The Quantitative Analysis of Coronal Suture Separation Due to Cranial Trauma

Morphometric analysis of cranial sutures can provide evidence of microfractures, diastasis, and early sutural closure. Recently, mCT has allowed for morphometric analyses on much smaller scales and has been used to differentiate normal cranial sutures from early sutural synostosis. Therefore, microscopic assessment of cranial sutures may provide additional data to forensic trauma analyses. Utilizing six adult human cranial trauma cases and three control specimens, I tested for asymmetrical separation in coronal sutures to determine if significant differences are detectable. Trauma cases included three intraoral gunshot wound and three blunt force trauma specimens. Cranial specimens were mCT scanned with Type-1 landmarks placed at their origin at sphenion and terminating at bregma. Due to the tortuous nature of the coronal suture, a comb-based approach was used to standardize sampling sites. Using Avizo segmenting software (Thermo Fisher Scientific), a chord line between bregma and sphenion was first defined and measured, which allowed for the placement of 20 and 50 equidistant sampling sites along the suture at orthogonal angles. ImageJ was used to calculate the total area of separation for individual scan slices at each sampling site. Asymmetry was determined by comparing differences in coronal suture separation between the sides delineated by bregma. Additionally, Avizo was used to segment total sutural volume using in program measuring tools. Bilateral asymmetry of coronal diastasis per specimen was determined using a paired t-tests. A one-way ANOVA was then used to test total coronal sutural separation by group. One-way ANOVAs were also used to test average control group diastasis with diastasis on the side of trauma groups both with and without damage. Finally, a two-way repeated measures ANOVA was used to determine if significant differences occur both within and between traumatized specimens. Results from paired t-tests showed significant differences between sides in individual crania using different numbers of landmarks. Alternately, no significant differences were found for overall coronal diastasis, side specific separation, or within trauma type using repeated measures. Ultimately, these data could potentially provide forensics with another method to assess injury and may lead to a more thorough understanding of sutural diastasis in human crania.