibular, canal alveolar inferior y canal dental inferior en la academia: un análisis bibliométrico

SUMMARY: A recent study found that the mandibular canal might be preferably called the inferior alveolar canal in recent publication years, certain journal categories, countries and departments with which the authors were affiliated. The canal can also be called the inferior dental canal that was not included in that study. This bibliometric analysis was conducted to evaluate the entire relevant literature, and to investigate if inferior alveolar canal was trending over the years. The Web of Science Core Collection electronic database was searched to identify publications exclusively mentioning mandibular canal, inferior alveolar canal, inferior dental canal, and publications mentioning them in combinations. Publication year, country of contributing authors, journal category, journal title, and citation count were recorded for the resultant publications. There were 1152 publications analyzed. Mandibular canal has always been the dominating term since the 1990s, whereas inferior alveolar canal seemed to become slightly more popular in the 2010s than in the past. Journals from dentistry, surgery, radiology, anatomy, and medicine all showed a preference towards mandibular canal. Leading dental surgery journals had a higher ratio of inferior alveolar canal usage than their dental radiology counterparts. Top 20 countries showed a preference towards mandibular canal except Saudi Arabia, which had 57.7 % of publications using inferior alveolar canal exclusively. Publications mentioning mandibular canal, inferior alveolar canal, and inferior dental canal did not differ in averaged citation count. The term mandibular canal was still dominating in all academic fields. The term inferior alveolar canal showed increased usage in the 2010s without an increasing trend. The argumentation of renaming mandibular canal as inferior alveolar canal has yet to accumulate considerable traction.

RESUMEN: Un estudio reciente encontró que el canal mandibular ha sido llamado en los últimos, canal alveolar inferior en ciertas categorías de revistas, países y departamentos con algunos autores asociadas a estas. El canal también se puede denominar canal dental inferior término que no se incluyó en ese estudio. Este análisis bibliométrico se realizó para evaluar la literatura relevante e investigar la frecuencia del uso de canal alveolar inferior en el tiempo. Se buscó en la base de datos electrónica de Web of Science Core Collection para identificar publicaciones que mencionan exclusivamente canal mandibular, canal alveolar inferior, canal dental inferior y publicaciones que las mencionan en combinaciones. El año de publicación, el país de los autores contribuyentes, la categoría de la revista, el título de la revista y el recuento de citas se registraron para las publicaciones resultantes. Se analizaron 1152 publicaciones. Desde la década de 1990, canal mandibular siempre ha sido el término predominante, mientras que canal alveolar inferior pareció volverse algo más popular en la década de 2010. Las revistas de odontología, cirugía, radiología, anatomía y medicina mostraron una preferencia por canal mandibular. Las principales revistas de cirugía dental tenían una proporción más alta de uso de canal alveolar inferior que sus contrapartes de radiología dental. Los principales 20 países mostraron una preferencia por canal mandibular, excepto Arabia Saudita, que tenía un 57,7 % de las publicaciones que usaban exclusivamente canal alveolar inferior. Las publicaciones que mencionan canal mandibular, canal alveolar inferior e canal dental inferior no difirieron en el recuento promedio de citas. El término canal mandibular todavía predomina en todos los campos académicos. El término canal alveolar inferior mostró un mayor uso en la década de 2010 sin una tendencia creciente, sin embargo el argumento de cambiar el nombre de canal mandibular a canal alveolar inferior en el futuro deberá ser ratificado.

Utilização e percepção da tomografia computadorizada de feixe cônico por especialistas em cirurgia e traumatologia bucomaxilofacial para avaliação de terceiros molares inferiores impactados / Use and perception of cone beam computed tomography by oral & maxillofacial surgeons for impacted lower third molars evaluation

