Hemifacial microsomia (HFM) is a congenital disorder marked by facial asymmetry. Whether facial asymmetry accounts for asymmetrical dental development is unknown. There are few data on dental development relative to mandibular development or severity of HFM, or on development over time. We hypothesized that when mandibular development was severely disturbed, local dental development was also affected. We compared dental development scores between affected and non-affected mandibular sides in patients with HFM (n = 84) and compared these data with those collected from Dutch control children (n = 451). Logistic functions were constructed for dental age over time for all four Pruzansky/Kaban types. The results showed a tendency toward delayed dental development in Pruzansky/Kaban types IIb and III at younger ages. The temporary delay of tooth formation in patients with severe forms of HFM and the distribution of agenic teeth suggest an interaction between mandibular and dental development.