Integration patterns of the asymmetric components of the skull: A covariational statistical approach on a modern Greek sample.

Objectives: The integration patterns of the asymmetric components of the skull can be informative, especially in the diagnosis and surgical treatment planning of patients. This research aims to explore the interactions of the asymmetric components between the mandible, the basicranium, and the upper face. Material and methods: The sample comprises 100 skulls of Greek adults and the three-dimensional coordinates of 35 landmarks, extracted from the cranial and mandibular virtual 3D bones, were analyzed using the generalized least-squares Procrustes method. The integration patterns of the asymmetric components of the shapes of the specific structures were evaluated through partial least-squares correlation analysis with a two-blocks approach. Results: When handling the skull regions separately, there is statistically significant integration of the asymmetric components between the mandible and the basicranium as well as between the mandible and the upper face. Furthermore, the mandible and the basicranium exhibit the strongest interaction among the three pairs examined. Conclusions: The asymmetric variation of the skull regions should be taken into consideration for surgical treatment planning. However, comparing our findings with other studies revealed that the utilization of the skull regions in the context of a structure as a whole while running the analysis, as well as different landmark combinations, may lead to different results. Furthermore, there might be population-specificity to certain integration patterns of the asymmetric component of the total shape variation among skull regions. Hence, surgical bone restoration, especially in the mandible, should consider overall skull asymmetry and population-specific data to ensure optimal integration.