Forensic dentistry is an interdiscipline of forensic medicine and stomatology, which provides legal information by collecting, testing and assessing the dental evidence scientifically. In this review, the present application of forensic dentistry has been described, such as the estimation of age, sex, species, occupation and living habit, as well as the identification of individual, domestic violence or abuse, which aims to enrich and improve forensic dentistry for making it be more useful in forensic medicine even in juridical practice.
Age Determination by Teeth ; Forensic Anthropology ; Forensic Dentistry/methods* ; Forensic Medicine ; Humans ; Tooth

Age estimation is a hot and difficult issue in forensic practice. Teeth are the most solid organs in human body and can be kept in vitro for a long time. With age, the secondary dentin gradually generates and the volume of pulp cavity constantly decreases. Therefore, forensic dentists proposed that age-related changes of dentin-pulp complex could be used to estimate age, which has been widely applied in forensic practice over the years. Due to the development of imaging technology, a variety of methods have been advocated by forensic dentists to detect the age-related changes of dentin-pulp complex for age estimation. However, different methods have their own advantages and limitations, forensic scientists should combine the use of different methods for improving the accuracy of age estimation according to the actual situation. This paper reviews current research of age estimation based on dentin-pulp complex, so as to provide reference for related research.
Age Determination by Teeth ; Dental Pulp ; Dentin ; Forensic Dentistry/methods* ; Humans

PURPOSE: It has been proposed that using new prediction methods, such as neural networks based on dental data, could improve age estimation. This study aimed to assess the possibility of exploiting neural networks for estimating age by means of the pulp-to-tooth ratio in canines as a non-destructive, non-expensive, and accurate method. In addition, the predictive performance of neural networks was compared with that of a linear regression model. MATERIALS AND METHODS: Three hundred subjects whose age ranged from 14 to 60 years and were well distributed among various age groups were included in the study. Two statistical software programs, SPSS 21 (IBM Corp., Armonk, NY, USA) and R, were used for statistical analyses. RESULTS: The results indicated that the neural network model generally performed better than the regression model for estimation of age with pulp-to-tooth ratio data. The prediction errors of the developed neural network model were acceptable, with a root mean square error (RMSE) of 4.40 years and a mean absolute error (MAE) of 4.12 years for the unseen dataset. The prediction errors of the regression model were higher than those of the neural network, with an RMSE of 10.26 years and a MAE of 8.17 years for the test dataset. CONCLUSION: The neural network method showed relatively acceptable performance, with an MAE of 4.12 years. The application of neural networks creates new opportunities to obtain more accurate estimations of age in forensic research.
Cone-Beam Computed Tomography ; Dataset ; Forensic Dentistry ; Humans ; Linear Models ; Methods ; Neural Networks (Computer)

OBJECTIVE: To explore more concise and unified forensic identification indexes for people with none dental disease in digital orthopantomogram. METHODS: To select randomly 170 digital orthopantomogram with none dental disease. Then to select indexes for full dentition patterns and dental alignment patterns according to the dental physiological variations and the characters of dental alignment respectively. Finally diversity of the indexes would be evaluated by statistical analysis. RESULTS: The group with none dental disease had 74 kinds of full dentition pattern in 170 samples, thus its diversity was 43.53%. The group had 129 kinds of dental alignment pattern, thus its diversity was 75.88%. The group had 150 kinds of full dentition/dental alignment pattern, thus its diversity was 88.24%. CONCLUSION The diversity of the full dentition pattern was not very good. So the full dentition coding was not very effective when it was used solely. The diversity of dental alignment pattern was good. So the method of dental alignment coding could be used in the maxillofacial forensic identification. If the group was coded by the full dentition and dental alignment pattern at the same time, its diversity was better than any single pattern. So the method would be valuable in forensic identification.
Dentition ; Forensic Dentistry ; Humans ; Mandible/diagnostic imaging* ; Maxilla/diagnostic imaging* ; Radiography, Dental, Digital ; Radiography, Panoramic/methods*

Dental age plays an important role in age estimation. It has often been used together with skeletal age to improve the accuracy of age estimation abroad, but seldom performed in China. As a noninvasive technology, dental radiological imaging has been widely used in age estimation. By observing the age-related changes such as the pulp cavity and development of crown and root on radiographs. Gleiser and Hunt, as well as Demirjian have developed different methods to determine the age of human. Demirjian's method has been proved to be more accurate but with limitation when used in persons of eighteen and above. The accuracy and reliability of the measurements on pulp cavity could be improved as the development of computed tomography with its high resolution and intelligent software. As a convenient and accurate method, age estimation from dental computed tomographs would be more promising in the future for forensic scientists and anthropologists.
Age Determination by Teeth/methods* ; Dental Pulp/diagnostic imaging* ; Forensic Dentistry ; Humans ; Radiography, Panoramic/methods* ; Tomography, X-Ray Computed/methods*

OBJECTIVE: To discuss the coding of full dentition with 32 locations and measure the characteristics of some bony indexes in occlusal-facial digital radiology (DR). METHODS: To select randomly three hundred DR orthopantomogram and code the full dentition, then analyze the diversity of dental patterns. To select randomly one hundred DR lateral cephalogram and measure six indexes (N-S,N-Me,Cd-Gn,Cd-Go,NP-SN,MP-SN) separately by one odontologist and one trained forensic graduate student, then calculate the coefficient variation (CV) of every index and take a correlation analysis for the consistency between two measurements. RESULTS: (1) The total diversity of 300 dental patterns was 75%.It was a very high value. (2)All six quantitative variables had comparatively high CV value.(3) After the linear correlation analysis between two measurements, all six coefficient correlations were close to 1. This indicated that the measurements were stable and consistent. CONCLUSION The method of coding full dentition in DR orthopantomogram and measuring six bony indexes in DR lateral cephalogram can be used to forensic identification.
Cephalometry/methods* ; Facial Bones/diagnostic imaging* ; Female ; Forensic Dentistry ; Humans ; Image Processing, Computer-Assisted/methods* ; Jaw/diagnostic imaging* ; Male ; Radiography, Dental, Digital/methods* ; Radiography, Panoramic ; Tooth/diagnostic imaging*

