Temporal and spatial characteristics of POTCs. (A) Schematic diagram depicting the technique used to visualize tooth vasculature. O/N, overnight. (B) Schematic diagram depicting molar structure. (C–I) Immunohistochemistry for a mandible centered on the first molar. Dotted lines indicate the border between the dental pulp (DP) and dentin. Many capillary ECs in the periphery (asterisk) were concomitantly Vegfr1^high and Vegfr2^high and actively sprouting (open arrowheads). (D)Fig. S1 I shows the same image for the sake of convenience. (I) See also Fig. S1 (A–C) for each channel. (J–M) Immunohistochemistry of the first molar at P12. POTCs perforate the basal layer of odontoblasts marked by Osx (arrows). (N–P) Immunohistochemistry for the first molar. POTCs (arrowheads) connecting to an arteriole (A) and venule (V) exhibited moderate CD31 intensity. Scale bars: 200 µm (C–E, J, and N); 50 µm (F, K, and M); 20 µm (G–I and L).