Tomographic, microbiological and histological characterization of secondary apical periodontitis: case series

Abstract This case series included a tomographic, microbiological, and histopathological description of 15 secondary apical periodontitis (SAP) lesions obtained by apical microsurgery performed in 10 patients to better understand the etiology and pathogenesis of SAP. Preoperative tomographic analyses were performed through Cone beam computerized tomography - Periapical index (CBCT-PAI), and apical microsurgeries were then carried out. The removed apices were used for microbial culturing and for molecular identification using PCR for the detection of 5 strict anaerobic bacteria (P. gingivalis, P. intermedia, P. nigrescens, T. forsythia, and T.denticola) and 3 viruses Herpes simplex viruses (HSV), Cytomegalovirus (CMG) and Epstein-Barr Virus (EBV) by nested PCR. The removed apical lesions were histologically described. Univariate statistical analyses were performed by using STATA MP/16 (StataCorp LLC, College Station, TX, United States). CBCT-PAI analyses revealed PAI 4 and PAI 5 score lesions that involved cortical plate destruction. Eight SAPs were positive by culture, while nine SAP lesions were positive by PCR. Fusobacterium species were the most frequently cultured organisms in 7 SAP lesions, followed by D. pneumosintes in 3. In contrast, by single PCR, T. forsythia and P. nigrescens were detected in 5 lesions, T. denticola in 4 lesions, and P. gingivalis in 2 lesions. Twelve periapical lesions were granulomas, and the remaining three SAP lesions were radicular cysts. In conclusion, this case series study revealed that secondary apical lesions presented tomographic involvement of PAI 3 to 5, and that most SAP lesions were apical granulomas containing anaerobic and facultative microorganisms.

Resumo Esta série de casos incluiu uma descrição tomográfica, microbiológica e histopatológica de 15 lesões de periodontite apical secundária (SAP) obtidas por microcirurgia apical realizada em 10 pacientes para melhor compreender a etiologia e patogénese do SAP. As análises tomográficas pré-operatórias foram realizadas através de tomografia computadorizada de feixe cônico - índice Periapical (CBCT-PAI), e as microcirurgias apicais foram então realizadas. Os ápices removidos foram utilizados para a cultura microbiana e também para a identificação molecular por PCR para a detecção de 5 bactérias anaeróbias rigorosas (P. gingivalis, P. intermedia, P. nigrescens, T. forsythia, e T.denticola) e 3 vírus Herpes simplex (HSV), Cytomegalovirus (CMG) e Epstein-Barr Virus (EBV) por PCR aninhada. As lesões apicais removidas foram descritas histologicamente. Foram realizadas análises estatísticas univariadas utilizando STATA MP/16 (StataCorp LLC, College Station, TX, Estados Unidos da América). As análises CBCT-PAI revelaram lesões PAI 4 e PAI 5 que envolveram a destruição da placa cortical. Oito SAPs foram positivos por cultura, enquanto nove lesões de SAP foram positivas por PCR. As espécies de Fusobacterium foram os organismos mais frequentemente cultivados em 7 lesões SAP, seguidas por D. pneumosintes em 3. Em contraste, por PCR simples, T. forsythia e P. nigrescens foram detectados em 5 lesões, T. denticola em 4 lesões, e P. gingivalis em 2 lesões. Doze lesões periapicais foram granulomas, e as restantes três lesões SAP foram cistos. Em conclusão, este estudo de série de casos revelou que as lesões apicais secundárias apresentavam envolvimento tomográfico de PAI 3 a 5, e que a maioria das lesões de SAP eram granulomas apicais contendo microrganismos anaeróbios e facultativos.

