Vattaraphudej 1986.

Methods	Randomised, parallel group, double blind study
Participants	83 enrolled to 4 groups, withdrawals unclear (16 from all groups) Number randomised to intervention: male 8, female 8 Number randomised to placebo: male 10, female 9 Number of third molars removed: mean for intervention 1.25, mean for placebo 1.32 Baseline pain intensity: mean for intervention 2.37, mean for placebo 2.26 Setting: Dept of Oral Surgery, Khon Kaen University, Thailand
Interventions	Paracetamol 650 mg versus placebo Formulation: capsules Anaesthesia not stated
Outcomes	PI at 4 hours: categorical scale 0‐3 (none ‐ severe) PR at 4 hours: categorical scale 0‐4 (no relief ‐ total relief) Global assessment: categorical scale 0‐3 (poor ‐ excellent) Adverse effects, none reported
Notes	Sponsored by Khon Kaen University, Thailand, Dr Sompong Thongpradith, Merck, and Russel
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment (selection bias)	Unclear risk	B ‐ Unclear

GA ‐ general anaesthetic, LA ‐ local anaesthetic, PI ‐ pain intensity, PR ‐ pain relief, SED ‐ sedation, TOTPAR ‐ total pain relief, VAS ‐ visual analogue scale