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.

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)