应用数字图像识别系统研究正畸治疗前后腭皱形态变化

目的利用腭皱数字图像识别系统对正畸治疗前后腭皱形态匹配正确率的分析研究,为法医学中同一认定提供理论依据。方法利用正畸患者治疗前后腭皱形态数字图像,通过腭皱数字图像识别系统对图像的特征进行提取并收录到腭皱数字库,运用Matlab软件完成对腭皱形态数字图像的信息匹配处理。结果正畸治疗前后,个体性检测匹配正确率各自都达到100%。正畸治疗前后腭皱形态匹配正确率为95.67%,配对检验结果 P0.05,具有统计学意义。结论腭皱形态具有高度的个体特异性,正畸治疗后腭皱形态会发生多种变化,但对同一认定的影响不大。腭皱形态识别为法医学同一认定提供一种新的方法和途径。     

腭皱法医学同一认定数字化系统的建立

目的建立腭皱法医学同一认定数字化系统并对其进行效果评价。方法在标准条件下获取腭皱的数字图像,对腭皱信息都进行采集、降噪、增强、分割、特征提取、边缘检测、信息匹配等处理,运用Matlab软件研制腭皱法医学同一认定系统,并进行效果评价。结果本研究成功建立腭皱法医学同一认定数字化系统,从匹配结果来看,正确率达到100%。结论腭皱法医学同一认定数字化系统的建立,为同一认定提供一种新的方法和途径。     

正畸治疗前后腭皱的法医同一认定研究

目的利用腭皱模型分析法评价腭皱形态的个体独特性及正畸治疗前后腭皱形态的稳定性,探索腭皱形态在法医齿科学个体识别应用中的可靠性。方法分别收集70例正畸治疗前、后的上颌模型。通过模型测量分析对腭皱形态及个体识别进行检测,包括数量、方向、形状及长度的变化和近、远中侧端点分别在近远中向及前后方向上的位移。同时对正畸治疗前、后及正畸治疗后与其复制后腭皱模型进行配对检测,计算其平均正确配对率(%)。结果 (1)正畸治疗后腭皱数量、方向、形状及长度均有变化,表现为长度变化(28.6%);分裂(4.3%);联合(2.9%);方向变化(1.4%);形状变化(1.4%)。并且治疗后腭皱远中端点的前后向位移变化占45.7%,近远中向位移占40%;而腭皱近中端在在前后向和在近远中向上位移变化分别为32.9%和17.1%。(2)正畸治疗前组及正畸治疗后组不同个体均未发现相同的腭皱模式。(3)正畸治疗前、后模型的腭皱平均正确配对率为92.19%。而治疗后模型与复制后模型的腭皱平均正确配对率是99.05%。结论腭皱形态具有高度的个体特异性,尽管正畸治疗后腭皱的形态有一定变化,但仍可作为一种新的方法应用于法医齿科的同一认定。     

X线头影侧位片同一认定指标的建立

目的探究口腔颌面X线头影侧位片的形态学分型,对识别指标进行数字编码,构建法医学同一认定体系。方法选取200例成年人口腔颌面的X线头影侧位片,通过SNA角、SNB角的相互关系及后面高与前面高比值,对颌面骨骼形态进行矢状向垂直向的综合分型,同时筛选出反映颌面特征的8个测量指标进行数字编码。结果依据矢状向、垂直向及8个测量指标构建的编码系统,其多样性较大,为99.5%。MP-FH和Y轴角的变异系数较大,同一认定价值较高。S-Ar-Go、Ar-Go-Me、MP-FH、1—-MP角、Y轴角、1—-SN角、1—-1—角各级别构成比间性别差异有统计学意义。结论利用头颅侧位片矢状向及垂直向分型并结合所选取的8项定量识别指标进行识别编码的方法,为法医同一认定提供了新思路。     

