Abstract: Fourteen new studies were added in this update resulting in a total of 15 studies reporting data from 561 randomised patients. The studies were conducted in Europe, India, China, South Korea and the USA. The age range of patients was commonly restricted to adolescents or young adults, however the participants of two studies were from a much wider age range (12 to 54 years). The distribution of males and females was similar in eight of the studies, with a predominance of female patients in seven studies. Eight studies were assessed to be at high overall risk of bias; six studies at unclear risk of bias; one study at low risk of bias. Ten studies with 407 randomised and 390 analysed patients compared surgical anchorage with conventional anchorage for the primary outcome of mesiodistal movement of upper first molars. We carried out a random-effects model meta-analysis for the seven studies that fully reported this outcome. There was strong evidence of an effect of surgical anchorage on this outcome. Compared with conventional anchorage, surgical anchorage was more effective in the reinforcement of anchorage by 1.68 mm (95% confidence interval (CI) -2.27 mm to -1.09 mm; seven studies, 308 participants analysed) with moderate quality of evidence (one study at high overall risk of bias, five studies at unclear risk of bias, one study at low risk of bias). This result should be interpreted with some caution, however, as there was a substantial degree of heterogeneity for this comparison. There was no evidence of a difference in overall duration of treatment between surgical and conventional anchorage (-0.15 years; 95% CI -0.37 years to 0.07 years; three studies, 111 analysed patients) with low quality of evidence (one study at high overall risk of bias and two studies at unclear risk of bias). Information on patient-reported outcomes such as pain and acceptability was limited and inconclusive. When direct comparisons were made between two types of surgical anchorage, there was a lack of evidence to suggest that any one technique was better than another. No included studies reported adverse effects. There is moderate quality evidence that reinforcement of anchorage is more effective with surgical anchorage than conventional anchorage, and that results from mini-screw implants are particularly promising. While surgical anchorage is not associated with the inherent risks and compliance issues related to extraoral headgear, none of the included studies reported on harms of surgical or conventional anchorage.

Plain-language summary: The evidence on which this review is based was correct as of 28 October 2013. This is an update to an existing review, which included one study. Fifteen studies were included in this review involving data from 561 participants. The studies were conducted in Europe, India, China, South Korea and the USA. Most took place in university settings or training hospitals and one in a specialist orthodontic practice. Most studies contained a similar number of males and females, however there were more females than males in five studies and only females in two. The age range varied from adolescents and young adults to adults up to the age of 54 years. All participants in the studies needed a course of orthodontic treatment with additional anchorage control. None of the studies reported adverse effects. When surgically implanted anchorage devices were compared to conventional anchorage devices, they were better in providing stabilisation for preventing unwanted movement in teeth during orthodontic treatment. There was limited information on patient-reported outcomes such as pain and how acceptable the devices were found to be. No information was reported on adverse events. The quality of the evidence for the important outcomes in this review ranged from moderate to low quality. The main shortcomings of all of the studies were related to issues with their design and the way they were carried out, with insufficient and low quality reporting of the study methods and outcomes.