Effects of interracial crosses on cephalometric measurements

The effects of race and interracial crossing were examined on six cephalometric measurements among 9,912 schoolchildren in Hawaii. The measurements studied were face height, bizygomatic diameter, bigonial diameter, head breadth, head length, and cephalic index. Racial effects were studied in terms of general racial effect, maternal effect, and hybridity and recombination effects based on a model of diallel cross. Generally, Chinese, Japanese, Koreans, and Filipinos were characterized by longer lateral and smaller anterior-posterior dimensions relative to Caucasians. Maternal effects appeared to be present in the measures of lateral dimension. No clear effects of hybridity and recombination were seen except for bizygomatic diameter, which appears to behave as a partial dominant trait. The racial mean of bizygomatic diameter, or the ratio of this measure to head length, were found to have a relationship with the racial incidences of cleft lip with or without cleft palate.