Sex estimation is very important in forensic applications as part of individual identification. Morphological sex estimation methods predominantly focus on anatomical measurements. Based on the close ...relationship between sex chromosome genes and facial characterization, craniofacial hard tissues morphology shows sex dimorphism. In order to establish a more labor-saving, rapid, and accurate reference for sex estimation, the study investigated a deep learning network-based artificial intelligence (AI) model using orthopantomograms (OPG) to estimate sex in northern Chinese subjects. In total, 10703 OPG images were divided into training (80%), validation (10%), and test sets (10%). At the same time, different age thresholds were selected to compare the accuracy differences between adults and minors. The accuracy of sex estimation using CNN (convolutional neural network) model was higher for adults (90.97%) compared with minors (82.64%). This work demonstrated that the proposed model trained with a large dataset could be used in automatic morphological sex-related identification with favorable performance and practical significance in forensic science for adults in northern China, while also providing a reference for minors to some extent.
•An automatic sex estimation model based on the CNN and a large sample of OPGs has a better effect than other algorithms.•The model has better performance for adults from Han population in northern China, with an accuracy of 90.97%.•The model could also provide a reference for sex estimation of children and adolescents, with an accuracy of 82.64%.
Two new species of Petrocosmea (Gesneriaceae), P. purpureomaculata M.Q. Han, J. Cai & J. D. Ya from Jinping County and P. wui M.Q. Han, J. Cai & J. D. Ya from Eshan County, Yunnan Province, China, ...are described and illustrated. Petrocosmea wui was previously misidentified as P. coerulea due to its shield‐shaped leaf base, but can be distinguished by several salient characters. Petrocosmea purpureomaculata is most similar to but distinguishable from P. parryorum. Additions and revisions of previously published descriptions of P. coerulea and P. parryorum, are also provided.
Petrocosmea chiwui M.Q.Han, H. Jiang & Yan Liu and P. rotundifolia M.Q.Han, H. Jiang & Yan Liu (Gesneriaceae), two new species native to Yunnan, China, are described and illustrated.
Two new species of Petrocosmea (Gesneriaceae), P. wangii M.Q.Han, J.Cai & J.D.Ya from Shiping County and P. yei M.Q.Han, C.Liu & Y.X.Gong from Mojiang and Zhenyuan Counties, Yunnan Province, China, ...are described and illustrated.
•The lowest RMS values of probable matches were all proven to be matches.•All of the RMS values of the matched models were below 0.27mm.•Correntropy introduced into ICP could improve registration ...accuracy.
Dentition is an individualizing structure in humans that may be potentially utilized in individual identification. However, research on the use of three-dimensional (3D) digital models for personal identification is rare. This study aimed to develop a method for individual identification based on a 3D image registration algorithm and assess its feasibility in practice. Twenty-eight college students were recruited; for each subject, a dental cast and an intraoral scan were taken at different time points, and digital models were acquired. The digital models of the dental casts and intraoral scans were assumed as antemortem and postmortem dentition, respectively. Additional 72 dental casts were extracted from a hospital database as a suspect pool together with 28 antemortem models. The dentition images of all of the models were extracted. Correntropy was introduced into the traditional iterative closest point algorithm to compare each postmortem 3D dentition with 3D dentitions in the suspect pool. Point-to-point root mean square (RMS) distances were calculated, and then 28 matches and 2772 mismatches were obtained. Statistical analysis was performed using the Mann-Whitney U test, which showed significant differences in RMS between matches (0.18±0.03mm) and mismatches (1.04±0.67mm) (P<0.05). All of the RMS values of the matched models were below 0.27mm. The percentage of accurate identification reached 100% in the present study. These results indicate that this method for individual identification based on 3D superimposition of digital models is effective in personal identification.
•The most significant correlation between actual age and ratios was for ratio B.•Six ratios of mandibular canine teeth showed a significant correlation with age.•A Chinese-specific equation could ...ameliorate age prediction accuracy.•The standard deviations for the Chinese-specific equation remained large.
The Kvaal method as a non-invasive method for age estimation based on the changes of pulpal size caused by secondary dentin deposition has been applied to different ethnics. However, its results are often conflicting and its accuracy is relatively poor. This study aimed to verify the applicability of the Kvaal method to estimate the ages of the Chinese population using digital panoramic radiographs and to formulate specific regression equations for use in Chinese subjects. A sample of 360 digital panoramic radiographs from northern Chinese population were selected, from which the pulpal size and width of six tooth types (maxillary central incisor, lateral incisor, second premolar, mandibular lateral incisor, canine, and first premolar) were measured using Kvaal’s method. Then, inter- and intra-observer reliabilities were calculated to evaluate the reproducibility of those measurements. The correlation between chronological age and measurements was also examined and the Chinese-specific equations for age estimation were conducted. After comparing the accuracy of the Chinese-specific equation with the original Kvaal equation, the age of the Chinese population was clearly overestimated by Kvaal’s equation, and a Chinese-specific equation could ameliorate age prediction accuracy. In addition, the residuals of the Chinese-specific equation were significantly lower than that of the original Kvaal’s method. Thus, we concluded that the original Kvaal equation cannot accurately estimate age in the Chinese population. Although accuracy improved using the Chinese-specific equation that was based on Kvaal’s methodology, the standard deviation remained large. In view of the lack of accurate age estimation methods for adults, we propose finding more correlated variables or combining other age estimation methods to increase the accuracy for adult age estimation.
