Haraji 2010.

Study characteristics
Methods	Study design: split‐mouth RCT Conducted in: Iran Number of centres: 1 Recruitment period: not stated
Participants	Inclusion criteria: patients with bilaterally impacted third molars with similar difficulty index Exclusion criteria: pre‐existing medical conditions, oral contraceptive use, systemic or neurological conditions, pregnancy, pericoronitis or pathological conditions associated with third molars Age: mean 19.94 ± 1.5 years Number randomised: 17 Number evaluated: unclear
Interventions	Buccal envelope versus modified triangular flap Group  A (n = 17): buccal envelope flap Group  B (n = 17): modified triangular flap All participants received local anaesthetic, oral cefalexin 500 mg 6 hourly for 5 days, and 500 mg acetaminophen codeine postoperatively.
Outcomes	Alveolar osteitis and "healing scores"
Notes	Sample size calculation: not reported E‐mail sent to Dr.a.Haraji@Dentaliau.ir on 12 March 2012 requesting further information. No reply received.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "allocated randomly" Comment: method of sequence generation not described
Allocation concealment (selection bias)	Unclear risk	Not mentioned
Blinding (performance bias and detection bias) patient	Low risk	Double‐blinded
Blinding (performance bias and detection bias) assessor	Low risk	Double‐blinded. Paper does not state who conducted outcome assessment.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Outcomes reported as percentage only with no indication of how many participants were evaluated.
Selective reporting (reporting bias)	High risk	Alveolar osteitis reported as percentage in each group and P value, no indication if paired data taken into account in analysis. Suggestion that a number of participants had bilateral osteitis. Pain and healing not reported.
Other bias	Unclear risk	41.7% control group rate of alveolar osteitis is very high, and it seems unlikely that a different flap design would have been solely responsible for the lower rate in the intervention group. Co‐intervention or aseptic conditions for surgery