Mocan 1996.

Study characteristics
Methods	Study design: RCT (parallel) Conducted in: Department of Oral and Maxillofacial Surgery, University of Ankara, Turkey
Participants	Inclusion criteria: patients with third molars requiring extraction. A criterion for inclusion in the study was that the third molars should be either partially or fully covered by bone, and only unilateral cases were included. Exclusion criteria: patients with complicating systemic disorders were accepted (ASA I and II) Age: mean 21.5 years Number randomised: 20 Number evaluated: 20
Interventions	Chisel versus bur for bone removal Group A (n = 10): lingual split with chisel for bone removal Group B (n = 10): buccal approach with bur for bone removal All procedures performed under local anaesthesia. Follow‐up: day 7
Outcomes	Analytical stereometric photogrammetrical assessment of swelling, calliper measure of mouth opening, and VAS (0 to 10) self‐assessment of postoperative pain
Notes	Sample size calculation: not reported Baseline comparability: the lingual split group had 4 mesioangular impactions, 2 distoangular impactions, and 4 vertical impactions, whereas the buccal approach group had 3 mesioangular impactions, 0 distoangular impactions, and 7 vertical impactions E‐mail correspondence in 2003; unpublished data were unavailable
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "...the patients were divided randomly into groups" Comment: method of sequence generation not described
Allocation concealment (selection bias)	Unclear risk	Not mentioned
Blinding (performance bias and detection bias) patient	Unclear risk	Participants were not blinded.
Blinding (performance bias and detection bias) assessor	High risk	No mention of assessor blinding
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	No withdrawals mentioned, but numbers evaluated unclear.
Selective reporting (reporting bias)	High risk	Quote: "...no one experienced sensory impairment of the inferior alveolar or lingual nerves" Comment: it was not mentioned at the outset that sensory assessments were being made, and no method of assessment was described. Raw data and standard deviations not reported for primary outcomes and not supplied by authors.
Other bias	High risk	Very small sample size, with only 10 participants in each intervention group Different distribution of impactions in the 2 intervention groups at entry Unable to include in meta‐analysis as raw data not available in the paper or after author contact