基于深度学习对口腔全景摄影片进行性别推断的研究

目的 探究深度学习技术对中国汉族人群口腔全景摄影图像（OPG）进行性别推断的可行性和准确性。方法 收集18～70岁汉族人群OPG影像数据10 600份（男性5 300份,女性5 300份）,按照8:1:1比例随机划分为训练集、验证集、测试集。采用MobileNetV2、Swin Transformer模型进行训练,通过准确率、F1分数及GradCAM算法评估模型分类性能及可视化展示。结果 MobileNetV2、Swin Transformer Small和Swin Transformer Tiny模型的准确率为97.57%、95.13%、96.28%,其中MobileNetV2模型表现最佳。Grad-CAM算法显示男性OPG图像主要关注左右侧下颌支及牙槽骨,而女性的OPG图像主要关注上颌窦、左侧下颌支及左侧后牙槽骨。结论 本研究基于深度学习技术构建的中国汉族人群OPG图像性别推断模型具有较高的准确性及泛化能力,为法医学性别推断提供了新的方法。     

数字全口牙位曲面体层片的法医学同一认定指标

目的采用颌面全口牙位曲面体层片,针对牙齿无病变者筛选简洁实用的法医学同一认定识别指标并进行编码、统计分析及评估。方法随机选取170例牙齿无病变者的颌面数字全口牙位曲面体层片进行观测．根据牙齿的生理变异特征和牙齿的排列特征分别筛选全口牙型和牙列型识别指标。按设计的编码标准对全口牙型、牙列型逐一编码,统计分析编码的多样性,以评估两类识别指标的应用价值。结果170例中共有74种全口牙型编码,多样性为43．53％：170例中共有129种牙列型编码,多样性为75．88％;170例同时进行全口牙型和牙列型编码．则共有150种全口牙型／牙列型编码,多样性为88．24％。结论全口牙型编码多样性较低,单独使用尚不能满足法医学同一认定的要求。牙列型编码的多样性比较高,具有一定的法医学同一认定价值。如果同时进行全口牙型和牙列型编码,多样性明显提高,有较高的法医学同一认定价值。     

成人腭皱三维数字模型特征与性别相关性研究

目的 建立成人腭皱三维数字模型并研究其特征与性别的相关性.方法 本研究收集102名成人的上颌三维数字模型,男女各51名;记录腭皱型及两侧第一条腭皱的位置,并对其进行统计分析,以评价腭皱特征与性别的关系.结果 在不同性别人群中共观察到共850条腭皱,其中男性420条(49.41％),女性430条(50.59％).直线形腭...     

颅脑CT及X片的同一认定

颅脑ＣＴ及Ｘ片的同一认定程亦斌，涂彬（司法部司法鉴定科学技术研究所；上海２０００６３上海医科大学法医学系，上海２０００３２）１概述同一认定（又称个人识别，Ｐｅｒｓｏｎａｌｌｄｅｎｔｉｆｉｃａｔｉｏｎ）是法医学领域中一个十分重要的研究课题。目前最常用的...     

原发性脑干损伤出血形态及分布特征分析

目的观察分析原发性脑干损伤出血灶的形态及分布特征,为法医学鉴定提供依据。方法选取34例原发性脑干损伤出血案例,常规制作病理切片,采用HE染色观察出血灶的形态及位置分布特征,并统计两者之间关系。结果原发性脑干损伤出血形态以裂隙样出血多见（61．6％）。出血灶位置分布组间比较显示,不同纤维走行和组织密度交界处、动脉周围、神经根等处以裂隙样出血多见（P〈0．005）;室管膜下主要表现为灶性出血（P〈0．001）;神经核团内出血较少,且裂隙样出血、灶性出血比例较为接近。结论不同纤维走行和组织密度交界处、动脉周围、神经根处的裂隙样出血是原发性脑干损伤的直接依据;神经核团内出血具有重要的法医学价值。     

用于法医学同一认定的额窦CT编码

目的 使用头颅CT图像重建冠状位鼻骨切面研究额窦观测指标,以编制特异的识别编码.方法 通过距离数值量和形态学描述对额窦CT图像进行分析.额窦同一认定识别编码为:右侧额窦部分隔数,形态一额窦中间隔位置,形态一左侧额窦部分隔数,形态;右侧额窦上缘弓形弯曲数(右侧最高峰位置,最低峰位置)-左侧额窦上缘弓形弯曲数(左侧最高峰位...     

