Karina Lopes Devito

Evaluation of the correlation between disc displacements and degenerative bone changes of the temporomandibular joint by means of magnetic resonance images

The aim was to evaluate the correlation between disc displacements and degenerative bone changes in magnetic resonance images (MRI) of 112 patients of both genders, with signs and symptoms of temporomandibular disorder. For this purpose, a calibrated examiner evaluated 224 MRI by assigning scores for the displacement of the disc and degenerative bone changes. Disc displacement was found in 58.42% of the temporomandibular joints (TMJs) evaluated. Anterior displacement of the disc with reduction was the most common, occurring in 67.18% cases of joints with disc displacement. Degenerative bone changes were observed in 53.94% of the TMJs analysed. There was significant correlation between disc displacement with reduction and condylar flattening, disc displacement without reduction and condylar flattening, disc displacement without reduction, and associated degenerative bone changes (flattening and erosion, flattening, osteophyte and erosion; flattening and osteophytes, erosion and sclerosis, flattening and sclerosis, flattening, osteophytes and sclerosis). The correlation between advanced cases of disc displacement and the occurrence of degenerative bone changes emphasises the importance of MRI for an accurate diagnosis and development of an appropriate treatment plan and in cases in which clinical examination is not sufficient for these purposes.

Temporomandibular disorder in patients with juvenile idiopathic arthritis: clinical evaluation and correlation with the findings of cone beam computed tomography

OBJECTIVE The objective of this study was to assess the presence of temporomandibular disorder (TMD) in patients with juvenile idiopathic arthritis (JIA), and correlate with tomographic findings and clinical aspects. STUDY DESIGN Fifteen patients with JIA were evaluated by means of RDC/TMD, and submitted to a cone beam computerized tomography (CBCT) examination, then correlated with the clinical diagnosis of TMD with tomographic findings, gender, age at the time of evaluation, time elapsed since the onset of symptoms, and time of treatment of JIA. RESULTS In the 30 temporomandibular joints evaluated, 25 (83.3%) were clinically diagnosed with TMD. Although tomographic alterations have frequently been found (83.3%), only 5 (16.7%) were clinically diagnosed with osteoarthritis/arthrosis. There was a difference in the degree of TMD when evaluated, the time elapsed since the onset of symptoms, and the time of treatment of JIA. CONCLUSIONS Diagnosis based on physical examination and complementary evaluation is necessary to provide early therapeutic procedures so that possible functional and/or anatomical problems do not develop.

An artificial multilayer perceptron neural network for diagnosis of proximal dental caries

OBJECTIVE To evaluate if the application of an artificial intelligence model, a multilayer perceptron neural network, improves the radiographic diagnosis of proximal caries. STUDY DESIGN One hundred sixty radiographic images of proximal surfaces of extracted human teeth were assessed regarding the presence of caries by 25 examiners. Examination of the radiographs was used to feed the neural network, and the corresponding teeth were sectioned and assessed under optical microscope (gold standard). This gold standard served to teach the neural network to diagnose caries on the basis of the radiographic exams. To gauge the networks capacity for generalization, i.e., its performance with new cases, data were divided into 3 subgroups for training, test, and cross-validation. The area under the receiver operating characteristic (ROC) curve allowed comparison of efficacy between network and examiner diagnosis. RESULTS For the best of the 25 examiners, the ROC curve area was 0.717, whereas network diagnosis achieved an ROC curve area of 0.884, indicating a sizeable improvement in proximal caries diagnosis. CONCLUSION Considering all examiners, the diagnostic improvement using the neural network was 39.4%.

Influence of maxillomandibular positioning in cone beam computed tomography for implant planning

The aim of this study was to evaluate the influence of changes in maxillomandibular positioning during cone beam computed tomography (CBCT) imaging on the planning of dental implants. Ten skulls were marked bilaterally with metal spheres in four regions: incisors, canine, premolars, and molars. CBCT scans were obtained in seven positions: standard position (SP), displacements of 10° and 20° above and below the SP, and lateral displacements of 10° and 20° from the SP. Subsequently, bilateral measurements of the height and width of the maxilla and mandible were performed on all images. The results showed that the position with a displacement of 20° above the SP presented the greatest differences in the measurements of bone height and width. In the bilateral comparisons, the maxillary bone width showed the greatest differences, especially for the regions of the premolars and molars. It is concluded that alterations of positioning during the acquisition of CBCT images can lead to alterations in the measurements of bone height and width, which may result in errors in implant planning and cause damage to anatomical structures.

