Francisco Haiter Neto

New formula to objectively evaluate skeletal maturation using lateral cephalometric radiographs.

The aim of this study was to establish two new formulas for objectively evaluating skeletal maturation of cervical vertebrae in female and male Brazilian subjects using lateral cephalometric radiographs. The sample included 128 girls and 110 boys, aged 7.0 to 15.9 years, from the files of the Oral Radiology Clinic, Piracicaba Dental School, University of Campinas (Unicamp), SP, Brazil. The cervical vertebral bodies of C3 and C4 were traced and measured and regression formulas were developed in order to determine cervical vertebral bone age. Another sample of lateral teleradiographs and hand-wrist radiographs of 55 girls and 54 boys (aged 7.0 to 15.9 years) was used to verify the reliability of the developed regression formulas, as compared with bone age assessed using the Tanner et al.15 (2001) Method (TW3) in hand-wrist radiographs. The analysis of both the boys and girls data (ANOVA) showed no statistical difference between cervical vertebral bone age, bone age, and chronological age, indicating that these formulas can be used in this population (p=0.5721 and p=0.6007 for girls and boys, respectively). Female cervical vertebral bodies of C3 and C4 increased in an accelerated manner from 10 to 13 years. Analysis of the male sample showed that C3 measurements increased in an accelerated manner from 12 to 15 years. The C4 measurements, however, did not increase at all. Using cervical vertebral bone age it is possible to evaluate skeletal maturation objectively in cephalometric radiographs.

In vitro analysis of the radiodensity of indirect composites and ceramic inlay systems and its influence on the detection of cement overhangs

The purpose of this study was to evaluate the radiodensity of indirect restorative systems and to determine its influence on detection of resin cement overhangs. Sixty sound molars with similar dimensions were selected, and MOD inlay preparations were made in a standardized fashion with 6° taper of the walls. Restorations were made with a porcelain, Duceram LFC, and with three indirect composites, Solidex, Artglass, and Targis. Digital radiographic images were taken before and after cementation of the inlays (Digora system) and were analyzed on two regions, the cervical and the isthmus floor. Digital radiodensity measurements were performed on standardized points symmetrically distributed over each restoration and tooth structure. Cement overhangs were detected through visual analysis by three evaluators. Data were statistically analyzed utilizing ANOVA following Tukey’s test (p < 0.05), showing that Solidex presented lower radiodensity than Duceram LFC, and both Artglass and Targis presented similar higher levels of radiodensity than the other groups. Radiodensity of cervical regions was always greater than for isthmus floor regions. Detection of the resin cement overhangs is easier observed on Solidex and Duceram LFC. Radiodensity is highly influenced by restorative material type and tooth regions. The detection of radiopaque resin cement overhangs is influenced by radiodensity of restorative materials.

Estudo comparativo dos métodos de estimativa da idade óssea de Greulich & Pyle e Tanner & Whitehouse

Este estudo teve como objetivo verificar se os metodos de estimativa da idade ossea de Greulich & Pyle (GP), Greulich & Pyle Visual (GPV) e Tanner & Whitehouse (TW) poderiam ser aplicados a populacao brasileira e qual destes metodos seria o mais confiavel, quando comparados a idade cronologica do individuo. A amostra estudada constituiu-se de 160 individuos brasileiros, leucodermas, de ambos os sexos, com idades variando de 6 anos e 10 meses a 14 anos e 9 meses. Os resultados mostraram que, para o metodo GP, as correlacoes com a idade cronologica foram de 0,95 para o sexo masculino e 0,97 para o sexo feminino. Para o metodo GPV, as correlacoes foram de 0,96 e 0,97, respectivamente e para TW, de 0,96 e 0,97. Os resultados obtidos permitiram-nos concluir que, mesmo tendo sido propostos para populacoes diferentes da populacao em estudo, os metodos de estimativa da idade ossea estudados apresentaram altas correlacoes, quando comparados com a idade cronologica. Ainda, foram estabelecidos fatores de correcao, de modo a torna-los aplicaveis a populacao brasileira.

