This study described the prevalence of adults with shortened dental arches (SDA) in Brazil, specifically assessing the differences of oral health-related quality of life [the prevalence and severity of oral impacts on daily performance (OIDP)] by dentition status. We analysed data from the 2010 National Survey of Oral Health in Brazil, including home interviews and oral examinations. The assessment of SDA used two alternative definitions: having 3-5 natural occlusal units (OUs) in posterior teeth or having 4 OUs in posterior teeth. Both definitions included having intact anterior region and no dental prosthesis. The analysis was weighted, and a complex sampling design was used. Negative binomial regression models assessed associations as adjusted for socio-demographic conditions and dental outcomes. A total of 9779 adults (35-44 years old) participated in the study. A non-negligible proportion had SDA: 9·9% and 3·8% for the first and second definition, respectively. Individuals with SDA (first definition) ranked higher in OIDP prevalence [count ratio (CR) 1·22; 1·09-1·36, 95% confidence interval (CI)] and severity (CR = 1·43; 1·19-1·72, 95% CI) than those with more natural teeth. This difference was not statistically significant when adjusted for socio-demographic and dental covariates: OIDP prevalence (CR = 1·04; 0·92-1·17, 95% CI) and severity (CR = 1·09; 0·91-1·30, 95% CI). Analogous results were obtained when the second definition of SDA was adopted. These findings suggest that a considerable contingent of adults may function well without dental prostheses, despite having several missing teeth. This conclusion challenges the traditional approach of replacing any missing tooth and instructs the allocation of more dental resources to preventive, diagnostic and restorative services.