Cleft lip and palate in the Oxford area. An examination of the evidence for clustering in space and time.

Children with cleft lip and/or palate born during the period 1965-74 inclusive in the Oxford area were examined for evidence of any tendency for clustering. The methods suggested by Knox (1963), David and Barton (1966), and Smith and Pike (1974) were used. No clustering was evident in space or in time. There was some indication of clustering in space-time for isolated cleft palate during the period 1965-71, but this was not repeated during 1972-74.