Temporary anchorage devices and the forces and effects on the dentition and surrounding structures during orthodontic treatment: a scoping review

BACKGROUND: Temporary anchorage devices (TADs) offer the clinician an immediate temporary source of skeletal anchorage for a range of orthodontic interventions. It is important to understand forces involved in using TADs and the effects on the dentition and surrounding structures, to improve clinical outcomes. OBJECTIVE: To examine and qualitatively synthesize literature on the forces involved with the use of TADs and the effects on the dentition and surrounding structures in orthodontic tooth movement, to provide better understanding of the complex interactions and the clinical implications. SEARCH METHODS: Electronic databases searched included: Cochrane Library [including Central Register of Controlled Trials (CENTRAL)], Embase via OVID, Pubmed, and Scopus. Study screening and selection were conducted in duplicate. SELECTION CRITERIA: Studies selected were clinical studies, simulation studies (computer or laboratory-based), or animal studies with no restriction over gender, age, study type (excluding case reports), or setting. Studies focusing on the forces involved with the use of TADs in orthodontic treatment and their effects on the dentition and surrounding structures were included. DATA COLLECTION AND ANALYSIS: A data charting form was piloted and refined. Data charting was performed independently and in duplicate. This consisted of key fields with predetermined options and free text. The extracted data were collated, and a narrative synthesis conducted. RESULTS: The results from 203 included studies were grouped into seven TAD based interventions combining the clinical, simulation, and animal studies. They were: En masse retraction of anterior teeth, intrusion, movement of a single tooth, orthopaedic interventions, distalisation, maxillary expansion and other types. The forces involved with the use of TADs, and their effects on the dentition and surrounding structures, were presented in descriptive and tabular formats. LIMITATIONS: This review restricted study language to English. Formal appraisal of the quality of evidence is not a required feature of scoping reviews, as per the PRISMA-ScR guidelines, however it was evident that a proportion of clinical studies were of high risk of bias and low quality and therefore any proposed changes the reader may consider to their clinical practice should be contextualized in light of this. CONCLUSIONS: Across the seven types of TAD based interventions the effects on the dentition and surrounding structures are described providing a better understanding of the complex interactions. A guide to the level and direction of forces in each type of intervention is provided to aid clinicians in achieving high quality outcomes. IMPLICATIONS: There is a need to validate future FEA simulation studies by comparing to clinical data. It is also recommended that future scoping reviews incorporate a formal critical appraisal of studies to facilitate the translation of the results into clinical practice. Development of a standard set of terms for TADs is recommended to facilitate future research. REGISTRATION: Registration of a scoping review is not possible with PROSPERO FUNDING: None to declare.