通过脚掌重压点压力面测量计算年龄

检案中以测量脚掌压力面前边沿至后边沿的长(以脚掌中轴线测量)×5=年龄与依其原理推论出的有关公式计算年龄,一般对青少年准确性较高,但对不同年龄阶段的人用此法计算推断误差较大,特别是推断40岁以上人的年龄误差更为明显。经对数百例的检验探索,根据随年龄的增长,压力中心点、压力面均逐渐向后向外转     

中国北方未成年人群牙龄推断研究

目的运用Cameriere法和Willems法推断中国北方5~14岁人群牙龄,并比较两种方法牙龄推断的准确性。方法收集西安交通大学口腔医院年龄在5~14岁的中国北方未成年人群拍摄的全口曲面断层片2000例,其中男性1000例,女性1000例。分别采用Cameriere法和Willems法进行牙龄推断,利用SPSS 18.0软件对两种方法的推断年龄与生理年龄进行配对t检验,比较推断年龄与生理年龄的差异。结果 Cameriere法的推断年龄比生理年龄平均低估了0.38岁(男性)和0.39岁(女性),而Willems法的推断年龄比生理年龄平均高估了0.61岁(男性)和0.39岁(女性)。对比两种方法的平均绝对误差(mean absolute error, MAE),Cameriere法的MAE为0.87岁,Willems法的MAE为0.91岁。结论 Cameriere法和Willems法均适用于中国北方5~14岁未成年人群的牙龄推断,但Cameriere法比Willems法更准确。     

基于胎脑磁共振测量胎儿颅脑径线推断胎龄

目的基于胎脑磁共振测量胎儿颅脑径线进行胎龄推断,分析颅脑各径线与胎龄(GA)之间的关系,评估不同径线在胎龄推断中的应用价值。方法收集1 388例胎龄144～271d的正常胎儿头部磁共振成像(MRI)资料,测量颅双顶径(BPD)、脑双顶径(cBPD)、颅枕额径(FOD)、脑枕额径(cFOD)、小脑横径(TCD),分析各径线与年龄相关性,并建立一元和多元胎龄推断模型。结果不同胎龄胎儿的BPD、cBPD、FOD、cFOD、TCD随胎龄呈线性相关,TCD与胎龄的相关性最好达0.901,由cBPD、cFOD、TCD建立的多元回归方程可较好推断胎龄,R~2=0.912,50例独立测试集回代检验平均绝对误差为6.982d。结论颅脑各径线随胎龄呈线性变化,对胎龄推断具有重要参考价值,所建立的回归方程可用于中国当代中晚期胎儿的胎龄推断。     

基于腰椎高度X线测量技术推断四川汉族女性身高

目的通过腰椎高度X线测量技术,建立四川汉族女性身高的数学模型,为法医人类学研究积累基础数据。方法收集206例四川汉族女性个体按年龄分为A、B、C 3组,其中A组(206例)不分年龄,B组(116例)为20~45岁,C组(90例)为45岁以上,并应用计算机X线摄影(computer radiography,CR)技术分别测量所有样本腰椎CR片中5个椎体(L1~L5)前缘、后缘、中央高度(x1~x15),脊柱腰段中央总长度(x16),同时测量每个个体真实身高,对各测量指标联合与身高的相关性进行线性回归分析,建立推断身高的数学模型,并重新选取62例样本代入数学模型,检验模型的准确性。结果所建立的数学模型经线性回归模型假设检验,均具有统计学意义(P0.05),回归方程的推断标准误为2.982~5.004cm,相关系数为0.370~0.779,复相关系数为0.533~0.834。对每组相关系数、复相关系数最高的方程进行回代检验,其中A组的y=100.33+1.489 x3-0.548 x6+0.772 x9+0.058 x12+0.645 x15的准确率最高,为80.6%(±1SE)、100%(±2SE)。结论本研究建立的数学模型适用于推断四川汉族女性身高。     

基于双能X线骨密度仪的骨折形成时间推断研究

目的 研究人体骨折部位骨矿物密度值(bone mineral density,BMD)在骨折愈合过程中的变化规律，分析其与骨折形成时间的关系。方法 共收集451例外伤性股骨骨折患者样本，其中男性233例，女性218例，年龄范围为20～79岁；采用双能X线吸收测量法，在骨折当时及骨折后2、4、6、8、10周分别对患者骨折区域R1和健侧对照区域R2进行BMD检测；应用SPSS22.0软件对数据进行统计学分析。结果 骨折患者的BMD值与年龄呈负相关，骨折区的BMD值低于正常人群，但会随着骨折时间的延长而升高，男性患者的BMD值大于女性患者，利用BMD值推断骨折时间的方程为：Y=(X₁-0.714+0.069×X₂+0.111×X₃)/0.036(X₁代表BMD值，X₂代表性别，X₃代表年龄分组，Y代表骨折时间)。结论 利用双能X线测量骨折区域的BMD值可以推断骨折形成时间，在人体损伤程度鉴定、损伤形成时间推断以及三期评定等法医临床学鉴定实践中有应用价值。     

