A system for automatic classification of endodontic treatment quality in CBCT.

OBJECTIVES: An evaluation of the effectiveness of a new computational system proposed for automatic classification, developed based on a Siamese network combined with Convolutional Neural Networks (CNNs), is presented. It aims to identify endodontic technical errors using Cone Beam Computed Tomography (CBCT). The study also aims to compare the performance of the automatic classification system with that of dentists. METHODS: One thousand endodontically treated maxillary molars sagittal and coronal reconstructions were evaluated for the quality of the endodontic treatment and the presence of periapical hypodensities by three board-certified dentists and by an oral and maxillofacial radiologist. The proposed classification system was based on a Siamese network combined with EfficientNet B1 or EfficientNet B7 networks. Accuracy, sensivity, precision, specificity, and F1-score values were calculated for automated artificial systems and dentists. Chi-square tests were performed. RESULTS: The performances were obtained for EfficienteNet B1, EfficientNet B7 and dentists. Regarding accuracy, sensivity and specificity, the best results were obtained with EfficientNet B1. Concerning precision and F1-score, the best results were obtained with EfficientNet B7. The presence of periapical hypodensity lesions was associated with endodontic technical errors. In contrast, the absence of endodontic technical errors was associated with the absence of hypodensity. CONCLUSIONS: Quality evaluation of the endodontic treatment performed by dentists and by Siamese Network combined with EfficientNet B7 or EfficientNet B1 networks was comparable with a slight superiority for the Siamese Network. CLINICAL RELEVANCE: CNNs have the potential to be used as a support and standardization tool in assessing endodontic treatment quality in clinical practice.

Evaluation of bone repair with platelet-rich fibrin following the extraction of impacted third molars - randomized clinical trial

Background: The aim of the present study was to evaluate postoperative effects of platelet-rich fibrin (PRF) in wound and bone healing, pain, swelling and periodontal complications outcomes after impacted third molars extraction. Material and methods: A prospective, randomized, split-mouth, double-blind clinical trial was conducted. PRF was placed within sockets following tooth removal and before suturing mucoperiosteal flap while no treatment was performed on control group's sockets. Patients were evaluated considering bone volume which was obtained in the 90-day postoperative period. Other variables included trabecular thickness, trabecular distance and grey values, pain, swelling, and wound healing. A Wilcoxon test and a t-Student test were used at a 5% significance level and a Friedman test was used to multiple comparisons. Results: Forty-four surgeries were performed in the present study. The patients' mean age was 22.41 (± 2.75 years) and 72.73% were women. PRF was associated to increased trabecular thickness and bone volume means (p < 0.001). The experimental group had significantly lower pain scores at 4h, 6h, 8h, 16h, 24h, and 72h (p ˂ 0.05). Mean swelling was lower on the experimental group (p < 0.001). The PRF group showed significant higher wound healing (p ˂ 0.001). Conclusions: Alveolar filling with PRF improves wound and bone healing after extractions while also decreasing pain and swelling in the postoperative period. (AU)

Influence of kilovoltage-peak and the metal artifact reduction tool in cone-beam computed tomography on the detection of bone defects around titanium-zirconia and zirconia implants.

Purpose: The aim of this study was to assess the influence of kilovoltage-peak (kVp) and the metal artifact reduction (MAR) tool on the detection of buccal and lingual peri-implant dehiscence in the presence of titanium-zirconia (Ti-Zr) and zirconia (Zr) implants in cone-beam computed tomography (CBCT) images. Materials and Methods: Twenty implant sites were created in the posterior region of human mandibles, including control sites (without dehiscence) and experimental sites (with dehiscence). Individually, a Ti-Zr or Zr implant was placed in each implant site. CBCT scans were performed using a Picasso Trio device, with variation in the kVp setting (70 or 90 kVp) and whether the MAR tool was used. Three oral radiologists scored the detection of dehiscence using a 5-point scale. The area under the receiver operating characteristic (ROC) curve, sensitivity, and specificity were calculated and compared by multi-way analysis of variance (α=0.05). Results: The kVp, cortical plate involved (buccal or lingual cortices), and MAR did not influence any diagnostic values (P>0.05). The material of the implant did not influence the ROC curve values (P>0.05). In contrast, the sensitivity and specificity were statistically significantly influenced by the implant material (P<0.05) with Zr implants showing higher sensitivity values and lower specificity values than Ti-Zr implants. Conclusion: The detection of peri-implant dehiscence was not influenced by kVp, use of the MAR tool, or the cortical plate. Greater sensitivity and lower specificity were shown for the detection of peri-implant dehiscence in the presence of a Zr implant.

