Background and objectives:The control of anchorage is integral to successful orthodontic treatment. The objective of this research was to undertake three related projects to evaluate methods of increasing anchorage with the aim of adding to orthodontic knowledge and improve methods of treatment delivery. Methods:Two Cochrane systematic reviews were undertaken according to the methods published in the Cochrane Handbook for Systematic Reviews of Interventions, version 5.1.0. The influence of functional appliances on tooth position and the extraction decision was performed as a retrospective study using participants from a completed multicentre randomized trial.Results: 1- Statistically and clinically significant differences were found between the mean values of distal molar movement when surgical anchorage and conventional anchorage were compared.2- Statistically significant differences were found between the mean values of distal molar movement and mesial upper incisor movement when intraoral distalising appliances and cervical headgear were compared.3- Fixed and removable functional appliances are equally effective in anchorage preparation. The type of functional appliance and time spent in Phase I treatment influenced the amount of lower incisor proclination. Conclusions:1- Surgical anchorage is more effective than headgear without the inherent risks and compliance issues. However, intraoral appliances used in adolescence for distalisation of upper molars do not appear to have any advantages over cervical headgear.2- Functional appliances reduce the anchorage requirements of a case primarily by reduction of the overjet, both fixed and removable functional appliances are equally effective in obtaining this. However, fixed functional appliances result in greater lower incisor proclination than removable functional appliances. 3- The type of functional appliance (removable or fixed) does not influence the extraction decision, however, this is influenced by overall space requirements.