Spheno-occipital synchondrosis: Examining the degree of fusion in a South African Black skeletal sample.

Estimating age-at-death is one of the many biological demographics that a forensic anthropologist needs to determine for a set of unknown skeletal remains. A useful skeletal developmental marker, which can aid in estimating age in sub-adult remains, is the state of fusion of the spheno-occipital synchondrosis. This study aimed to determine the repeatability of a three-stage scoring method and the age at which the spheno-occipital synchondrosis begins and completes fusion in a Black South African sample. A total of 147 male and female skeletal individuals aged between 12-30 years from the Raymond A. Dart Collection of Human Skeletons were included. The mean age-at-death noted for the commencement of fusion at the spheno-occipital synchondrosis was 16.2 (±2.9) years in females and 16.7 (±1.2) years in males, with females displaying signs of fusion taking place approximately three years before their male counterparts. Complete fusion of this skeletal developmental marker was observed in 100% of the sample over the age of 20 years, regardless of sex. A Kappa value of 1.0 was achieved when the repeatability and reproducibility of the three-stage scoring method was tested. Complete fusion of this synchondrosis occurred slightly later in this South African sample than that noted in previous literature. This finding may be attributed to the differences in health and socio-economic statuses between these different population groups, reiterating the need for population-specific data to be developed. The importance of noting the state of fusion of the spheno-occipital synchondrosis during the examination of relevant forensic cases may aid in the formation of a narrower age-at-death range for sub-adult and young adult skeletal remains.

Mahon TJ ，Friedling LJ ，Gordon GM 《-》

Age determination by spheno-occipital synchondrosis fusion in Central Indian population.

The spheno occipital suture synchondrosis is a vital contributor to adolescent and adult age estimation in that it can provide an upper or lower age bound depending on its state of fusion. The present study evaluates the utility of the spheno-occipital suture fusion in age estimation of the Central Indian population. The sample includes 198 (117 males and 81 females) cadavers aged between 8 to 26 years. Grading was done using Mitra-Akhlaghi Scale as - Open, Semi closed and Closed. Our study demonstrates that a significant linear correlation exists between the age of an individual and spheno-occipital suture closure for both the sexes and observation of the degree of fusion of this single suture allows the prediction of age in mature individuals.

Pate RS ，Tingne CV ，Dixit PG 《-》

Age estimation by an analysis of spheno-occipital synchondrosis using cone-beam computed tomography.

The spheno-occipital synchondrosis has a relatively late ossification in comparison with other cranial base synchondroses, which makes it a point of interest for forensic age determination studies. The purpose of the present study was to evaluate the reliability of spheno-occipital synchondrosis development in age determination in a Turkish population and to evaluate the reproducibility and reliability of cone beam computed tomography (CBCT) in an evaluation of the fusion stages of spheno-occipital synchondrosis. CBCT mid-sagittal images of 238 (90 males and 148 females) patients between the ages of 7 and 25, with a mean age of 15.45±0.26 and 16.43±0.37, respectively, were examined by three Oral and Maxillofacial Radiologists who evaluated the degree of synchondrosis fusion using a four-stage system. A reevaluation of 50 cases was conducted for intraobserver assessment. Multiple statistical analyses were used to assess the correlation between age and the fusion stage, to compare gender and age according to stages, and to evaluate the inter- and intraobserver agreement. The mean ages for complete fusion (Stage 3) were 18 and 20 for females and males, respectively. The interobserver agreement ranged between substantial and perfect, while the intraobserver agreement was substantial for all three observers. Based on these results, CBCT, when available, might be the method of choice for age estimation using the spheno-occipital synchondrosis fusion stages. Evaluating spheno-occipital synchondrosis has a value for age estimation around the age of 18 years, which affects the legal decisions in Turkey.

Sinanoglu A ，Kocasarac HD ，Noujeim M 《-》

Brief communication: timing of spheno-occipital closure in modern Western Australians.

The spheno-occipital synchondrosis is a craniofacial growth centre between the occipital and sphenoid bones-its ossification persists into adolescence, which for the skeletal biologist, means it has potential application for estimating subadult age. Based on previous research the timing of spheno-occipital fusion is widely variable between and within populations, with reports of complete fusion in individuals as young as 11 years of age and nonfusion in adults. The aim of this study is, therefore, to examine this structure in a mixed sex sample of Western Australian individuals that developmentally span late childhood to adulthood. The objective is to develop statistically quantified age estimation standards based on scoring the degree of spheno-occipital fusion. The sample comprises multidetector computed tomography (MDCT) scans of 312 individuals (169 male; 143 female) between 5 and 25 years of age. Each MDCT scan is visualized in a standardized sagittal plane using three-dimensional oblique multiplanar reformatting. Fusion status is scored according to a four-stage system. Transition analysis is used to calculate age ranges for each defined stage and determine the mean age for transition between an unfused, fusing and fused status. The maximum likelihood estimates for the transition from open to fusing in the endocranial half is 14.44 years (male) and 11.42 years (female); transition from fusion in the ectocranial half to complete fusion is 16.16 years (male) and 13.62 years (female). This study affirms the potential value of assessing the degree of fusion in the spheno-occipital synchondrosis as an indicator of skeletal age.

Franklin D ，Flavel A 《-》

Analysis of time of closure of the spheno-occipital synchondrosis using computed tomography.

Current knowledge concerning closure of the spheno-occipital synchondrosis is inadequate for age estimation purposes in that of the few detailed studies conducted, these demonstrate considerable variation concerning the age at which the synchondrosis commences and completes fusion, thus creating uncertainty for forensic investigators who may use this developmental feature for age determinations. The aim of the present study was to determine the sequence and timing of closure of the spheno-occipital synchondrosis for a large sample of a modern Australian population to assess if this age marker is a useful tool for age estimation for individuals around the age of 18 years. The sample consisted of 666 individuals in the age range 15-25 years, who were admitted to the Victorian Institute of Forensic Medicine (VIFM) mortuary and who had undergone routine full body multi-slice CT imaging. Results show that fusion was well underway by the age of 15 years and was complete by 17 years. Fusion begins superiorly and progresses inferiorly. Persistence of a scar at the site of fusion was demonstrated through to age 25 years. After the age of 16 years there was no significant difference in progress of fusion between males and females. The study showed that this age marker is of limited value for age estimations around the age of 18 years in this population.

Bassed RB ，Briggs C ，Drummer OH 《-》