Petrocosmea viridis M.Q. Han & Yan Liu, a new tiny but pretty species from Guizhou, China, is described and illustrated. It was found on damp cliffs in an enormous limestone sinkhole called Dadaihe ...Tiankeng. It is mostly similar to P. minor in its conformation of the corolla, but differs from the latter by having numerous leaves and a tiny, light green corolla. While comparing these two species, some additions and revisons of previous descriptions of P. minor had to be made.
The nose is the most prominent part of the face and is a crucial factor for facial esthetics as well as facial reconstruction. Although some studies have explored the features of external nose and ...predicted the relationships between skeletal structures and soft tissues in the nasal region, the reliability and applicability of methods used in previous studies have not been reproduced. In addition, the majority of previous studies have focused on the sagittal direction, whereas the thickness of the soft tissues was rarely analyzed in three dimensions. A few studies have explained the specific characteristics of the nose of Chinese individuals. The aim of this study was to investigate the relationship between the hard nasal structures and soft external nose in three dimensions and to predict the morphology of the nose based on hard-tissue measurements. To eliminate the influence of low resolution of CBCT and increase the accuracy of measurement, three-dimensional (3D) images captured by cone-beam computed tomography (CBCT) and 3dMD photogrammetry system were used in this study. Twenty-six measurements (15 measurements for hard tissue and 11 measurements for soft tissue) based on 5 craniometric and 5 capulometric landmarks of the nose of 120 males and 120 females were obtained. All of the subjects were randomly divided into an experimental group (180 subjects consisting of 90 males and 90 females) and a test group (60 subjects consisting of 30 males and 30 females). Correlation coefficients between hard- and soft-tissue measurements were analyzed, and regression equations were obtained based on the experimental group and served as predictors to estimate nasal morphology in the test group. Most hard- and soft-tissue measurements appeared significantly different between genders. The strongest correlation was found between basis nasi protrusion and nasospinale protrusion (0.499) in males, and nasal height and nTr-nsTr (0.593) in females. For the regression equations, the highest value of R
2
was observed in the nasal bridge length in males (0.257) and nasal tip protrusion in females (0.389). The proportion of subjects with predicted errors < 10% was over 86.7% in males and 70.0% in females. Our study proved that a combined CBCT and 3dMD photogrammetry system is a reliable method for nasal morphology estimation. Further research should investigate other influencing factors such as age, skeletal types, facial proportions, or population variance in nasal morphology estimation.
In many countries, assessment of legal age, also known as age of majority, has become increasingly important over the years. In China, individuals older than 18 years of age have full capacity ...regarding civil conduct and can be tried as an adult for criminal charges. Therefore, from a legal point of view, it is crucial to determine whether an individual is an adult. The developmental degree of the third molar is widely recognized as a suitable site for age estimation in late adolescence. This article uses the third molar maturity index (
I
3M
) with a cutoff value of
I
3M
= 0.08, which was established by Cameriere et al. in 2008, to distinguish whether an individual is a minor or an adult (≥ 18 years of age) in a northern Chinese population. A total of 840 digital orthopantomograms (OPTs) from 420 male and 420 female northern Chinese subjects aged 12 to 25 years were evaluated. It was found that an increase in
I
3M
corresponded to a decrease in chronological age. In our study,
I
3M
= 0.10 showed better accuracy in age discrimination in both men and women. This threshold also resulted in high sensitivity (0.929 and 0.809) and specificity (0.940 and 0.973) in males and females, respectively. The proportion of correctly classified subjects was 0.917 (95% CI, 0.898 to 0.935) in total, 0.938 (95% CI, 0.915 to 0.961) in male and 0.895 (95% CI, 0.866 to 0.925) in female subjects. Bayes post-test probabilities were 0.967 (95% CI, 0.947 to 0.986) in males and 0.983 (95% CI, 0.966 to 0.998) in females. These differences in threshold values between Chinese and Caucasian populations might be because the development of third molars is delayed in the Chinese population compared to the Caucasian population. In conclusion,
I
3M
might be a useful method in legal and forensic practices to determine ages in late adolescence in northern Chinese individuals. However, a specific population should be tested before
I
3M
is used for legal age estimation.
Lips are the main part of the lower facial soft tissue and are vital to forensic facial approximation (FFA). Facial soft tissue thickness (FSTT) and linear measurements in three dimensions are used ...in the quantitative analysis of lip morphology. With most FSTT analysis methods, the surface of soft tissue is unexplicit. Our study aimed to determine FSTT and explore the relationship between the hard and soft tissues of lips in different skeletal occlusions based on cone-beam CT (CBCT) and 3dMD images in a Chinese population. The FSTT of 11 landmarks in CBCT and 29 lip measurements in CBCT and 3dMD of 180 healthy Chinese individuals (90 males, 90 females) between 18 and 30 years were analyzed. The subjects were randomly divided into two groups with different skeletal occlusions distributed equally: 156 subjects in the experimental group to establish the prediction regression formulae of lip morphology and 24 subjects in the test group to assess the accuracy of the formulae. The results indicated that FSTT in the lower lip region varied among different skeletal occlusions. Furthermore, sex discrepancy was noted in the FSTT in midline landmarks and linear measurements. Measurements showing the highest correlation between soft and hard tissues were between total upper lip height and Ns-Pr (0.563 in males, 0.651 in females). The stepwise multiple regression equations were verified to be reliable with an average error of 1.246 mm. The method of combining CBCT with 3dMD provides a new perspective in predicting lip morphology and expands the database for FFA.
