The challenge of extra-intra craniometry: a computer-assisted three-dimensional approach on the equine skull.

This research explored a method for examining topographical connections between specific points inside and outside horse skulls using three-dimensional measurements to avoid the limitations of traditional two-dimensional methods. The study specifically looked at how these points changed with age, which is necessary knowledge for surgical or diagnostic procedures. The findings showed variable changes depending on locations within the skull structure, with some areas showing stable relationships and others demonstrating significant shifting with age.

Research methodology and purpose

• The research aimed to assess the relationship and age-related changes between precise points inside and outside horse skulls, which are critical to consider for diagnostic or surgical procedures.
• The research utilized a three-dimensional (3D) methodology that mitigated perspective distortions, a common issue when using traditional two-dimensional (2D) morphometric analysis.
• The skulls of four warmblood horses from two age groups (young at 6 weeks and old at 14 and 17 years) were used in the study.
• Particular points of interest (POIs) inside and outside the skulls were identified, and their x-, y-, and z-coordinates were determined with a measurement device.
• The data gathered was then analyzed by creating virtual triangles, which illustrated the relationship and shifts in position of the POIs.

Key findings

• Some parts of the skull, like the Arcus zygomaticus, grew in size with age but remained constant in their proportional relationship.
• Some points, such as the Crista nuchae, showed disproportionate growth, shifting significantly in the caudal direction as the horse’s age increased.
• The study also attempted to determine a fixed reference point or ‘anchor point,’ but found this challenging. Two points, one at the Synchondrosis intersphenoidalis and another at the Synchondrosis sphenooccipitalis, remained relatively stable in their positions. However, the growth epicenter of the cranial could only be localized to an area between these points.

Implications of the study

• The study’s findings help provide a better understanding of the changes in the horse’s cranial structure with age, a critical factor in planning surgical or diagnostic procedures on the brain.
• The research exemplifies the importance of 3D over 2D morphometry in understanding the detailed topographical correlations of the skull’s points of interest.
• The findings could potentially lead to the development of new surgical techniques or modifications of existing ones, specifically accounting for the changes in cranial structure with age.