| Methods |
Trial design: single‐centre RCT (4 parallel groups) Location: Gävleborg County Council, orthodontic clinic, public dental service Recruitment period: 2 years, 2 months Funding source: The Centre for Research and Development, Uppsala University, Uppsala, and Gävleborg County Council, Gävle, Sweden; the Swedish Dental Society; and the Faculty of Odontology, Malmö University, Malmö, Sweden Source of participants: patients attending clinic Study duration: not stated Time points at which follow‐up are reported: from start of treatment to the end of levelling and alignment, from the end of levelling and alignment to the end of space closure, from the start of treatment to the end of space closure |
| Participants |
120 participants in total, mean age 14.3 years 30 in Nobel Biocare onplant group: mean age 14.0 years (SD 1.53); 15 males, 15 females 30 in Orthosystem implant group: mean age 14.6 years (SD 1.99); 15 males, 15 females 30 in headgear group: mean age 14.0 years (SD 1.72); 15 males, 15 females 30 in the transpalatal arch group: mean age 14.4 years (SD 1.65); 15 males, 15 females
healthy, non‐smoking adolescents no previous orthodontic treatment permanent dentition, no transverse discrepancies treatment plan involves extraction of at least 2 upper premolars upper and lower fixed appliances required require additional form of anchorage on upper 6's
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| Interventions |
7.7 mm, placed near the palatal midline Loaded after 16 weeks with a 1.3 mm transpalatal arch connected to maxillary first molars
3.3 mm x 4 mm Loaded after 16 weeks with a 1‐2 mm transpalatal arch connected to maxillary first molars
Attached to maxillary first molars Medium pull with a duration of 10‐12 hours/day and 400 gm force level Checked every 6 weeks
2.0 x 1.0 mm Attached to maxillary first molars
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| Outcomes |
‐ measured in mm on cephalometric radiographs using Bjork and Pancherz analyses
‐ measured at the end of levelling and alignment (start of space closure) and at the end of space closure (including and excluding the levelling and alignment phase)
‐ data included in this review were from the end of space closure excluding the levelling and alignment phase
Success of anchorage device (successful anchorage comprises anchorage loss of less than 1 mm, no failures of osseointegration or failures during anchorage system placement, and no drop‐outs after the treatment started) Pain and discomfort associated with insertion of anchorage device:
‐ comparisons were made between Nobel Biocare onplants, Orthosystem mid‐palatal implants and conventional anchorage (headgear and palatal arches combined)
‐ self reported on a VAS from 0 to 100 where 'no pain/discomfort' and 'worst imaginable pain/discomfort' were the endpoints of the scale
‐ assessed at 4 time points, during the anaesthetic injection, during surgery/extractions, the evening after surgery/extractions and 1 week after surgery
‐ pain in the first 2 groups was related to mid‐palatal implant placement and in the third group related to premolar extractions
‐ daily activities included leisure time, speech, ability to take a big bite, ability to chew hard and soft food, the ability to chew against resistance, schoolwork, drinking, laughing, yawning, kissing, in addition to how the orthodontic treatment affected mood and appearance
‐ comparisons were made between the surgical anchorage group (Nobel Biocare onplants and Orthosystem implants combined), headgear and palatal arches
‐ self reported on a VAS from 0 to 100, or a 4‐point scale
‐ there were multiple time points; at the start of treatment, each day for a week after the start of treatment, 6 weeks into treatment, after levelling and alignment, after space closure, and 6 weeks into retention |
| Notes |
Participants were treated by 2 orthodontists in a county council setting in Sweden A straight‐wire appliance with an MBT prescription and a 0.022 slot was used Other cephalometric variables were reported that are not related to this review |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
Low risk |
Quote: "The allocation sequence was computer generated by a statistician at..."
Quote: "the patients were randomised in blocks of 4 and stratified by sex into 1 of 4 groups" |
| Allocation concealment (selection bias) |
Unclear risk |
Quote: "The allocation sequence was ..., and concealed in envelopes until randomization"
Comment: not stated whether envelopes were opaque and sequentially numbered |
| Blinding of outcome assessment (detection bias)
All outcomes |
High risk |
Outcome assessment was not blinded because the appliances were visible on the radiographs |
| Incomplete outcome data (attrition bias)
mesial movement of upper first maxillary molar |
Low risk |
At the end of space closure the following drop‐outs were reported:
Nobel Biocare onplant group: 25 out of 30 randomised patients were included in the analysis because 1 patient moved away before the commencement of treatment, 1 implant failed to osseointegrate, 2 implants were incorrectly positioned and 1 patient had poor oral hygiene Orthosystem implant group: 29 out of 30 randomised patients were analysed because 1 implant failed to osseointegrate Headgear group: all randomised patients were included in the analysis Transpalatal bar group: 29 out of 30 randomised patients were included in the analysis because 1 patient had severe illness and dropped out before commencement of treatment
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| Selective reporting (reporting bias) |
Unclear risk |
|
| Other bias |
High risk |
Fixed size blocks were used in a single‐centre unblinded trial. This may make it possible to predict future assignments |
