Indicator Of Chronological Age Research Articles

Dental age estimation using three different methods in monozygotic and dizygotic twins

ABSTRACT Dental development, one of the most reliable indicators of chronological age (CA), has been believed to be fundamentally influenced by genetics rather than environmental factors. The study aims (i) to compare dental ages (DAs) in monozygotic (MZ) and dizygotic (DZ) twins using three different DA methods and determining the most appropriate method, and (ii) to determine the possible effects of genetics on DA by evaluating the differences in the estimated DAs of MZ and DZ twins. The study sample consisted of 171 twin pairs (47 monozygotic, 124 dizygotic) between the ages of 5.0 and 12.9. In order to estimate DA, Demirjian, Willems and Nolla methods were used. The mean CA of group was 8.42 (2.05) years. The Demirjian, Willems and Nolla methods overestimated the DAs by 0.69, 0.60 and 0.56 years, respectively. The estimated DAs in age groups were similar, and differences were not statistically significant for intrapair DZ and MZ twins. As a result, it was not correct to state that any method was more appropriate and better than others for studies of twins. All methods’ standards were not suitable for any age groups of MZ and DZ twins, except for twins aged 12–12.9 years. Country-wide samples are needed to gather enough data to create valuable results and to establish the applicability of methods used.

Relationship between endothelium-dependent vasodilation, carotid intima-media thickness and atherosclerotic plaques: is it preserved in the elderly?

Abstract Introduction Vascular ageing refers to the age-related deterioration in vascular structure and function. Endothelial dysfunction (ED), carotid intima-media thickness (CIMT) and atherosclerotic plaques are key-players in this process, but also are indicators of chronological age. As established, they are jointly associated in young and middle age populations but this pattern could be changed over the lifetime. Purpose We aimed to assess the association between endothelium-dependent vasodilation, CIMT, atherosclerotic plaques and cardiovascular risk factors in elder and senile population sample. Methods The study was carried out in the population sample of men and women aged 58–82 years (n=788/424 women). The intima-media thickness and presence of carotid plaques were assessed by high-resolution ultrasound. The ED was detected with ultrasound reactive hyperemia test (Celermajer) by measurement of flow-mediated dilation (FMD) of brachial artery; ED was identified if FMD lower than 10%. Medical history of cardiovascular diseases and risk factors were assessed by standard methods. Results The mean FMD was 2.7% in men (SD 7.32), and 3.2% in women (SD 7.19) and did not differ by sex. The frequency of ED was 88.2% in men and 85.8% in women. The mean CIMT was higher in men than in women (0.95 mm (SD 0.18) vs. 0.88 mm (SD 0.17), p<0.001). Men with ED had significantly higher triglycerides level (125.1 mg/dl (SD 71.2) vs. 102.7 mg/dl (SD 45.7), p=0.033) and ratio “waist circumference/hip circumference” (0.94 (SD 0.05) vs. 0.92 (SD 0.076), p=0.009) than men without ED. Moreover, men with ED had higher body-mass index, but the difference did not reach statistical significance. There was borderline association between smoking and ED found in women (p=0.067) and poor association in men (p=0.106). No linear association was found between CIMT and FMD in men (β=−1.76, SD 2.25; p=0,436) and in women (β=−2.19, SD 2.15; p=0.309); however, the regression coefficients in age-adjusted models were of negative direction as expected. In addition, there was no difference in the mean CIMT and frequency of atherosclerotic plaques in groups with and without ED either in men or in women. There was a tendency of greater CIMT in those men with ED in the youngest of the studied group (58–62 years) vs. the same age men without ED (p=0.242). In women, we encountered significant increase of CIMT among those with ED in age group 63–77 years against women without ED (p=0.047), which faded out in older group. Conclusions In our population sample we did not observe the associations of frequency of ED or FMD% neither with CIMT nor presence of atherosclerotic plaques. Only in women below 78 years, the presence of ED was associated with increased CIMT. The subclinical markers of atherosclerosis – synergistically expressed in younger populations – lose their associations in elderly. We should take this into account in development of novel therapies for elderly and senile population. Funding Acknowledgement Type of funding sources: Foundation. Main funding source(s): Wellcome Trust No. 081081AIA,Russian Academy of Sciences No. AAAA-A-17-117112850280-2

