title: Accuracy of an equation for estimating age from mandibular third molar development in a Thai population.
abstract: OBJECTIVE
  This study assessed the accuracy of age estimates produced by a regression equation derived from lower third molar development in a Thai population.
  
  
  METHODS
  The first part of this study relied on measurements taken from panoramic radiographs of 614 Thai patients aged from 9 to 20. The stage of lower left and right third molar development was observed in each radiograph and a modified Gat score was assigned. Linear regression on this data produced the following equation: Y=9.309+1.673 mG+0.303S (Y=age; mG=modified Gat score; S=sex). In the second part of this study, the predictive accuracy of this equation was evaluated using data from a second set of panoramic radiographs (539 Thai subjects, 9 to 24 years old). Each subject's age was estimated using the above equation and compared against age calculated from a provided date of birth. Estimated and known age data were analyzed using the Pearson correlation coefficient and descriptive statistics.
  
  
  RESULTS
  Ages estimated from lower left and lower right third molar development stage were significantly correlated with the known ages (r=0.818, 0.808, respectively, P≤0.01). 50% of age estimates in the second part of the study fell within a range of error of ±1 year, while 75% fell within a range of error of ±2 years. The study found that the equation tends to estimate age accurately when individuals are 9 to 20 years of age.
  
  
  CONCLUSIONS
  The equation can be used for age estimation for Thai populations when the individuals are 9 to 20 years of age.
authors.affiliation: Division of Oral and Maxillofacial Radiology, Faculty of Dentistry, Chiang Mai University, Chiang Mai, Thailand.
authors.forename: Karune
authors.initials: K
authors.lastname: Verochana
authors.affiliation: Division of Oral and Maxillofacial Radiology, Faculty of Dentistry, Chiang Mai University, Chiang Mai, Thailand.
authors.forename: Sangsom
authors.initials: S
authors.lastname: Prapayasatok
authors.affiliation: Division of Oral and Maxillofacial Radiology, Faculty of Dentistry, Chiang Mai University, Chiang Mai, Thailand.
authors.forename: Apirum
authors.initials: A
authors.lastname: Janhom
authors.affiliation: Division of Oral and Maxillofacial Radiology, Faculty of Dentistry, Chiang Mai University, Chiang Mai, Thailand.
authors.forename: Phattaranant May
authors.initials: PM
authors.lastname: Mahasantipiya
authors.affiliation: Division of Comminunity Dentistry, Faculty of Dentistry, Chiang Mai University, Chiang Mai, Thailand.
authors.forename: Narumanas
authors.initials: N
authors.lastname: Korwanich
keywords: Age Determination by Teeth; Forensic Dentistry; Molar, Third; Radiography, Panoramic