Automatic Classification System for Periapical Lesions in Cone-Beam Computed Tomography.

Imaging examinations are of remarkable importance for diagnostic support in Dentistry. Imaging techniques allow analysis of dental and maxillofacial tissues (e.g., bone, dentine, and enamel) that are inaccessible through clinical examination, which aids in the diagnosis of diseases as well as treatment planning. The analysis of imaging exams is not trivial; so, it is usually performed by oral and maxillofacial radiologists. The increasing demand for imaging examinations motivates the development of an automatic classification system for diagnostic support, as proposed in this paper, in which we aim to classify teeth as healthy or with endodontic lesion. The classification system was developed based on a Siamese Network combined with the use of convolutional neural networks with transfer learning for VGG-16 and DenseNet-121 networks. For this purpose, a database with 1000 sagittal and coronal sections of cone-beam CT scans was used. The results in terms of accuracy, recall, precision, specificity, and F1-score show that the proposed system has a satisfactory classification performance. The innovative automatic classification system led to an accuracy of about 70%. The work is pioneer since, to the authors knowledge, no other previous work has used a Siamese Network for the purpose of classifying teeth as healthy or with endodontic lesion, based on cone-beam computed tomography images.

Tomographic evaluation of the effect of simvastatin topical use on alveolar bone microarchitecture, pain and swelling after mandibular third molar extraction: a randomized controlled trial.

OBJECTIVES: To evaluate the effect of a collagen sponge containing simvastatin on socket healing in terms of bone microarchitecture through tomographic analysis, pain, and swelling after impacted third molar extraction. MATERIALS AND METHODS: In this single-blind, split-mouth, randomized clinical trial, 29 patients undergoing impacted third molar extraction were allocated into two groups: (i) test group, a collagen sponge containing simvastatin was inserted within the sockets; and (ii) control group, in which sockets retained the clot. Bone volume (BV), bone volume fraction (BV/TV), trabecular thickness (Tb.Th), trabecular spacing (Tb.Sp), and gray scale were evaluated using cone beam computed tomography (CBCT) acquired immediately postoperative and 3 months after surgery. Pain, swelling, and wound healing were evaluated using the 10-point visual analogue scale, three extra-oral reference measurements, and the Landry index. RESULTS: In total, 22 participants remained in the study; no loss-to-follow-up was related to the intervention. BV and BV/TV were significantly higher at 3 months postoperatively in the test group compared with the control group and were correlated with greater bone trabeculation. Pain, edema, and the Landry index revealed a greater inflammatory response in the test group during early repair. Simvastatin contributed to bone healing, with no adverse effects or postoperative complications. CONCLUSIONS: The absorbable collagen sponge containing simvastatin improved BV, BV/TV, and trabecular bone, indicating the potential of this drug to induce the formation of autogenous bone. CLINICAL RELEVANCE: Intraosseous statins represent a promising, low-cost, and easy-to-use alternative for alveolar ridge preservation and bone regeneration. TRIAL REGISTRATION: Brazilian Registry of Clinical Trials (REBEC), No. RBR-523N7R.

Automatic exposure compensation in intraoral digital radiography: effect on the gray values of dental tissues.

BACKGROUND: This study aimed to investigate the effect of automatic exposure compensation (AEC) of intraoral radiographic systems on the gray values of dental tissues in images acquired with or without high-density material in the exposed region using different exposure times and kilovoltages. The influence of the distance of the high-density material was also investigated. METHODS: Radiographs from the molar region of two mandibles were obtained using the RVG 6100 and the Express systems, operating at 60 and 70 kV and 0.06, 0.10, and 0.16 s. Subsequently, a titanium implant was inserted in the premolar's socket and other images were acquired. Using the ImageJ software, two regions of interest were determined on the enamel, coronary dentine, root dentine, and pulp of the first and second molars to obtain their gray values. RESULTS: In the RVG 6100, the implant did not affect the gray values (p > 0.05); the increase in kV decreased it in all tissues (p < 0.05), and the exposure time affected only the root dentine and pulp. In the Express, only enamel and coronary dentine values changed (p < 0.05), decreasing with the implant presence and/or with the increase in exposure factors. The distance of the implant did not affect the results (p > 0.05). CONCLUSIONS: AEC's performance varies between the radiographic systems. Its effect on the gray values depends not only on the presence or absence of high-density material but also on the kV and exposure time used.