Reabsorción dentinaria interna coronaria: informe de un caso clínico / Coronary internal dentine resorption: report of a clinical case

Objetivo: La reabsorción dentinaria interna es un pro- ceso causado por la actividad odontoclástica asociada princi- palmente a la inflamación pulpar crónica y/o traumatismos, y se caracteriza por la pérdida progresiva de tejido dentinario y la posible invasión al cemento. El presente informe describe el diagnóstico y tratamiento de un molar inferior que presentó un cuadro sintomático de reabsorción dentinaria interna. Caso clínico: Un paciente de 38 años fue derivado a la consulta por presentar una zona de reabsorción interna en un segundo molar inferior. Durante el examen clínico y ra- diográfico se tomó una radiografía preoperatoria periapical con radiovisiógrafo en la que se observó la presencia de un área compatible con el diagnóstico de reabsorción dentinaria interna, el que fue posteriormente confirmado por medio de una tomografía computada de haz cónico. La imagen de la lesión se presentó como una zona radiolúcida deformante de bordes nítidos, localizada a nivel de la cámara pulpar. El tra- tamiento consistió en la extirpación de la pulpa coronaria y de la instrumentación, desinfección y obturación de los conduc- tos radiculares y la cavidad de acceso. En el control clínico y radiográfico realizado luego de 3 años se observó que el paciente estaba asintomático y las estructuras perirradiculares se encontraban dentro de los límites normales. La observación histológica del material removido de la cámara pulpar reveló la presencia de un tejido granulomatoso con numerosos vasos sanguíneos y escasos focos micro hemorrágicos. Hasta el momento, el tratamiento endodóntico es el pro- cedimiento indicado para el tratamiento de la reabsorción dentinaria interna. Se destaca la importancia de la tomografía computada de haz cónico para el diagnóstico y tratamiento temprano de las reabsorciones dentinarias internas a efectos de contar con un pronóstico favorable (AU)

Aim: Internal dentine resorption is aprocess caused by odontoclastic activity, mainly associated with chronic pulpal inflammation and/or trauma, and it'scharacterized by a pro- gressive loss of dentine tissue and the possible invasion of the cementum. This report describes the diagnosis and treatment of a lower molar that presented a symptomatic case of inter- nal dentine resorption. Clinical case: A 38-years old patient was referred to the office because of presenting an area of internal resorption in a lower second molar. During clinical and radiographic exam- ination, a periapical preoperative radiograph with radiovisio- graph was taken, in which the presence of an area compatible with the diagnosis of internal dentine resorption was observed, which was later confirmed by a cone-beam computed tomog- raphy.The image of the lesion was presented as a deforming radiolucent area with sharp edges, located at pulp chamber level. Treatment consisted of the removal of the coronary pulp and the instrumentation, disinfection and filling of the root ca- nals and the access cavity. In the clinical and radiographic control carried out 3 years after procedure, it was observed that the patient was asymptomatic and the periradicular struc- tures were within normal limits. The histological observation of the removed material from the pulp chamber revealed the presence of a granulomatous tissue with numerous blood ves- sels and scarce micro hemorrhagic focus. Until now, the endodontic treatment is the indicated pro- cedure to treat internal dentine resorption. It is necessary to highlight the importance of the cone-beam computerized to- mography for the early diagnosis and treatment of internal dentine resorptions in order to have a favorable outlook (AU)

Can Implant-Retained Fixed Prostheses Trigger Bone Response in the Posterior Region of Edentulous Mandibles? A 32-Month Cone-Beam Computerized Tomography Study Analyzing Bone Height and Density.

Research has shown that the presence of implants can revert bone resorption and thus contribute to a greater preservation of the residual bone ridge, especially in edentulous mandibles. Bone remodeling has yet to be extensively studied in the context of prosthetic options for edentulous arches. This study aims to evaluate the long-term behavior of bone tissue in the posterior region of edentulous mandibles rehabilitated with implant-retained fixed prostheses using cone-beam computerized tomography (CBCT). Selected individuals were rehabilitated with 5 external hexagon platform implants and an implant-retained fixed prosthesis. The CBCT scans were performed immediately after surgery and after 8, 22, and 32 months (T0, T8, T22, and T32, respectively). Implants were installed between the mental foramen. Subsequently, bone crest height and density were measured in the posterior region of the mandible on the images in 3 distinct areas at 5, 10, and 15 mm from the center of the distal implant axis. Analysis of variance and the Bonferroni post hoc test were used for multiple analyses. The results indicate a statistically significant difference in bone height between T0 and all subsequent times; the bone height at T32 was 8.85% higher than at T0 (P = .05). There was a difference in bone height between all analyzed regions. The bone growth difference between the 5-mm and 15-mm positions was 28.42% after 32 months (P = .00). A significant increase of 5.76% in bone density was observed between T0 and T22 (P = .03). Within the limitations of this study (sample size, follow-up duration), it was demonstrated that the use of implant-retained fixed prostheses in the mandible resulted in qualitative and quantitative bone growth (bone preservation) in the posterior region of the mandible. Further research is needed to identify the validity of our findings for other populations and to determine the duration of the bone-remodeling process in rehabilitated edentulous mandibles.

