Eissa 2017.
| Methods | Location: Tanta, Egypt Number of centres: 1 Recruitment period: not reported Funding source: not reported Trial design: parallel group RCT |
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| Participants | Inclusion criteria: skeletal Class II malocclusion with mandibular retrognathia (ANB > 4.5, SNB > 76); normal vertical growth pattern (SN‐MP angle in 258 to 358 range); minimal or no crowding in the mandibular arch (0 to 5 mm), based on Little’s irregularity index; no extracted or missing permanent teeth (third molars excluded); undergoing circumpubertal phase of skeletal development (CVMI 2 to 4); no medical history or systemic disease that could affect normal growth of the body or jaws. Exclusion criteria: not reported Age at baseline: Gp 1: 12.76 (SD 1.0); Gp 2: 12.52 (SD 1.12); Gp 3: 12.82 (SD 0.9) Number randomised: 45 Number evaluated: 38 |
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| Interventions | Gp 1: conventional FRD Gp 2: miniscrew‐anchored FRD Gp 3: untreated control |
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| Outcomes | All cephalometric variables, success rate for screws and harms | |
| Notes | "Sample size calculation was based on the ability to detect a clinically meaningful difference in mandibular length of 2 mm (6 1.5 mm), with an alpha error of 0.05 and a test power of 80%. The calculation was carried out using software G* Power (Universitat Dusseldorf, Germany). The recommended sample size was 12 patients in each group. To compensate for a possible dropout rate of 20% during the study period, 15 patients were included in each group." | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | "Patients were randomly assigned using a computer generated random list." |
| Allocation concealment (selection bias) | Low risk | "The patients were randomly allocated into three groups using sequentially numbered, opaque, sealed envelopes." |
| Blinding of outcome assessment (detection bias) All outcomes | Unclear risk | "...the investigator who analyzed the cephalograms was blinded regarding the origin of the films and the group to which the individual subjects belonged. All data were labeled with numbers and sent to the statistician, who was also blinded to the patients’ groups. For the control group, it was impossible to be completely blinded as there were no appliances in the patients’ mouths, but blinding was achieved regarding the time point of the cephalograms." |
| Incomplete outcome data (attrition bias) All outcomes | Unclear risk | Gp 1: recruited 15, analysed 14 Gp 2: recruited 15, analysed 15 Gp 3: recruited 15, analysed 9 Uneven dropout rate between groups |
| Selective reporting (reporting bias) | Low risk | All variables reported |
| Other bias | Low risk | No other source of bias identified |