Nitecka–Buchta A, et al. – The researchers performed this work to assess the plasma level of CGRP in patients with myofascial pain (RDC/TMD Ia) and myofascial pain with limited opening (RDC/TMD Ib) before and after occlusal splint therapy (Michigan splint). They observed that venepuncture of an external jugular vein was more accurate than venepuncture of a cubital vein in evaluating CGRP plasma level changes in patients with TMD.

Methods

• It was a randomised trial.
• This trial was performed including thirty nine patients (males = 3, females = 36).
• After that, blood samples were taken from the external jugular vein (JUG) and cubital vein (CUB) before and after 30 days of occlusal splint therapy.
• Finally, plasma levels of CGRP were measured with ELISA KIT for Human Calcitonin Gene Related Peptide (CGRP) 96T (USCNK Business Co. Ltd.).

Results

• The analysis in this study showed that the plasma CGRP level was higher in the external jugular vein (JUG1 = 5.07pg/mL [SD = 1.99]) than in cubital vein (CUB1 = 4.3 pg/mL [SD = 1.6]).
• Findings revealed that after 30 days of the occlusal splint therapy the levels in both veins increased: JUG2 = 6.07 pg/mL (SD = 2.19), and CUB2 = 4.9 pg/mL (SD = 1.4).
• It was noted that the CGRP plasma level increase was statistically significant only in the external jugular vein (JUG) (p < 0.05).
• In addition, statistically significant pain intensity reduction was observed: VAS1 = 5.4 (SD = 2.08) decreased to VAS2 = 1.7 (SD = 2.07) after splint therapy (p < 0.05).