Estimation Of Chronological Age Using Quantitive Measurement Of Aging In Young Adults Of Central China

In the field of forensic science and orthodontics, measurement and analysis of chronological age of young adults has become very much a pioneering research issue.It will give much helps to the identification of forensic and the dental science if we can find an appropriate and accurate method to estimation the chronological age of young adults.Lots of research to estimate chronological age based on the using different measurements. Nowadays age estimation of young adults basically focused on the skeleton age and dengtal age, and the methods also based on the atlas of the growing.Because of different observers and determine indicators, there are poor stability and accuracy on the results.Based on a review of its current condition and development home and abroad, the thesis systematically expounds some achievements in the theory and the methodology that is used quantitive measurement of aging in young adults of Central of China to estimation the chronological age. Quantitive measurement of aging in young adults also based on the third molar, cervical vertebra and index of dental maturity. And we want to establish a new quantitive formula with young adults of central china.In the first part, the development of the third molar was assessed according to the Demirjian's method. of each the third molar was rated on an 8-stage scale from A to H. Each stage of the third molar was allocated a score, and the sum of the scores gave an evaluation of the subject's dental maturity, measured on a scale which were given separately for each gender.In the second part, the following cervical vertebrae were traced and measured with computer system:anterior vertebral body height (AH), vertebral body height (H),posterior vertebral body height (PH), and anteroposterior vertebral body length (AP) on the third and fourth cervical vertebrae. A formula for obtaining cervical vertebral bone age was determined from the ratios and the chronological age using a stepwise multiple regression analysis.In the third part, The purpose of the investigation was to present a method for assessing chronological age based on the relationship between age and measurement of the open apices in teeth of young adults. A formula was determined from the ratios and the chronological age using a stepwise multiple regression analysis.Formula 1 is based between the development of the third molar and the chronological ageMale:Age=8.33+1.51 Development stageFemale:Age=9.10+1.43 Development stageFormula 2 is based between the cervical vertebrae and the chronological ageMale:Age=-0.528+4.534 PH/AP3+1.463 AH/H4+5.364 AH/AP3-1.894 AH/PH4+3.345AH/H3Female:Age=1.679+5.503 AH/AP3+3.432 AH/H4+3.528 H/PH3-3.278 PH/AP4+2.502AH/H3Formula 3 is based between the measurement of the open apices and the chronological ageAge=9.231-0.723 N0-1.588X5+0.592S-0.099 s·N0In the forth part, the purpose of this part was to evaluate the applicability of these three methods related to the chronological age assessment for young adults of the central china. And we also find even if in the same sample of the young adults in central of China, the accuracy of the three methods has difference. In the year of 8-10 the Formula 3 is the best way of these three methods of determining the chronological age. Formula 1 is best for the young adults of 15-18. In the meanwhile, Formula 2 is suitable for the young adults with growing spurt(11-13 years old).In summary, the development of puberty in the process of ageing changes of chronological age to determine the individual has a better result, and the quantitative indicators can greatly improve the accuracy of determining the result. At the same time in different age groups for adolescents should also be roughly estimated on the basis of age, more appropriate use of quantitative indicators of aging in the determination of individual chronological age.