Fatal non-accidental pediatric cranial fracture risk and three-layered cranial architecture development

Abstract

This study examines the influence of three-layered cranial architecture development upon blunt force trauma (BFT) cranial outcomes associated with pediatric non-accidental injury (NAI). Macroscopic and microscopic metric and morphological comparisons of subadult crania ranging from perinatal to 17 years of age chronicle the ontogenetic development and spatial and temporal variability in the emergence of a mature cranial architecture. Cranial vault thickness increases with subadult age, accelerating in the first 2 years of life due to rapid brain growth during this period. Three-layer differentiation of the cranial tables and diploë initiates by 3-6 months but is not consistently observed until 18 months to 2 years; diploë formation is not well developed until after age 4 and does not manifest a mature appearance until after age 8. These results allow topographic documentation of cortical and diploic development and temporal and spatial variability across the growing cranium. The lateral cranial vault is identified as expressing delayed development and reduced expression of the three-layer architecture, a pattern that continues into adulthood. Comparison of fracture locations from known BFT pediatric cases with identified cranial fracture high-risk impact regions shows a concordance and suggests the presence of a higher fracture risk associated with non-accidental BFT in the lateral vault region in subadults below the age of 2. The absence or lesser development of a three-layered architecture in subadults leaves their cranial bones, particularly in the lateral vault, thin and vulnerable to the effects of BFT.

Keywords: blunt force trauma; forensic anthropology; fracture risk; ontogenetic development; pediatric non-accidental injury; three-layer cranial architecture.

FIGURE 1

Cranial locations examined: A, anterior (most anterior point on the frontal, typically at the midline); AL, anterolateral (most lateral point on the frontal); L, Parieto‐lateral (most lateral point on the parietal); PL, posterolateral (most lateral point on the posterior occipital); P, posterior (most posterior point on the occipital, typically at the midline). [Color figure can be viewed at wileyonlinelibrary.com]

FIGURE 2

Unilaminar cranial table (anterior frontal; perinatal; 10×). [Color figure can be viewed at wileyonlinelibrary.com]

FIGURE 3

(A) Three‐layer initial architecture development and differentiation—Initial thickening of the unilaminar table (anterolateral frontal, 4–6 months; 20×). (B) Advanced three‐layer architecture development and differentiation (anterolateral frontal, 18–23 months; 10×). (C) Spatial variability in three‐layer development and differentiation—Immature cavitation and cranial table differentiation in parietal (18–23 months; 20×). [Color figure can be viewed at wileyonlinelibrary.com]

FIGURE 4

(A) Initial diploe development (anteromedial frontal, 3–6 months; 20×). (B) Advanced diploe development (medial occipital, 5–6 years; 10×). (C) Spatial variability in diploe development (anteromedial frontal, 18–23 months; 40×). (D) Spatial variability in diploe development (lateral parietal, 3 years; 40×). [Color figure can be viewed at wileyonlinelibrary.com]

FIGURE 5

(A) Tri‐layer cranial topographic contour (anterolateral frontal and lateral parietal, 18–23 months; 5×). (B) Tri‐layer cranial topographic contour (4–5 years old). [Color figure can be viewed at wileyonlinelibrary.com]