Tooth length

  • 文章类型: Journal Article
    法医牙齿学分析的主要步骤是性别确定。本研究是评估犬齿牙根长度和牙冠测量相结合进行性别确定的准确性的少数研究之一。研究样本包括196个年龄在20-80岁之间的个体,分布在五个年龄段:20-29、30-39、40-49、50-59和60岁。不同的参数,如宽度,长度,每个上颌和下颌犬齿的牙冠和牙根的比率测量,进行检查和记录。结果表明,上颌犬的性别二态能力(87.3%)高于下颌犬(80.6%)。上颌犬齿总长和根长是性别区分中最明显的变量。当考虑下颌和上颌测量的组合时,性别二态的准确率为85.7%.通过使用比率变量,准确度降至68.9%。根据这项研究的结果,牙齿总长和牙根长度是犬齿最具判别力的变量。这些变量是比冠测量更可靠的性别指标。
    The primary step in forensic odontological analysis is sex determination. The present study is one of the few studies that evaluated the accuracy of the combination of canine tooth root length and crown measurements for sex determination. The study sample comprised 196 cone-be am computed tomographic scans of individuals aged 20-80 years distributed in five age categories: 20-29, 30-39, 40-49, 50-59, and 60+ years old. Different parameters, such as width, length, and ratio measurements for the crown and root of each maxillary and mandibular canine tooth, were examined and recorded. The findings indicated that maxillary canines had greater sex dimorphism ability (87.3%) than mandibular canines (80.6%). Total tooth length and root length of maxillary canine were the most pronounced variables in the differentiation of sex groups. When the combination of the mandibular and maxillary measurements was considered, the accuracy for sex dimorphism was 85.7%. By using ratio variables, the accuracy was reduced to 68.9%. According to the findings of this study, total tooth length and root length are the most discriminant variables of canine teeth. These variables are more reliable sex indicators than crown measurements.
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  • 文章类型: Journal Article
    OBJECTIVE: The aim of this retrospective study is to compare external apical root resorption (EARR) after labial and lingual fixed orthodontic treatment, as detected with panoramic radiographs.
    METHODS: Sixty subjects were divided into two groups according to the treatment type: lingual (30 patients) and labial (30 patients) fixed orthodontic treatment. Panoramic radiographs which were obtained at the beginning of treatment (T0) and at the end of the treatment (T1) were evaluated. The maxillary and mandibular central and lateral incisors, as well as canine crown and root lengths were measured for T0 and T1. Crown to root ratios were used to determine EARR. Data were evaluated using analysis of variance and χ2 analysis.
    RESULTS: In all, 5 patients (16.7%) in the lingual group and 7 patients (23.3%) in the labial group had a minimum of one tooth with severe EARR, while 9 patients (30%) in the lingual group and 14 patients (46.7%) in the labial group had no EARR. A total of 26 teeth (7.2%) in the lingual group and 34 teeth (9.4%) in the labial group developed severe EARR; however, 184 teeth (51.1%) in the lingual group and 202 teeth (56.1%) in the labial group did not reveal any EARR. No statistically significant difference was found for the resorption rates between the treatment groups (p > 0.05). Although not statistically significant, there was a higher percentage of severe EARR in the mandible within the labial group.
    CONCLUSIONS: Both lingual and labial orthodontic techniques showed statistically similar root resorption rates. EARR is a multifactorial issue and individual predispositions must also be taken into consideration.
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  • 文章类型: Journal Article
    BACKGROUND: Sex determination is an important step in establishing the biological profile of unidentified human remains.
    OBJECTIVE: The aims of the study were, firstly, to assess the degree of sexual dimorphism in permanent teeth, based on digital tooth measurements performed on panoramic radiographs. Secondly, to identify sex-related tooth position-specific measurements or combinations of such measurements, and to assess their applicability for potential sex determination.
    METHODS: Two hundred digital panoramic radiographs (100 males, 100 females; age range 22-34 years) were retrospectively collected from the dental clinic files of the Dentomaxillofacial Radiology Center of the University Hospitals Leuven, Belgium, and imported in image enhancement software. Tooth length- and width-related variables were measured on all teeth in upper and lower left quadrant, and ratios of variables were calculated. Univariate and multivariate analyses were performed to quantify the sex discriminative value of the tooth position-specific variables and their combinations.
    RESULTS: The mandibular and maxillary canine showed the greatest sexual dimorphism, and tooth length variables had the highest discriminative potential. Compared to single variables, combining variables or ratios of variables did not improve substantially the discrimination between males and females.
    CONCLUSIONS: Considering that the discriminative ability values (area under the curve (AUC)) were not higher than 0.80, it is not advocated to use the currently studied dental variables for accurate sex estimation in forensic practice.
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  • 文章类型: Comparative Study
    OBJECTIVE: Electronic apical foramen locators are now widely used to determine working length. This study was designed to determine whether tooth length influenced the accuracy of the Root ZX device.
    METHODS: Forty extracted maxillary canine teeth with a length range of 27-29 mm were selected. Access cavities were prepared and coronal flaring of canals performed. The teeth were mounted in self-polymerizing acrylic resin to facilitate horizontal sectioning except for the apical 3-4-mm portion of the root and embedded in alginate as the electronic medium. Electronic measurements were taken at the major foramen, \'zero\' reading using the Root ZX and compared with the actual root canal length. The teeth were sectioned 3 mm from the coronal reference point to create a second group with shorter length; these reductions in the length continued six times in all to create seven groups of 40 specimens each. The actual and electronic lengths of specimens in each group were measured. Data were analyzed by Pearson\'s correlation coefficient.
    RESULTS: Identical measurements between the actual and electronic root canal length from the longest to the shortest groups were 12.5%, 10.0%, 20.0%, 27.5%, 37.5%, 35.0% and 45.0%, respectively. There was a mild negative correlation between the precise measurements of the Root ZX and root canal lengths in the seven groups (r = -0.964, p < 0.001).
    CONCLUSIONS: Under the conditions of the study, the Root ZX device was more accurate in shorter teeth compared to longer ones.
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