Correlation between patient complaint, temporomandibular disorder diagnosis and mandible head morphology

The aim of this study was to evaluate the correlation between patient complaints, clinical diagnosis of temporomandibular disorder (TMD) based on the diagnostic criteria for TMD, and morphology of the mandibular condyle obtained by cone-beam computed tomography (CB-CT). Data were collected from 40 patients. The anatomy of the mandibular condyle was assessed using CB-CT, the diagnosis of TMD according to diagnostic criteria for TMD, and patients' complaints was registered at the appointment. Data were explored and all statistical references were completed in bicaudal tests, with 95% confidence level (α=0.05). The Chisquared test was used with Bonferroni correction (z-tests). Main complaints found were grouped as muscular, articular, muscular and articular, or headache and articular symptoms. Clinical diagnosis of TMD involved myalgia, local myalgia, myofascial pain, myofascial pain with reference, myofascial pain with arthralgia, arthralgia, or disc displacement with reduction. At least one joint showed condylar flattening, erosion, sclerosis, or osteophytes. No correlation was observed between main complaints, clinical diagnosis, and morphology of the mandibular condyle in all comparisons. The findings suggest that due to the absence of clinical and morphological correlation, CB-CTs should be requested only in specific cases, when doubt remain after careful TMD diagnosis, to avoid their over-indication(AU)

CBCT analysis of rabbit temporomandibular joints with osteoarthrosis induced by monoiodoacetate and papain / Análisis por TCCB de la articulación temporomandibular de conejos con osteoartrosis inducida por monoiodoacetato y papaina

Osteoarthrosis (OA) is a degenerative disease characterized by loss of joint cartilage, remodelling of the subchondral bone, narrowing of joint spaces and the formation of osteophytes. Animal models are used to study the mechanisms of OA, as well as to test the effects of anti-osteoarthrosis drugs. The objective of the present study was to determine the changes identifiable by imaging techniques occurring in rabbit temporomandibular joints (TMJ) at 15, 25 and 45 days after OA inducement by monoiodoacetate (MIA) and papain. The imaging technology used was cone-beam computerised tomography (CBCT). The model animals were 22 young adult male New Zealand rabbits, divided randomly into three study groups: Four rabbits in the control group, nine in the papain experimental group and nine in the monoiodoacetate (MIA) experimental group. OA was induced by arthrocentesis in the lower compartment of both TMJs. The rabbits were examined by CBCT at 15, 25 and 45 days after the injection of MIA and papain. The mandibular condyles presented loss of their rounded shape, deformation of the condyle or mandibular fossa, cortical irregularity, cortical wear and changes in the dimensions of the condyle. OA induction by MIA and papain generates changes observable by CBCT in the dimensions of the mandibular condyle in rabbits. Both inducers promote signs compatible with OA on the joint surfaces of the TMJ; MIA promotes more expressive changes.

La osteoartrosis (OA) es una enfermedad degenerativa caracterizada por la pérdida de cartílago articular, remodelación ósea subcondral, estrechamiento del espacio articular y formación de osteofitos. El modelo animal es utilizado para estudiar los mecanismos de la OA, así como testar el efecto de drogas anti-osteoartrosis. El objetivo de este estudio fue determinar los cambios imagenológicos, mediante tomografía computarizada cone-beam (TCCB), que se generan en 15, 25 y 45 días, luego de la inducción de OA por medio de Monoiodoacetato (MIA) y Papaína sobre la ATM de conejos. Fueron utilizados 22 conejos machos, adultos jóvenes, de raza New Zealand divididos aleatoriamente en 3 grupos de estudio: 4 conejos para un grupo control, 9 conejos para el grupo experimental con Papaína y 9 conejos para el grupo experimental con monoiodoacetato (MIA). Se realizó la inducción de OA por la técnica de artrocentesis en el compartimiento inferior de ambas ATMs. Se les realizó examen de TCCB en los días 15, 25 y 45 tras la inyección de MIA y de papaina. Los cóndilos mandibulares presentaron pérdida de forma redondeada de cóndilo, deformidad de cóndilo o fosa mandibular, irregularidad de corticales, desgaste de corticales, cambio de dimensiones de cóndilo. La inducción de OA por medio de MIA y papaína genera cambios en la dimensión del cóndilo mandibular de conejos observables a través de TCCB. Además, ambos inductores promueven signos compatibles con OA en las superficies articulares de la ATM, siendo que la MIA promueve cambios más expresivos.