Computer-assisted analysis of cervical vertebral bone age using cephalometric radiographs in Brazilian subjects

The aims of this study were to develop a computerized program for objectively evaluating skeletal maturation on cephalometric radiographs, and to apply the new method to Brazilian subjects. The samples were taken from the patient files of Oral Radiological Clinics from the North, Northeast, Midwest and South regions of the country. A total of 717 subjects aged 7.0 to 15.9 years who had lateral cephalometric radiographs and hand-wrist radiographs were selected. A cervical vertebral computerized analysis was created in the Radiocef Studio 2 computer software for digital cephalometric analysis, and cervical vertebral bone age was calculated using the formulas developed by Caldas et al.17 (2007). Hand-wrist bone age was evaluated by the TW3 method. Analysis of variance (ANOVA) and the Tukey test were used to compare cervical vertebral bone age, hand-wrist bone age and chronological age (P < 0.05). No significant difference was found between cervical vertebral bone age and chronological age in all regions studied. When analyzing bone age, it was possible to observe a statistically significant difference between cervical vertebral bone age and hand-wrist bone age for female and male subjects in the North and Northeast regions, as well as for male subjects in the Midwest region. No significant difference was observed between bone age and chronological age in all regions except for male subjects in the North and female subjects in the Northeast. Using cervical vertebral bone age, it might be possible to evaluate skeletal maturation in an objective manner using cephalometric radiographs.

Diagnosis of invasive cervical resorption by using cone beam computed tomography: report of two cases

A radiographic interpretation is essential to the diagnosis of invasive cervical resorption (ICR) and the difficulty in distinguishing this lesion from internal root resorption has been highlighted in the literature. This paper reports the use of cone beam computed tomography (CBCT) in the diagnosis of ICR. The cases reports describe how CBCT can be used to make a differential diagnosis and also show that the use of this technology can provide relevant information on the location and nature of root resorption, which conventional radiographs cannot. As a result, the root canal treatment was not initially considered. The patients will be monitored and will undergo a scan after a short period of time to detect any small changes. It was observed that both cases benefited from CBCT in the diagnosis of ICR, because this imaging modality determined the real extent of resorption and possible points of communication with the periodontal space.

Interexaminer agreement in caries radiographic diagnosis by conventional and digital radiographs

The purpose of this research was to compare two digital storage phosphor systems and conventional film, as well as verify the interexaminer agreement in radiographic diagnosis on occlusal and proximal cavities. Two digital systems and conventional radiographic film were used to evaluate 144 tooth surfaces with and without cavities; the radiographs were analyzed and scored in a scale of 4 points. Thirteen undergraduates and an oral radiologist participated as examiners. A light microscopy analysis was accomplished in order to validate the research. The results showed that there was no significant difference between the radiographic systems, however all of them had significant differences when compared to light microscopy, except for the Digora system on the proximal surface when the radiologist was the examiner. In the interexaminer evaluation, a moderate agreement level was obtained, and a fair to moderate level was obtained between the students and the oral radiologist. Regarding the validation (sensitivity, specificity, positive predict and negative predict) the values were similar between students and the oral radiologist, except for the sensitivity value on the occlusal surface. The students had the highest number of false-positive results and the oral radiologist the highest number of false-negative results.

Avaliação de três métodos radiográficos (periapical convencional, periapical digital e panorâmico) no diagnóstico de lesões apicais produzidas artificialmente

This research was carried out in order to evaluate three radiographic methods--conventional periapical, digital periapical and panoramic--in the diagnosis of artificially produced periapical lesions. For this purpose, 5 mandibles, with lesions produced by means of spherical drills of different sizes, were used. The research was divided into five distinct phases, as follows: phase Z (initial)--characterized by the absence of lesion; phase R--lesion produced with a number 6 drill; phase J--lesion produced with a number 8 drill; phase D--lesion produced with a number 10 drill; and phase H--lesion reaching the vestibular cortex. The lesions were produced in quadrants. Radiographs were made after each phase and analyzed by 4 experts in radiology. For the digital system there was statistically significant difference in phase R (in the region of incisors) and in phase H (in the region of premolars). In the region of molars there was statistically significant difference in phase D for panoramic radiography. It must be pointed out that panoramic radiography produced the less effective results in phase H.

