Cone-beam computed tomography (CBCT) analysis of maxillary sinus septa in Indians.

It is of interest to assess the presence of maxillary sinus septae in patients undergoing implant treatment using Cone Beam Computed Tomography (CBCT).This retrospective study evaluated CBCT scans of 99 patients who opted for implant placement. A total of 198 sinuses were analyzed. The cases were divided into two group's namely edentulous group and non-edentulous groups. The location of septa was divided for analysis into 3 regions namely, the anterior (1st and 2nd premolar), middle (1st and 2nd molar) and posterior (behind 2nd molar) regions. Out of 198 sinuses assessed 15 sinuses had septa. It was more common in males. Mean height of septa was 7.7mm. It was more commonly seen in the middle region (1st and 2nd molar). All of the septa were partial in nature. Septa were common on the right side. It was absent in the edentulous group. To conclude this study showed low prevalence of septa in patients who were assessed as a part of pre-operative planning for implant placement. Modified sinus lift procedures were completed for placement of bone grafts in patients with septa,. This reduced the chances of membrane perforation and increases the chances of better outcomes. CBCT with its low cost and high resolution is useful for assessing the sinus.

Knowledge, attitude and practice of dental practitioners, interns and post-graduate trainees about COVID-19 pandemic in Chennai.

BACKGROUND: Coronavirus disease-2019 COVID-19) pandemic has been sweeping around the globe and the cases have been reported in India since the second week of March, with Chennai being one of the most affected cities. Healthcare professionals, particularly the dental personnel have a higher risk of infection due to close face-to-face contact and the risk of inhalation of aerosolised particles. AIM: The aim of this study was to assess the knowledge, attitude and practice about COVID-19 among interns, post-graduate trainees and dental practitioners. MATERIAL AND METHODS: A cross-sectional survey was conducted using Google forms among three groups: interns, post-graduate trainees and dental practitioners. Data obtained was analysed by Chi-square test, Kruskal-Wallis and post hoc test using SPSS IBM software. RESULTS: Of total score of 9 for knowledge-based questions, the score obtained by interns, post-graduate trainees and practitioners were 7.2, 7.2 and 7.5, respectively, with no statistically significant difference among the groups (P = 0.24). Of total score of 4 for attitude-based questions, the score obtained by interns, post-graduate trainees and practitioners were 1.6, 2.0, and 1.9, respectively, with statistically significant difference among the groups (0.009). Of total score of 7 for practice-based questions, the score obtained by interns, post-graduate trainees and practitioners were 3.2, 3.3, and 3.1, respectively, with no statistically significant difference among them (P = 0.63). CONCLUSION: Though the knowledge about COVID-19 appeared adequate, the attitude and practice component needs improvement. Continuing dental education programs and webinars can be conducted to update the dental professionals about the protocols to be followed during COVID-19 pandemic.

Application of spectrum shifting methodology to restore NaI(Tl)-recorded gamma spectra, shifted due to temperature variations in the environment.

A method has been standardized for restoring a shifted differential pulse height spectrum from a scintillator based gamma ray spectrometer recorded at measurement temperature, to the position of a desired spectrum, recorded at a reference temperature. The method is based on the assumption that the spectrum obtained at measurement temperature represents the same statistical distribution as that at reference temperature but with different energy scales. A computer program has been developed for calculation of the transformation between the energy scales and for the restoration of the shifted spectrum. The method developed has been successfully applied for the restoration of gamma spectra measured at different temperatures.

Role of trabecular bone in visibility of laminadura: A cross-sectional radiographic study.

AIM: To determine the degree to which trabecular bone contributes to the radiographic visibility of laminadura (LD). STUDY DESIGN: Human dry mandibles were obtained, and a series of radiographs were acquired in the premolar region. Radiographs taken were: (1) Before removal of any bone, (2) After removal of small amount of cortical bone at the apex of tooth, (3) Removal of trabecular bone, (4) Smoothing of endosteal surface of cortical bone. The radiographs were projected to a panel of six oral radiologists, and they were asked to judge the visibility of LD. RESULTS: Chi-square analysis revealed a significant radiographic difference between radiographs made initially and after removal of trabecular bone, cortical bone and smoothing the endosteal surface of cortical bone. CONCLUSION: There was statistically significant difference in the visibility of loss of LD when trabecular bone is lost. LD can be visible only if the endosteal surface of the cortical bone and trabecular bone is intact.

Distribution of norm and 137Cs in soils of the Visakhapatnam region, Eastern India, and associated radiation dose.

The specific activity of naturally occurring radioactive materials and (137)Cs in surface soils around the new Bhabha Atomic Research Centre site at Visakhapatnam region, Eastern India, has been determined using high-resolution gamma-ray spectrometry as part of a baseline radiological survey. Radiation hazard for the samples was assessed by radium equivalent activity (Raeq) and absorbed gamma dose rate (D). The mean absorbed gamma dose rate was found to be 104.9 nGy h(-1). The average annual effective dose equivalent was found to be 0.13 mSv y(-1).

Application of thoron interference as a tool for simultaneous measurement of radon and thoron with a pulse ionisation chamber.

Pulse ionisation chamber (PIC)-based monitors measuring radioactive gas radon ((222)Rn) without energy discrimination will have interference due to thoron ((220)Rn) present in the atmosphere. A technique has been developed to use this property of interference for simultaneous measurement of radon and thoron gas. These monitors work on the principle of counting of gross alphas emitted from radon and its progeny. A theoretical model has been developed for the variation of thoron sensitivity with respect to the flow rate of gas through the monitor. The thoron sensitivity of the monitor is found to vary with the flow rate of gas through the monitor. Using this sensitivity, the sampling procedure has been developed and verified for simultaneous measurement of radon and thoron. The PIC-measured radon and thoron concentration using this procedure agrees well with those measured by using standard radon and thoron discriminating monitor.

Monitoring and modelling of indoor radon concentrations in a multi-storey building at Mumbai, India.

Radon (Rn(222)) levels in an indoor atmosphere of a multi-storey building at Mumbai have been measured for one year covering all the four seasons. Monitoring was carried out using the time-integrated passive detector technique, using Kodak-115 type Solid State Nuclear Track Detector (SSNTD) films of 2.5x2.5 cm size. Measured indoor radon levels showed a decreasing trend with height with concentration ranging from 41 Bq m(-3) at ground floor level to 15 Bq m(-3) at 19th floor level. Using the dose conversion factors, the inhalation dose due to breathing of radon gas is estimated to be 1.03 mSv y(-1) at the ground floor to 0.38 mSv y(-1) at the 19th floor level. Measured indoor radon concentrations on each floor were compared with the computed values using a mathematical model. The agreement between measured values and calculated values of indoor concentrations at different floors was very good within the limitations of various field parameter values.

Daily intake of aluminium by adult population of Mumbai, India.

Electrothermal atomic absorption spectrophotometry (ET-AAS) has been used for the determination of Al in environmental and food samples with a detection limit of 0.3 ng ml(-1). The reliability of estimation is assessed through the analysis of Standard Reference Materials (IAEA SRMs) of Soil-7, SL-3, SD-M2/TM and Hay (V-10). The results indicate that the average concentration of aluminium in air particulate samples is 5.3 microg m(-3). The daily intake of Al by the adult population of Mumbai is 6.4 mg day(-1).