Relation between periapical lesions and sinus membrane thickening assessed by Cone Beam Computed Tomography.

The aim of this study was to evaluate thickening of the Schneiderian membrane and to determine its association with periapical pathologies, using computerized cone beam tomography. An observational, analytical, cross-sectional retrospective study was conducted. A total 179 maxillary sinuses were evaluated using CBCT. The presence of sinus membrane thickening and its association with unhealthy teeth was analyzed. Results are shown as percentages with 95% confidence intervals (95%CI); Chi square test was used with a significance level of 5%.Sinus membrane thickening was detected in 70 cases (39%; 95%CI=32% to 46%) and no sinus membrane thickening was observed in 109 (61%; 95%CI = 54% to 68%) (p<0.05). The 70 cases showing sinus membrane thickening included 46 of odontogenic origin (66%; 95%CI = 54% to 76%) and 24 (34%; 95%CI = 24% to 46%) of non odontogenic origin (p<0.05). The frequency of odontogenic causes followed a heterogeneous distribution (p<0.05): penetrating caries, failing endodontic therapy, root remnants, deep restorations, implants, periodontal pathology. The main cause was caries (46%; 95%CI=32% to 60%) followed by failing endodontic therapy (26%, 95% CI=16% to 40%). The frequency distribution of involved teeth was uneven (p<0.05), with tooth 16 (33%; 95%CI=21% to 47%) being the most frequently involved, followed by tooth 26 (30%; 95%CI=19% to 45%).The high incidence of sinus pathology of odontogenic origin shows the need for interdisciplinary work involving dentists and ear-nose-throat specialists. Caries, inadequate restorations, periodontal lesions, implants, and the presence of root remnants are the main causes of Schneiderian membrane thickening. The use of CBCT for diagnosis and treatment planning allows detecting maxillary sinus membrane thickening and determining its association with an odontogenic etiology.

El objetivo del presente trabajo fue evaluar el engrosamiento de la membrana de Schneider y determinar su asociación con patologías periapicales, mediante tomografía computarizada cone beam (CBCT). Se realizó un estudio observacional, analítico, retrospectivo y transversal. Un total de 179 senos maxilares fueron evaluados utilizando CBCT. Se analizó la presencia de engrosamiento de la membrana sinusal y su asociación con piezas dentarias sin vitalidad pulpar. Los resultados se muestran como porcentajes con intervalos de confianza del 95% (IC del 95%). Se utilizó la prueba de Chi cuadrado con un nivel de significación del 5%. Se detectó engrosamiento de la membrana sinusal en 70 casos (39%; IC del 95% = 32% a 46%) y no se observó engrosamiento de la membrana sinusal en 109 (61%; IC del 95% = 54% a 68%) (p < 0.05). Los 70 casos que mostraron engrosamiento de la membrana sinusal incluyeron 46 de origen odontogénico (66%; IC del 95% = 54% a 76%) y 24 (34%; IC del 95% = 24% a 46%) de origen no odontogénico (p <0,05). La frecuencia de las causas odontogénicas siguió una distribución heterogénea (p <0.05): caries penetrantes, tratamiento endodóntico deficiente, restos radiculares, restauraciones profundas, implantes, patología periodontal. La principal causa fue la caries (46%; IC 95% = 32% a 60%), seguida por endodoncia deficiente (26%, IC 95% = 16% a 40%). La frecuencia se distribuyó en forma heterogénea entre las distintas piezas (p<0,05). Las piezas más afectadas fueron la 16 (33%; IC95=21% a 47%) y la 26 (30%; IC95=19% a 45%). La alta incidencia de patología sinusal de origen odontogénico implica la necesidad del trabajo interdisciplinario entre odontólogos y otorrinolaringólogos. Caries, restauraciones inadecuadas, lesiones periodontales, implantes y la presencia de restos radiculares son las principales causas del engrosamiento de la membrana de Schneider. El uso de CBCT para el diagnóstico y la planificación del tratamiento permite detectar el engrosamiento de la membrana del seno maxilar y determinar su asociación con una etiología odontogénica.