9-CpG年龄推断在不同海拔地域和性别人群中的验证及优化

目的本研究旨在对早先建立的9-CpG年龄推断模型在不同海拔地域和不同性别人群中年龄推断的适用性进行验证及优化,提升年龄推断的准确性,并研究检测体系的灵敏度。方法采集367份不同海拔地域、不同性别个体的血液样本,使用EpiTYPER技术平台检测9个CpG位点的甲基化值,利用年龄推断模型预测样本提供者的年龄,综合评估年龄预测的准确性。结果所有测试样本均获得相对准确的年龄预测值(N=367, MAD=4.0岁,R~2=0.83)。平原女性样本(N=40),MAD=3.63岁,R~2=0.88。平原男性样本(N=123)MAD=3.42岁,R~2=0.83;其中随机选取平原男性样本(N=40)MAD=3.39岁,R~2=0.83;高原男性样本(N=204)MAD=4.42岁,R~2=0.86。加入平原与高原变量,新建立8-CpG年龄推断模型,MAD=2.90岁,R~2=0.86(验证集MAD=3.31岁,R~2=0.83)。灵敏度分析中转化前最低DNA用量为250ng(转化后最低DNA用量约为8ng)可获得9个位点完整甲基化信息。结论本研究证明了9-CpG年龄推断模型在不同性别间无显著差异。同一模型应该考虑高原和平原人群血液样本DNA甲基化差异。加入平原与高原变量,新建立8-CpG年龄推断模型可提高高原地区人群年龄预测准确性。     

基于PMCT三维重建盆部骨骼推断华北汉族人群身高的研究

目的 通过PMCT研究我国汉族人群骨盆特征，通过统计学方法分析盆部骨骼各测量指标与身高之间的线性关系，获得身高预测方程，并评价其推断身高的准确性。方法 筛选满足一定条件的尸体影像共420例，测量骨盆髂前上棘宽、中骨盆宽度、髂前上棘与坐骨结节之间的距离等14个指标。测量尸体长度。建立单一测量指标与多指标的身高回归方程。计算每个公式的相关系数(R)、决定系数(R²)和估计标准误差(SEE,cm)，以评估回归的显著性。结果 除女性骨盆髂前上棘宽(X₁,p=0.446)外，其他测量指标均与身高之间存在显著的正相关关系。单一测量指标LHAIT(X⁴)获得了最高的相关系数(R=0.726)和最低的SEE值(SEE=5.906)。多指标逐步回归分析可获得的最高相关系数为0.761。结论 在无法获得更理想的骨骼元素(如完整的长骨)时，使用盆部骨骼PMCT测量结果可能有助于我国华北地区汉族人群身高的推断。     

X线计测法推断骨龄的研究进展

利用计测法推断年龄是指应用X线摄片技术,测量不同年龄人群全身不同部位骨骼相关数据,如四肢长骨、短骨及椎骨的长度、宽度、厚度,骨化中心面积、干骺端横径、骨骺端横径、骺线宽度、干骺比值等,经过统计学分析探讨这些测量数据与真实年龄（即生活年龄）之间的相关性,并据此推断活体年龄（即骨龄）。本文对有关掌指骨、腕骨、肱骨、股骨及颈椎骨推断骨龄的计测方法和骨龄推断结果进行回顾性分析和总结,并对其应用价值和应用前景进行了初步探讨。     

上颌尖牙髓腔体积与牙体积比值在个体性别判定中的应用

目的探讨三维重建的上颌尖牙髓腔体积与牙体体积在个体性别判定中的临床应用价值。方法选取2015年9月-2016年8月山西医科大学口腔医院放射科患者的CBCT影像资料片103例(男51例,女52例),利用Mimics17.0分析软件测量上颌尖牙髓腔体积(PV)、牙体积(TV)及髓腔体积与牙体积比值(PV/TV),使用SPSS16.0统计软件和Fisher判别法对数据处理,得出性别判定函数,并采用Cross-Validated法进行效果评价。结果以牙体积(TV)和髓腔体积与牙体积比值(PV/TV)作为研究指标进行性别推断时,个体性别判别函数为Y=0.009(TV)+28.896(PV/TV)-6.962,采用Cross-validated法进行效果评价,判别符合率为男51例,判断正确率为64.7%;女52例,判断正确率为78.8%。结论上颌尖牙牙体积(TV)和髓腔体积与牙体积比值(PV/TV)能够做为性别推断的研究指标,它为法医个体性别推断提供一种新的方法和途径。     

