Study	Reason for exclusion
Adame 1979	Title not in journal quoted, unable to find paper.
Barden J 2004	Meta‐analysis, dental papers included individually where appropriate.
Becker 1990	Not a third molar study.
Bentley 1987	Unable to extract data for third molars only, written to authors.
Breivik 1998	Dose given at 3 hours postoperatively regardless of baseline pain, unable to get 4‐hour data. Study used for side effects only.
Cooper 1986	Unable to extract third molar data, written to authors.
Cooper 1989	Unable to extract third molar data, written to authors.
Cooper 1991	Unclear if third molars only, written to authors.
Dionne 1983 (1)	Not single dose, administered preoperatively.
Dionne 1983 (2)	Not placebo controlled, not single dose, administered preoperatively.
Dionne 1986	Not placebo controlled.
Dolci 1993	The data for the participants in this study are duplicated in Dolci 1994.
Edwards 2002	This was a meta‐analysis. Need to identify source of data to clarify whether third molar studies, and exclude duplication. Written to authors.
Forbes 1982	Unable to extract third molar data, written to author.s
Forbes 1984a	Not third molar study.
Gallardo 1990	Not third molar study (periodontal surgery).
Gustafsson 1983	Patients given either paracetamol preoperatively and placebo postoperatively or vice versa, unable to extract relevant data.
Haanaes 1986	Not placebo controlled. Study used for side effects only.
Irvine 1982	Not placebo controlled.
Laska 1983	Not placebo controlled.
Lecointre 1991	Not placebo controlled.
Liashek 1987	Multiple doses, unable to extract single dose data.
Macleod 2002	Not placebo controlled.
Medve 2001	Only 8‐hour SPID and TOTPAR available, need 4‐hour and/or 6‐hour to include in review, written to authors.
Mehlisch 1984	Unable to extract third molar data, written to authors.
Mehlisch 1990	Unable to extract third molar data.
Moore 1986	Multiple doses given, unable to extract single dose data.
Nystrom 1988	Not placebo controlled.
Petersen 1983	Unable to locate complete article.
Quiding 1981	Not placebo controlled.
Quiding 1982 (1)	Not placebo controlled.
Quiding 1982 (2)	Not placebo controlled.
Quiding 1984	No placebo used.
Ragot 1991	Not placebo controlled.
Reijntjes 1987	Not placebo controlled.
Rodrigo 1987	Mixed parallel and cross‐over trial, multiple doses, unable to extract relevant data.
Rodrigo 1989	Not placebo controlled.
Rosen 1985	Not placebo controlled, multiple doses used, unable to extract single dose data.
Sakata 1989	Unable to obtain study.
Selcuk 1996	Not placebo controlled.
Seymour 1981	Cross‐over trial, baseline pain not stated, unable to extract relevant data.
Seymour 1983	Acetaminophen administered intravenously.
Skjelbred 1979	Multiple doses, unable to extract single dose data.
Strom 1990	Not placebo controlled.
Van Aken 2004	Propacetamol administered intravenously.
Winter 1983	Unable to extract third molar data, written to authors.

SPID ‐ summed pain intensity difference, TOTPAR ‐ total pain relief