Avaliação das vias aéreas superiores por meio de tomografia computadorizada de feixe cônico em indivíduos submetidos à cirurgia ortognática: revisão de literatura / Upper airway evaluation by cone beam computerized tomography in individuals who underwent ortognactic surgery: literature review

Introdução: além de amplamente utilizada na área odontológica Recebido em: 06/01/2018 para avaliação de tratamentos ortodônticos e para planejamento de cirurgias, a Tomografia Computadorizada de Feixe Cônico tem ganhado espaço também na literatura médica para avaliação das vias aéreas superiores. Isto porque as imagens tridimensionais da TCFC permitem a avaliação das áreas seccionais e volumes do espaço aéreo faríngeo. Objetivo: demonstrar, por meio de revisão da literatura, os efeitos da cirurgia ortognática sobre as vias aéreas superiores, avaliados por meio de tomografia computadorizada de feixe cônico (TCFC) e sua relação com a AOS. Material e Método: foi realizada uma busca nas bases de dados Lilacs e Pubmed utilizando como palavras-chave: tomografia computadorizada de feixe cônico, apneia do sono e cirurgia ortognática. Foram incluídos artigos nos idiomas português e inglês, sem limitação temporal, que tinham como principal foco avaliar as mudanças na via aérea superior após a cirurgia ortognática por meio de TCFC. Resultados: ao todo foram encontrados 11 artigos, dos quais 5 atenderam os critérios de inclusão e foram, portanto, analisados. Observou-se que: 3 artigos realizaram cirurgia bimaxilar e, neles, os resultados mostraram que não houve alteração da via aérea total após a cirurgia; 1 utilizou a técnica de retroposicionamento mandibular e observou que, após a cirurgia, houve diminuição significativa do volume total da via aérea e do seu segmento hipofaríngeo, bem como redução da área seccional faríngea mínima; 2 realizaram cirurgia de avanço maxilar que levou ao aumento significativo do volume da via aérea superior em ambos; 1 realizou cirurgia de avanço maxilomandibular que levou ao aumento significativo do espaço aéreo posterior. Conclusão: os resultados da presente revisão de literatura mostraram que a cirurgia ortognática levou a alterações da dimensão da via aérea superior na maior parte dos estudos analisados, a depender da técnica utilizada, que não se relacionou com a ocorrência de sintomas respiratórios ou AOS.

Introduction: in addition to being widely used in the dental area, for the evaluation of orthodontic treatments and for the planning of surgeries, Cone-Beam Computed Tomography has also gained space in the medical literature for evaluation of the upper airways. This is because the three-dimensional images of the CBCT allow the evaluation of the sectional areas and volumes of the pharyngeal space. Objective: to demonstrate, through a literature review, the effects of orthognathic surgery on the upper airways, by means of cone-beam computed tomography (CBCT), and its relationship with OSA. Material and Method: a search was carried out at Bireme and Pubmed databases using the following keywords: CBCT, sleep apnea and orthognathic surgery. Articles with the main focus of evaluating changes in the upper airway after an orthognathic surgery by means of CBCT was included in the study. Results: A total of 11 articles were found, of which 5 met the inclusion criteria and were, therefore, analyzed. It was observed that: in 3 studies bimaxillary surgery was performed and the results showed that there was no alteration of the total airway after surgery; 1 used the mandibular setback technique and observed that, after surgery, there was a significant decrease in the total volume of the airway and its hypopharyngeal segment, as well as reduction of the minimal pharyngeal cross-sectional area; in 2 maxillary advancement surgery was performed, which led to a significant increase in upper airway volume; 1 performed maxillomandibular advancement surgery, which led to a significant increase in posterior airway space. Conclusion: the results of the present literature review showed that orthognathic surgery led to alterations in the size of the upper airway in most of the studies analyzed, depending on the technique used. These alterations were not related to the occurrence of respiratory symptoms or OSA.

