Accuracy of the London Atlas to estimate the age of legal majority in a sample of the Amazon Regio.

Background: Estimating the age of majority is a challenging task in forensic odontology, especially because the third molars are usually the only developing teeth between the ages of 16 and 21 years. The London Atlas emerged as an alternative to estimate age using dental development, eruption and deciduous root resorption as parameters. The method has performed well in young age categories, while its performance for age estimation via third molars has been disputed. The present study tested the performance of the London Atlas to estimate the age of legal majority in a sample of individuals from the Amazon Region. Material and Methods: The sample consisted of 1.256 panoramic radiographs of women (n = 694) and men (n = 562) between 16 and 22.9 years. The method was applied to the maxillary (#28) and mandibular (#38) left third molars. For comparative purposes, the sample was divided into seven age groups: 16├ 16.99; 17├ 17.99; 18├ 18.99; 19├ 19.99; 20├ 20.99; 21├ 21.99; and 22├ 22.99 years. Chronological and estimated ages were compared descriptively by means of mean absolute errors (MAE) and root mean squared errors (RMSE), as well as through Receiver Operating Characteristic (ROC) curves and their area under the curve (AUC). Results: The MAE of the age estimates using tooth #28 was 1.76 years for females and 1.52 years for males. When the tooth #38 was used, the MAE for the females and males were 1.68 and 1.51 years, respectively. The MAE and RMSE increased in ascending order between age categories. Tooth #28 led to 74% of correct classifications around the age of legal majority, while tooth #38 reached 77%. The area under the curve was 0.75 for tooth #28 and 0.73 for tooth #38. Conclusions: The London Atlas should be used carefully to estimate the age of legal majority and not as a single method when the age threshold is 18 years. Key words:Age determination by teeth, forensic dentistry, forensic science, third molar.

Accuracy of the third molar maturity index (I3M) for diagnosing the legal majority of young southern Brazilians.

Background: The numerous techniques for identifying adulthood require research testing the accuracy of each method in different populations. This study verified the accuracy of the third molar maturity index (I3M) proposed by Cameriere et al. (2008) for diagnosing the age of majority in a southern Brazilian population sample. Material and Methods: Panoramic radiographs of patients with dental element 38 treated at the School of Dentistry of the University of Passo Fundo (UPF), RS, Brazil, were analyzed. The patients were separated into age groups between 15.00 and 22.99 years. The Cameriere (2008) method was applied to each radiograph. The study sample comprised 671 individuals, with 385 women (mean age 19.67 ± 2.05) and 286 men (mean age 19.5 ± 2.11). Results: The original cut-off value of I3M≤0.08 classified individuals younger and older than 18 years. ROC curve plotting resulted in an overall accuracy of 0.69 and 0.84 for women and men, respectively. The most favorable cut-off value for southern Brazilian men was 0.06, and women showed better results with an I3M adjusted to 0.13. The new cut-off values produced an accuracy of 0.78 for women and 0.84 for men. The original cut-off point to the I3M (0.08) was not the most appropriate for the studied sample. Conclusions: Thus, index adjustments to 0.13 for women and 0.06 for men may improve method performance among southern Brazilian individuals. Key words:Molar, third, radiography, panoramic, forensic dentistry, age groups, imputability.

Evaluation of the Genotoxicity of Tobacco and Alcohol in Oral Mucosa Cells: A Pilot Study.

AIM AND OBJECTIVE: To define the genotoxic potential of tobacco and alcohol in the oral mucosa through a micronuclei (MN) test. MATERIALS AND METHODS: Samples of exfoliative cells from oral mucosa were collected using superficial scraping of the right- and left-cheek mucosa of 83 patients divided into four groups, namely: (G1) 24 individuals abstaining from tobacco and alcoholic beverages; (G2) 23 individuals who smoke and abstain from alcoholic beverages; (G3) 24 smokers and alcoholics; and (G4) 12 individuals who consume alcohol and abstain from tobacco. The samples were stained with Giemsa-Wright, and the frequencies of MN, binucleated cells, and metanuclear changes were recorded in the samples of each group (1,000 cells per patient). RESULTS: Analysis of variance (ANOVA) showed a difference between groups for changes concerning karyorrhexis (p = 0), pycnosis (p = 0.002), karyolysis (p = 0.003), and binucleated cells (p = 0.046). As for the total number of changes, G3, G2, and G4, respectively, were significantly higher than G1. CONCLUSION: It is suggested that the influence of smoking and drinking on exfoliating cells of oral mucosa may cause metanuclear changes due to genetic changes that these products cause, and the MN test is effective in detecting and monitoring such changes. CLINICAL SIGNIFICANCE: MN test may work for constantly monitoring the oral mucosa of smokers and/or alcoholic patients, so that early cell changes may be diagnosed, preventing the genesis of oral cancer.

Testing international techniques for the radiographic assessment of third molar maturation.

BACKGROUND: To assess the radiographic third molar maturation with internationally developed techniques for age estimation. MATERIAL AND METHODS: The study analyzed 1,062 panoramic radiographs of patients treated at the School of Dentistry of the University of Passo Fundo/RS/Brazil, between 2009 and 2020. The patients were separated into ages between 15.00 and 23.99 years and, for each radiograph, the third molars were classified into stages from 1 to 10, with the subsequent application of one of the formulae proposed by Gunst et al. A dichotomous variable indicating whether each individual was younger or older than 18 was calculated from the chronological age of the individuals. A logistic regression model was adjusted to assess whether the third molar stages are correlated with the age of individuals. RESULTS: The error indicators between estimated and chronological ages showed that mean errors closer to zero are seen in the 18-18.9 and 17-17.9 age groups, respectively. Male individuals were earlier in terms of dental mineralization but there were no significant differences between sexes regarding the applicability of the method. The ROC curve shows that the analysis of a single third molar for age estimation gives a maximum of 70.4% reliability. CONCLUSIONS: The moderate performance of the technique tested in the present study justify future country-specific corrections to improve age estimation from the radiographic assessment of third molar maturity. Key words:Dental age estimation, forensic dentistry, radiology, third molar.