Influência dos terceiros molares inferiores sobre a saúde periodontal dos segundos molares / Influence of third lower molars on periodontal health of second molars

Introdução: Quando presente, o terceiro molar inferior (3MI) pode causar vários problemas aos pacientes, dentre esses os defeitos periodontais com comprometimento do segundo molar inferior (2MI). Esta pesquisa teve como objetivo avaliar a correlação do posicionamento dos 3MI com as alterações periodontais nos 2MI. Metodologia: Tratou-se de um estudo prospectivo de coorte, do qual participaram pacientes com presença de 3MI. As tomografias foram avaliadas, e registrada a posição do 3MI, de acordo com a classificação de Winter (vertical, mésio-angular, disto-angular e horizontal). Foram avaliadas as variáveis índice de placa, profundidade de sondagem, sangramento à sondagem, nível clínico de inserção e recessão gengival. Resultados: A amostra foi composta por 32 pacientes (42 dentes). Os dentes classificados como mésio-angulares apresentaram os maiores índices de profundidade de sondagem tanto nos sítios distais quanto nos mesiais do 2MI (média 3,41mm), em comparação às demais angulações. Sangramento à sondagem (7 dentes) e índice de placa (12 dentes) estiveram mais presentes nos dentes verticais. Nenhum dente apresentou recessão gengival. Conclusões: Os 3MI mesioangulares demonstraram os piores resultados em relação à profundidade de sondagem do 2MI, e os verticais apresentaram maior sangramento à sondagem e maior índice de placa... (AU)

Introduction: When present, the lower third molar (3MI) can cause several problems to patients, including periodontal defects with involvement of the second lower molar (2MI). The objective of this research was to evaluate the correlation of the 3MI positioning with the periodontal changes in the 2MI. Methodology: This was a prospective cohort study involving patients with 3MI. The tomographs were evaluated and the position of the 3MI was recorded according to Winter's classification (vertical, mesio-angular, distal-angular and horizontal). The variables plaque index, probing depth, bleeding on probing, clinical insertion level and gingival recession were evaluated. Results: The sample consisted of 32 patients (42 teeth). The mesioangular teeth presented the highest probing depth indices in both the distal and mesial sites of the 2MI (average 3.41mm), compared to the other angles. Bleeding the probing (7 teeth) and plaque index (12 teeth) were more present in the vertical teeth. No teeth showed gingival recession. Conclusions: The mesioangular 3MI showed the worst results in relation to the 2MI probing depth, and the vertical ones showed greater bleeding on probing and higher plaque índex... (AU)

Positioning errors of dental implants and their associations with adjacent structures and anatomical variations: A CBCT-based study.

PURPOSE: The objective of the present study was to evaluate the prevalence of dental implants positioning errors and their associations with adjacent structures and anatomical variations by means of cone-beam computed tomography (CBCT). MATERIALS AND METHODS: CBCT images of 207 patients (584 dental implants) were evaluated by 2 oral radiologists. The distance between the implant and the adjacent teeth/implants was measured and classified as adequate (≥1.5 mm and ≥3 mm, respectively) or inadequate. The presence of thread exposure, cortical perforation, implant dehiscence, implant penetration into adjacent structures, and anatomical variations was also recorded. The incisor canal diameter and the depth of the concavity of the submandibular fossa were measured in order to evaluate their correlations with the frequency of implant penetration in these structures. Descriptive analyses, the Fisher exact test, and Spearman correlation analysis were performed (α=0.05). RESULTS: The overall prevalence of positioning errors was 82.9%. The most common error was the inadequate distance between the implant and the adjacent teeth/implants. The presence of anatomical variations did not significantly influence the overall prevalence of errors (P>0.05). There was a positive correlation between the diameter of the incisor canal and the frequency of implant penetration in this structure (r=0.232, P<0.05). CONCLUSION: There was a high prevalence of dental implant positioning errors, and positioning errors were not associated with the presence of anatomical variations. Professionals should be aware of the space available for implant placement during the preoperative planning stage.