Uso da tecnologia CAD/CAM na Odontologia: do enceramento diagnóstico ao desenho digital integrado. A mudança de um paradigma / The use of CAD/CAM technology in dentistry: from the diagnostic wax-up to the integrated digital design. A paradigm shift

O objetivo deste trabalho foi descrever a técnica de DDI (desenho digital integral) em substituição ao ED (enceramento diagnóstico), mudando um paradigma na Odontologia. Com o uso do DDI, não é necessário realizar o enceramento diagnóstico para estabelecer a meta protética. Esta é obtida digitalmente em um ambiente 3D, com mais requinte de informações e maior precisão. O DDI é então materializado (prototipado) utilizando uma impressora 3D, dentro do ambiente do consultório. Atualmente, os recursos CAD/CAM de baixo custo estão disponíveis para uso odontológico, e os resultados obtidos com esta tecnologia justificam a incorporação do tratamento 3D. Desta forma, a técnica do enceramento dental estaria próxima do fim, sendo que, em um futuro próximo, dentistas/técnicos de prótese serão dental digital designers e todo o conhecimento se voltará para o domínio dos programas de informática, e não para aquisição de equipamentos complexos e de alto custo.

The objective of this study was to describe the IDD technique (integrated digital design) to replace the DW (diagnostic waxing) as a paradigm shift in Dentistry. In this way, it is not necessary to perform the diagnostic waxing to establish the prosthetic outcomes. This is achieved in a 3D environment, with more information refi nement and greater accuracy. The IDD is then materialized (prototyped) using a 3D printer within the dental offi ce. Currently, the CAD/CAM resources are low-cost and available for dental use, with the obtained results justifying the incorporation of the 3D dental treatment. Thus, the diagnostic waxing would be close to an end; in the near future, clinicians/laboratory technicians will be dental digital designers and all knowledge will be managed to computer software domain and not to the acquisition of complex and expensive production equipment.

Anatomical variations of mandibular canal detected by panoramic radiography and CT: a systematic review and meta-analysis.

OBJECTIVES: To investigate the anatomical variations of the mandibular canal through assessment in situ, panoramic radiography, CT or CBCT and assess their frequency. METHODS: Articles were selected from databases (Cochrane Library, LILACS, ProQuest, PubMed, Scopus, Web of Science and Google Scholar), articles without limitations of language, in which the main objective was to evaluate the frequency of bifurcation of the mandibular canal through assessment in situ, panoramic radiography, CT or CBCT were selected. A meta-analysis of prevalence using random effects was performed. RESULTS: Using a selection process in two phases, 15 articles were identified, and a meta-analysis was conducted. The results from these meta-analyses showed that the overall prevalence of anatomical variations for in situ studies was 6.46%, and through assessment of panoramic radiography and CT or CBCT the overall prevalence shown was 4.20% and 16.25%, respectively. CONCLUSIONS: There are two types of variations of the mandibular canal: the retromolar canal and bifid mandibular canal. The frequency variations through assessing in situ, panoramic radiography and CT or CBCT were 6.46%, 4.20% and 16.25%, respectively.

Estudio morfológico y morfométrico del agujero mentoniano mediante evaluación por tomografía computarizada Cone Beam en pacientes adultos dentados / Morphological and morphometric study of the mental foramen using cone-beam CT in dentate adult patients

Objetivo. Estudiar la morfología y morfometría del agujero mentoniano mediante tomografía ConeBeam en pacientes adultos dentados Metodología. Estudio descriptivo transversal. Se estudiaron 180 tomografías ConeBeam analizando la distancia de la cortical superior e inferior del agujero mentoniano hasta la cresta alveolar y la basal mandibular respectivamente, así como la ubicación, forma, tamaño y presencia de agujeros accesorios. Resultados. Se encontró que la media respecto de la cortical superior a la cresta alveolar fue de 15.00 mm y la media respecto de la cortical inferior a la basal mandibular de 13.75 mm. La ubicación más frecuente se apreció en el eje longitudinal del segundo premolar (44.4% en el lado derecho y 47.2% en el lado izquierdo). La forma predominante fue la oval y el tamaño se ubicó en el rango de 2 mm a 2.99mm. Los agujeros accesorios estuvieron presentes en 55.5% de los casos. Conclusión. El conocimiento exacto de la ubicación del agujero mentoniano y sus variaciones, ayuda a una correcta planificación para los procedimientos quirúrgicos, y a una eficaz colocación de anestesia, evitando daños al paquete vasculonervioso.