Length of the ramus of the mandible as an indicator of chronological age and sex: A study in a group of Egyptians

BackgroundThe determination of age and sex is crucial for establishing a human identity. The mandible is an accessible and a durable bone that would be very useful in this respect. AimTo test if the length of the ramus of the mandible can be used to predict the age and the sex in a group of Egyptians Subjects and methodsThe length of the ramus of the mandible was measured in lateral craniofacial scans of 213 individuals (99 males and 114 females) with an age range of 7–58 years using cone-beam computerized tomography (CBCT). ResultsSexual dimorphism was not observed until the age of 17 years in this sample of population. There was not found any significant differences in the length of the ramus of the mandible between males and females in the age range of 7 to less than 17 years (P-value = 0.2495). There was found a significant difference between males and females for the mean length of the mandible ramus in the age range of 17–58 years (P-value < 0.0000). It predicts sex with an accuracy of 67 %. There was a positive correlation between ln (age) and ln (ramus) (r = 0.73, P-value < 0.0001 for females and r = 0.85, P-value <0.0001 for males). ConclusionThe mandibular ramus length is valuable in age estimation and less valuable in sex determination. Computerized tomography examination is a safe and an accurate procedure with minimal radiation exposure, and provides valuable precise information regarding mandible measurements.

CircRNA: A novel biomarker for forensic age estimation?

Aging is a complex process and is associated with various molecular regulations on DNA or RNA levels. In forensic science, accurate age estimation of an unknown individual can be of extremely important. Recent years, age-related molecular biomarkers have been proposed as indicators of chronological age. There were studies showing that circular RNAs (circRNAs) change significantly during aging. Here, the correlation of circRNAs expression levels and age was investigated by detecting circRNA levels in peripheral whole blood utilizing next-generation RNA sequencing (RNA-seq). We suggest that circRNA can be a novel biomarker for forensic age estimation.

Mandibular Ramus linear measurements as an Indicator of Chronological Age and Sex in Egyptian Population

Background: The determination of age and sex is crucial for establishing human identity. Themandible is an accessible and durable bone that is very useful in this respect.Aim: To assess the efficacy of measuring the mandible ramus length in the identification of ageand sex in a group of Egyptians.Subjects and Methods: The length of the ramus of the mandible was measured in lateralcraniofacial scans of 213 individuals (99 males and 114 females) with an age range of 7-58 yearsusing cone-beam computerized tomography (CBCT).Results: Sexual dimorphism was not observed until age of 17 years in this sample. There wasnot found any significant differences in the length of the ramus of the mandible between malesand females in the age range of 7 to less than 17 years (P-value = 0.2495). There was a significantdifference between males and females for the mean length of the ramus in the age range of 17 to 58years (P-value < 0.0000). It predicts sex with an accuracy of 67%. There was a positive correlationbetween and (age) and loge (ramus length) (r=0.73, P-value < 0.0001 for females and r=0.85,P-value his or her mandible ramus length.Conclusion: The mandibular ramus length is valuable in age estimation and less valuable insex determination. Computerized tomography examination is a safe and an accurate procedurewith minimal radiation exposure, and provides valuable precise information regarding mandiblemeasurements.