Effect of different exposure times on caries detection and pixel value in a wireless digital system.

OBJECTIVES: : The aim of this study was to assess, using the CDR Wireless®, the effect of different exposure times on caries detection and pixel intensity values. MATERIALS AND METHODS: Forty teeth were x-rayed using a Schick CDR Wireless sensor at eight different exposure times - 0.06, 0.10, 0.13, 0.16, 0.20, 0.25, 0.30, and 0.32 s. Four observers evaluated the images for presence of carious lesions scoring proximal surfaces of each tooth on a 5-point scale. Scores were compared to histological sections of the teeth. Accuracy was evaluated by means of ROC curve analysis. Radiographs of an aluminum step wedge were obtained using the same eight exposure times. Pixel intensity measurements were obtained, and mean pixel values were statistically analyzed using linear regression. RESULTS: The Az for each exposure time varied from 0.53 to 0.62. Two-way analysis of variance and Tukey test demonstrated that the exposure time of 0.25 s presented the best result and was significantly higher than 0.30 s and 0.35 s. In regard to mean pixel values, two different behaviors were observed, and the exposure time of 0.20 s presented mean pixel values in both phases. CONCLUSION: The performance of the exposure times from 0.06 s to 0.25 s was satisfactory for proximal caries detection, and 0.25 s is the best as indicated for this finality. CLINICAL RELEVANCE: Considering that a reduction of exposure time represents a reduction of patient exposure dose, and this reduction cannot neglect image quality, the behavior of any digital system must be carefully evaluated.

Cemento-Osseous Dysplasias: Imaging Features Based on Cone Beam Computed Tomography Scans

Abstract Imaging exams have important role in diagnosis of cemento-osseous dysplasia (COD). Cone beam computed tomography (CBCT) stands out for allowing three-dimensional image evaluation. This study aimed to assess the prevalence of cases diagnosed as COD on CBCT scans, as well identify the main imaging features related to these lesions. An analysis was performed in a database containing 22,400 radiological reports, in which all cases showing some type of COD were initially selected. These CBCT exams were reevaluated to confirm the radiographic diagnosis and determine the prevalence and distribution of the types of COD with regard to gender, age and preferred location, while describing its most common imaging aspects. Data were presented using descriptive analyses. There were 82 cases diagnosed as COD in the CBCT images (prevalence of 0.4%). The distribution of patients was 11 (13.4%) male and 71 (86.6%) female, with a mean age of 49.8 years (age-range 17-85 years). There were 47 (57.3%) cases of periapical COD, 23 (28%) of focal COD and 12 (14.6%) of florid COD. The mandible was more affected than the maxilla. In most cases, the lesions were mixed or hyperdense. All COD had well-defined limits and there were no cases of tooth displacement. In conclusion, periapical COD was the most common type and the most affected bone was the mandible. Imaging evaluation is critical for diagnosis and dentists should bear in mind all possible radiographic presentations of COD in order to prevent misleading diagnoses and consequently, inadequate treatments.

Resumo Os exames por imagem têm papel importante no diagnóstico da displasia cemento-óssea (DCO). A tomografia computadorizada por feixe cônico (TCFC) se destaca por permitir a avaliação tridimensional da imagem. O objetivo neste estudo foi avaliar a prevalência de casos diagnosticados como DCO nos exames de TCFC, bem como identificar as principais características de imagem relacionadas a essas lesões. Uma análise foi realizada em um banco de dados contendo 22.400 laudos radiológicos, no qual todos os casos que apresentavam algum tipo de DCO foram inicialmente selecionados. Estes exames foram reavaliados para confirmar o diagnóstico radiográfico e determinar a prevalência e distribuição dos tipos de DCO em relação ao sexo, idade e localização preferencial, além de descrever seus aspectos imaginológicos mais comuns. Os dados foram apresentados por meio de análise descritiva. Oitenta e dois casos foram diagnosticados como DCO nas imagens de TCFC (prevalência de 0,4%). A distribuição dos pacientes foi de 11 (13,4%) homens e 71 (86,6%) mulheres, com idade média de 49,8 anos (faixa etária de 17 a 85 anos). Houve 47 (57,3%) casos de DCO periapical, 23 (28%) de DCO focal e 12 (14,6%) de DCO florida. A mandíbula foi mais afetada que a maxila. Na maioria dos casos, as lesões foram mistas ou hiperdensas. Todas as DCO apresentaram limites bem definidos e não houve casos de deslocamento dentário. Em conclusão, a DCO periapical foi o tipo mais comum e o osso mais afetado foi a mandíbula. A avaliação da imagem é crítica para o seu diagnóstico e os dentistas devem ter em mente todas as possíveis apresentações radiográficas da DCO, a fim de prevenir diagnósticos enganosos e, conseqüentemente, tratamentos inadequados.

