Is ossification of sternum at all a valuable guide for determination of age at middle age group?

In spite of stringent rulling on compulsory birth and death registration there are many cases that do not have a birth certificate even today. Forensic Pathologists often required to estimate the chronological age of a subject biologically for various reasons. It is particularly a increasing problem with advancing age above 25 yrs. As from around 25 years untill old age there is no dramatic events as eruption of tooth or the appearance of ossification center.