The Closure Stage of Cranial Sutures in Correlation with Age

증령적 변화로서의 두개골 봉합의 유합 상태

In order to study the closure stage of cranial sutures and its correlations with age, the ectocranial closure stage of coronal suture, sagittal suture, and lambdoidal suture of 67 skulls was measured. Among the skulls kept at the department of anatomy, college of medicine, Yonsei University, the ones with ages identified were used for this study. These measurements of suture closure were conducted by 4 examiners independently. The sutures were further divided by Frederic's method into 16 suture parts. The closure stages were classified by five stages of Broca-Ribbe. The following results were obtained: 1. The inter-observer reliability among 4 examiners showed high intraclass correlation coefficient of over 0.75(mean : 0.856) in all suture parts. Therefore, the determination of closure stage wasn't influenced by the subjective view of each examiner. 2. In all suture parts, the closure stage increased proportionally with age.(p<0.01) In terms of each suture part, the S2 part of sagittal suture showed the highest correlation(68.1%) while the L1-R part of lambdoidal suture showed the lowest correlation(51.3%). In addition, in terms of suture types, the correlation with age decreased in the order of sagittal suture(60.0%), coronal suture(57.7%), and lambdoidal suture (55.7%). In general, the average value of suture closure stages had 57.8% correlation with age(p<0.01). 3. The most frequent suture closure stage according to age group was '0' for ages below 30, '0' and '1' for ages within the 30's, '1' and '2' for ages within the 40's, and '2' for ages within the 50's. With older age groups, the frequency of '3' and '4' increased, and the suture closure stage increased proportionally with age. 4. The mean age by closure stage of each suture were within the 40's for the closure stage of '1', within the 50's for the closure stage of '2', and from 50's through 60's for the closure stage of '3'. The standard deviation was over 10 for all closure stages. In addition, at the same suture closure stage, the mean age according to the coronal suture was higher than the ages according to the sagittal suture or lambdoidal suture. Especially, C1-R, C1-L, C2-R, and C2-L parts showed the highest age when at the same suture closure stage. 5. The values appropriate for age estimations using suture closure stages of 16 suture parts were calculated, and a calculator for age estimation ($R^2=0.6944$, p<0.01) by ectocranial suture closure stage for Koreans is presented. From the above results, the method of using the closure stage of sutures of the skull to estimate age can be useful in individual identification of forensic science. Further extensive and accurate research using larger samples would be worthy of study.