Methods	Randomised, double-blind, placebo-controlled, parallel-group, not enriched. No imputation method mentioned Titration to adequate pain relief, limit of tolerability or 4200 mg daily, then stable dose for remainder of 12-week study
Participants	Chronic masticatory myalgia (pain classification based on defined criteria) lasting ≥ 6 months, not resulting from trauma or active inflammatory cause. N = 50, mean age 34 years, 100% women. PI at randomisation ≥ 50/100, initial average daily pain score 6. 2/10
Interventions	Gabapentin 4200 mg daily (max), n = 25 Placebo, n = 25 Stable doses of antidepressants continued Paracetamol (max 4000 mg daily) allowed as rescue medication
Outcomes	≥ 30% reduction in pain Adverse events Withdrawals
Notes	Oxford Quality Score: R = 2, DB = 2, W = 1, Total = 5 Note: withdrawals > 10%
Risk of bias
Item	Authors’ judgement	Description
Allocation concealment?	Yes	“concealed randomization and the according allocation were implemented by a research assistant” (not involved with patients or investigators)
Blinding? All outcomes	Yes	“identical looking capsules … packaged in identical clear bottles”
Incomplete outcome data addressed? Efficacy	Unclear	Imputation not mentioned
Size Efficacy	Unclear	50 randomised
Study duration Efficacy	Yes	12 weeks
Outcomes reported	Unclear	Pain reduction of 30% or more