Koyuncu 2015.

Study characteristics
Methods	Study design: prospective RCT, single‐blind, parallel Conducted in: Turkey
Participants	Inclusion criteria: bilateral vertically symmetrical impacted third molars on panoramic radiographs. All impacted mandibular third molars had to be in a comparable position bilaterally and carry the same degree of surgical difficulty requiring the same technique. All teeth were fully covered by mucosa and bone. All participants were non‐smokers, periodontally healthy, and well‐educated about their daily oral hygiene. Exclusion criteria: history of medical illness or medication that could influence the course of postoperative wound healing or alter wound healing after extraction. Also excluded were patients who had any pathological lesion in the area of the impacted third molar. The periods between the incision and insertion of the last suture were recorded, and if the operating time differed by more than 5 minutes between the 2 sides, the patient was withdrawn from the study. Age: 18 to 29 years Number randomised: 40 Number evaluated: 40
Interventions	Effect of tube drainage versus conventional suturing on postoperative discomfort after extraction Group experimental: a tube drain (n = 40 teeth): an infant feeding tube 3 cm long and 2.67 mm in diameter (8 Ch) (Bıc¸akcılar, Istanbul, Turkey) was inserted in the buccal incision line between the first and second molar. The tube drain was sutured to the vestibular mucosa to prevent it from coming out or becoming lost in the wound. Group B control: no drain (n = 40): a 3‐cornered mucoperiosteal flap was raised to expose the third molar. Bone was removed under constant irrigation with sterile 0.9% saline on the occlusal and buccal aspect of the third molar with rotating instruments of diminishing size. After extraction, potential nests of the dental follicle were removed. Primary wound closure with atraumatic silk sutures without tension (Medico Co. Ltd, China) was used on the side that had no drain.
Outcomes	Pain (VAS) from zero (no pain) to 10 (worst pain imaginable) daily for 7 days Degree of swelling (mm) at days 2 and 7 Maximum mouth opening at days 2 and 7 A quality of life questionnaire was used; all participants returned the questionnaires on day 7
Notes	Sample size calculation: not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "groups by random selection in a cross‐over pattern. The trial was randomised, prospective, and single‐blind." Comment: method of randomisation not described
Allocation concealment (selection bias)	Unclear risk	Comment: concealment methods not described
Blinding (performance bias and detection bias) patient	High risk	Comment: "a single blinded study". It is unlikely that participants could be blinded with this study design.
Blinding (performance bias and detection bias) assessor	Low risk	Quote: "The surgeon who had operated on the patients was not involved in either the preoperative or the postoperative assessment"
Incomplete outcome data (attrition bias) All outcomes	Low risk	Outcomes reported for all participants.
Selective reporting (reporting bias)	Low risk	All outcomes reported.
Other bias	Unclear risk	Carry‐over effect not evaluated.