Şimşek Kaya 2019.

Study characteristics
Methods	Study design: split‐mouth RCT Conducted in: Turkey
Participants	Inclusion criteria: patients for surgical removal of bilaterally impacted mandibular third molars (with the ability to understand verbal and written instructions) were included in study. Additional inclusion criteria were American Society of Anesthesiologists (ASA) physical status class I (indicating a normally healthy patient), no medication use, asymptomatic bilateral symmetrically impacted mandibular third molars with mesioangular (Winter classification) 18 class II B impaction (Pell and Gregory classification) 19 and healthy dental and periodontal status with no local inflammation or pathology at the time of surgery. Exclusion criteria: patients with allergies or contraindications to the anaesthetics employed, with local inflammation or pathology in the oral cavity, with poor oral hygiene, ASA > 1, pregnant or lactating women, or women regularly using oral contraceptives were excluded Age: 18 to 40 years Number randomised: 30 Number evaluated: 30
Interventions	Envelope flap versus modified triangular flap techniques Group A: modified triangular flap techniques Group B: envelope flap A minimum of 1 month was allowed to elapse between the 2 procedures. In the postoperative period, amoxicillin (1000 mg, 2 x 1/day), ibuprofen (400 mg, 3 × 1/day), and 0.2% chlorhexidine gluconate (30 mL, 2 × 1/day) were prescribed to all participants for 5, 7, and 5 days, respectively.
Outcomes	Pain (0‐to‐10‐centimetre scale), swelling, trismus, alveolar osteitis (Blum's criteria), wound dehiscence
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "Treatment modalities for each patient were determined by a nurse not involved in the study using the lottery method"
Allocation concealment (selection bias)	Low risk	Quote: "The treatment allocation sequence was concealed using sequentially numbered, opaque, sealed envelopes. Allocation concealment was intended to prevent selection bias and to protect the assignment sequence until the first procedure." "The treatment allocation sequence was concealed using sequentially numbered, opaque, sealed envelopes. Allocation concealment was intended to prevent selection bias"
Blinding (performance bias and detection bias) patient	Unclear risk	Comment: it is not explicitly stated that the participants were blinded as to which intervention they received, but it seems unlikely that they would have been aware of the type of intervention
Blinding (performance bias and detection bias) assessor	Low risk	Quote: "One author, responsible for calculation and calibration and not involved in the selection and intervention of participants (GYY), performed all the measurements." Comment: of note, the authors state that the operator and dental assistant who performed the surgical intervention could not be blinded due to the nature of the interventions
Incomplete outcome data (attrition bias) All outcomes	Low risk	Comment: no withdrawal
Selective reporting (reporting bias)	Low risk	Comment: all prespecified outcomes were reported on
Other bias	Low risk	Comment: no other sources of bias identified

CAL: clinical attachment level; CHX: chlorhexidine; IDN: inferior dental nerve; IID: interincisal distance; IND: inferior dental nerve; IOPA: intra‐oral periapical; MMO: maximum mouth opening; OPG: orthopantomogram; PPD: probing pocket depth; PRF: platelet rich fibrin; RCT: randomised controlled trial; SD: standard deviation; TMD: temporomandibular disorder; rmp: revolutions per minute; VAS: visual analogue scale