Four RCTs were included in the review (n=83, range 15 to 27). Study quality scores ranged from 7 to 9; there was inadequate allocation concealment in three studies, no blinding of the outcome assessor in one study, no blinding of the carer in four studies and more than 20% dropout in one study.
All four studies reported temporomandibular disorder pain reduction for both verum and sham acupuncture; compared to sham acupuncture, verum acupuncture yielded a statistically significant pain reduction based on VAS scores (three studies). There was limited evidence that stimulation of LI-4 alone reduced temporomandibular disorder pain (three studies). Two studies used specific local acupoints (ST-6 and ST-7) of which ST-7 produced statistically significant reductions of temporomandibular disorder pain (one study)