Accuracy of the third molar index cut-off value for estimating 18 years of age: Validation in a Japanese samples

Akiko Kumagai; Noriaki Takahashi; Luz Andrea Velandia Palacio; Agnese Giampieri; Luigi Ferrante; Roberto Cameriere

doi:10.1016/j.legalmed.2019.03.001

Accuracy of the third molar index cut-off value for estimating 18 years of age: Validation in a Japanese samples

Leg Med (Tokyo). 2019 May:38:5-9. doi: 10.1016/j.legalmed.2019.03.001. Epub 2019 Mar 4.

Authors

Akiko Kumagai¹, Noriaki Takahashi², Luz Andrea Velandia Palacio³, Agnese Giampieri⁴, Luigi Ferrante⁵, Roberto Cameriere⁴

Affiliations

¹ Division of Forensic Odontology and Disaster Oral Medicine, Department of Forensic Science, Iwate Medical University, 2-1-1, Nishitokuta, Yahaba-cho, Shiwa-gun, Iwate 020-3694, Japan. Electronic address: kumagaia@iwate-med.ac.jp.
² Division of Dental Radiology, Department of Reconstructive Oral and Maxillofacial Surgery, School of Dentistry, Iwate Medical University, 19-1, Uchimaru, Morioka, Iwate 020-08505, Japan.
³ AgEstimation Project, University of Macerata, Macerata, Italy.
⁴ AgEstimation Project, Macerata, Italy.
⁵ Center of Epidemiology, Biostatistics and Medical Information Technology, Department of Biomedical Sciences and Public Health, School of Medicine, Polytechnic University of Marche, 60126 Ancona, Italy.

PMID: 30878703
DOI: 10.1016/j.legalmed.2019.03.001

Abstract

Aims: To evaluate the cut-off value of third molar maturity index (I_3M) = 0.08 for discriminating minors from adults in Japanese population.

Material and methods: 276 panoramic radiographs of healthy Japanese subjects (139 girls and 137 boys) age range from 14 to 24 years were evaluated.

Results: ICC (Intra-class correlation coefficient) for intra-rater and inter-rater agreement of I_3M was 99.6% (95% CI 98.6-99.9%) and 98.9% (95% CI 98.8-99.9%) respectively. The proportion of correctly classified in girls was 87% (95% CI 81-93%) and in boys was 91% (95% CI 87-96%). The sensitivity of the test in girls and boys was 84% (95% CI 77-92%) and 89% (95% CI 83-95%) respectively and specificity was 93% (95% CI 85-100%) and 96% (95% CI 90-100%) in girls and in boys. The PPV (Positive Predictive Value) was 87% (95% CI 69-95%) in girls and 92% (95% CI 74-98%) in boys.

Conclusion: The results of the study show that I_3M is capable of discriminating adults and minors in subjects around legal age of 18 years old in Japanese population.

Keywords: Adult age; Dental age estimation; Forensic odontology; Japanese; Third molar maturity.

Publication types

Validation Study

MeSH terms

Adolescent
Adult
Age Determination by Teeth / methods*
Asian People
Female
Forensic Medicine / methods*
Humans
Male
Molar, Third / diagnostic imaging
Molar, Third / growth & development*
Radiography, Panoramic
Sensitivity and Specificity
Young Adult