应用膝关节MRI T_2加权脂肪抑制像推断活体年龄

目的探索膝关节MRI T2加权脂肪抑制像(T2-FS)在法医年龄推断中的应用价值,建立安全可靠的四川汉族年龄推断方法。方法收集膝关节MRI 324例(男性170例,女性154例),年龄范围为10~30岁。采用西门子1.5T磁共振仪摄片,MRI参数:T2-FS TSE序列,矢状位。将股骨远端、胫骨近端骨骺发育分为6个等级并赋分,分析各指标性别差异及年龄相关性,建立年龄推断回归模型。结果男女性股骨远端、胫骨近端MRI等级与年龄呈正相关性,股骨远端与年龄的相关性男性0.687,女性0.661;胫骨近端与年龄的相关性男性0.684,女性0.488。股骨远端骨骺完全闭合,骺线消失的最小年龄男性18.42岁,女性19.36岁;胫骨近端男性骺线消失的最小年龄为16.93岁,女性为14.68岁。股骨远端等级1~3、5、6和胫骨近端等级1~3、5年龄分布性别差异不显著。分别建立男女年龄推断模型,男性年龄推断平均绝对误差(MAD)=2.90岁;女性年龄推断MAD=3.30岁。结论膝关节MRI T2-FS影像可作为活体年龄推断的指标之一,股骨远端等级6可作为判断18岁的指标之一。     

Relationship Between Pulp Tooth Area Ratio and Chronological Age Using Cone‐beam Computed Tomography Images

This study investigated the relationship between chronological age and pulp tooth area ratio (PTR) in maxillary central teeth using cone‐beam computed tomography (CBCT) images in the Turkish population. The sample consisted of CBCT images of 120 male and female subjects between 14 and 75 years old. The PTR of the maxillary central teeth was calculated using inVivo 5 software (Anatomage, San Jose, CA). Data were analyzed with independent t‐test and Pearson's rank correlation test. There was a significant negative correlation between chronological age and PTR (r = ?0.615). The results showed that the PTR of maxillary central teeth is a reliable method for age estimation in the Turkish population.     

Variations in pulp/tooth area ratio as an indicator of age: a preliminary study

This paper details a method for age determination of adults from single rooted teeth. The sample consisted of 100 Italian white Caucasian patients (46 men, 54 women) aged between 18 and 72 years. The single rooted maxillary right canine was utilized in this preliminary study. Pulp/root ration, tooth length, pulp/tooth length ratio, pulp/tooth area and pulp/root width ratios at three different levels were computed. Pearson's correlation coefficients between age and these variables showed that the ratio between pulp and tooth area correlated best with age (r2 = 0.85). Stepwise multiple regression models yielded a linear relationship between pulp/root width at mid-root level and chronological age and a linear relationship when pulp/tooth area was compared to age. Statistical analysis indicated that these two variables explain 84.9% of variations in estimated chronological age. The median of the absolute value of residual errors between actual and estimated ages was less than four years.     

Reliability in age determination by pulp/tooth ratio in upper canines in skeletal remains

Estimation of age of skeletal remains is one of the most complex questions for anthropologists. The most common macroscopic methods are based on dental wear and histological evaluation of bone remodeling. These methods are often qualitative, require great technical expertise, and have proved inexact in the estimation of ages over 50 years. Certain dental methods investigate the apposition of secondary dentine, in the study of tooth cross-sections, and X-rays to study width, height, and pulp area. The primary author previously proposed a method of estimating the age of a living person based on the pulp/tooth ratio (PTR) method in the upper canines. The aim of the present study is to verify whether the PTR method can also be used to estimate the age at death of skeletal remains. This paper investigates the study of historical samples of known age as a means to validate the proposed method.     

