Fig 1.
The CONSORT flow diagram.
Fig 2.
At 0 minutes hypertonic saline is injected into the masseter muscle, every fifth minute PPT is assessed for 30 minutes, then this is repeated after intake of either white, milk, or dark chocolate, in healthy age-matched men and women (15 of each). DC/TMD = Diagnostic Criteria for Temporomandibular Disorders. VAS = Visual Analogue Scale (0–100). PPT = Pressure Pain Threshold.
Table 1.
Baseline demographic status of 15 healthy, pain-free women and 15 healthy, pain-free age-matched men, i.e. before injection of any of the substances.
Fig 3.
The mean (SEM) changes in experimentally induced pain intensity (VAS; visual analogue scale), by hypertonic saline injections, compared with baseline (BL) before and after intake of white, milk, and dark chocolate in 30 healthy, pain-free participants (A) and divided by sex into 15 women and 15 age-matched men (B-D). Assessments displayed were made every 15th s beginning immediately after injection up to 300 s after injection. The changes in pain intensity are presented both for the entire group and for the sexes separately. *Significant difference compared to baseline after intake of white chocolate (Tukey test, p<0.05). #Significant difference compared to baseline after intake of milk chocolate (Tukey test, p<0.05). §Significant difference compared to baseline after intake of dark chocolate (Tukey test, p<0.05).
Fig 4.
Changes in pressure pain threshold.
The mean (SEM) percentage changes in pressure pain threshold (PPT; kPa), by hypertonic saline injections, compared with the baseline (BL) before and after intake of white, milk, and dark chocolate in 30 healthy, pain-free participants (A) and divided by sex into 15 women and 15 age-matched men (B-D). Assessments displayed were made every 15th s beginning immediately after injection up to 300 s after injection. The changes in pain intensity are presented both for the entire group and for the sexes separately. *Significant difference compared to baseline after intake of white chocolate (Tukey test, p<0.05). #Significant difference compared to baseline after intake of milk chocolate (Tukey test, p<0.05). §Significant difference compared to baseline after intake of dark chocolate (Tukey test, p<0.05).