Aim: To describe links between the care course of individuals suffering from rare diseases and socio-behavioural risk factors and to ascertain the impact of dental conditions on the quality of life. Design: A cross–sectional comparative study involving self-reported questionnaire was performed. Care course was evaluated using Predisposing, Enabling and Needs factors. The impacts of dental conditions on quality of life were measured with the OHIP 14 questionnaire. Proportions were compared by Chi-square test. Logistic regression for multivariate analysis assessed statistical association between variables. Results: Responses were received from 355 subjects (mean age 36.9 years, 67.6% females). Thirty-three rare diseases were recorded. Respondents were classified as group A, individuals suffering from rare diseases with a dental component (n=207, 58.3%), and group B, without dental component. Group A reported earlier diagnosis, more positive attitude toward dentists, functional limitation and higher prosthetic treatment needs. Only 17.4% of subjects having fewer than 20 teeth wear prosthetics. A higher percentage of individuals claiming pain, physical disability, psychological discomfort and social disability, was found among group B (p<0.001). Logistic regression analysis retained two impact factors: psychological disability (Exp(B)=8.66; 95% CI 1.86-40.34) and social wellbeing (Exp(B)=0.06; 95% CI 0.02-0.215). Conclusion: Rare diseases with a dental component benefited from earlier identification of symptoms. Dentists could contribute to patients’ quality of life by helping in early diagnosis, reducing functional limitation and improving social wellbeing. Key words: rare diseases, stomatognathic diseases, dental care, quality of life