Figure 7.

Coordinated craniofacial tissue interactions during palatal shelf elevation. (A) Diagram showing space formation (asterisk) in the posterior palatal region through lower jaw-mediated tongue movement on a sagittal plane. The blue line contours the cranial base and upper jaw. The solid red line contours the tongue and lower jaw in the oral-nasal cavity before palatal shelf elevation. The arrow indicates anterior movement of the lower jaw and tongue during developmental progression. The dashed red line contours the tongue and lower jaw after anterior movement. (B) Diagram showing that space (asterisk) allows coordinated medial wall protrusion (arrowhead) and tongue flattening (arrow) occurred in the posterior palatal region. Noted that medial wall protrusion occurs in the region where both Fgfr1 and Fgfr2 are expressed (blue-colored area). p, palatal shelf; t, tongue.