Koyuncu 2013.

Study characteristics
Methods	Study design: a randomised single‐blind clinical trial, parallel Conducted in: Turkey
Participants	Inclusion criteria: patients with no history of medical illness or medication that could influence the course of postoperative wound healing or alter their wound healing after surgery were selected Exclusion criteria: patients were excluded from randomisation if they had a pre‐existing abscess or cellulitis, acute pericoronitis, or pre‐existing conditions associated with their third molars. Those who required antibiotics for some other reason (such as prophylaxis for endocarditis) were also excluded, as were those who had been given radiotherapy. Immunocompromised patients, pregnant women, those already taking antimicrobials, and those with systemic diseases, such as diabetes, cancer, or renal failure, were excluded. Age: 18 to 29 Number randomised: 80 Number evaluated: 80
Interventions	Envelope flap type versus modified triangular flap type Group A (40 participants): envelope flap type Group B (40 participants): modified triangular flap type All operations were done under local anaesthesia (inferior alveolar block, 2 mL 2% lidocaine with 1:80,000 epinephrine). A primary wound closure was carried out in all cases. All participants were given amoxicillin (500 mg/8 h) for 7 days and diclofenac potassium (50 mg/12 h) for pain after surgery. Postoperative instructions for the participants included soft diet and oral hygiene with 0.2% chlorhexidine mouth rinse. Sutures were removed 7 days after surgery.
Outcomes	Primary outcome: any postoperative complication; alveolar osteitis classified as present or absent Secondary outcomes: postoperative side effects (including pain, swelling, and trismus assessed during the postoperative time periods) pain (0‐to‐10 VAS), daily for 7 days swelling (subjective and objective measurements). Subjective assessment was made of swelling on the second and seventh days after extraction, based on a 4‐point scale: 1 no swelling; 2 mild swelling; 3 moderate swelling; and 4 severe swelling. Objective measurement: 2 distances were measured by a modification of a tape‐measuring method on the second and seventh days after extraction. These 2 measurements were made between 3 reference points: tragus, pogonion, and the corner of the mouth. The preoperative sum of the 2 measurements was considered to be the baseline. trismus: maximum mouth opening was measured before surgery and again on the second and seventh days after extraction
Notes	This study was mentioned in the previous review update, but was not published at that time. Sample size calculation: not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "investigators designed and implemented a randomized single‐blind clinical trial. The flap design was randomly assigned for each patient" Comment: unclear how the participants were recruited and randomised
Allocation concealment (selection bias)	Unclear risk	Comment: concealment approaches were not described
Blinding (performance bias and detection bias) patient	Low risk	Comment: unclear as it was not described. However, it is unlikely that the participant would have known which flap they had unless they were explicitly told.
Blinding (performance bias and detection bias) assessor	Low risk	Quote: "The surgeon that had operated on the patients was never involved in the preoperative or postoperative assessment" Comment: assessor blinding was appropriate
Incomplete outcome data (attrition bias) All outcomes	Low risk	Comment: outcomes were reported for all participants (n = 80). 100 participants were initially recruited; the reason for the final number (80) was explained appropriately (they did not meet the inclusion criteria).
Selective reporting (reporting bias)	Low risk	All intended outcomes were reported.
Other bias	Low risk	No other sources of bias identified.