Fig. 2

a Adaptation plot for tongue back. The intrafractional variability of tongue back was significantly correlated with the interfractional variability, which means that intrafractional deviations may be larger for large interfractional deviations (p = 0.0076). b Adaptation plot for os hyoideum. The intrafractional variability of maximum cranicocaudal deviation of the os hyoideum was significantly correlated with the interfractional variability, which means that intrafractional deviations may be larger for large interfractional deviations (p = 0.0008). c Adaptation plot for os hyoideum. The intrafractional variability of maximum overall deviation of the os hyoideum was significantly correlated with the interfractional variability, which means that intrafractional deviations may be larger for large interfractional deviations (p = 0.0002)