Objective. To study the morphology and morphometry of the mental foramen using cone-beam CT in dentate adult patients. Methods. Transversal descriptive study in which 180 cone-beam CTs were studied to analyze the distance between the upper and lower cortical areas of the mental foramen to the alveolar crest and the mandibular basal bone respectively, as well as the location, shape, size and presence of accessory holes. Results. It was found that the mean of the upper cortical area in relation to the alveolar crest was 15.00 mm and the mean of the lower cortical area to the mandibular basal bone was 13.75 mm. The most frequent location was the longitudinal axis of the second premolar (44.4% right side and 47.2% left side). The predominant shape was oval and the size was in the range of 2.00 mm to 2.99 mm. Accessory holes were present in 55.5% of cases. Conclusion. Knowing the exact location of the mental foramen and its variations helps to properly plan surgical procedures and to administer anesthesia effectively without damaging the neurovascular bundle.

Evaluation of diagnostic accuracy of conventional and digital periapical radiography, panoramic radiography, and cone-beam computed tomography in the assessment of alveolar bone loss.

BACKGROUND: To evaluate the diagnostic accuracy of different radiographic methods in the assessment of proximal alveolar bone loss (ABL). MATERIALS AND METHODS: ABL, the distance between cement-enamel junction and alveolar bone crest, was measured in 70 mandibular human teeth - directly on the mandibles (control), using conventional periapical radiography with film holders (Rinn XCP and Han-Shin), digital periapical radiography with complementary metal-oxide semiconductor sensor, conventional panoramic, and cone-beam computed tomography (CBCT). Three programs were used to measure ABL on the images: Image tool 3.0 (University of Texas Health Sciences Center, San Antonio, Texas, USA), Kodak Imaging 6.1 (Kodak Dental Imaging 6.1, Carestream Health(®), Rochester, NY, USA), and i-CAT vision 1.6.20. Statistical analysis used ANOVA and Tukey's test at 5% significance level. RESULTS: The tomographic images showed the highest means, whereas the lowest were found for periapical with Han-Shin. Controls differed from periapical with Han-Shin (P < 0.0001). CBCT differed from panoramic (P = 0.0130), periapical with Rinn XCP (P = 0.0066), periapical with Han-Shin (P < 0.0001), and digital periapical (P = 0.0027). Conventional periapicals with film holders differed from each other (P = 0.0007). Digital periapical differed from conventional periapical with Han-Shin (P = 0.0004). CONCLUSIONS: Conventional periapical with Han-Shin film holder was the only method that differed from the controls. CBCT had the closest means to the controls.

Retratamento endodôntico: casuística e comparação de dois métodos de diagnóstico por imagem / Endodontic retreatment: case studies and comparison of two methods of diagnosis by image

