Osteogenesis imperfecta (OI) is a heterogeneous connective tissue disorder characterized by repeated fractures and skeletal disorders. At present, bisphosphonate (BP) therapy is the gold standard for OI treatment. The present retrospective study evaluated the effect of BP therapy on tooth development and eruption of permanent teeth in a cohort of children receiving pamidronate. Three groups were studied: patients with OI who were treated with BPs (n = 45), patients with OI who were not treated with BPs (n = 117), and age- and gender-matched healthy controls (n = 121). Dental age, dental maturity, and tooth eruption were assessed on panoramic radiographs using the methods of Demirjian et al. (Hum Biol 45(2):211–227, 1973) and Haavikko (Suom Hammaslaak Toim 66(3):103–170, 1970) and were evaluated using the t-test, Chi-square test, and the Mann–Whitney U test. Dental age in the study group was significantly (p < 0.05) lower than chronological age compared with both control groups. Dental maturity and the eruption of permanent teeth were also significantly (p < 0.05) delayed in the study group in relation to the two control groups. The dental age was significantly lower (p < 0.001) in patients with OI type III treated with BPs compared with healthy controls and the dental maturation was significantly delayed in patients with OI type IV treated with BPs compared with those not treated. In conclusion, BP therapy in OI patients seems to lower the dental age, delay the dental maturity, and tooth eruption. BP administration before 2 years of age might be a contributing factor.