Cleidocranial dysplasia (CCD), a rare, inherited, generalized, skeletal and dental dysplasia, exhibiting an autosomal dominant mode of transmission, may be associated with delays during tooth maturation. To test whether permanent tooth formation is delayed in patients with CCD and if the presence of supernumerary teeth adversely influences maturation of the dentition, a group of CCD patients (eight females, three males) was compared to an equal number of control subjects matched for age and gender. Dental maturity was assessed using panoramic radiographs and the Dental Maturity Ratio, (DMR = mean dental age divided by the chronological age) was calculated. The mean DMR in CCD patients (0.87 +/- 0.14) was lower than in the control group (1.06 +/- 0.14), p < 0.01. Among patients with CCD, patients with supernumerary teeth, had a lower DMR (0.82 +/- 0.13 vs. 0.91 +/- 0.16), but the difference did not reach statistical significance. After adjusting for the presence of supernumerary teeth the diagnosis of CCD was still found to be associated with lower DMR than controls, p = 0.0569. We conclude that CCD patients have delayed tooth development of approximately 2.1 years and that among these patients, those with supernumerary teeth were further delayed by 1.5 years.