Bite Force in Elderly with Full Natural Dentition and Different Rehabilitation Prosthesis.

(1) Background: This study aimed to investigate maximum bite force (MBF) in elderly patients with natural full dentition (FD), patients rehabilitated with Traditional Complete Dentures (CD), with overdentures (IRO) and edentulous patients (ED). We also tested whether MBF changes are associated with gender, age of the patients and body mass index (BMI) as result of altered food; (2) Methods: Three hundred and sixty-eight geriatric patients were included. We studied two types of prostheses: (a) IRO with telescopic attachments. (b) CD (heat polymerized polymethyl methacrylate resin). The MBF was measured using a digital dynamometer with a bite fork; (3) Results: We found that MBF is higher in males than females, regardless of teeth presence or absence ( < 0.01). In patients with CD or IRO, there are no differences between males and females; prostheses improve MBF compared to edentulous patients ( < 0.0001) and this effect is greater with IRO prostheses ( < 0.0001); the chewing force of FD subjects remains greater ( < 0.0001); there are no differences among chewing strength based on different BMI categories, although FD subjects have a reduced incidence of obesity; there is a significant negative correlation between MBF and age ( = 0.038; R = 0.145), and no correlation between MBF and BMI; (4) Conclusions: This study showed that MBF improves more in patients using IRO prostheses, although not reaching the MBF of FD subjects. MBF does not correlate with BMI, although we found increased percentages of obesity in edentulous subjects or those with prostheses. Thus, old people wearing prostheses require special attention by a nutritionist to avoid risk of malnutrition.