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

Abstract

Summary 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.

Uprighting horizontally impacted third molars by super-elastic nickel-titanium wire in patients with an extracted first molar

“…Su-Jung reported the placement of two 2 mini-screws with slots that could accommodate rectangular orthodontic wires to push the horizontally impacted teeth backwards to upright tilted molars [18]. However, we must consider the risk of placing the mini-screw between the first and second premolars; furthermore, the overall failure rate is 24.2% for TADs [23]. The light forces in our biomechanical system minimized the anchorage burden on the teeth before the third molars.…”

How Effective Are the Nance Appliance and Transpalatal Arch at Reinforcing Anchorage in Extraction Cases?

“…Comfort and adaptability to the appliance are significant, as both devices may cause initial discomfort due to their positioning close to the palatal tissues. The acrylic button of the NPA may sometimes lead to tissue irritation, inflammation, or even tissue necrosis in sensitive patients, requiring vigilant monitoring and potential removal if complications arise [ 27 ]. The TPA, on the other hand, is generally more comfortable, but maintaining proper hygiene is important to prevent plaque accumulation around the wire.…”

“…Moyers [2] emphasized that strong anchorage control reduces treatment time by minimizing unintended corrections, thereby improving patient comfort and satisfaction. Different methods to minimize undesired tooth movements have been proposed, including incorporating multiple teeth [7,8], the use of headgear [9][10][11][12], protraction face masks [13][14][15], transpalatal arch (TPA) [16][17][18], Nance buttons [19][20][21], lingual arch [22][23][24], elastics [25], or buccal or palatal skeletal anchorage [26][27][28].…”

The Surgical Guides for TADs: The Rational and Laboratory Procedures

“…Placement typically occurs at a speed of 25 Rpm, while drilling occurs at 800 Rpm with water irrigation [37]. It is better to load immediately rather than waiting for weeks and leaving it unloaded [38,39]. 5.…”

“…1. In the maxilla, CBCT is used to look for the ideal places and the palatal sites in the T-zone, as described by Wilmes [39]. The system's benefit is two screws being used to connect a plate to make it a sturdy anchorage for 3D movement of the upper teeth.…”