Craniometric Method for Age Estimation by the Degree of Lambdoid Suture Obliteration

Background : In anthropology age of skeletal remains can be estimated without specific equipment by the degree of serrate suture obliteration; however, standard methods of obliteration measurement cannot be used to calculate age of a skull with a fragmented or damaged calvaria, which significantly complicates age estimation. Objective : To assess validity of a new method for age estimation relying on data of lambdoid suture obliteration on skulls of both sexes from the craniological collection at the Department of Normal Anatomy of Kuban State Medical University (Krasnodar, Russian Federation) and compare with that of a conventional method. Materials and methods : We determined sex and age of 41 skulls using craniometry. Based on the sex and calvaria condition, the skulls were divided into 2 groups and further subdivided by sex: male and female skulls with preserved calvariae (age was estimated by Zvyagin’s standard regression equations [N=20]) and male and female skulls without calvariae (age was estimated by a new equation taking into account lambdoid suture obliteration [N=21]). The skulls with calvariae were subjected to double independent craniometry to find absolute and relative errors. Quantitative indicators of suture obliteration and the estimated age were assessed for normal distribution using the Kolmogorov-Smirnov test. Data collection, correction, and systematization were conducted using Microsoft Access 2016 and Microsoft Excel 2016 (Microsoft Corp, USA). Statistical analysis was performed using Statistica 10.0 (StatSoft Inc, USA). Results and discussion : We determined age and sex of 36 skulls (87.80%) using craniometry. When comparing age values calculated using the standard regression equations and the new equation for the lambdoid suture, the absolute and relative errors for male skulls were 3.05% and 6.09%, respectively. For female skulls, the absolute and relative errors were 9.39% and 19.42%, respectively. Conclusions : Equations that take into account lambdoid suture obliteration enable to estimate age of male and female skulls, including fragmented skulls, and can be used in anatomical and paleoanthropological studies, as well as in medical and forensic identification.