The ossification process begins in the shaft during prenatal life, and in the head between the 11th and 27th months.1
This article incorporates text in the public domain from page 228 of the 20th edition of Gray's Anatomy (1918)
Balachandran, Ajay; Anooj Krishna; Moumitha Kartha; Libu G. K.; Liza John; Krishnan B (30 December 2013). "A Study of Ossification of heads of 2nd to 5th Metacarpals in Forensic Age Estimation in the Kerala Population" (PDF). Journal of Evolution of Medical and Dental Sciences. 2 (52): 10165–10171. doi:10.14260/jemds/1751. Retrieved 26 December 2013. http://www.jemds.com/data_pdf/dr%20ajay%20balachandran.pdf ↩