Incomplete median cleft of the lower lip associated with cleft palate, the Pierre Robin anomaly or hypodontia

12 female subjects with an incomplete median cleft of the lower lip associated with cleft palate in 7 subjects, with the Pierre Robin anomaly in 3 and with only agenesis of the lower permanent central incisors in 2, are presented. In all subjects, the bony structure of the lower jaw was within normal limits and without cleft. The literature on median clefts of the lower lip and mandible is reviewed and the findings in the present 12 cases compared with 46 reviewed cases.