Forty‐five Northern Irish families: A cephalometric radiographic study

Abstract

D e p a r t m e n t of A n a t o m y , University of London King's College. Strand, W C P R 2LS, Engkcnd KEY WORDS Genetics . Family study . Skull . Radiographs . Continuous variables. ABSTRACTThe individual bones that are identifiable from lateral skull radiographs have been analysed for the parents and growing children of 45 families. There were at least four children in each family and altogether there were 95 sons and 102 daughters. The youngest child was not less than seven years of age. Traced outlines were made of the bones and 24 linear and angular measurements were made; the raw data were transformed into scores to overcome differences due to age and sex. Analyses of variance of within and between families showed that for all the variables, the scores for persons in different families were significantly less similar, (P <0.001), than scores to be found within families. Correlations were then computed for each variable between the mothers and fathers, the mothers and sons, the mothers and daughters, the fathers and sons, the fathers and daughters, brothers and sisters, paired brothers and paired sisters. It was found that there were no statistically significant correlations between the mothers and fathers, but for all the other combinations that were examined there were many 1.0% level.

Frontal Sinus Accuracy in Identification as Measured by False Positives in Kin Groups

“…These data belong to a larger sample of 45 families studied by Brown (18); all subjects being radiographed with their heads in an identically located position, as described in Adams and Brown (19). The positioning of the heads for the anterior/posterior cephalograms was also identical for all the heads aligned on the Frankfurt Plane.…”

“…The minimum age was 15 years, when the frontal sinuses are complete (18). X‐rays were digitalized and images were recorded on a computer file.…”

An analysis of crania from Tell‐Duweir using multiple discriminant functions

“…3. Nasal breadth (NASALBTH) shows high heritabilities (Clark, 1956, in 5/6 studies in Vandenberg's 119621 summary, in Susanne, 1973, and significant within-family correlation (Brown, 1973). 4.…”

“…5. Bizygomatic breadth (BIZYGBTH) shows high heritabilities (Clark, 1956, in 515 studies [Vandenberg 19621;Da Rocha et al, 1972;Susanne, 1973;Brown, 1973). 6.…”

Family resemblance for cranio‐facial measurements in Velanti Brahmins from Andhra Pradesh, India

“…It is therefore surprising that relatively few family studies of cranial and facial metrics have been undertaken. Several authors report familial correlations for selected cranio-facial measures as part of a larger study of anthropometric variability (Howells, 1966;Susanne, 1975;Sharma et al, 1984) or for measurements taken from cephalic radiographs (Brown, 1971; Nakata et al, 1974;Saunders et al, 1980). Analyses of twin resemblance for cranial measurements have also been reported (Clark, 1956;Orczy-kowska8wiatkowska and Lebioda, 1975;Weaver and Christian, 1980).…”