Occurrence of cleft lip and palate in the Faroe Islands and Greenland from 1950 to 1999.

Objective: To describe the occurrence of cleft lip with or without cleft palate (CL/P) and isolated cleft palate (CP) in the Faroe Islands and Greenland over a 50-year time period that has included substantial changes in lifestyle.

Design: A prevalence study based on patient records obtained from the Institute of Speech and Hearing Disorders in Copenhagen, Denmark, at which the treatment of patients with CP and CL/P from Greenland, the Faroe Islands, and Denmark is coordinated.

Participants: All live-born children in the Faroe Islands, Greenland, and Denmark with CL/P or CP born in the period 1950 to 1999 (Faroe Islands and Greenland) and 1950 to 1987 (Denmark).

Results And Conclusion: The mean prevalence of CL/P in the Faroe Islands and Greenland during the period 1950 to 1999 was 1.0 and 0.6 per 1000 live births, respectively. This is significantly lower than the mean prevalence of 1.4 (p <.05 and p <.001) per 1000 live births found in Denmark. The mean prevalence of CP in the Faroe Islands and Greenland was 1.5 and 1.1 per 1000 live births, respectively, which is significantly higher than the Danish prevalence of 0.5 per 1000 live births (p <.001 in both tests). There was no clear time trend in the prevalence, indicating that genetic factors or timetable environmental factors play a dominating role in the etiology of CL/P and CP in the Faroe Islands and Greenland.