During eruptive movements, what signal prompts the dental follicle to promote alveolar bone growth at the base of the crypt?

• A. BMP6
• B. SHH
• C. FGF8
• D. VEGF

Answer: (A)

During eruption, the dental follicle sends osteogenic cues to shape the surrounding bone. The signal that directly promotes new alveolar bone formation at the base of the crypt is a bone morphogenetic protein, specifically BMP6. When BMP6 acts on mesenchymal cells at the crypt’s base, it drives osteoblast differentiation and bone deposition, building the supporting wall that the erupting tooth moves against. This targeted osteogenesis helps create a stable path for eruption.

Other molecules listed play different roles: SHH mainly guides tooth germ growth and patterning, FGF8 is important earlier in tooth development, and VEGF focuses on blood vessel formation. While vascularization is important for eruption, BMP6 is the key cue for the bone formation at the crypt base.