中国土家族人群头面部软组织厚度的测量

目的测量中国土家族人群头面部软组织厚度。方法156名中国湖南西部土家族成年男女(男80,女76),经拍摄头面部侧位X线片,选取正中矢状面5个部位上的10个点,测量其软组织厚度,并对所得数据进行统计学处理。结果中国土家族成年人群头面部10个点的软组织厚度测量值,男性在(3.46±0.09)mm~(9.11±0.14)mm范围,女性在(3.29±0.16)mm~(9.05±0.18)mm;除鼻下点外(男性9.06mm±0.15mm,女性9.02mm±0.19mm),男女性之间各点均有显著性差异,且下面部软组织厚度较上面部大。结论土家族成年男女性头面部软组织厚度存在着性别差异和年龄差异。     

褥垫层厚度对带帽刚性桩性状的研究

对三个不同地点的带帽刚性桩复合地基工程进行试验监测,根据试验监测数据结果进行分析,可见褥垫层不同厚度对带帽刚性桩承载力和沉降变形的影响：设计褥垫层在某一合适的厚度,能有效降低桩身承载力,提高桩间土的承载力,使桩和桩间土合理共同承担荷载,降低复合地基沉降变形,减少地基对基础的应力集中,对工程实际有一定的指导意义.在试验分析的基础上,理论研究刚性桩带帽的条件,在褥垫层合适厚度下,单桩承载力、桩间土承载力、桩间土折减系数对刚性桩带帽都有影响,当条件符合时设置刚性桩带帽可以提高复合地基承载力,降低沉降变形.     

Reproducibility of facial soft tissue thicknesses for craniofacial reconstruction using cone-beam CT images

The purpose of this study was to evaluate the reproducibility of the soft tissue (ST) thicknesses at 31 landmarks using the cone-beam computed tomography (CBCT) images obtained from 20 adult subjects. Four observers carried out ST thickness measurements using Skull Measure software, and the inter- and intra-observer error rates were evaluated. Only five of 31 landmarks showed significant differences in recorded ST thickness between the observers. When excluding inexperienced observers, only one landmark showed a significant difference between the observers. Regarding the intra-observer reproducibility, the ST thickness measurements at three landmarks showed low correlation coefficients. The results of this study indicate that CBCT images can be used to measure ST thickness with high reproducibility. However, some landmarks need to be redefined to reliably measure ST thickness on CBCT images.     

A Radiographic Study on the Utility of Cranial Vault Outlines for Positive Identifications

A standard method for positive identification is the use of antemortem and postmortem radiographic comparisons. The purpose of this research is to test the visual accuracy of antemortem and postmortem radiographic comparisons of cranial vault outlines and to evaluate their uniqueness using geometric morphometric methods. A sample of 106 individuals with varying levels of education and forensic case experience participated in a visual accuracy test. Of the 106 individuals, only 42% correctly assigned all of the radiographs, with accuracy rates ranging from 70 to 93% for each radiographic comparison. Vault shape was further examined using elliptic Fourier analysis, and paired t‐tests were computed on the first 10 principal components accounting for 100% of the variance, which found no significant differences. The visual accuracy test and elliptic Fourier analysis shows that vault outlines may not be unique enough for positive identifications when used as a sole indicator.     

Vertical Lip Position and Thickness in Facial Reconstruction: A Validation of Commonly Used Methods for Predicting the Position and Size of Lips

This study examined several methods used to estimate oral fissure position, lip margin position, and lip thickness recommended by Angel, George, Lebedinskaya, Taylor, Wilkinson et al., Balueva and Veselovskaya. A sample of 86 lateral head cephalograms of adult subjects from central Europe were measured and the actual and predicted dimensions were compared. The best estimation for oral fissure position was “opposite the lower ¾ mark of maxillary incisors” (error of 1.3 mm). Upper lip margin was predicted best by “upper ¼ mark of maxillary incisors” (error of 1.7 mm), and lower lip margin by “cementum‐enamel junction of mandibular incisors” (error of 2.3 mm). The regression equations of Wilkinson et al. displayed least error (1.3 mm and 1.8 mm, respectively) for upper and lower lip thickness, and method of George (error of 3.4 mm) for total lip thickness.     

Application of Enhanced Point Estimators to a Sample of In Vivo CT‐derived Facial Soft Tissue Thicknesses

Facial approximations based on facial soft tissue depth measurement tables often utilize the arithmetic mean as a central tendency estimator. Stephan et al. (J Forensic Sci 2013;58:1439) suggest that the shorth and 75‐shormax statistics are better suited to describe the central tendency of non‐normal soft tissue depth data, while also accommodating normal distributions. The shorth, 75‐shormax, arithmetic mean, and other central tendency estimators were evaluated using a CT ‐derived facial soft tissue depth dataset. Differences between arithmetic mean and shorth mean for the tissue depths examined ranged from 0 mm to +2.3 mm (average 0.6 mm). Differences between the arithmetic mean plus one standard deviation (to approximate the same data points covered by the 75‐shormax) and 75‐shormax values ranged from ?0.8 mm to +0.7 mm (average 0.2 mm). The results of this research suggest that few practical differences exist across the central tendency point estimators for the evaluated soft tissue depth dataset.     

Dental Cementum in Age Estimation: A Polarized Light and Stereomicroscopic Study

Abstract: Dental hard tissues are good candidates for age estimation as they are less destructive and procedures to determine age can be easily performed. Although cementum annulations and cementum thickness are important parameters in this regard, they are seldom used. This study was undertaken to review the methods, difficulties in execution of techniques, and accuracy of cementum thickness and annulations in estimating the age. Unstained and stained ground sections of tooth were used to measure cemental thickness and count cemental annulations based on which age was estimated and was compared with known age. Although there was positive relation between cemental thickness and annulations with age, only in 1–1.5% of cases, age could be predicted with accuracy.     

GC-HPLC法考察圆珠笔字迹油墨厚度对溶剂挥发速率的影响

目的考察圆珠笔字迹油墨厚度对溶剂挥发速率的影响。方法采用GC/HPLC联用技术对不同时间、不同字迹油墨厚度在同种纸张上的圆珠笔油墨字迹中的溶剂、染料成分的定量分析。结果字迹油墨较厚的苯甲醇、苯氧基乙醇的含量随时间的变化比字迹油墨较薄的慢。结论字迹油墨的厚度对溶剂的挥发速率影响较大。     

Facial soft tissue depths in craniofacial identification (part II): An analytical review of the published sub-adult data

Prior research indicates that while statistically significant differences exist between subcategories of the adult soft tissue depth data, magnitudes of difference are small and possess little practical meaning when measurement errors and variations between measurement methods are considered. These findings raise questions as to what variables may or may not hold meaning for the sub-adult data. Of primary interest is the effect of age, as these differences have the potential to surpass the magnitude of measurement error. Data from the five studies in the literature on sub-adults which describe values for single integer age groups were pooled and differences across the ages examined. From 1 to 18 years, most soft tissue depth measurements increased by less than 3 mm. These results suggest that dividing the data for children into more than two age groups is unlikely to hold many advantages. Data were therefore split into two groups with the division point corresponding to the mid-point of the observed trends and main data density (0-11 and 12-18 years; division point = 11.5 years). Published sub-adult data for seven further studies which reported broader age groups were pooled with the data above to produce the final tallied soft tissue depth tables. These tables hold the advantages of increased sample sizes (pogonion has greater than 1770 individuals for either age group) and increased levels of certainty (as random and opposing systematic errors specific to each independent study should average out when the data are combined).