Assessment of the Relationship Between the Eruption Stage of Lower Third Molars and Chronological Age in 17‒21-Old Subjects

Tooth eruption stages include a series of fixed and continuous measurable processes that can be used for age estimation. After 14 years of age the only teeth that are still developing are the third molar tooth. Therefore during 17‒21 years of age only these teeth can be used for estimation of age.
In this analytical study, 125 panoramic radiographs of 74 females and 51 males, 17‒21 years of age, were assessed. Stages of lower third molar eruption were divided into 4 stages (no eruption, alveolar eruption, gingival eruption and complete eruption). Then the relationship between eruption stages and chronological age was used to predict each subject’s age. Pearson’s correlation coefficient and regression analyses were used for the analysis of data.
Correlation coefficients between the right and left side eruption stages and chronological age were 0.367 and 0.315, respectively. In addition, the correlation coefficient between the right and left sides was significant (0.932). Regression equation derived from this study for age estimation is: estimated age = 16.85 (1.055 stage of Rside) – (0.398 stage of Lside) Mean ages at alveolar, gingival and complete eruption stages were 18.2, 19 and 19.5 years, respectively.
The results of this study can be used as an adjunctive technique to determine the age in subjects older than 15 years of age.