Fourier analysis of human sagittal sutures

Objective: To evaluate the complexity of human sagittal suture patterns and to investigate whether the suture complexity correlates with age. Design: Geometric patterns of the sagittal sutures from 104 dry human skulls from the Terry Collection and 16 computed tomography images from the Bosma Collection, aged 2 months to 60 years, were digitized. The complexity of the patterns was presented by suture length, curved suture (or skull) length, and length ratio and the frequency and amplitude contents by the discrete Fourier transform (DFT) analysis. Results: The suture length along the skull showed a positive correlation with age from 2 months to 10 years, reflecting the growth of the skull. The suture length ratio, R, a measure of the complexity of the suture pattern, had a similar trend to suture length (i.e., increased with age to about 10 years and leveled off afterward, accompanied by a large scatter). The major frequency from the DFT analysis indicated an age-related development in suture complexity from infants to about 10 years and no further change for individuals older than 10 years. Conclusions: Quantitative analyses of human sagittal suture using length, length ratio, and DFT indicated that there is a progressive increase in the complexity of sagittal sutural waveform with age, especially in the early ages. These findings agree with the observations from animal experiments that sagittal sutural waveform is the result of intrinsic tissue response to extrinsic forces such as those generated by the temporalis.