Quantification of spheno-occipital synchondrosis fusion in a contemporary Malaysian population.

Timing of fusion of the spheno-occipital synchondrosis (SOS) is correlated with age. Previous research, however, has demonstrated variation in the timing of closure among different global populations. The present study aims to quantify the timing of SOS fusion in Malaysian individuals as visualised in multi-detector computed tomography (CT) scans and to thereafter formulate age estimation models based on fusion status. Anonymised cranial CT scans of 336 males and 164 females, aged 5-25 years, were acquired from the National Institute of Forensic Medicine, Hospital Kuala Lumpur and Department of Diagnostic Imaging, Hospital Sultanah Aminah. The scans were received in DICOM format and reconstructed into three-dimensional images using OsiriX. The SOS is scored as open, fusing endocranially, fusing ectocranially or completely fused. Statistical analyses are performed using IBM SPSS Statistics version 24. Transition analysis (Nphases2) is then utilised to calculate age ranges for each stage. To assess the reliability of an observation, intra- and inter-observer agreement is quantified using Fleiss Kappa and was found to be excellent (κ=0.785-0.907 and 0.812). The mean (SD) age for complete fusion is 20.84 (2.84) years in males and 19.78 (3.35) years in females. Transition ages between Stages 0 and 1, 1 and 2, and 2 and 3 in males are 12.52, 13.98 and 15.52 years, respectively (SD 1.37); in females, the corresponding data are 10.47, 12.26 and 13.80 years (SD 1.72). Complete fusion of the SOS was observed in all individuals above the age of 18 years. SOS fusion status provides upper and lower age boundaries for forensic age estimation in the Malaysian sample.

Hisham S ，Flavel A ，Abdullah N ，Noor MHM ，Franklin D ... -  《-》

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 《-》

A Computed Tomographic Analysis of Spheno-Occipital Synchondrosis Ossification for Age Estimation in a Sample of Egyptians.

The aim of the present work was to create statistically quantified age estimation standards based on spheno-occipital synchondrosis (SOS) fusion state as visualized in computed tomography in Egyptians. The study included 208 Egyptians between the ages of 5 and 30 years (117 male and 90 female participants). Spheno-occipital synchondrosis was visualized in a midsagittal view in a neutral head position. Degree of ossification of SOS was assessed using a 4-stage system. Interobserver agreement and intraobserver agreement were almost perfect with Cohen κ values of 0.863 and 0.983, respectively. The mean ages of complete fusion (stage 3) were 20.36 ± 3.11 and 20.94 ± 4.06 years in male and female participants, respectively. Nonfusion (stage 0) was observed up to 15 and 13 years in male and female participants, respectively. Complete fusion occurred as early as 15 and 13 years in male and female participants, respectively. All subjects with nonfused SOS were minors (<18 years). A total of 87.9% of male participants and 85.3% of female participants with completely fused SOS were legally adults (≥18 years). Significant regression models were formulated to predict age from SOS fusion stage (adjusted R2 = 0.779 for male participants and 0.780 for female participants). Regression models predicted that male and female participants 18 years or older with 96.30% and 95.59% accuracy, respectively.

Sobh ZK ，Mohamed AS 《-》