Salivary Periodontopathic Bacteria in Children and Adolescents with Down Syndrome.

Objective To assess and compare salivary periodontopathic bacteria between groups of Down syndrome and non-Down syndrome children and adolescents. Materials and Methods This study included a sample of 30 Down syndrome children and adolescents (G-DS) and 30 age- and sex-matched non-Down syndrome subjects (G-ND). Clinical examination determined the gingival bleeding index (GBI) and plaque index. Unstimulated whole saliva samples were collected from all participants. The fluorescence in situ hybridization (FISH) technique identified the presence and density of eight periodontopathic bacteria in saliva. The statistical analysis included chi-square and Mann-Whitney U tests. Results In the G-DS group, bleeding on probing was more frequent (p = 0.037) and higher densities of Campylobacter rectus (p = 0.013), Porphyromonas gingivalis (p = 0.025), Treponema denticola (p = 0.026), Fusobacterium nucleatum (p = 0.013), Prevotella intermedia (p = 0.001) and Prevotella nigrescens (p = 0.008) were observed. Besides, in the G-DS, the densities of bacteria from the orange complex were significantly higher in the age group 3–7 years for F. nucleatum (p = 0.029), P. intermedia (p = 0.001) and P. nigrescens (p = 0.006). C. rectus was higher in the age group 8–12 years (p = 0.045). Conclusion The results showed that children and adolescents with Down syndrome have higher susceptibility to periodontal disease and number of periodontopathic bacteria.

Tomografía Computarizada de Haz Cónico como Instrumento Complementario de Diagnóstico y Planeamiento Quirúrgico de Quiste Dentígero: Reporte de un Caso

El quiste dentigero es una de las patologias oseas que mas frecuentes en el maxilar y la mandibula. Se evidencia radiograficamente como una imagen radiolucida y unilocular en la mayoria de los casos. Generalmente es detectado en examenes de rutina o cuando se investiga la presencia de dientes no erupcionados. El quiste dentigero aparece principalmente en las tres primeras decadas de vida, con crecimiento lento y asintomatico. Los terceros molares,asi como dientes supernumerarios, pueden estar relacionados con su formacion, sin embargo, su etiopatologia no es totalmente conocida. La descompresion, marsupializacion y la enucleacion son las principales formas de tratamiento, pero algunos criterios deben ser considerados, como tamano del quiste, edad del paciente, proximidad con estructuras anatomicas nobles e importancia clinica del diente involucrado. Para que se establezca un correcto diagnostico y plan de tratamiento es esencial la utilizacion de examenes complementarios de calidad, siendo, actualmente, la tomografia computarizada de haz conico el mas completo y preciso metodo de diagnostico por imagen empleado en estas lesiones. El objetivo de este estudio fue resaltar, por medio de la presentacion de un caso clinico, la importancia de la tomografia computarizada de haz conico en el diagnostico y planeamiento quirurgico de un quiste dentigero asociado a un diente no erupcionado.

USING A NEURAL NETWORK FOR SUPPORTING RADIOGRAPHIC DIAGNOSIS OF DENTAL CARIES

This study uses an artificial intelligent model, a radial basis function neural network (RBF), to support radiography diagnosis of dental caries. One hundred and sixty radiography images of proximal faces of extracted human teeth were analyzed by 25 examiners, which diagnosed the presence or absence of dental caries. The same teeth were then subjected to optical microscope analysis, which allowed the verification of their actual conditions. Such information was classified as gold standards, and was employed to training a neural network to diagnose caries by means of radiography images. In order to verify the networks ability to diagnose new cases, data were organized in two subgroups: a training subgroup and a test subgroup. Receiver operating characteristics (ROC) curves allowed the comparison between diagnosis efficacy with or without the use of a neural network, showing that the adopted artificial intelligent model significantly improved diagnosis qualities.