Stress Distribution in Human Zygomatic Pillar Using Three-Dimensional Finite Element Analysis

El objetivo de este articulo fue analizar la distribucion de la tension en el pilar cigomatico humano durante la contraccion del musculo masetero utilizando analisis de elementos finitos tridimensionales. Un modelo de tres dimensiones de dientes del hemicraneo facial fueron producidos sobre la base de datos de CT-scan. Se utilizo como modelo un craneo adulto de sexo masculino con la integridad de la anatomia estructural. Fuerzas musculares se aplicaron en el origen de los ascensores de los musculos de la mandibula y soportes se aplicaron a la superficie oclusal del primer y segundo molar para simular una carga masticatoria y estimular el pilar cigomatico. Condiciones de simetria se colocaron en el plano mediano. Se utilizaron restricciones en los planos superior y posterior. El analisis de las tensiones equivalentes von-Mises y maximo director se realizo a traves del campo de esfuerzos a lo largo del pilar cigomatico. Fue representada la concentracion de esfuerzos en el proceso alveolar, hueso cigomatico, proceso frontal y temporal del hueso cigomatico y el arco superciliar. La linea de tension indica la distribucion de la tension del maxilar hacia el hueso frontal y temporal. Las tensiones se produjeron debido a las fuerzas oclusales resultantes, que se apoyan principalmente por el hueso cigomatico, distribuidas de manera no uniforme y sobre todo a traves del pilar cigomatico. Este estudio ha contribuido a una mejor comprension de la distribucion de la tension en el pilar cigomatico para entender la influencia de la masticacion sobre la morfologia de este pilar y ser de utilidad en la practica clinica.

Estudo clínico comparativo da qualidade de imagem de três sistemas radiográficos digitais, filmes E-speed e filme digitalizado

The aim of this study was to evaluate, subjectively, the image quality of two CCD digital systems, a digital storage phosphor system, a digitized film and an E-speed film. Five objects were radiographed with 50, 60 and 70 kVp, with exposure times of 0.08, 0.13, 0.2, 0.4 and 0.8 s. In order to maximize the fidelity of the results, the dental X-ray unit employed was submitted to an evaluation so that the relation between exposure time and dose could be established. A good reproducibility was obtained. Six evaluators analyzed 375 images, using a scoring scale which ranged from 0 to 4. The results revealed different responses, indicating that the storage phosphor system had the best performance, in the various exposures employed. However, it was possible to conclude that all systems studied, except for the Sens-A-Ray, can offer images in ideal conditions for the diagnosis, as long as their latitudes are respected.The aim of this study was to evaluate, subjectively, the image quality of two CCD digital systems, a digital storage phosphor system, a digitized film and an E-speed film. Five objects were radiographed with 50, 60 and 70 kVp, with exposure times of 0.08, 0.13, 0.2, 0.4 and 0.8 s. In order to maximize the fidelity of the results, the dental X-ray unit employed was submitted to an evaluation so that the relation between exposure time and dose could be established. A good reproducibility was obtained. Six evaluators analyzed 375 images, using a scoring scale which ranged from 0 to 4. The results revealed different responses, indicating that the storage phosphor system had the best performance, in the various exposures employed. However, it was possible to conclude that all systems studied, except for the Sens-A-Ray, can offer images in ideal conditions for the diagnosis, as long as their latitudes are respected.

Linear density analysis of bone repair in rats using digital direct radiograph

The objective of this study was to assess bone density measurements for analysis of repairing fractures in rats using direct digital radiography under Dexamethasone effects. Thirty (30) young adult male Wistar rats were used, with an average weight of 200g, which were submitted to general anesthetics by ethyl ether. One rib of each animal was fractured by surgical technique. The rats were divided into 2 groups, named Control group - intraperitoneal administration of saline solution 1 hour prior to operation, and Group 1: intraperitoneal administration of Dexamethasone 0.1mg/Kg of weight 1 hour prior to operation, and two postoperative doses every 12 hours. The animals were sacrificed at 2, 3, 4, 7 and 14 days. The parts containing the hemi-thorax with the fractured rib were removed and submitted to direct digital radiography, where the linear density of the two extremities of the fracture were analyzed by the Digora System. The results showed that in the control group and in Group 1 there was a gradual and significant increase in linear density. The method used made it feasible to supply data that were statistically significant in assessing the gain in bone density during the period of time analyzed. In conclusion, direct digital radiograph is useful for bone density analysis for fracture repairing. The dose of Dexamethasone was not sufficient to alter the gain in bone density at the extremities of fracture.