Objetivo: conhecer o perfil demográfico e as características que levam à solicitação de tomografia computa-dorizada de feixe cônico (TCFC) pelos especialistas em Cirurgia e Traumatologia Bucomaxilofacial (CTBMF) do estado do Rio Grande do Sul, para diagnóstico e planejamento cirúrgico de terceiros molares inferiores (3MI) impactados. Métodos: foram enviados questionários eletrônicos para todos os especialistas em CTBMF do RS. O questionário compreendia perguntas demográficas, clínicas e imaginológicas. O teste Qui-Quadra-do foi utilizado para verificar a associação entre as variáveis. Resultados: 115 questionários foram respondi-dos.O exame mais solicitado foi a panorâmica (95%). A TCFC foi solicitada por 50 especialistas (30 utilizam software). Localização do canal mandibular, dilaceração radicular e reabsorção do segundo molar são os aspectos mais avaliados na TCFC (P < 0,05); já o contato da raiz com o canal mandibular foi dito ser avaliado nos dois exames. Complicações permanentes foram relatadas por 21 especialistas, associadas a profissionais com maior tempo de graduação e/ou especialização (P < 0,05), mas não com o tipo de exame solicitado (P > 0,05). Na percepção dos especialistas, a TCFC tem papel importante em casos de alta complexidade. Con-clusão: a panorâmica ainda é o exame mais utilizado para avaliação de 3MI impactados pelos especialistas em CTBMF do RS, porém a TCFC tem sido solicitada para complementação do diagnóstico e planejamento e como meio de segurança jurídica do profissional.(AU)

Objective: to recognize the demographic profile and the characteristics that lead to the request of cone beam computed tomography (CBCT) by Oral & Maxillofacial (OMF) Surgeons in the state of RS for the diagnosis and surgical planning of impacted lower third molars (3LM). Methods: electronic questionnaires were sent to all OMF surgeons in RS. The questionnaire comprised demographic, clinical, and imaging questions. The chi-square test was used to verify the association between variables. Results: 115 questionnaires were answered. The most requested exam was the panoramic (95%). CBCT was requested by 50 specialists (30 use software). Localization of the mandibular canal, root dilaceration, and resorption of the second molar are the most evaluated aspects in the CBCT (P <0.05); the contact of the root with the mandibular canal was said to be evaluated in both exams. Permanent complications were reported by 21 OMF surgeons, and were related to the time of graduation and/or specialization (P < 0.05), but not to the type of exam (P > 0.05). In the OMF surgeons' perception, the CBCT has an important role in cases of high complexity. Conclusion: panoramic radiograph still is the most used exam for the assessment of impacted 3LM by OMF surgeons in RS, however, CBCT has been requested to complement the diagnosis and treatment plan, and as a means of professional legal security.(AU)

Coronectomia em terceiro molar inferior: relato de casos / Coronectomy in lower third molar: case reports

O princípio da coronectomia ou odontectomia parcial intencional é a remoção da coroa do dente, deixando a raiz in situ. Essa técnica, quando aplicada para a remoção de um terceiro molar ou qualquer dente posterior incluso na mandíbula, tem o intuito de evitar danos ao nervo alveolar inferior. O objetivo do presente estudo foi relatar dois casos clínicos de terceiro molar inferior incluso apresentando suas raízes em íntima relação com o canal mandibular, e, para o tratamento, foi realizada a técnica da odontectomia parcial intencional. Informações sobre o déficit neurosensorial, infecção pós-operatória, tempo do pós-operatório e a taxa de sucesso são enfatizadas no estudo. Conclui-se que a odontectomia parcial intencional é uma técnica previsível e de fácil execução, podendo ser realizada em ambiente ambulatorial. Trata-se de um procedimento alternativo, útil nas extrações de terceiros molares inferiores inclusos que apresentam relação de proximidade com o canal mandibular... (AU)

The principle of coronectomy or intentional partial odontectomy is the removal of the tooth crown, leaving the root in situ. This technique aims to prevent damage to inferior alveolar nerve while applying to removal a third molar or posterior tooth impacted in mandible. In this study, we report two clinical cases with the impacted lower third molar presented roots in close proximity to the mandibular canal and the treatment was performed by intentional partial odontectomy. Neurosensory deficits, postoperative infection, periods off follow up and surgical outcomes were emphasized in this study. We concluded that the intentional partial odontectomy is a foreseeable technique and easy to perform in an outpatient setting. It is an alternative procedure in the extraction of impacted lower third molar that has a close relationship with mandibular canal... (AU)

Aspectos Biométricos del Canal Mandibular / Biometric Aspects of the Mandibular Canal