O exame radiográfico é um componente de diagnóstico essencial no plano de tratamento de problemas de origem endodôntica. Apesar do desenvolvimento técnico-científico da endodontia, o número de retratamentos endodônticos continua elevado. Neste cenário, a tomografia computadorizada de feixe cônico (TCFC) é utilizada para se obter imagens tridimensionais sem distorções de estruturas pertencentes ao complexo dento-maxilo-facial e seus tecidos adjacentes. Frente aos fatos, este estudo teve como objetivos comparar a incidência de retratamento endodôntico nos anos de 1997, 2001 e 2007 de pacientes atendidos nas clínicas de endodontia da FOB. Foi analisado e quantificado o total de casos de retratamento de canais, os grupos de dentes mais envolvidos, sua distribuição segundo o gênero, relacionando-se também os possíveis motivos dessa ocorrência; comparar dois métodos de diagnóstico por imagem em odontologia, a tomografia computadorizada de feixe cônico e a radiografia periapical. A comparação foi realizada por dois EXAMINADORES, um endodontista e outro radiologista, os quais analisaram as 102 imagens geradas dos exames de 41 pacientes com a necessidade de retramento endodôntico. Não houve aumento na incidência nos três períodos estudados; houve predomínio para o sexo feminino; o retratamento ocorreu em maior número para o dente incisivo central superior e como motivo para sua realização, a maior incidência foi para obturação endodôntica aquém do limite CDC. Quanto à comparação dos exames por imagem, a TCFC revelou-se o procedimento de maior concordância de diagnóstico entre os profissionais, fato que aponta tal método relevante na concretização do diagnóstico, localização e reconstrução de imagens de ótima resolução, contribuindo com os profissionais no planejamento e no sucesso terapêutico, diminuindo a possibilidade de falhas e o consequente insucesso do tratamento endodôntico.

The radiographic test is an essential diagnosis component in the treatment of problems of endodontic origin. Despite the technical and scientific developments in endodontics, the number of endodontic retreatment continues high. In this scenario, Computerized Beam Cone Tomography (CBCT) is used to obtain three-dimensional images without distortions of structures belonging to the dentomaxillofacial complex and its adjacent tissues. The CBCT allows a precocious detection of the dimension and extension of periapical and resorptive diseases, even before they appear in periapical radiographs. In face of such facts, this study aimed at comparing the incidence of endodontic retreatment in 1997, 2001 and 2007 in patients assisted at FOBs endodontic clinics. For this end, all cases of root canal retreatment were analyzed and quantified, as well as the group of teeth with higher incidence, the distribution according to gender, including a survey of the possible reasons for such occurrence, compare two methods of diagnosis by image in endodontics, the Computerized Beam Cone Tomography and the periapical radiograph. Such comparison was performed by two examiners, an endodontist and a radiologist, who analyzed the 102 images obtained from 41 cases of endodontic retreatment assisted at FOB between 2008 and 2009. For this comparison, a questionnaire about the main findings detected in the images was used. There was no increase in incidence in the three periods on focus and a higher incidence among females; the tooth with higher incidence for retreatment was the maxillary central incisor. The main reason for retreatment was endodontic restoration beneath cement-dentin-root canal limit. As for the comparison of tests by image, CBCT showed to be the procedure of higher concordance of diagnosis among the professionals, what indicates that this method is relevant in the diagnosis, localization and reconstruction of images of fairly good resolution...

Estudo tomodensitométrico de áreas desdentadas da mandíbula por meio da tomografia computadorizada de feixe-cônico / Tomodensitometric study of edentulous mandibular areas through cone beam computerized tomography

Objetivo - O uso da tomografia computadorizada de feixe-cônico (CBCT) é útil para avaliar a densidade mandibular durante o planejamento de implantes. Métodos - Os autores utilizaram a escala de cinza para mensurar os valores de densidade de cinco regiões: linha mediana,pré-molares direito/esquerdo e molares direito/esquerdo. Utilizaram cinquenta cortes transaxiais obtidos de dez mulheres (de 40 a 49 anosde idade) examinadas em um aparelho Newtom 3G. Resultados - Os valores de densidade para molares foram mais altos do que os da linha mediana. As regiões de pré-molares apresentaram os valores mais baixos. Não houve diferenças estatisticamente significantes entre os lados (nível de 5%). Conclusões - Outros estudos devem ser desenvolvidos para avaliar estes achados iniciais utilizando diferentes equipamentos de CBCT e grupos de pacientes.

Objective - The use of cone beam computerized tomography (CBCT) is useful to evaluate the mandibular density during the implants planning. Methods - The authors had used the gray scale to measure density values from five different regions: midline, right and left premolars and, right and left molars. They used fifty transaxials tomograms assessed from ten women (from 40 to 49 years-old) scanned on a Newtom 3G unit. Results - The density values to molars were higher then to midline. Premolars regions had presented the lowest values. There are no statistically significant differences between sides (level of 5%). Conclusions - Others studies must be developed to evaluate these initialfindings applying different CBCT machines and groups of patients.