Editing Frontal bone (section)

== Development ==
The frontal bone is presumed to be derived from [[neural crest cell]]s.<ref>{{cite journal |last1=Kirby |first1=M. L. |last2=Waldo |first2=K. L. |title=Role of neural crest in congenital heart disease |journal=[[Circulation (journal)|Circulation]] |year=1990 |volume=82 |issue=2 |pages=332–340 |doi=10.1161/01.CIR.82.2.332 |pmid=2197017 |doi-access=free }}</ref>

The frontal bone is [[ossified]] in membrane from two primary centers, one for each half, which appear toward the end of the second month of [[fetal]] life, one above each [[supraorbital margin]]. From each of these centers, ossification extends upward to form the corresponding half of the [[squama frontalis|squama]], and backwards to form the orbital plate. The spine is ossified from a pair of secondary centers, on either side of the middle line; similar centers appear in the nasal part and zygomatic processes.

At birth the bone consists of two pieces, separated by the [[frontal suture]], which is usually obliterated by [[Intramembranous ossification]], except at its lower part, by the eighth year, but occasionally persists throughout life. It is generally maintained that the development of the [[frontal sinuses]] begins at the end of the first or beginning of the second year, but may begin at birth. The sinuses are of considerable size by the seventh or eighth year, but do not attain their full proportions until after [[puberty]].