El canal mandibular recorre este hueso longitudinalmente, relacionándose en su segmento medio con las piezas dentarias molares y premolares. El conocimiento de la relación del canal mandibular con las piezas dentarias y con las corticales mandibulares es de gran importancia para la práctica de la implantología. En el presente estudio se analizan las relaciones de la porción media del canal mandibular con las corticales mandibulares pertenecientes a individuos de sexo femenino, de entre 50 y 65 años, con caracterización antropométrica coincidente con el registro. Se realizaron mediciones en tres niveles del segmento medio (A-B-C). Los resultados muestran que el canal mandibular presenta una forma ovoidea y que sus diámetros disminuyen a medida que desciende hasta el agujero mentoniano. Se observó además, un trayecto oblicuo y descendente, aproximándose a la cortical vestibular de la mandíbula. Se discute la importancia del conocimiento de las características biométricas del canal mandibular, en individuos de sexo femenino, del grupo etario seleccionado, debido a que estos son pacientes quienes tienen mayor necesidad de rehabilitación con implantes óseointegrados.

The mandibular canal have as longitudinally course, being related in its average segment to the dental pieces molars and premolars. The knowledge of the relation of the mandibular canal with the dental pieces and cortical bone is of great importance for the practice of the implant therapy. In the present study the relations of the average portion of the canal are analyzed to mandible with cortical mandibular bone pertaining to female sex of between 50 and 65 years obtained of different cemeteries, with coincident anthropometric characterization with the registry. Measurements were made in three levels of the average segment (A-B-C). The results show that the mandibular canal presents a ovoid form and that their diameters diminish as it descends until the mentoniano hole. It was observed, in addition an oblique and descendent passage, coming near to the cortical one to vestibular of the jaw. The importance of the knowledge of the biometrics aspects of the mandibular canal is discussed in female of the selected age group, because they are these patients who have greater necessity of implant therapy.

Reprodutibilidade diagnóstica das imagens radiográficas panorâmicas convencional e digitalizada invertida na detecção do teto do canal da mandíbula e do forame mentual / Diagnostic reproducibility of the conventional and negative digitized panoramic images of mandibular canal's superior wall and mentual foramen

Com o advento do implantes, a precisa localização de estruturas anatômicas, dentre elas o canal da mandíbula e o forame mentual, tornou-se uma necessidade primordial para os implantodontistas. O objetivo deste trabalho foi avaliar a reprodutibilidade diagnóstica da imagem panorâmica convencional e digitalizada invertida na detecção do teto do canal da mandíbula e do forame mentual. Foi utilizada uma amostra de setenta e sete radiografias panorâmicas de edentados totais. Estas foram digitalizadas por meio de um escaner, tendo o brilho e o contraste ajustado, bem como a transformação em negativo. A área posterior ao forame mentual foi dividida em três regiões e a presença do teto do canal foi classificada em uma escala de confiança de cinco pontos. O forame mentual foi classificado segundo os critérios propostos por Yosue et al.74 (1989). Tanto a panorâmica convencional, como a digitalizada invertida foram avaliadas por três implantodontistas, previamente calibrados, em duas ocasiões distintas com intervalo mínimo de dez dias. A reprodutibilidade intra-examinador foi avaliada empregando-se a estatística Kappa (k), segundo Light (kL). A concordância intra- examinador, segundo Landis & Kock31, variou em sofrível, regular e boa; entretanto, não houve diferença estatísticamente significante na maioria das situações. Concluímos que os valores foram de baixa concordância por ponto e por intervalo de confiança, quando os três examinadores avaliaram a presença do teto do canal da mandíbula e do forame mentual

The knowledge of precise location of mandibular canal and mentual foramen are very important in mandibular implant surgery. The aim of this study was to evaluate the diagnostic reproducibility of conventional and negative digitized conventional panoramic images of superior wall of mandibular canal and mentual foramen. A sample of 77 edentulous patient's panoramic radiographs was used. These radiographs were digitized by a scanner with adjusted bright and contrast and it showed in a negative mode. The posterior segment behind mentual foramen was divided into three parts and the presence of the superior wall of mandibular canal was classified according to five points scale. The mental foramen was classified according to criteria of Yosue et al,77 (1989). The conventional panoramic and digitized radiographies were evaluated twice by three previously calibrated implantodontits. The intra-observer reproducibility was found using Kappa's statistic, according Ligth. The intra-observer agreement varied between bearable and good according to Landis & Kock. However, there was no significant difference. We observed low agreement in the Kappa's values