| Methods |
Trial design: single‐centre RCT (parallel group) Location: Orthodontic Department at Yonsei University Dental Hospital, South Korea Recruitment period: not stated Funding source: not stated Source of participants: patients attending clinic Study duration: not stated Time points at which follow‐up are reported: T0: before retraction of the anterior segment, T1: after retraction (end of space closure) |
| Participants |
25 participants in total 12 in single mini‐screw implant group: mean age 23.58 years (SD 6.92), 1 male, 11 female 13 in dual mini‐screw implant group: mean age 22.92 (SD 7.1), 2 male, 11 female
adult individuals with normal or mild skeletal Class II skeletal relationship no significant craniofacial defects or asymmetries intact maxillary permanent dentition including second molars moderate Class II occlusion minimal crowding (< 3 mm) in the maxilla
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| Interventions |
7.0 mm in length, 1.8 mm in coronal diameter, and with a tapered body (Orlus 18107, Ortholution, Seoul, Korea) Inserted between the maxillary second premolar and first molar
7.0 mm in length, 1.8 mm in coronal diameter, and with a tapered body (Orlus 18107, Ortholution, Seoul, Korea) Inserted between the maxillary second premolars and first molars Additional mini‐screws were placed between the maxillary first and second premolars
|
| Outcomes |
Distal movement in mm was measured on lateral cephalometric radiographs: perpendicular from the VR (a line perpendicular to the occlusal plane) to the distal cusp tip of the upper first molar; differences between T0 (before canine retraction) and T1 (after canine retraction) were calculated Duration of treatment in months from start of canine retraction to the end of canine retraction |
| Notes |
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| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
Unclear risk |
Quote: "Subjects were randomly allocated to either group A …. or group B"
Comment: insufficient information about the sequence generation process to permit judgement |
| Allocation concealment (selection bias) |
Unclear risk |
Not addressed |
| Blinding of outcome assessment (detection bias)
All outcomes |
Unclear risk |
Not addressed |
| Incomplete outcome data (attrition bias)
mesial movement of upper first maxillary molar |
Low risk |
All randomised patients were accounted for |
| Selective reporting (reporting bias) |
Unclear risk |
Selective reporting of outcomes: insufficient information to permit judgement, (no protocol) Selective reporting of data: no suggestion of incomplete reporting of data |
| Other bias |
Low risk |
Study appears to be free of other sources of bias |