Effect of anatomical region on the formation of metal artifacts produced by dental implants in cone beam computed tomographic images

OBJECTIVES To quantitatively compare metal artefacts produced by implants in different maxillomandibular regions on cone beam CT (CBCT) images. METHODS A total of 200 implants selected from CBCT examinations were divided into four groups: Group 1 (n = 50)-implants located in the anterior maxilla; Group 2 (n = 50)-implants located in the posterior maxilla; Group 3 (n = 50)-implants located in the anterior mandible and Group 4 (n = 50)-implants located in the posterior mandible. The implants were further classified as isolated or adjacent to other implants. Three axial reconstructions were selected for each sampled implant (apical, middle and cervical). On each slice, the artefacts produced by the implants were counted. The Mann-Whitney test was used to compare the variables between groups. The Kruskal-Wallis and Student-Newman-Keuls tests were used to compare the axial reconstructions. RESULTS The mandible showed a greater number of artefacts than the maxilla (apical image: p = 0.0024; middle image: p < 0.0001). The anterior region produced more artefacts than the posterior region (apical image: p = 0.0105; middle image: p < 0.0316). There was no significant difference in the number of artefacts between isolated and adjacent implants, and the cervical image was most affected by artefacts. CONCLUSIONS Dental implants always produce metal artefacts in CBCT images, and these artefacts are affected by the anatomical location in the dental arch.

Correlation between Endodontic Infection and Periodontal Disease and Their Association with Chronic Sinusitis: A Clinical-tomographic Study

Introduction The proximity of the roots of maxillary posterior teeth to the maxillary sinus floor can be associated with the development of chronic maxillary sinusitis (CMS). Therefore, this study evaluated the correlation between the presence of endodontic infection and periodontal disease in maxillary posterior teeth and the presence of CMS. Methods A total of 83 patients (159 maxillary sinuses) were selected and underwent clinical dental examination to assess tooth mobility and pulp condition. In addition, cone‐beam computed tomography was performed to evaluate the presence of periapical lesion and periodontal bone loss, and measure the distance from the root apex to the cortical of the maxillary sinus. The maxillary sinuses were divided into 2 groups: CMS and no maxillary sinusitis. Data were analyzed using χ2 test and binary logistic regression analysis (P < .05). Results Periodontal disease was positively associated with CMS, leading to a 3.45‐fold higher association between these disorders (P < .05). CMS was significantly more common in patients with periodontal disease or endodontic infection in close proximity with the maxillary sinus. Periodontal disease or endodontic infection that was more distant from the maxillary sinus was more common in patients with no maxillary sinusitis (P < .05). To the extent that the tooth is more distant from the maxillary sinus floor, the chance of presenting CMS is reduced up to 2.5‐fold (P < .05). Conclusion Periodontal disease and proximity to the maxillary sinus are more common in cases of CMS, requiring a dental assessment and cone‐beam computed tomography evaluation in patients with CMS with ineffective treatment.

Assessment of mandibular posterior regional landmarks using cone-beam computed tomography in dental implant surgery

The aim of this study has been to evaluate and correlate the anatomical features of the posterior mandibular region (submandibular fossa depth, bone height and thickness, and mandibular canal corticalization) to improve accident prevention and allow safe planning in implantology. Four parasagittal sections of cone-beam computed tomography (CBCT) from 100 patients were bilaterally analyzed. Linear measurements of the submandibular fossa depth, bone height and thickness were performed. The submandibular fossa was also classified into non-influential undercuts and influential undercuts for implant placement. Mandibular canal corticalization was also evaluated and classified according to the visualization. Data on patient age and gender were also collected. Forty-one scans (41%) were from male patients, and 59 (59%) were from female patients. Patient age ranged between 18 and 84 years, with an average age of 51.37 years. The submandibular fossa depth and implant bone thickness had a significant effect on the variability of the sample (46.1% and 22.3%, respectively). The submandibular fossa depth was quite variable, and the highest values were observed in the posterior regions. In 18.27% of the cases, the presence of the fossa directly influenced implant placement, considering a bone height of 10mm (standard implant). A significant correlation was observed between fossa depth and bone thickness. Thus, greater attention should be paid to thick ridges; although thick ridges are favorable, they may be associated with deeper submandibular fossae. The mandibular canal was the most influential anatomical structure in the premolar region due to the reduced bone height in this region and the greater difficulty in viewing the canal, and the submandibular fossa was the most influential structure in the molar region due to lower bone height leading up to the fossa and the greater fossa depth in this region. Therefore, CBCT is an important tool for assessing the mandibular region and planning for safe implant installation in the posterior mandible. Furthermore, comprehensive evaluation of the characteristics of this region is necessary, as the variables - submandibular fossa depth, bone height and thickness, and mandibular canal corticalization - are related and must be considered together when planning.