Age estimation of adults from dental radiographs

Previous studies have shown that with advancing age the size of the dental pulp cavity is reduced as a result of secondary dentine deposit, so that measurements of this reduction can be used as an indicator of age. The aim of the present study was to find a method which could be used to estimate the chronological age of an adult from measurements of the size of the pulp on full mouth dental radiographs. The material consisted of periapical radiographs from 100 dental patients who had attended the clinics of the Dental Faculty in Oslo. The radiographs of six types of teeth from each jaw were measured: maxillary central and lateral incisors and second premolars, and mandibular lateral incisors, canines and first premolars. To compensate for differences in magnification and angulation on the radiographs, the following ratios were calculated: pulp/root length, pulp/tooth length, tooth/root length and pulp/root width at three different levels. Statistical analyses showed that Pearson's correlation coefficient between age and the different ratios for each type of tooth was significant, except for the ratio between tooth and root length, which was, therefore, excluded from further analysis. Principal component analyses were performed on all ratios, followed by regression analyses with age as dependent variable and the principal components as independent variables. The principal component analyses showed that only the two first of them had significant influence on age, and a good and easily calculated approximation to the first component was found to be the mean of all the ratios. A good approximation to the second principal component was found to be the difference between the mean of two width ratios and the mean of two length ratios, and these approximations of the first and second principal components were chosen as predictors in regression analyses with age as the dependent variable. The coefficient of determination (r²) for the estimation was strongest when the ratios of the six teeth were included (r² = 0.76) and weakest when measurements from the mandibular canines alone were included (r² = 0.56). Measurement on dental radiographs may be a non-invasive technique for estimating the age of adults, both living and dead, in forensic work and in archaeological studies, but the method ought to be tested on an independent sample.     

Human dental age estimation by calculation of pulp-tooth volume ratios yielded on clinically acquired cone beam computed tomography images of monoradicular teeth

Abstract: Secondary dentine is responsible for a decrease in the volume of the dental pulp cavity with aging. The aim of this study is to evaluate a human dental age estimation method based on the ratio between the volume of the pulp and the volume of its corresponding tooth, calculated on clinically taken cone beam computed tomography (CBCT) images from monoradicular teeth. On the 3D images of 111 clinically obtained CBCT images (Scanora^®3D dental cone beam unit) of 57 female and 54 male patients ranging in age between 10 and 65 years, the pulp–tooth volume ratio of 64 incisors, 32 canines, and 15 premolars was calculated with Simplant^® Pro software. A linear regression model was fit with age as dependent variable and ratio as predictor, allowing for interactions of specific gender or tooth type. The obtained pulp–tooth volume ratios were the strongest related to age on incisors.     

Pulp volume quantification methods in cone-beam computed tomography for age estimation: A critical review and meta-analysis

The secondary dentin deposition that occurs after the tooth formation process results in a decrease in pulp cavity volume in adolescents and adults. The purpose of this critical review was to correlate pulpal and/or dental volume on cone-beam computed tomography (CBCT) with chronological age approximation. A subobjective was to investigate which methodology and CBCT technical parameters would be most appropriate to evaluate this correlation. This critical review followed the PRISMA guidelines, and it was conducted by a search through PubMed, Embase, SciELO, Scopus, Web of Science, Cochrane Library databases, as well as gray literature. Primary studies that used pulp volume, or pulp chamber to tooth volume ratio measured using CBCT were included. Seven hundred and eight indexed and 31 non-indexed records were identified. A qualitative analysis was performed including 25 selected studies with a total of 5100 individuals, age ranging from 8 to 87 years without sex predilection. The most used method was pulp volume/tooth volume. CBCT voxel size ranged between 0.09 and 0.5. Manual segmentation associated with threshold algorithms was used in most of the studies. Correlation between the pulp volume/tooth volume ratio was moderate: −0.66 for the upper central incisors, −0.59 for upper canines and −0.56 for lower canines. High heterogeneity was observed among the studies. It is concluded that pulp volume should be used with caution in age estimation. Evidence supports the preferable use of upper incisors with pulp volume/tooth volume ratio for age estimation. There is not enough evidence that voxel size interferes in age estimation by pulp volume.     

