Mohajerani 2018.

Study characteristics
Methods	Study design: split‐mouth RCT Conducted in: Iran, 2016
Participants	Inclusion criteria: adult patients had indication of impacted wisdom molar removal Exclusion criteria: patients were excluded from the study if any of following conditions were observed Presence of periapical acute or chronic inflammation Presence of systemic problems Pregnancy Emergence of a special problem during surgery Follow‐up missing during re‐examination Presence of prescription for not using any particular flap Presence of neurological diseases Unreliable patients Age: mean 20.1 years (between 17 and 24 years) Number randomised: 31 Number evaluated: 28
Interventions	Envelope flap versus modified triangular flap Group A (n = 28 sites): envelope flap Group B (n = 28 sites): modified triangular flap All procedures performed under local anaesthesia. All participants were given amoxicillin (500 mg/8 hours) for 7 days and codeine/paracetamol (10 mg/325 mg) every 6 hours for pain relief.
Outcomes	Alveolar osteitis; healing degree
Notes	3 participants were excluded due to poor co‐operation with follow‐up.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Comment: the method of randomisation is unspecified
Allocation concealment (selection bias)	Unclear risk	Comment: the method of allocation concealment is unclear
Blinding (performance bias and detection bias) patient	Low risk	Participants were unlikely to know the differences between procedures.
Blinding (performance bias and detection bias) assessor	Low risk	Comment: study is double‐blinded. The surgeon informed the examiner (evaluator) only about the area of surgery and the code of the treatment group designated to that side, and the patient and evaluator were not aware of which side had EF.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Comment: 3 participants were excluded by the research team because of their poor co‐operation
Selective reporting (reporting bias)	Low risk	All planned outcomes were reported.
Other bias	Low risk	It seems that both surgeries were done on the same day; however, pain and trismus were not considered.