Fractal dimension, lacunarity, and cortical thickness in the mandible: Analyzing differences between healthy men and women with cone-beam computed tomography.

Purpose: The objective of this study was to assess the fractal dimension, lacunarity, trabecular microarchitecture parameters, and cortical linear measurements in the mandibles of male and female individuals to identify differences between them. Materials and Methods: In total, 116 cone-beam computed tomography scans of healthy individuals of different ages (57 men and 59 women, aged between 20 and 60 years) were selected. The following bone parameters were measured: 1) buccal, lingual, and basal cortical bone thickness in 5 standard parasagittal sections (the midline, the left and right sides of the lower lateral incisors, and the left and right sides of the lower canines); 2) the bone volume fraction of 10 sequential axial sections from each patient by creating a volume of interest in the area between the lower canines; and 3) fractal dimension and lacunarity using grayscale images of the same region of the volume of interest in the anterior mandible. Spearman correlation coefficients and the Mann-Whitney test were used. Results: A significant and positive correlation was found between age and cortical thickness, especially in the region of the central incisors. Significant differences between sexes in terms of fractal dimension, lacunarity, and bone volume were found. Women revealed lower fractal dimension values and higher lacunarity and bone volume ratio values than men. Conclusion: Fractal dimension, lacunarity, trabecular bone volume, and cortical thickness were different between men and women of different ages.

Biosafety in Dental Practices Versus COVID-19 Outbreak

ABSTRACT Objective: To evaluate the dentists' knowledge about biosafety considering the SARS-CoV-2 and the risks of increasing the COVID-19 outbreak by dental practices during the pandemic in Brazil. Material and Methods: A cross-sectional study was performed by internet-based snowball sampling technique. A questionnaire with questions about different content was applied, and then analyzed the following two parameters: participants' Brazilian region and professional's specialty. Results: A total of 413 e-questionnaires from all Brazilian regions were considered valid. There were no significant differences among biosafety measures adopted by participants from different Brazilian regions (p≥0.05), except for those from North region, which have applied less previous oral antisepsis, temperature screening, and specific anamnesis tracking COVID-19 symptoms (p<0.05). The unique use of N95 mask was positively associated with North region (p<0.05). Expert participants of Groups 2 (oral surgery and correlate areas) and 4 (orthodontics, oral radiology and facial jaw orthopedics) were more updated than other ones (p<0.05). Conclusion: The biosafety protocols applied by participants were not adequate for the epidemiologic status of COVID-19 in each region of Brazil, from 13th May to 17th June 2020. Specialties linked to microbiology area or structured social networks have better applied preventive measures for COVID-19.