Cemento-Osseous Dysplasias: Imaging Features Based on Cone Beam Computed Tomography Scans.

Imaging exams have important role in diagnosis of cemento-osseous dysplasia (COD). Cone beam computed tomography (CBCT) stands out for allowing three-dimensional image evaluation. This study aimed to assess the prevalence of cases diagnosed as COD on CBCT scans, as well identify the main imaging features related to these lesions. An analysis was performed in a database containing 22,400 radiological reports, in which all cases showing some type of COD were initially selected. These CBCT exams were reevaluated to confirm the radiographic diagnosis and determine the prevalence and distribution of the types of COD with regard to gender, age and preferred location, while describing its most common imaging aspects. Data were presented using descriptive analyses. There were 82 cases diagnosed as COD in the CBCT images (prevalence of 0.4%). The distribution of patients was 11 (13.4%) male and 71 (86.6%) female, with a mean age of 49.8 years (age-range 17-85 years). There were 47 (57.3%) cases of periapical COD, 23 (28%) of focal COD and 12 (14.6%) of florid COD. The mandible was more affected than the maxilla. In most cases, the lesions were mixed or hyperdense. All COD had well-defined limits and there were no cases of tooth displacement. In conclusion, periapical COD was the most common type and the most affected bone was the mandible. Imaging evaluation is critical for diagnosis and dentists should bear in mind all possible radiographic presentations of COD in order to prevent misleading diagnoses and consequently, inadequate treatments.

Effects of Zoledronic Acid in Experimental Periapical Lesions in Rats: An Imaging and Histological Analysis.

The aim of this study was to assess the imaging and histological features of experimental periapical lesions, including the adjacent alveolar bone, in rats under zoledronic acid treatment. The study used 40 male Wistar rats distributed into 8 groups of 5 animals each: G1: induction of periapical lesion (PL) and weekly intraperitoneal administration (WIPA) of saline solution (0.9% NaCl) for 4 weeks; G2: PL induction and WIPA of zoledronic acid (0.15 mg/kg/week) for 4 weeks; G3: PL induction and WIPA of saline solution for 8 weeks; G4: PL induction and WIPA of zoledronic acid for 8 weeks; G5:WIPA of saline solution for 4 weeks and subsequent PL induction; G6: WIPA of zoledronic acid for 4 weeks and subsequent PL induction; G7: WIPA of saline solution for 8 weeks and subsequent PL induction; G8: WIPA of zoledronic acid for 8 weeks and subsequent PL induction. The administration of zoledronic acid or saline solution continued after PL induction until the euthanasia. Thus, cone beam computed tomography and histological analysis were performed. Statistical analyzes were performed by ANOVA and Kruskal-Wallis test. Groups treated with zoledronic acid showed significantly smaller size of PL than the groups treated with 0.9% NaCl (p<0.05). PLs were formed by chronic inflammation ranging from mild to moderate, with no difference between groups. In all specimens, no mandibular necrosis was observed. In conclusion, the presence of PLs apparently does not represent an important risk factor for the development of bisphosphonate-related osteonecrosis of the jaws.

Effects of Zoledronic Acid in Experimental Periapical Lesions in Rats: An Imaging and Histological Analysis

