Praveen 2007.

Study characteristics
Methods	Study design: parallel‐group RCT Conducted in: India Number of centres: 1 Recruitment period: not stated
Participants	Inclusion criteria: healthy patients with symptomatic impacted mandibular third molars Exclusion criteria: not explicitly stated Number randomised: 90 Number evaluated: unclear
Interventions	Lingual split with chisel versus surgical bur versus simplified split bone technique Group A (n = 30): lingual split, bone removed with a 5‐millimetre mono bevelled chisel Group B (n = 30): bone removal with 702 bur at 15,000 rpm Group C (n = 30): "Simplified split bone technique" using chisel from buccal aspect "The lingual nerve was protected by a Howarth's periosteal elevator in all cases." All procedures performed under local anaesthetic.
Outcomes	Pain, swelling, and sensory disturbances recorded at 6, 24, and 48 hours and on day 7 using VAS
Notes	Sample size calculation: not reported E‐mail sent to Dr Rajesh (rajeshomfs@gmail.com) seeking clarifications on 28 February 2012. No reply received.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "The methods for a particular patient were selected randomly" Comment: method of sequence generation not described
Allocation concealment (selection bias)	Unclear risk	Not mentioned
Blinding (performance bias and detection bias) patient	Unclear risk	Not mentioned
Blinding (performance bias and detection bias) assessor	High risk	Not mentioned
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Unclear how many extractions are included in the reported outcomes
Selective reporting (reporting bias)	Unclear risk	There appear to be omissions and errors in the reported data, where different aspects are contradictory.
Other bias	Low risk	No other sources of bias identified.