Objective: To investigate the factors that influence oral health of girls, with developmental disabilities, attended by a dental service. Material and Methods: A Cross-sectional epidemiological study was carried out using information collected from 171 dental charts of children aged one to 13 years, with developmental disabilities who were treated between 1998 and 2013. Studied variables were: dental caries, gingivitis, bruxism, xerostomia, ingestion of cariogenic food and oral hygiene. Statistical analysis was performed using proportion calculations of each variable and by cluster analysis. Results: Three types of clusters were formed from girls based on three variables (presence of dental caries, gingivitis and bruxism). The choice of two clusters was due to a better understanding of the phenomenon (oral conditions). There was an average of 0.77 of deciduous and 0.21 permanent decayed teeth. Cluster 1 is composed of younger children with lower caries and gingivitis experiences; lower proportion of xerostomia and ingestion of cariogenic food, higher proportion of good oral hygiene and more bruxism experience. Conclusions: Dental caries and gingivitis among girls with developmental disabilities are influenced by factors whose relation of cause and effect has been discussed in the literature. Bruxism is a protective factor against these diseases.Results reinforce the need for early preventive interventions in this population.