Heredity is one of the possible factors associated with congenitally missing mandibular incisors. We report four cases--a mother and three daughters--in an attempt to examine this hypothesis. Different treatment modalities have been used to treat malocclusions stemming from this problem. The treatment philosophy of consolidating mandibular spaces and obtaining a stable occlusion, thereby preventing the removal of maxillary teeth or the use of a mandibular prosthesis, is presented.