How do BMP and FGF pathways interact in tooth development?

• A. They coordinate proliferation and differentiation; BMP promotes differentiation while FGF supports proliferation and signaling balance.
• B. BMP inhibits differentiation while FGF inhibits proliferation.
• C. BMP and FGF pathways do not interact.
• D. BMP exclusively promotes eruption; FGF only regulates root length.

Answer: (A)

Proliferation and differentiation in tooth development are guided by signaling that must be balanced. BMP and FGF pathways don’t work in isolation; they tune each other to drive the right progression of the tooth organ. BMP signaling tends to push dental cells toward differentiation, contributing to the formation of dentin and enamel-producing cells. FGF signals help keep cells proliferating and maintain a pool of progenitor cells in both the dental epithelium and mesenchyme, while also shaping growth and morphogenesis. The interaction between these pathways creates a coordinated transition from growth to maturation, influencing tooth size, cusp patterning, and the timing of tissue formation. That balance—BMP driving differentiation and FGF supporting proliferation and signaling modulation—best captures how the two systems work together.