Abstract The aim of this study was to assess the imaging and histological features of experimental periapical lesions, including the adjacent alveolar bone, in rats under zoledronic acid treatment. The study used 40 male Wistar rats distributed into 8 groups of 5 animals each: G1: induction of periapical lesion (PL) and weekly intraperitoneal administration (WIPA) of saline solution (0.9% NaCl) for 4 weeks; G2: PL induction and WIPA of zoledronic acid (0.15 mg/kg/week) for 4 weeks; G3: PL induction and WIPA of saline solution for 8 weeks; G4: PL induction and WIPA of zoledronic acid for 8 weeks; G5:WIPA of saline solution for 4 weeks and subsequent PL induction; G6: WIPA of zoledronic acid for 4 weeks and subsequent PL induction; G7: WIPA of saline solution for 8 weeks and subsequent PL induction; G8: WIPA of zoledronic acid for 8 weeks and subsequent PL induction. The administration of zoledronic acid or saline solution continued after PL induction until the euthanasia. Thus, cone beam computed tomography and histological analysis were performed. Statistical analyzes were performed by ANOVA and Kruskal-Wallis test. Groups treated with zoledronic acid showed significantly smaller size of PL than the groups treated with 0.9% NaCl (p<0.05). PLs were formed by chronic inflammation ranging from mild to moderate, with no difference between groups. In all specimens, no mandibular necrosis was observed. In conclusion, the presence of PLs apparently does not represent an important risk factor for the development of bisphosphonate-related osteonecrosis of the jaws.

Resumo O objetivo deste estudo foi avaliar as características histológicas e de imagem de lesões periapicais experimentais, incluindo o osso alveolar adjacente, em ratos sob tratamento com ácido zoledrônico. O estudo utilizou 40 ratos Wistar, machos, distribuídos em 8 grupos de animais cada: G1: indução de lesão periapical (LP) e administração intraperitoneal semanal (AIS) de solução salina (NaCl 0.9%) por 4 semanas; G2: indução de LP e AIS de ácido zoledrônico (0,15 mg/kg/week) por 4 semanas; G3: indução de LP e AIS de solução salina por 8 semanas; G4: indução de LP e AIS de ácido zoledrônico por 8 semanas; G5- AIS de solução salina por 4 semanas e subsequente indução de LP; G6- AIS de ácido zoledrônico por 4 semanas e subsequente indução de LP; G7: AIS de solução salina por 8 semanas e subsequente indução de LP; G8: AIS de ácido zoledrônico por 8 semanas e subsequente indução de LP. A administração de ácido zoledrônico ou solução salina continuou após indução de LP até a eutanásia. Após isso, tomografia computadorizada de feixe cônico e análise histológica foram realizadas. Análises estatísticas foram realizadas por ANOVA e teste de Kruskal-Wallis. Os grupos tratados com ácido zoledrônico mostraram LPs significativamente menores que os grupos tratados com NaCl 0.9% (p <0.05). LPs eram formadas por inflamação crônica variando de leve a moderada, sem diferença entre os grupos. Em todos os espécimes, necrose mandibular não foi observada. Em conclusão, a presença de LPs aparentemente não representa um fator de risco importante para o desenvolvimento de osteonecrose relacionada ao uso de bisfosfonatos.

Microbial contamination in intraoral phosphor storage plates: the dilemma.

OBJECTIVES: The aims of this study were to evaluate microbial contamination in phosphor storage plates in dental radiology services and discuss the possible origin of this contamination. MATERIALS AND METHODS: The sample comprised 50 phosphor plates: 14 plates from service A, 30 from service B, and 6 in the control group, consisting of plates never used. Damp sterile swabs were rubbed on the phosphor plates, and then transferred to tests tubes containing sterile saline solution. Serial dilutions were made, and then inoculated in triplicate on Mueller Hinton agar plates and incubated at 37 °C/48 h, before counting the colony-forming units (CFU). The samples were also seeded in brain-heart infusion medium to confirm contamination by turbidity of the culture medium. All solutions, turbid and clean, were seeded in selective and non-selective media. RESULTS: At service A and B, 50 and 73.3 % of the phosphor plates were contaminated, respectively. This contamination was mainly due to bacteria of the genus Staphylococcus. CFU counts ranged from 26.4 to 80.0 CFU/plate. CONCLUSIONS: Most of the phosphor plates evaluated shown to be contaminated, mainly by Staphylococcus ssp. Quantitatively, this contamination occurred at low levels, possibly arising from handling of the plates. The use of a second plastic barrier may have diminished contamination by microorganisms from the oral cavity. CLINICAL RELEVANCE: There is a risk of cross-contamination by phosphor storage plates used in dental radiology services.

Human identification study by means of frontal sinus imaginological aspects.

