| Study | Reason for exclusion |
|---|---|
| Abu‐Serriah 2004 | Most study participants had both maxillary and mandibular third molars extracted in the same procedure. Also, bur group participants were irrigated with saline and those in the laser group were irrigated with water. This was thought to be a confounding factor. |
| Afat 2018 | Not a surgical technique |
| Akota 1998 | Surgical drain used in 1 group was coated with chlortetracycline ointment. It was thought that the antibiotic confounded the effect of the drain. |
| Al‐Moraissi 2016 | It is a review not an RCT. |
| Alqahtani 2017 | No data could be used from this study. |
| Ayad 1995 | Unclear study design ‐ both parallel‐group and split‐mouth study. Also, wisdom teeth in the maxilla were included. |
| Bilginaylar 2016 | Ineligible trial design |
| Cetinkaya 2009 | Primary outcome measures of this review not reported. Trial looks at effects on periodontal disease. |
| Chang 2015 | Ineligible surgical technique |
| Chen 2016 | Ineligible outcomes |
| Chossegros 2002 | Study describes germectomy not extraction of third molars. |
| Clauser 1994 | Not all participants had incision and flap raised. Some third molars were removed using an elevator. |
| Cortell‐Ballester 2015 | Ineligible outcomes |
| de Carvalho 2015 | Ineligible outcomes |
| Desai 2014 | Ineligible outcomes |
| Ding 2000 | No mention of incision or flap being raised |
| Dubois 1982 | Split‐mouth trial, but allocation of 1 side of face to treatment was not randomised |
| Dutta 2015 | Ineligible outcomes |
| Egbor 2014 | The use of white head varnish is not a surgical technique. |
| Elo 2016 | Data could not be used as there were no raw data. |
| Eshghpour 2018 | Not a surgical technique |
| Finne 1981 | Study describes germectomy not extraction of third molars. |
| Gao 2011 | Ineligible outcomes |
| Gawai 2015 | Not an RCT |
| Gay‐Escoda 2015 | Data presented in graph/figures only. |
| Gazivoda 2015 | Ineligible comparison ‐ synthetic suture materials |
| Genu 2008 | Unclear whether study was truly randomised; appeared to have 2 interventions, and there was confounding of the effects. Unable to contact authors to obtain further information |
| Gonzalez 2001 | Abstract only; insufficient information to include. No subsequent publication identified. |
| Goyal 2012 | Allocation by alternation |
| Guo 2012 | Not an RCT |
| He 2015 | Not available in English. Study was sent to a translator, but insufficient data or information to make an assessment. We contacted the study authors but received no reply. |
| Holland 1984 | Comparison is between 2 types of wound closure, but 1 incision also had a dressing, which acted as a confounder. |
| Jain 2016 | Ineligible technique |
| Jakse 2002 | Not an RCT |
| Jiang 2015 | A review, not an RCT |
| Kerdvongbundit 1989 | Unable to locate a copy of this paper. There is no abstract, and based on title it is unclear whether this was a randomised trial. |
| Korkmaz 2015 | Inappropriate techniques |
| Li 2012 | Systematic review |
| Li 2014 | Ineligible techniques; we contacted the authors but received no reply. |
| Ma 2015 | Ineligible outcomes |
| Martin 2015 | Systematic review |
| Mavrodi 2015 | Inappropriate techniques |
| Oyri 2016 | Not an RCT |
| Quee 1985 | Trial of the effect of flap design on subsequent periodontal health. Not relevant to this review |
| Robinson 1996 | The study compared removal of wisdom teeth with or without lingual flap retraction. Prior to operation the operator was aware of allocation. The authors found significant differences in the grades of surgical difficulty between the 2 groups. On investigation some of the operators had deviated from the protocol. In an unknown number of easier surgical cases, the lingual flap was not raised when it should have been. We are unable to quantify the bias caused by this protocol violation. |
| Rosa 2002 | Not an RCT |
| Sala‐Perez 2016 | Ineligible techniques |
| Salentijn 2011 | Ineligible techniques |
| Sener 2015 | Not evaluating a surgical technique |
| Shevel 2001 | This study included both mandibular and maxillary molar teeth. The removal of the maxillary teeth may affect pain and swelling, so we could not use the data for the mandibular teeth. |
| Sivolella 2011 | Study describes germectomy not extraction of third molars. |
| Smith 2000 | Not an RCT |
| Sortino 2008 | Not an RCT |
| Strukmeier 1980 | Probably not RCT after translation from German |
| Suarez‐Cunqueiro 2003 | This study is confounded by the surgical removal of unerupted maxillary third molars. |
| Suddhasthira 1991 | Paper in Thai language. Sent to translator. Not an RCT |
| Sun 2009 | Not available in English |
| Sweet 1978 | Contradiction on state of teeth. They are described as all being impacted, and then some are described as being erupted. We are also unsure whether the same surgical technique was used bilaterally. |
| Tabrizi 2014 | Ineligible techniques |
| Tan 2015 | Ineligible techniques |
| Torres‐Lagares 2006a | Ineligible techniques |
| Torres‐Lagares 2006b | Intervention is postsurgical use of chlorhexidine gel to prevent infection. Not a surgical intervention |
| Tuffin 1990 | Design fault. This study compared irrigation of the socket at the end of surgery with bupivacaine versus no irrigation. Apart from the planned interventions, the participants were also treated by chisel or drill technique, with 16 treated by drill but only 1 of them in the control group and the other 15 being in the treatment group. We felt this could be a confounding factor. |
| Yang 2015 | Ineligible techniques |
| Yolcu 2015 | Ineligible techniques |
| Zhang 1997 | No mention of incision or flap being raised |
| Zhou 2016 | Ineligible intervention |
RCT: randomised controlled trial