Table 1: Dahlberg’s test: applied to the entire sample and repeated twice revealed no statistically significant systematic measurement errors. The systematic error calculated via Student’s t-test for paired data yielded a significance level of 0.05.

Variable Dahlberg’s test value ANB 0.11905 0.950475 IMPA-r 0.53631 0.369756 11/SNA-SNP 0.64845 0.165493 OJ-r 0.00690 0.065285 IMPA-l 1.49048 0.673221 OJ-l 0.00417 0.617962 21/SNA-SNP 1.35000 0.098852