BACKGROUND Orofacial regulation therapy for children with Down's syndrome was introduced to Europe in Munich in 1978. Since then, many clinical studies have provided scientific evidence that this therapeutic approach enhances the orofacial function and facial appearance of children with trisomy 21. Only few long-term results have been published to date. RESULTS In the present study, 20 children with trisomy 21 were examined more than 12 years after starting treatment in infancy with a Castillo Morales stimulating plate. The follow-up examination showed that the improved orofacial appearance resulting from the early treatment had remained stable in most cases. Although the mechanical stimulus of the stimulating plate was absent during the follow-up period, some patients revealed a lip and tongue posture superior to that recorded at baseline. CONCLUSIONS According to the results of the present study, the orofacial status in early childhood is decisive for the subsequent development of the orofacial region and the long-term stability of the achieved improvements: Children with a pronounced orofacial dysfunction showed a greater stimulation-plate-induced improvement than those with initially moderate orofacial findings. This observation was confirmed by the findings of the 12-year follow-up: Children with Down's syndrome and initially slight orofacial impairment displayed only slight improvements or unchanged findings.