Epidemiology and laboratory parameters related to tooth loss in obese candidates to bariatric surgery Obesity can be labeled as a worldwide outbreak thus, it has led to a serious public health problem. Oral health can be worsened if it is combined with obesity and metabolic X syndrome. The tooth loss usually harms masticatory function, essential status to whom will be submitted to bariatric surgery. This study aimed to assess epidemiologic parameters and blood tests concerning the number of dental functional units, in patients applying to bariatric surgery, who belong to distinct socioeconomic class range, in order to recognize hazard factors and the bias of this condition over them. Observational cross-section study, with samples comprised by two groups of patients, with distinct socioeconomic class range, one of them belonging to public health system (SUSG) and the other to private clinic (CPG), applicants to bariatric surgery. It was assessed the general healthy conditions, including anthropometric data, comorbidities (hypertension, diabetes mellitus, sleep apnea, dyslipidemias and arthropathy) and medicines usage (antihypertensive, oral hypoglycemic agents, insulin, simvastatin, diuretics, vasodilators and platelet antiaggregant). Blood tests data (hemoglobin, ferritin, protein, albumin, total cholesterol, glycaemia, triglycerides), habits (smoking and alcoholism) and the number of dental functional units presents (masticatory function). The tests applied were Chi-Square, ANOVA, Goodman, Multivariable Logistic Regression e Bonferroni. The groups SUSG and CPG were homogeneous taking into account gender and age range. Regarded as the number of dental functional units, was higher in the private group (p<0.001). The impaired masticatory function was rather present among female public group (p<0.001). Regarded as blood tests, fasting glycaemia were mainly above in female SUSG patients (p<0,001). The following hazard factors have corroborated to have patients rated as impaired masticatory function: Belong to public service (OR: 8.420, p=0.003), higher aging (OR: 1.186, p<0.001), female gender (OR: 0.153, p=0.029), with diabetes mellitus (OR: 2.545, p=0.045) and smoking (OR: 2.951, p=0.043). The general and oral health of obese SUSG patients were worse and the tooth loss was higher in female patients in this same group, highlighting as hazard factor the socioeconomic condition.