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. 2014 Aug 19;2014(8):CD005098. doi: 10.1002/14651858.CD005098.pub3

Shi 2008.

Methods

  • Trial design: single‐centre RCT (parallel group)

  • Location: Department of Orthodontics, Second Hospital of Hebei Medical University, China

  • 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: before and after treatment
Participants

  • Patients with severe maxillary or bimaxillary protrusion

  • 20 participants in total (14 females, 6 males), 15‐27 years old, mean age 20.7 years

  • 10 in mini‐implant group

  • 10 in the conventional anchorage group

  • Inclusion criteria:

  1. maxillary or bimaxillary protrusion

  2. extraction of the upper and lower first premolars, or the upper first premolars and lower second premolars
Interventions

  • Comparison 1: Mini‐screw implants

  1. 1.5 mm diameter, 8 mm length

  2. Positioned in the buccal alveolar crest between upper first molar and second premolar

  3. Loaded by a force of 150 g on each side, every 4 weeks

  • Comparison 2: Conventional anchorage

  1. Consisting of headgear and transpalatal arches
Outcomes Molar mesiodistal movement on lateral cephalometric radiographs; U6‐PTV (distance from mesiobuccal apex of the upper first molar to PTV)
Notes The full text article is in Chinese; this information was obtained from a translation of the article
Risk of bias
Bias Authors' judgement Support for judgement
Random sequence generation (selection bias) Unclear risk 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 There were 2 drop‐outs in the mini‐screw implant group; due to loss of implants
Selective reporting (reporting bias) Unclear risk

  • Selective reporting of outcomes: anchorage loss was not an objective of this study; however it would have been an expected outcome in this type of study

  • Selective reporting of data: no suggestion of selective reporting
Other bias Low risk Study appears to be free of other sources of bias