Forensic age estimation methods are biased to sex and population; in general, accuracy is reduced when applied to foreign populations. This study assessed the accuracy of the Suchey-Brooks method in contemporary Malaysian individuals and aimed to formulate population-specific standards. Multi-detector computed tomography scans of 355 individuals (165 male; 190 female) of 15-83 years of age were reconstructed using 3D-volumetric rendering in RadiAnt. Pubic symphyseal phase, bias, inaccuracy, and percentage correct age classifications are examined. Transition analysis was used to develop age estimation standards. High observer agreement (κ = 0.763-0.832) and a positive relationship between age and pubic symphyseal phase (r = 0.884-0.90) were demonstrated. Mean inaccuracies were 8.62 and 8.95 years for males and females, respectively; overall correct classification was 97.8%. Transition ages between phases in males were 18.79, 23.29, 28.85, 43.64, and 61.15 years; in females, the corresponding data were 19.77, 22.53, 32.62, 41.85, and 57.39 years.
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.
Different non-invasive methods have been proposed for dental age estimation in adults, with the Kvaal et al. method as one of the more frequently tested in different populations. The purpose of this study was to apply the Kvaal et al. method for dental age estimation on modern volumetric data from 3D digital systems. To this end, 101 CBCT images from a Malaysian population were used. Fifty-five per cent were female (n = 55), and forty-five percent were male (n = 46), with a median age of 31 years for both sexes. As tomographs allow the observer to obtain a sagittal and coronal view of the teeth, the Kvaal pulp/root width measurements and ratios were calculated in the bucco-lingual and mesio-distal aspects of the tooth. From these data different linear regression models and formulae were built. The most accurate models for estimating age were obtained from a diverse combination of measurements (SEE ±10.58 years), and for the mesio-distal measurements of the central incisor at level A (SEE ±12.84 years). This accuracy, however is outside an acceptable range in for forensic application (SEE ±10.00 years), and is also more time consuming than the original approach based on dental radiographs.