Figure 1. The time (minutes) until initial supplemental infiltration anesthesia. During the period of the initial dose of infiltration anesthetics, there was a significant difference (P = .0000004) between elevation of a periosteal flap (EPF) (4.3 ± 1.4 mL, 2–7.2 mL) and nonelevation of a periosteal flap (NEPF) (1.8 ± 0.9 mL, 0.3–4.4 mL). During the period before initial supplemental infiltration anesthesia, there was a significant difference (P = .0015) between EPF (38 ± 26 minutes, 10–100 minutes) and NEPF (65 ± 27 minutes, 15–120 minutes).