The relationship between age and arachnoid depressions in humans

The human skeletal collection housed in the Department of Anthropolog y at the University of Alberta was used to determine the relationship between age and the occurrence of arachnoid depressions on the endocranial aspect of the skull. There were significant differences between the total number of arachnoid depressions found on the vaults of juveniles, adolescents, and adults. When mean ages were compared with total number of arachnoid depressions on the vault, a significant relationship did not emerge. When age was grouped into nine-year intervals to counteract the effect of idiosyncratic variation, the mean number of depressions increased with age, as did the maximum number of arachnoid depressions. The frequency of older individuals without arachnoid depressions waslow. Older individuals were more likely to have larger and deeper arachnoid depressions. There were no sex-based differences in the expression of arachnoid depressions. There were no significant differences between archaeological, historic, and modern samples or between pathological and healthy individuals. Although this study verifies the association between arachnoid depressions and senescence, the presence of arachnoid depressions is highly variable andcannot be used reliably as an indicator of chronological age or even as a sign of senescence.

Radiographic evaluation of dental age maturity in 3-17-years-old saudi children as an indicator of chronological age.

OBJECTIVE:This study was aimed to evaluate the dental age in Saudi children from panoramic radiographs using the Demirjian method to estimate their chronological age.MATERIALS AND METHODS:This retrospective cross-sectional study consisted of 1902 panoramic radiographs of 955 boys and 947 girls between the ages of 3–17 years. All children were placed in the age group closest to their chronological age. The dental age was scored on all seven left mandibular teeth by calibrated examiners. Bivariate analyses using the t-test and Pearson correlation were performed.RESULTS:There was significant difference in both boys and girls in all the age groups between their chronological age and dental age. Even though there was a slight overestimation in boys in some age groups and slight underestimation in girls in some groups, correlation analysis showed that there was a highly significant correlation between the chronological age and dental age for both boys (r2 = 0.96, P < 0.001) and girls (r2 = 0.98, P < 0.001). Moreover, correlation analyses for each age group showed a significant correlation between the chronological age and the dental age, using the Demirjian method, in most age groups (P < 0.01). When comparing the maturation score between boys and girls, the Student's t-test showed that there were no statistical differences between boys and girls in most age groups.CONCLUSION:Saudi boys and girls living in the western region of Saudi Arabia exhibited similar pattern of dental development when compared to the Demirjian method. Hence, the Demirjian method could be used as reference in children from the western region of Saudi Arabia.

Direct age determination by growth band counts of three commercially important crustacean species in Chile

Management of commercially important crustacean stocks has been hindered by the inability to directly determine individual age. A lack of comprehensive age information leads to poor understanding of life history schedules, difficulty in estimation of parameters necessary for modeling population dynamics, and uncertainty in the determination of appropriate harvest levels. This study applied a novel direct age determination method based on band counts to three Chilean crustacean species: red squat lobster (Pleuroncodes monodon), yellow squat lobster (Curvimunida johni), and nylon shrimp (Heterocarpus reedi) for the first time. The growth bands were observed and counted in the endocuticle layer in thin longitudinal sections of the meso-cardiac ossicles of the gastric mills in the two squat lobster species and in the eyestalks of the nylon shrimp. Comparison of growth band counts with independent estimates of age strongly suggests that the bands form annually, thus providing a direct and accurate method of age determination in all of the species examined. Sex-specific growth curves were produced and demonstrated that the females grow at a slower rate than the males in the three species. Size and age-at-sexual maturity were also estimated. Application of this technique to known-age individuals will be necessary to validate band counts as indicators of chronological age.

Dental and chronological age in children under oncological treatment.

The current oncology treatment has improved the survival of children with several types of cancer, and the effect of radiotherapy and/or chemotherapy treatment on dental maturation in comparison with chronological age is not widely known. The aim of this work was to evaluate and compare the impact of radiotherapy and/or chemotherapy treatment during dental maturation with chronological age in Chilean children diagnosed with cancer. Study Design was cross-sectional study on children diagnosed with different types of cancer and treated with radiotherapy and/or chemotherapy when they were ages of 0.1 to 13 years. Demirjian tables for both girls and boys are used to determine the dental age. The association between chronological and dental age was highly significant. Nevertheless, a linear relation between chronological and dental age was not observed when the data were stratified by BMI and type of treatment. This study confirmed that dental age is an indicator of chronological age but that other variables, such as body mass index, in children with cancer could be confounder variables. Thus, further studies are necessary to investigate the influence of BMI on tooth eruption/maturation in children under oncological treatment.

