Frontal sinus anatomy of the noble Swéerts-Sporck family and verification of their biological relationships using similarity analysis.

The evaluation of frontal sinus similarity is one way to detect biological relationships, especially in small groups, including families of historically known personalities. However, possibilities for studying this issue are currently limited. This contribution deals with the frontal sinuses of a rare osteological sample with known genealogical data, members of the noble Swéerts-Sporck family from the 17th to 20th centuries. The aim is to verify whether the frontal sinuses reflect documented family relationships. Basic dimensions of the frontal sinus such as total surface area and volume, and maximum height and width, and also morphology and anatomical features were evaluated using computed tomography scans. The portions of the frontal sinus above the "external supraorbital line" were analyzed. The degree of similarity between biologically related individuals was determined for each variable and compared with their known biological distance. The degree of similarity based on dimensions was evaluated using both the unadjusted measured data and standardized data adjusted to size. For the unadjusted dimensions, a positive correlation between morphological similarity and biological relatedness was apparent. On the other hand, no positive correlation was apparent for most of the standardized data. Only total volume showed a very weak indication of a positive trend in the standardized data, but this was weaker than in the original values. A positive quantifiable relationship between morphological patterns and biological distance is not clearly indicated. However, nonmetric features do support the documented relationships of the individuals.