1. Department of Public Health, National School of Higher Studies, León Unit, National Autonomous University of Mexico, Leon 37684, Guanajuato, Mexico
2. Department of Oral Pathology and Oral Medicine, Graduate and Research Division, Dental School, National Autonomous University of Mexico, Mexico City 04360, Mexico
3. Department of Medical Sciences, Health Sciences Division, University of Guanajuato, León 37320, Guanajuato, Mexico