The objective of this study was to evaluate the applicability of human identification parameters, established by Tatlisumak et al. (2007), by means of cone-beam computed tomography and extraoral radiographs of the frontal sinus region. From a total of 58 dry skulls, 26 were selected. Posteroanterior, profile cephalometric radiographs and cone-beam computed tomography images were acquired, adopting a specific method for reproducibility purposes. The images were evaluated by two examiners, previously calibrated, in a darkened environment and at two distinct sessions, with a minimum of 15 days between them. The characteristics of the frontal sinus were analyzed using the Cohen's kappa test, for categorical variables, and Lin's concordance correlation coefficient (CCC) for continuous variables. Acceptable values of inter method variability for the categorical variables were found, while same cannot be told for continuous variables. The parameters evaluated for the frontal sinus on extraoral radiographs and cone-beam computed tomographs were mostly concordant, with the exception of three. Categorical and discrete variables showed an intra- and interexaminer concordance ranging from good to perfect, and the quantitative continuous variables showed concordance ranging from moderate to excellent. The parameters examined are applicable and reproducible using multiplanar reconstructions of cone-beam computed tomography and extraoral radiographs of the frontal sinus.

Evaluation of third molar development in the estimation of chronological age.

The purpose of this study was to evaluate the correlation between chronological age and the degree of third molar mineralization by Demirjian's developmental stages (Demirjian et al., 1973) using panoramic radiography. From a total of 11.396 digital panoramic radiographs of patients from three oral radiology private clinics from the northeast region of Brazil, obtained from January to June 2009, 2097 radiographic images from patients aged between 6 and 22 years were selected. The images were analyzed individually by two obsevers using a 21-inch computer screen and Windows Picture and Fax Viewer. Reliability was achieved by intra- and interobserver evaluation, using the Kappa test. Chronological age, calcification stage, gender and third molar were interrelated using a multiple linear regression model, considering age as a response variable. There was reliability with Demirjian et al.'s developmental stage assesment, displaying a significant relationship between mineralization stages and patients' age (P<0.05). There was no significant difference between the average age and the calcification stage taking gender and localization of the third molar into consideration. It is possible to estimate chronological age based on Demirjian's stage of a third molar, regardless of gender and location.

Avaliação de fraturas radiculares em imagens digitais com variações de angulagens / Evaluation of root fracture using digital images with angular

O objetivo da pesquisa foi avaliar a influência da variação da angulagem horizontal no diagnóstico de FRVs em dentes tratados endodonticamente. Vinte e dois pré-molares permanentes com raízes retas e ápices formados foram divididos em grupos: Grupo 01(controle): dois dentes, um deles com núcleo intrarradicular; Grupo 2: dez dentes com fratura; Grupo 3: dez dentes com fratura e núcleo intrarradicular. As amostras foram submetidas a testes de compressão com uma carga de 200 kg a uma velocidade de 0,5 mm / min. Radiografias periapicais foram obtidas (70 kVp, 10 mA, e tempo de exposição de 0,3 seg.) pelo Sistema Digora® em ângulos horizontais, na direção orto radial e com uma mudança de ângulo de 25º para a direita e para a esquerda. As imagens foram avaliadas por cinco endodontistas. O diagnóstico de dentes fraturados e não fraturados foi maior para o 1.º pré-molar (51,66%) que para o 2.º (43,1%). A presença de fratura vertical foi registrada em 60,9% e 66,7% para o 1.º e 2.º prémolares, respectivamente. A presença de fratura mostra associação estatisticamente significante com a presença de núcleo intrarradicular e a variação de angulagem no 2.º pré-molar (p-valor = 0,011). Esses resultados sugerem que variações na angulagem horizontal podem otimizar o diagnóstico de FRVs... (AU)

This study aimed to evaluate the influence of changing horizontal angle during periapical radiography on the diagnosis of VRFs in endodontically treated teeth. Twenty-two single-rooted premolars with straight root canals and apex formation were divided into groups: Group 1 (control) - two non-fractured teeth, one of them with intraradicular post; Group 2 - ten fractured teeth; and Group 3 - ten fractured teeth with intraradicular post. Specimens were subjected to compression testing with a load of 200 kg at a speed of 0.5 mm/min. Periapical radiographs were obtained (70 kVp, 10mA, and 0.3 sec exposure time) in a Digora™ system at horizontal angles in the orthoradial direction and with a 25º angle shift to the right and to the left. Images were evaluated by five endodontists. The diagnosis of fractured and non-fractured roots was higher for the first premolar (51.6%) than for the second premolar (43.1%). The presence of VRFs was recorded in 60.9% of cases for the first premolar, and in 66.7% for the second premolar. Presence of VRFs showed a statistically significant association with presence of intraradicular post and angle variation in the second premolar (p=0.011). These results suggest that changes in horizontal angulation, may optimize the diagnosis of VRFs... (AU)

The effect of two enhancement tools on the assessment of the relationship between third molars and the inferior alveolar canal.

