It has been discovered that that certain growth factors can delay the ossification of a tissue site, such as a cranial suture, via the promotion of fibroblast differentiation and/or inhibition of osteoblast differentiation. Provided herein are methods for treating bone formation conditions or disorders, such as synostotic conditions, or ectopic mineralization conditions, via administration of compositions comprising connective tissue growth factor (CTGF), and optionally other growth factors or fibroblast or progenitor cells, to a tissue site of a subject in need thereof.