Age estimation by pulp/tooth ratio in canines by peri-apical X-rays

Estimation of age in individuals has received considerable attention in forensic science, in which it is a widely used method for individual identification, together with paleo-demographic analyses to establish mortality patterns in past populations. The present investigation, which is a continuation of a previously published pilot study, was conducted to examine the possible application of the pulp/tooth area ratio by peri-apical images as an indicator of age at death. A total of 200 peri-apical X-rays of upper and lower canines were assembled from 57 male and 43 female skeletons of Caucasian origin, aged between 20 and 79 years. They belong to the Frassetto osteological collection of Sassari (Sardinia) and are housed in the Museum of Anthropology, Department of Experimental and Evolutionistic Biology, University of Bologna. For each skeleton, dental maturity was evaluated by measuring the pulp/tooth area ratio on upper (x(1)) and lower (x(2)) canines. Very good agreement was found between intraobserver measurements. Statistical analysis was performed in order to obtain multiple regression formulae for dental age calculation, with chronological age as dependent variable, and gender, and upper and lower canines as independent variables. Stepwise regression analysis showed that gender did not contribute significantly to the fit (p=0.881) whereas variables x(1) and x(2) and the first-order interaction between them did. These two variables explained 92.5% of variations in estimated chronological age and the residual standard error was 4.06 years. Lastly, two simple linear regression equations were obtained for age estimation using canines from the maxilla and mandible separately. Both models explained 86% of variations in estimated chronological age and allowed an age-at-death estimate with a residual standard error of about 5.4 years.     

Age Estimation Based on Pulp Cavity to Tooth Volume Ratio Using Postmortem Computed Tomography Images

Pulp cavity size is known to decrease with age and can therefore serve as an indicator for age estimation. Here, we evaluated whether reconstructed images of multidetector‐row computed tomography (MDCT) acquired before forensic autopsy are useful for estimating age at death. Images of 136 mandibular first premolars obtained from bodies of known age at death were analyzed, and the volume of the regions corresponding to pulp cavity and that of the whole tooth were determined using a voxel counting function. The pulp cavity was clearly distinguishable from dental hard tissue on the reconstructed images when using a cutoff value of 1400 Hounsfield units. Regression analysis adjusted for sex showed that estimated age correlated significantly with the pulp cavity to tooth volume ratio (r = 0.76). MDCT is gaining more widespread use in forensic medicine, and analyzing dental images to obtain parameters for age prediction is a practical approach for postmortem identification.     

Age estimation by pulp/tooth ratio in canines by mesial and vestibular peri-apical X-rays

Changes in the size of the pulp canal, caused by apposition of secondary dentine, are the best morphometric parameters for estimating age by X-rays. The apposition of secondary dentine is the most frequently used method for age estimation in adult subjects. In two previous papers, we studied the application of the pulp/tooth area ratio by peri-apical X-rays as an indicator of age at death. The aim of the present study was to test the accuracy of age evaluation by combined analysis of labio-lingual and mesial peri-apical X-rays of lower and upper canines. A total of 200 such X-rays were assembled from 57 male and 43 female skeletons of Caucasian origin, aged between 20 and 79 years. For each skeleton, dental maturity was evaluated by measuring the pulp/tooth area ratio according to labio-lingual and mesial X-rays on upper (x(1), x(2)) and lower (x(3), x(4)) canines. Very good agreement was found between intra-observer measurements. Statistical analysis showed that all variables x(1), x(2), x(3), and x(4) and the first-order interaction between x(1) and x(3) contributed significantly to the fit, so that they were included in the regression model, yielding the following regression formula: Age = 120.737 - 337.112x(1) - 79.709x(2) - 364.534x(3) - 65.655x(4) + 1531.918x(1)x(3) . The residual standard error of estimated ages was 3.62 years, with 94 degrees of freedom, and the median of the residuals was -0.155 years, with an interquartile range of 4.96 years. The accuracy of the method was ME = 2.8 years, where ME is the mean prediction error. The model also explained 94% of total variance (R(2) = 0.94).     

Age estimation by pulp/tooth ratio in lower premolars by orthopantomography

Accurate age estimation has always been a problem for forensic scientists, and apposition of secondary dentine is often used as an indicator of age. Since 2004, in order to examine patterns of secondary dentine apposition, Cameriere et al. have been extensively studying the pulp/tooth area ratio of the canines by panoramic and peri-apical X-ray images. The main aim of this paper is to examine the relationship between age and age-related changes in the pulp/tooth area ratio in monoradicular teeth, with the exception of canines, by orthopantomography. A total of 606 orthopantomograms of Spanish white Caucasian patients (289 women and 317 men), aged between 18 and 75 years and coming from Bilbao and Granada (Spain), was analysed. Regression analysis of age of monoradicular teeth indicated that the lower premolars were the most closely correlated with age. An ANCOVA did not show significant differences between men and women. Multiple regression analysis, with age as dependent variable and pulp/tooth area ratio as predictor, yielded several formulae. R(2) ranged from 0.69 to 0.75 for a single lower premolar tooth and from 0.79 to 0.86 for multiple lower premolar teeth. Depending on the available number of premolar teeth, the mean of the absolute values of residual standard error, at 95% confidence interval, ranged between 4.34 and 6.02 years, showing that the pulp/tooth area ratio is a useful variable for assessing age with reasonable accuracy.