Stability of Palatal Rugae as a Forensic Marker in Orthodontically Treated Cases

The palatal rugae have been used as a reference landmark and identification marker by orthodontists and forensic analysts. However, the reliability of palatal rugae as a forensic marker remains questionable once an individual is subjected to orthodontic treatment. This study aimed at evaluating the changes in the rugae pattern after nonextraction, extraction, and maxillary expansion orthodontic treatment. The lengths and shapes of palatal rugae were evaluated on the pretreatment and post‐treatment dental casts of 168 subjects using the Thomas and Kotze classification. Extraction treatment significantly reduced the second and third rugae lengths (p < 0.05), whereas the third rugae length was significantly increased after palatal expansion (p < 0.05). The shape of rugae remained consistent in all the study groups which may be used as a reliable forensic marker in subjects undergoing orthodontic treatment. However, the use of the lengths of palatal rugae in forensic odontology must be made with caution.     

Palatal rugae pattern in a Portuguese population: a preliminary analysis

Palatal rugae have been related with specific racial groups and are said to be useful in sex discrimination. This work aimed to characterize the palatal rugae patterns in a Portuguese population. Fifty plaster casts were examined for first and third rugae shape evaluation; shape, frequency, and association with sex were studied. In females, the most prevalent first rugae were the straight type on the right and the curve type on the left; in males, the straight type was the most prevalent on both sides. The most frequent third rugae type was sinuous on both sides, in both sexes. No significant sexual dimorphism in rugae shape was found (p > 0.05). When comparing these results with those from other investigations, it was clear that a particular rugae pattern could be established for different ethnic groups. However, the small sample size justifies further work in larger samples to validate these findings.     

The Heritability of Palatal Rugae Morphology Among Siblings*†

Although there is clinical applicability of the palatal rugae as an identification tool in forensic odontology, controversy exists whether the palatal rugae patterns are stable or variable. The greater the genetic component, the higher the probability that palatal rugae patterns are stable. The aim of this study was to compare the palatal rugae morphology between full siblings and the proportion of variability due to genetic component. This cross-sectional study was conducted on digital models of 162 siblings aged 15–30 years old. The palatal rugae patterns were assessed with Thomas and Kotze (1983) classification using Geomagic Studio software (3D Systems, Rock Hill, SC). The palatal rugae morphology between siblings showed significantly similar characteristics for total number of left rugae (p = 0.001), left primary rugae (p = 0.017), secondary rugae for right (p = 0.024) and left sides (p = 0.001), right straight rugae (p = 0.010), and right convergent rugae (p = 0.005) accounting for at least 6.25%-12.8% of the variability due to heredity. Despite the similarities found, the palatal rugae patterns showed significant differences between siblings of at least 46.9% (p = 0.001). Zero heritability was found in 9 of the 14 rugae patterns. Meanwhile, total number of rugae, primary, backward, and convergent rugae showed moderate heritability (h² > 0.3) and total number of secondary rugae showed high heritability (h² > 0.6). In conclusion, despite the individuality characteristics, an appreciable hereditary component is observed with significant similarities found between sibling pairs and the palatal rugae patterns were both environmentally and genetically influenced.     

Rugoscopy: Predominant Pattern,Uniqueness, and Stability Assessment in the Indian Goan Population

The palatine rugae possess unique characteristics that could be used when it is difficult to identify a dead person according to fingerprints or dental records. They are permanent and unique to each person. The rugae are surrounded by cheeks, lips, tongue, and buccal pad of fat; hence, they remain protected in trauma, incineration, or mass disasters. Their pattern of orientation is formed by the 12th to 14th week of gestation and remains stable throughout life. In this study, dental casts of 120 patients were analyzed for individual rugae characteristics and strength and subsequent individual codes were given. No two individuals were having exactly matching rugae codes. Dimensions of rugae pattern, incisive papilla, and midpalatal raphe were also noted. Rugae were reevaluated after one year to check its stability, which showed no significant difference. The coding system followed can be adopted as a good and simple technique to achieve electronic transfer of the records of the palatal rugae.     

Morphological pattern of palatal rugae in children of Davangere

The aim of this study was to identify and compare the rugae pattern between males and females of two different communities in the city of Davangere, Karnataka, India, which may be an additional method of identification in cases of crimes or communal riots. Elastomeric impressions of the maxillary arch of 100 selected children were made; casts were poured in Type IV stone. The method of identification of rugae pattern followed was that of Lysell and Thomas and Kotze, which includes the number, shape, direction, and unification of rugae. The study revealed no significant difference in the total number or length of rugae between the two communities and sexes. However, with regard to shape and unification, females showed a significantly higher diverging rugae type while males had a significant number of circular and converging type of rugae. Also, discrimination function analysis allowed a moderate differentiation of the population. Hence, the rugae pattern can be an additional method of differentiation in conjunction with the other methods such as visual, fingerprints, and dental characteristics in forensic sciences.     