Mandibular ramus length as an indicator of chronological age and sex

Age and sex estimation is crucial in forensic investigations, whether in legal situations that involve living people or to identify mortal remains. The aim of this study was to establish reference values in a Brazilian population to estimate age and sex by measuring the length of the mandibular ramus on lateral cephalometric radiographs, and to determine the probability that an individual being is 18 years or older, based on the results that were obtained. Two hundred and eighteen scanned lateral cephalograms of individuals between 6 and 20 years of age (101 males and 117 females) were measured with reference to mandibular ramus length (the distance between Condylion superior (Cs) and Gonion (Go)) using ImageJ 1.41 software (NIH, Bethesda, MA, USA). The results showed that sexual dimorphism was not observed until 16 years and, based on the ramus length measurements in this sample, it is possible to predict sex with an accuracy of only 54 %. There was a positive correlation between age and ramus length (r = 0.90; p < 0.001). From the linear regression analysis, one formula was derived; therefore, it was possible to calculate the individual's age, given his or her ramus length. The results showed that if an individual's ramus length is 7.0 cm or more, then there is an 81.25 % chance that the individual is 18 years old or older. In conclusion, the mandibular ramus length was not effective in discriminating sex. Mandibular length is strongly related to chronological age and can be used to predict whether an individual is 18 years or older with high degree of expected accuracy.

The persistence of epiphyseal scars in the adult tibia

Estimation of chronological age from skeletal material is dependent upon estimation of maturational stage observed. Following completion of epiphyseal fusion, a transverse radio-opaque line, termed "epiphyseal scar", may be observed in the region of the former growth plate. According to the literature, this line is likely to become obliterated shortly after completion of epiphyseal fusion. Consequently, presence of an epiphyseal scar has been interpreted as an indication of recent epiphyseal fusion; however, this has not been validated by quantitative research. A study was undertaken to determine persistence of the epiphyseal scars in a cross-sectional population of adults between 20 and 50 years of age. This study examined 1,216 radiographs of proximal and distal tibiae from both sexes and sides of the body. This study suggested that 98.05% of females and 97.74% of males retained some remnant of the epiphyseal scar at the proximal tibia whilst 92.72% of females and 92.95% of males retained some remnant of the epiphyseal scar at the distal tibia. General linear model (GLM) analysis determined that chronological age accounted for 2.7% and 7.6% of variation in persistence of the epiphyseal scar at the proximal and distal tibiae, respectively. This study suggests that obliteration of the epiphyseal scar is not as dependent on chronological age as previously thought. It is, therefore, recommended that this feature not be used as an indicator of chronological age during forensic age assessment.

Automated dental aging for child victims of disasters

In disasters, one of the major challenges is the identification of the dead. This is complicated in cases where young victims and, sometimes, young survivors are involved. Often, there are no dental treatment records that can be usefully employed and, hence, identification has to be relied heavily on ageing. Developing teeth are generally considered to be the most reliable indicators of maturation and, by extension, of chronological age at death. This is because teeth are more durable, their degree of development can be observed directly from the living or deceased individual, and tooth formation is relatively unaffected by disease, malnutrition, or endocrine disorders. Unfortunately, the calculation of dental maturation and its conversion to a useful indicator of chronological age is a time-consuming process, which can be frustrating in the face of an overwhelming demand after a disaster such as the Thai Tsunami or Hurricane Katrina. The authors report on the development of a novel, automated "point and click" graphical user interface that can be used to calculate the age of a known individual from a simple dental radiograph. The authors apply the method to three ethnic populations living in New Zealand: children of European, Maori, and Pacific Island descent.