This experiment was designed to study the method of human bitemarks digital analysis and its accuracy. The human bitemarks were made on the dog skin by human dentition. The related parameters of human bitemarks and suspects criminal dentitions were digitally recorded and managed. The digital picture of human bitemark was obtained, and the dental study model, bite in wax and bitemark on pig skin of suspected criminal were scanned. The overlay was prepared with Adobe Photoshop 5. 5 and the parameters were measured with AutoCAD R14, then their matches were compared. The result shows that the human bitemarks digital analysis is a more accurate approach to human bitemarks identification. Three methods for collecting evidence dental study model, bite in wax and bitemark on pig skin all can be used as aids in forensic sciences. Dental study model is the most accurate one of all the three methods mentioned above.
Animals ; Bites and Stings ; diagnosis ; Bites, Human ; diagnosis ; Dental Models ; Dogs ; Forensic Dentistry ; methods ; Humans ; Image Processing, Computer-Assisted ; Photography ; Sensitivity and Specificity ; Skin ; pathology ; Swine

OBJECTIVE: To explore the value of estimating chronologic age based on the grades of mandibular third molar development. To evaluate whether mandibular third molar could be used as an indicator for estimating the age under or over 18 years. METHODS: The mineralization status of mandibular third molar of 1 845 individuals aged 10 - 30 was graded and marked based on Demirjian's classification of grades reformed by Orhan. Gender difference was examined by t-test. A cubic regression model was established to analyze the correlation between third molar and chronologic age. Each grade of age cumulative distribution diagram and ROC curve was respectively performed to evaluate the relationship between third molar and the age of 18. Using Bayes discriminant analysis, an equation was established for estimating the age of 18. RESULTS: The inner-rater reliability was 0.903. Statistical analysis showed a moderate correlation between age and grade. Significant differences of both genders were found only in grade D and H (P < 0.05). Males at the grades from 1 to D and females at the grades from 1 to C were under 18 years old, and both males and females at grade H were over 18 years old. The area under the ROC curve was 0.797 (P < 0.05). CONCLUSION Third molar development shows a high correlation with age, and combined with other indicators, it can be used to estimate the age of 18.
Age Determination by Teeth/methods* ; Asian People ; Bayes Theorem ; China ; Female ; Forensic Dentistry ; Humans ; Male ; Molar, Third/diagnostic imaging* ; Radiography, Panoramic ; Reproducibility of Results ; Sex Characteristics

The present study was aimed to use the 3-D cone beam CT (CBCT) as a new method in human bite marks identification which was carried out in experimental pigskin to assess its effectiveness in our laboratory. Bite marks were digital photographed according to American Board of Forensic Odontology (ABFO) guidelines. In this study, the data of the suspect's dental casts were collected by scanning in two ways: one was after plate scanning, in which the comparison overlays were generated by Adobe Photoshop 8.0 software; the other was by CBCT, which generated comparison overlays automatically. The bite marks were blind identified with the two kinds of data of the suspect's dental casts respectively. ROC curve was used to analyze the sensitivity, specificity, and 95% confidence interval. The results showed that CBCT method got a larger area under the ROC curve: 0.784 (SE = 0.074, 95% CI = 0.639-0.929), and got a very high specificity (specificity 98.7%, 95% CI = 94.5%-99.8%). Thus, this study illustrates that the CBCT used in bite mark identification is an effective and accurate tool and has stronger ability to exclude suspects compared with the conventional method, but the comparison process needs further study to enhance its effectiveness in bite mark identification.
Adolescent ; Adult ; Bites, Human ; diagnostic imaging ; Cone-Beam Computed Tomography ; methods ; Copying Processes ; Dental Models ; Dentition ; Female ; Forensic Dentistry ; methods ; Humans ; Imaging, Three-Dimensional ; methods ; Male ; Radiographic Image Interpretation, Computer-Assisted ; methods ; Young Adult

OBJECTIVE: Developing teeth are used to assess maturity and estimate age in a number of disciplines. The aim of this study was to determine the accuracy of Demirjian method (Panoramic radiographs were examined and seven mandibular teeth staged according to Demirjian's dental maturity scale) in the forensic clinical medicine. METHODS: Tooth formation was assessed with orthopantomographs in healthy children in dental teaching hospital. There were total 828 children, with 279 boys and 549 girls, aged from 11 to 19 years. The difference between dental and real age was compared and measured, using t-test. RESULTS: The Demirjian method overestimated age in the aged 11-16 years group and had limitations in aged group over 17 years. CONCLUSION The 95% confidence interval of the mean was least for mean of all developing teeth using Demirjian method (age 11-16 years).
Adolescent ; Age Determination by Teeth/methods* ; Age Factors ; Child ; China ; Dentition, Permanent ; Female ; Forensic Dentistry/methods* ; Humans ; Male ; Mandible/diagnostic imaging* ; Radiography, Panoramic ; Reproducibility of Results ; Tooth/growth & development* ; Young Adult