Indication and limitations of using palatal rugae for personal identification in edentulous cases

To explore the availability and the limitations of using the palatal rugae pattern in forensic practice for personal identification in edentulous cases, we set up an experiment, which involved 48 patients who had both old and new complete dentures and we observed their rugae. First, we made 48 pairs of maxillary casts from their old and new dentures and a further 50 maxillary casts from complete dentures at random, to use as variables. All the initial impressions taken from the mucosal surfaces of complete dentures were made from alginate impression materials, and the maxillary casts were made from hard dental plaster. Secondly, all 146 casts were trimmed so that all the areas except for the rugae area were removed. Subsequently, 50 examiners were given the 48 casts from the old dentures and were then asked to compare them with the other 98 casts for possible matches. The case numbers, which matched correctly, were recorded. The median percentage of correct matches among the 50 examiners was 94%, despite variations in their experience with forensic identification, and this accuracy does not differ significantly from that in dentate cases, as described in previous publications. The median percentage of correct matches among the 48 cases was 90%. Analyzing the incidence of obtaining a correct match in each case revealed that there were three major misleading shapes that could give rise to a low rate of correct matches; (1) severely low and poorly demarcated eminences of rugae, (2) change of palatal height, and (3) non-complex rugae pattern. These features are mainly due to the shape of the edentulous palate itself and rarely due to the dentures, and could lead to difficulties in finding unique points for use in matching rugae patterns. The results suggest that an appropriate selection of cases, taking into consideration the above misleading shapes, may establish an increased rate of accuracy for identification with this method, thereby bringing the percentage of correct matches closer to 100% in edentulous cases, which is also the percentage of correct matches previously reported in dentate cases.     

道路交通事故中涉案者交通行为方式的法医学鉴定

目的回顾道路交通事故中需要进行涉案者交通方式鉴定的案例。探讨此类案例鉴定的思路和技术方法。方法收集28例近年本单位进行的道路交通事故涉案者交通行为方式鉴定案例,统计涉案者一般情况、损伤程度与交通行为方式的关系,交通事故发生的时间和地点、交通事故中车辆碰撞类型、采用的技术方法等,进行统计学处理。结果本组资料共28起道路交通事故案件,涉案人员共57人,男性50人．女性7人。交通事故发生时间夜间为19例（67．86％）,白天为9例（32．14％）。道路类型中,城市市区道路10例（35．7％）,城市郊区道路1例（3．6％）,省级道路10例（35．7％）,高速公路7例（25％）。酒后驾车9例（32．1％）。交通事故类型中,电动自行车与机动车事故5例（17．8％）,机动车与自行车事故1例（3．6％）,机动车单方事故7例（25．0％）;机动车与机动车事故11例（39．3％）,机动车与行人事故4例（14．3％）。涉案人员死亡27人,损伤29人,无明显伤害1人。损伤存活者中轻微伤10例（34．5％）,轻伤8例（27．6％）,重伤1l例（37．9％）。涉案者交通行为方式鉴定种类中,汽车驾驶人和乘车人认定16例（57．1％）,摩托车驾驶人和乘车人认定1例（3．6％）,电动自行车驾驶人和乘车人认定5例（17．8％）,自行车推行和骑行状态认定1例（3．6％）,摩托车推行和骑行状态认定1例（3．6％）,行人横过公路方向4例（14.3％）。涉案者交通行为方式鉴定采用的技术手段和方法．包括法医学活体损伤检验、法医学尸表检验、涉案肇事车车辆痕迹检验、DNA检验鉴定、现场人体模拟实验等。结论根据人体（活体或尸体）的体表损伤形态特征、痕迹分布,分析其致伤物和致伤方式,结合车辆痕迹检验结果,得出确认符合某种交通行为方式或者不符合某种交通行为方式的判断,结合案件的相关情况分析重建交通事故过程．是进行涉案者交通行为方式鉴定的基本思路。