Figure 1.
Measurement of injection pressure during local anesthetic. A, A computer-controlled local anesthetic delivery system syringe. B, Pressure transducer and connection to tubes. C, Invasive sphygmomanometer. D, Analytical software and personal computer. E, The patient marks the perceived level of pain and anxiety on the linear Visual Analogue Scale and Faces Anxiety Scale. F, Puncture site and injection of local anesthetic. The hand piece, shortened to half-length, is held like a pen. G, Cheek retractor pulling the lower lip. H, The syringe's foot pedal.