Jamilian 2011.

Methods	Location: University of Islamic Azad and Shahid Beheshti, Tehran, Iran Number of centres: not specified Recruitment period: not stated Funding source: not stated Trial design: parallel group RCT
Participants	Inclusion criteria: ANB > 4°, SNB < 78° degrees, overjet ≥ 5 mm at the start of treatment, no syndromic or medically compromised patients, no previous surgical intervention, no use of other appliances before or during the period of functional treatment, a normal mandibular growth pattern: neither horizontal nor vertical, no skeletal asymmetry Age at baseline: R‐appliance group 10.5 (SD 0.7) years and Twin Block group 11.3 (SD 1.3) years Number randomised: 55 Number evaluated: 55 (no dropouts)
Interventions	Gp A (n = 30): R‐appliance ‒ Tooth‐ and tissue‐born functional appliance worn full time Gp B (n = 25): Twin Block appliance with upper labial bow worn full time
Outcomes	Skeletal measurements from cephalograms, occlusal changes
Notes	Duration of randomised treatment: R‐appliance 16.2 months (SD 0.3) months, Twin Block appliance 16.1 (SD 1.4) months Sample size calculation: not specified
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomised. "...patients were randomly divided to two groups using random number tables" (unpublished data)
Allocation concealment (selection bias)	Unclear risk	Allocation concealment not clearly described. "Specific codes were assigned to each patient for their concealment" (unpublished data)
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Outcome assessors were blinded (unpublished data). However, the method of blinding was not described.
Incomplete outcome data (attrition bias) All outcomes	Low risk	No dropouts
Selective reporting (reporting bias)	Low risk	All variables reported
Other bias	Low risk	No other bias detected