Cleft lip and palate in Denmark, 1976-1981: epidemiology, variability, and early somatic development.

The present investigation describes the incidence and variability of the primary cleft condition in all Danish infants born with cleft lip, cleft palate, or both, from 1976 to 1981 and analyzes general somatic growth from birth to age 22 months. Because of excellent sampling conditions in Denmark, the study material is nearly complete. Six hundred and seventy-eight infants with facial clefts were born during the period, corresponding to 1.89 per 1,000 of all newborns. Six hundred and two patients were examined--most of them twice: at 2 months and at 22 months. Material uptake included plaster casts of the upper jaw, cephalometric films in three projections, anthropometric registrations, and information from hospital charts. A detailed grading of the clefts according to severity was carried out. Sex distribution was 61% males and 39% females, of whom 34% had isolated cleft lip, 39% combined cleft lip and palate, and 27% an isolated cleft palate. Left-sided clefts were most frequent. In the combined cleft lip and palate group, 90% exhibited subtotal or total clefts, whereas the clefts were less severe in the isolated cleft lip and isolated cleft palate patients. Birth weight and length showed values close to the average for Danish newborns, but a lag was seen in infants in whom severe palatal cleft was included. The extended method of classification was suggested to select subgroups for special care.