Ontogeny of the spheno‐occipital synchondrosis in a modern Queensland, Australian population using computed tomography

Abstract

Due to disparity regarding the age at which skeletal maturation of the spheno-occipital synchondrosis occurs in forensic and biological literature, this study provides recalibrated multislice computed tomography (MSCT) age standards for the Australian (Queensland) population, using a Bayesian statistical approach. The sample comprises retrospective cranial/cervical MSCT scans obtained from 448 males and 416 females aged birth to 20 years from the Skeletal Biology and Forensic Anthropology Research Osteological Database. Fusion status of the synchondrosis was scored using a modified six-stage scoring tier on an MSCT platform, with negligible observer error (κ = 0.911 ± 0.04, intraclass correlation coefficient = 0.994). Bayesian transition analysis indicates that females are most likely to transition to complete fusion at 13.1 years and males at 15.6 years. Posterior densities were derived for each morphological stage, with complete fusion of the synchondrosis attained in all Queensland males over 16.3 years of age and females aged 13.8 years and older. The results demonstrate significant sexual dimorphism in synchondrosis fusion and are suggestive of intrapopulation variation between major geographic regions in Australia. This study contributes to the growing repository of contemporary anthropological standards calibrated for the Queensland milieu to improve the efficacy of the coronial process for medicolegal death investigation. As a stand-alone age indicator, the basicranial synchondrosis may be consulted as an exclusion criterion when determining the age of majority that constitutes 17 years in Queensland forensic practice.

Assessing the fusion of the ischiopubic synchondrosis using predictive modeling

“…Our results report older ages of fusion than reported by Flecker () in a similar Australian population, however it is not possible to determine whether this difference is due to differences in the imaging technology used where computed tomography allows a higher degree of accuracy in discriminating active fusion from complete fusion compared to plain radiography, whether the difference is due to secular change in maturation, and/or whether the difference is due to geographic population differences possibly due to variance in socioeconomic status between the States of Australia. Comparison of radiographic studies have suggested that fusion can be detected earlier and later in computed tomography compared to plain radiography (Langley‐Shirley and Jantz, ; Lottering et al, ) and Jantz et al () demonstrate significant changes in bone length and proportion in the long bones of American whites between 1840 and 1989 demonstrating the impact of secular change on skeletal development. Therefore, comparison of fusion times from studies using different imaging modalities, and on children of significantly different generational origins is cautioned.…”

“…Therefore, comparison of fusion times from studies using different imaging modalities, and on children of significantly different generational origins is cautioned. Lottering et al () recommend that independent reference standards be available for each Australian State, with evidence of intrapopulation variation in the timing of fusion of the spheno‐occipital synchondrosis between Queensland, Western Australian (Franklin and Flavel, ) and Victorian (Bassed et al, ) studies. Queensland children demonstrated earlier fusion of the spheno‐occipital synchondrosis compared to their Australian interstate counterparts by 1–2 years (Lottering et al, ).…”

The ontogeny of occipital bone convexity in a longitudinal sample of extant humans

“…The basilar process meets with the body of the sphenoid at the spheno-occipital synchondrosisan important postnatal growth area (Moore and Lavelle, 1974;Sperber, 1989;Scheuer and Black, 2004;Standring and Gray, 2008;Lottering et al, 2015).…”

“…Though the mid-sphenoidal synchondrosis remains active later in non-human primates, this synchondrosis closes before birth in humans (Ford, 1958;Scott, 1958;Michejda, 1971;Lieberman et al, 2008). The sphenooccipital synchondrosis is the last of the three synchondroses to fuse in human development, with growth at this site continuing into adolescence (Björk, 1955;Scott, 1958;Lieberman et al, 2000b;Lottering et al, 2015). This synchondrosis has been argued to play a major role in postnatal cranial base flexion (Lieberman, 2000;Lieberman et al, 2000b;.…”

“…On average, fusion of the spheno-occipital synchondrosis occurs approximately two years earlier in females than in males, with various studies citing female fusion occurring in the range of 10.5 to 17 years, and male fusion occurring in the 12.5 to 19 year range (Konie, 1964;Moore and Lavelle, 1974;Sperber, 1989;Sahni et al, 1998;Scheuer and Black, 2004;Standring and Gray, 2008;Akhlaghi et al, 2010;Lottering et al, 2015). The disparate age ranges cited in different studies can be attributed to variation in sample populations and fusion scoring methods.…”