Maxillary sinus volumetric changes in jet aircraft pilots: A multislice computed tomography pilot study

Purpose@#This study evaluated maxillary sinus volume changes in military jet aircraft pilot candidates before and after the training program, in comparison with a control group, considering the effects of pressurization, altitude, and total flight hours, through multislice computed tomography. @*Materials and Methods@#Fifteen fighter pilots were evaluated before initiating the training program and after the final approval. The control group consisted of 41 young adults who had not flown during their military career. The volumes of each maxillary sinus were measured individually before and at the end of the training program. @*Results@#When comparing the initial and final volumes in the pilots, a statistically significant increase was observed both in the left and right maxillary sinuses. When evaluating the average total volume of the maxillary sinuses (i.e., the average volume of the right and left maxillary sinuses together), a significant increase in the volume of the maxillary sinuses was observed in the pilot group when compared to the control group. @*Conclusion@#The maxillary sinus volumes in aircraft pilot candidates increased after the 8-month training program. This may be explained by changes in the gravitational force, the expansion of gas, and positive pressure from oxygen masks. This unprecedented investigation among pilots might lead to other investigations considering paranasal sinus alterations in this singular population.

Comparison between different cone-beam computed tomography devices in the detection of mechanically simulated peri-implant bone defects

Purpose@#This study compared 2 cone-beam computed tomography (CBCT) systems in the detection of mechanically simulated peri-implant buccal bone defects in dry human mandibles. @*Materials and Methods@#Twenty-four implants were placed in 7 dry human mandibles. Peri-implant bone defects were created in the buccal plates of 16 implants using spherical burs. All mandibles were scanned using 2 CBCT systems with their commonly used acquisition protocols: i-CAT Gendex CB-500 (Imaging Sciences, Hatfield, PA, USA; field of view [FOV], 8 cm×8 cm; voxel size, 0.125 mm; 120 kVp; 5 mA; 23 s) and Orthopantomograph OP300 (Intrumentarium, Tuusula, Finland; FOV, 6 cm×8 cm; voxel size, 0.085 mm; 90 kVp; 6.3 mA; 13 s). Two oral and maxillofacial radiologists assessed the CBCT images for the presence of a defect and measured the depth of the bone defects. Diagnostic performance was compared in terms of the area under the curve (AUC), accuracy, sensitivity, specificity, and intraclass correlation coefficient. @*Results@#High intraobserver and interobserver agreement was found (p<0.05). The OP300 showed slightly better diagnostic performance and higher detection rates than the CB-500 (AUC, 0.56±0.03), with a mean accuracy of 75.0%, sensitivity of 81.2%, and specificity of 62.5%. Higher contrast was observed with the CB-500, whereas the OP300 formed more artifacts. @*Conclusion@#Within the limitations of this study, the present results suggest that the choice of CBCT systems with their respective commonly used acquisition protocols does not significantly affect diagnostic performance in detecting and measuring buccal peri-implant bone loss.

Parotid mandibular bone defect: A case report emphasizing imaging features in plain radiographs and magnetic resonance imaging

Mandibular bone depression, also known as Stafne bone cavity, is defined as a bone depression filled mainly with salivary gland tissue. Parotid gland bone defects are infrequently observed. We report the case of a 52-year-old male patient who underwent radiographic examinations due to temporomandibular joint dysfunction, and a radiolucent area was detected in the mandibular ramus, with a provisional diagnosis of traumatic bone cyst or parotid mandibular bone defect. The patient was then referred for magnetic resonance imaging, which demonstrated a hyperintense area eroding the mandibular ramus, which corresponded to glandular tissue. Although the defect was a benign lesion, radiolucencies in the mandibular ramus lead to concerns among professionals, because their radiographic features can resemble various intrabony neoplastic lesions, such as giant cell tumors or benign tumors of the parotid gland.

Infection on the meshes implantation area in the abdominal wall of rats with induced bacterial peritonitis

OBJETIVO: Avaliar a incidência do crescimento bacteriano em telas de polipropileno implantadas na parede abdominal de ratos, após a indução de peritonite bacteriana.MÉTODOS: Utilizaram-se 36 animais alocados em dois grupos: grupo B, experimento (n=18) e grupo S, controle (n=18). Os ratos foram submetidos ao implante de telas de polipropileno na parede abdominal, no espaço pré-peritoneal. Em seguida, nos animais do grupo experimento, procedeu-se à indução de peritonite pela inoculação na cavidade peritoneal de solução padronizada de Escherichia coli. Nos animais do grupo controle procedeu-se à inoculação de solução fisiológica. Os animais de ambos os grupos foram realocados em três subgrupos de seis animais e acompanhados até as reoperações para avaliação dos sítios de implantação, coleta das telas para culturas, avaliação da cavidade e lavados peritoneais para culturas. As reoperações ocorreram com 24, 48 e 72 horas.RESULTADOS: Todos os animais do grupo experimento apresentaram quadro de peritonite. As culturas das telas retiradas dos sítios de implantação mostraram-se positivas em 83% dos animais quando o momento das avaliações foi de 24 horas, diminuindo para 33% em 48 horas e 17% em 72 horas, globalmente foi de 44%. Nos animais do grupo controle não houve nenhum caso de cultura positiva, tanto nas telas quanto nos lavados peritoneais. CONCLUSÕES: O modelo experimental utilizado foi efetivo produzindo 100% de peritonites. A incidência de crescimento bacteriano nas telas de polipropileno implantadas foi de 83% com 24 horas, decrescendo com o passar do tempo.