OBJECTIVE: This study aims to assess the relationship between the inferior alveolar canal (IAC) and inferior third molars using digital panoramic images (DPI) with and without enhancement and compare the panoramic signs with cone beam computed tomography (CBCT) findings. METHODS: The DPIs and CBCT of 50 patients were analyzed. The DPIs were copied and enhanced using edge enhancement and an invert tool and then analyzed by two observers using the scores: darkening of the root; deflection of the root; narrowing of the root; superimposition of the root; bifurcation of the root over the IAC; diversion of the IAC; interruption of the cortex of the IAC, and no radiographic findings noted. Kappa and exact binominal tests were used to analyze the correlation between DPIs and CBCT images. The intimate relationship scores were evaluated using a t-test and Mann-Whitney test. RESULTS: The original DPIs, and the edge enhanced and invert tool images produced kappa coefficients of 0.528, 0.528 and 0.551, respectively. There was no difference among the methods evaluated in this study (p = 0.981). CONCLUSION: Similar agreement was observed between DPIs with and without enhancement. However, panoramic radiography is not the ideal method to analyze the relationship between lower third molars and the IAC.

The influence of display modalities on proximal caries detection and treatment decision / Influência dos meios de apresentação radiográfica no diagnóstico e tratamento da cárie

The aim of this study was to investigate the influence of digital radiographic display on caries detection and choice of treatment among undergraduate students. Forty images of extracted human teeth were acquired using a PSP digital system. The proximal surfaces were evaluated for the presence of proximal caries and choice of treatment by 36 undergraduate students,divided into three groups according to the semester they were taking. The images were evaluated in two forms of image display: laptop, and printed on acetate viewed on a lightbox.The accuracy of the different forms of image display on caries detection was evaluated by means of ROC curve analysis andits effect by mixed linear regression. Residue analysis was used to verify the adequacy of the treatment of choice for the chosen diagnosis. There was no significant effect either for the display modalities (p=0.058) or for the different undergraduate student groups (p=0.991). The Az was 0.539 for printed images and0.516 for laptop. The decisions based on treatment of choice were consistent with the scores achieved for caries detection. Accuracy of caries detection using a laptop was comparable to accuracy using printed images. Treatment decision was not affected by image display modality. The semester of the dentistry course that undergraduate students were taking did not significantly increase the accuracy of their proximal caries detection.

Objetivo deste estudo foi investigar a influência do meio de apresentação da imagem radiográfica digital no diagnóstico dacarie e na decisão de tratamento realizado por alunos de graduação. Foram obtidas 40 imagens digitais de dentes humanos extraídos através do sistema digital PSP. As superfícies proximais dos dentes foram avaliadas quanto à presença de cárie proximal por 36 estudantes de odontologia, distribuídos em três grupos de acordo com o nível de formação. As avaliações foram efetuadas em um laptop e em imagens impressas com o auxílio do negatoscópio. A acurácia dos meios de apresentação quanto à detecção de cárie incipiente foi avaliada pela média das áreas sob as curvas ROC e seu efeito por uma análise de regressão linear mista. Para a tomada de decisão terapêutica foi realizada uma análise de resíduos para verificar sua adequação ao diagnóstico. Não houve efeito significativo nem para a modalidade de visualização (p=0.058) e nem para os grupos de alunos (p=0.991). A média das áreas sob as curvas Roc para o filme foi de 0.539 e de 0.516 para negatoscópio. A decisão de tratamento foi condizente com o diagnóstico efetuado. A acurácia do diagnóstico da cárie proximal realizado em tela de laptop é comparável ao realizado em negatoscópio. A tomada de decisão terapêutica não foi afetada pelo meio de apresentação da imagem radiográfica digital. A progressão do aluno no curso não melhora a precisão diagnóstica da cárie proximal.