Human age estimation combining third molar and skeletal development

Abstract

The wide prediction intervals obtained with age estimation methods based on third molar development could be reduced by combining these dental observations with age-related skeletal information. Therefore, on cephalometric radiographs, the most accurate age-estimating skeletal variable and related registration method were searched and added to a regression model, with age as response and third molar stages as explanatory variable. In a pilot set up on a dataset of 496 (283 M; 213 F) cephalometric radiographs, the techniques of Baccetti et al. (2005) (BA), Seedat et al. (2005) (SE), Caldas et al. (2007) and Rai et al. (2008) (RA) were verified. In the main study, data from 460 (208 F, 224 M) individuals in an age range between 3 and 26 years, for which at the same day an orthopantogram and a cephalogram were taken, were collected. On the orthopantomograms, the left third molar development was registered using the scoring system described by Gleiser and Hunt (1955) and modified by Köhler (1994) (GH). On the cephalograms, cervical vertebrae development was registered according to the BA and SE techniques. A regression model, with age as response and the GH scores as explanatory variable, was fitted to the data. Next, information of BA, SE and BA + SE was, respectively, added to this model. From all obtained models, the determination coefficients and the root mean squared errors were calculated. Inclusion of information from cephalograms based on the BA, as well as the SE, technique improved the amount of explained variance in age acquired from panoramic radiographs using the GH technique with 48%. Inclusion of cephalometric BA + SE information marginally improved the previous result (+1%). The RMSE decreased with 1.93, 1.85 and 2.03 years by adding, respectively, BA, SE and BA + SE information to the GH model. The SE technique allows clinically the fastest and easiest registration of the degree of development of the cervical vertebrae. Therefore, the choice of technique to classify cervical vertebrae development in addition to third molar development is preferably the SE technique.

Combining dental and skeletal evidence in age classification: Pilot study in a sample of Italian sub-adults

“…Among all methods applied here TW3 resulted the most accurate for male individuals (83.5%), whilst all methods produced very similar accuracy (~77%) for females. As previously reported in literature wrist-hand bone maturation and dental calcification resulted to be affected by gender [15,23,[54][55][56][57][58][59].…”

“…The combination of dental and skeletal age estimation methods has consistently been regarded as a procedure endowed with higher accuracy than age assessments performed using only either wrist or dental maturation evidence [54][55][56][57][58]. Despite limitations due to the sample size and the uneven age distribution, the combination of dental method with a skeletal method through LDA improves accuracy in classifying subjects over/under the age threshold of 12 years and reduces false positive rate for both genders with respect to original methods.…”

Validation of third molar maturity index (I 3M ) for discrimination of juvenile/adult status in South Indian population

“…Since the development of teeth "No.38" and "No.48" is symmetric and strongly correlated, multicollinearity problems in the regression models could be detected 29,30 . Therefore, for standardization, and according to the original study by Cameriere et al 21 , only TMs from the left side of the mandible were evaluated, i.e.…”

Age estimation among Brazilians: Younger or older than 18?

“…Among living people, especially children and adolescents, age estimation is required for civil purposes, such as for adoption processes, or for criminal reasons to check whether the accused has reached legal majority 5 ; in other circumstances, it would be necessary to perform age estimation when unattended young individuals ask for asylum (protection). 6 Dental age estimation through the third molar (3 rd M) evaluation is of particular importance because they are the last teeth to develop 7 and they can offer information with regard to this critical age. Furthermore, in many countries, including Brazil, this age (18) represents the legal majority.…”