Dental maturity as an indicator of chronological age: radiographic assessment of dental age in a brazilian population

Objective:The purpose of this investigation was to evaluate the applicability of the methods proposed by Nolla and by Nicodemo and colleagues for assessing dental age and its correlation to chronological age.Methods:Panoramic radiographs of 360 patients from the city of Fortaleza (CE, Brazil) aged 7-15 years were used to assess the associations between dental and chronological age. Data were submitted to statistical analysis using the BioEstat 2.0 (2000) software. Student-Neuman-Keuls test was performed and Pearson's correlation coefficients were calculated at 5% significance level.Results:When the Nolla method was applied, the mean difference between true and estimated age for males and females was underestimated. The use of the method proposed by Nicodemo and colleagues also resulted in underestimation, although it was more evident in male subjects. The correlation coefficients between chronological age and estimated dental age were high, with mean values ranging between 0.87 and 0.91 for males and between 0.84 and 0.93 for females.Conclusion:Although both methods proved to be reliable in estimating age, the use of correction factors is recommended.

Reproducibility of radiographic stage assessment of third molars

The aim of this study was to determine intra- and inter-observer variability of the developing third molar from panoramic radiographs. Formation of third molars was assessed according to stages described by modified Demirjian et al.'s methods: Moorrees et al. [C.F.A. Moorrees, E.A. Fanning, E.E. Hunt, Age variation of formation stages for ten permanent teeth, J. Dent. Res. 42 (1963) 1490–1502] and Solari and Abramovitch [A.C. Solari, K. Abramovitch, The accuracy and precision of third molar development as an indicator of chronological age in Hispanics, J. Forensic Sci. 47 (2002) 531–535]; in addition, data were also analysed unmodified, i.e. Haavikko [K. Haavikko, The formation and alveolar and clinical eruption of the permanent teeth, an orthopantomograph study, Proc. Finn. Dent. Soc. 66 (1970) 104–170] and Demirjian et al. [A. Demirjian, H. Goldstein, J.M. Tanner, A new system of dental age assessment, Hum. Biol. 45 (1973) 211–227]. The sample was a random selection of 73 panoramic radiographs from patients aged 8–24 years. After training, the left maxillary and mandibular third molars were scored on two separate occasions without knowledge of previous scores. Cohen's Kappa and percentage agreement were calculated for each method, for maxillary, for mandibular third molars and combined. Percentage agreement for stages was also calculated. Intra-observer agreement was greater for mandibular third molars compared to maxillary third molars, and better for methods with fewer stages. Kappa values indicated good agreement for most methods; the best was Demirjian et al.'s method for mandibular third molar with very good agreement ( K = 0.80) for the first author, good agreement for the second author ( K = 0.75) and good agreement between observers ( K = 0.75). The stages with best agreement were Demirjian's stage E [A. Demirjian, H. Goldstein, J.M. Tanner, A new system of dental age assessment, Hum. Biol. 45 (1973) 211–227] and Moorrees et al.'s stage Cc and R1/4 [C.F.A. Moorrees, E.A. Fanning, E.E. Hunt, Age variation of formation stages for ten permanent teeth, J. Dent. Res. 42 (1963) 1490–1502]. Conclusions: Having clearly defined stages and fewer stages allowed better reproducibility of third molar formation.

Screen-detected vs clinical breast cancer: the advantage in the relative risk of lymph node metastases decreases with increasing tumour size

Screen-detected (SD) breast cancers are smaller and biologically more indolent than clinically presenting cancers. An often debated question is: if left undiagnosed during their preclinical phase, would they become more aggressive or would they only increase in size? This study considered a registry-based series (1988–1999) of 3329 unifocal, pT1a-pT3 breast cancer cases aged 50–70 years, of which 994 were SD cases and 2335 clinical cases. The rationale was that (1) the average risk of lymph node involvement (N+) is lower for SD cases, (2) nodal status is the product of biological aggressiveness and chronological age of the disease, (3) for any breast cancer, tumour size is an indicator of chronological age, and (4) for SD cases, tumour size is specifically an indicator of the duration of the preclinical phase, that is, an inverse indicator of lead time. The hypothesis was that the relative protection of SD cases from the risk of N+ and, thus, their relative biological indolence decrease with increasing tumour size. The odds ratio (OR) estimate of the risk of N+ was obtained from a multiple logistic regression model that included terms for detection modality, tumour size category, patient age, histological type, and number of lymph nodes recovered. A term for the detection modality-by-tumour size category interaction was entered, and the OR for the main effect of detection by screening vs clinical diagnosis was calculated. This increased linearly from 0.05 (95% confidence interval: 0.01–0.39) in the 2–7 mm size category to 0.95 (0.64–1.40) in the 18–22 mm category. This trend is compatible with the view that biological aggressiveness of breast cancer increases during the preclinical phase.

