Table 5. Risk of bias in Howley et al. 2012.

Howley et al. 2012 9
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	An incisor in each pair was randomly assigned by a coin toss.
Allocation concealment (selection bias)	Low risk	Quote: An incisor in each pair was randomly assigned, by a coin toss to either the experimental group or the control group with the contralateral- paired incisor being designated to the other treatment group
Blinding of participants and personnel (performance bias)	Low risk	It is not possible to blind the operator and the participant blinding is ineffective on outcomes
Blinding of clinical outcomes assessment	unclear risk	Insufficient information to make a clear judgement
Blinding of radiological outcomes assessment	Low risk	Quote: The radiographs were evaluated independently by 2 standardized and calibrated examiners who were not otherwise involved in the study. It is not possible to blind the assessors due to the nature of treatment received.
Incomplete outcome data (attrition bias)	Low risk	29 study patients, 3 patients failed to return for follow-up.