Third mandibular molar radiological development as an indicator of chronological age in a European population

Assessing biological age in the youth nearby legal age has always represented a stimulating issue for the Italian forensic scientist as far as he deals with matter of imputability and legal or illegal immigration of uncertain age subjects. Since any method of evaluation should of course be accurate, not invasive, reproducible and, as possible, easily exploitable, radiological investigation of age dependent features is the most appropriate instrument to the purpose. Dental development is slower and delayed compared with skeletal bone one, occurring according to a known, regular pattern from whose evaluation a biological age can be assessed with a reasonably restricted span for a certain radiological image. This is the assumption which inspired since 1941 (Schour e Massler) so many anthropologists and forensic and clinic odontologist in investigating biological age by the study of radiological dental morphology. Demirjian and Goldstein [New systems for dental maturity based on seven and four teeth, Ann. Hum. Biol. 3 (1976) 411–421] obtained no differences between two groups of subjects whose age was extimated by the evaluation of 14 teeth in one case and 7 teeth in another, the last being greatly simpler. Afterwards, Thorson (1991), Mincer et al. [The A.B.F.O. study of third molar development and its use as estimator of chronological age, J. Forensic Sci. 38 (1993) 379], Solari and Abramovitc [The accuracy and precision of third molar development as an indicator of chronological age in Hispanic, J. Forensic Sci. (3) (2002) 531–535] and then Prieto Carrero [Evaluation of Chronological Age Based on Third Molar Development in the Spanish Population, Atti del XIX Congresso IALM, Milano, 2003], developed a method based on the evaluation of the radiological development of the alone third molar, according to Demirjian's schematic definitions of crown and root formation. Eight stages of development of the third molar are defined from the time of mineralization appearance of the cusp tips up to complete closing of the apexes. In order to achieve grater precision in discriminating stages F and G, Solari added two stages (F1 and G1), determining 10 stages of maturation of root and crown. Prieto tested the accuracy and precision of this method by the evaluation of about 1300 orthopantomographs of juveniles and young Spanish adults of known age, divided for gender. We analyzed a total of 400 orthopantograms of young Spanish dental patients to evaluate the chronology of the right mandibular third molar development and to assess its correlation with the biological age of the tested. Biological age is attributed with a maximum standard deviation of 2.47 from the mean in the eight stages outline. The greatest limit of the method seems to be the operator experience in determining the dental stage of development. We think that age data coming from such evaluation method should be clearly explained to the magistrate in their true statistical significance and limits.

The Accuracy and Precision of Third Molar Development as an Indicator of Chronological Age in Hispanics

The accuracy and precision of chronological age estimation based on the stages of third molar tooth development was studied in a sample of 679 radiographs from individuals of Hispanic origin. The age range was 14.0 to 25.0 years. Eight raters from the University of Texas Health Science Center at Houston Dental Branch evaluated the radiographs according to Demirjian's schematic definitions of crown and root formation. The objective of this study was to evaluate the chronology of third molar development in Hispanics following the protocol of a previous study. Within the Hispanic population, the rate of male third molar development is greater than that of female third molar development for ten stages of crown-root formation. Also within this Hispanic population sample, the rate of maxillary third molar development is ahead of mandibular third molar development. The mean absolute difference between chronological age and estimated age was +/-3.0 years in females and +/- 2.6 years in males.