Success rates and factors associated with failure of temporary anchorage devices: A prospective clinical trial

The Orthodontic Mini-Implants Failures Based on Patient Outcomes: Systematic Review

Anchorage is a challenge and essential issue for an orthodontist in determining the success of orthodontic treatment. Orthodontic anchorage is defined as resistance to unwanted tooth movement. Mini-implant is one of the devices that can be used as an anchor in orthodontic treatment. Many cases have reported successful treatment using mini-implant, but there are cases where mini-implants may fail. Failure of mini-implants can affect orthodontic treatment, and it is known that several factors may lead to mini-implant loss in orthodontic treatment. This systematic review aimed to determine the factors influencing mini-implant failure in orthodontic treatment. Articles were selected from electronic databases (PubMed, Google Scholar, The Cochrane Library, ScienceDirect) from January 2015 until 2023 according to the PRISMA method (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) under the PEOS (Population-Exposure-Outcome-StudyType) framework questions for systematic review. The study was registered in the International Prospective Register of Systematic Reviews (PROSPERO) database (CRD42022337684). All data collected were in English, and filtering was done by eliminating duplicate data, meta-analysis, case reports, case series, mini-reviews, and animal studies. The analysis was further divided into three groups, that is, patient-related, implant-related, and operator-related and operator-related (A graphical abstract provided as a Supplementary information [available in the online version]). Twenty-one articles were identified according to the inclusion criteria in the form of retrospective, prospective, in vivo, and randomized controlled trial studies. Mini-implant failures due to patient-related showed six etiological factors, failures due to implant-related had eight etiological factors, and only one factor was operator-related, which may lead to mini-implant failure. The data was extracted without a computerized system and only in English. Mini-implant failure can be caused by many factors; we could not accuse one major factor as a cause. However, the quality or condition of the bones and oral hygiene are factors that play a significant role in obtaining the stability of implants. Mini-implant failure is highly influenced by poor oral hygiene and peri-implant inflammation. Comprehensive diagnostic prior to mini-implant insertion should be appropriately considered. This systematic review describes several factors that can influence mini-implant failure, divided into three groups: patient-related, implant-related, and operator-related (A graphical abstract provided as a Supplementary information [available in the online version]).

Success rates of single-thread and double-thread orthodontic miniscrews in the maxillary arch

AIM

There is limited research on the clinical performance of double-thread orthodontic miniscrews. This study aimed to compare the stability of double-thread and single-thread orthodontic miniscrews and identify the potential associations between patient-related and location-related factors with miniscrew stability.

METHODS

This retrospective cohort study involved 90 orthodontic miniscrews (45 single-thread, 45 double-thread) with identical dimensions (8 mm length, 1.6 mm diameter). The screws were inserted in various locations within the upper jaw of 83 patients (54 females, 29 males; mean age = 15.1 ± 2.4 years). Failure was defined as excessive mobility or loss of miniscrew after placement. The data recorded were patient age, gender, insertion site, side of insertion (buccal or lingual), duration of force application, and failure occurrence.

RESULTS

The overall success rate within the sample was 92.2%. Double-thread miniscrews exhibited a significantly higher success rate than single-thread miniscrews (P = 0.049), with 97.8% and 86.7% success rates, respectively. Gender, age, insertion location, and side of insertion did not show significant associations with failure (P > 0.05). Log-rank analysis revealed a significant difference between the two groups (P = 0.046), indicating a higher probability of survival for the double-thread design.

CONCLUSIONS

The overall success rate of orthodontic miniscrews was high in the present sample. Double-thread miniscrews placed in various locations within the maxillary arch demonstrated superior stability and survival rates compared to their single-thread counterparts. Therefore, double-thread miniscrews may be preferred when bone quality is inadequate, such as in young patients.

Oral microbiome contributes to the failure of orthodontic temporary anchorage devices (TADs)

BACKGROUND

The stability of temporary anchorage devices (TADs) is critical in orthodontic clinics. The failure of TADs is multifactorial, and the role of the oral microbiome has not been clearly defined. Herein, we attempted to analyze the contribution of the oral microbiome to the failure of TADs.

METHODS

Next-generation sequencing was adopted for analyzing the microbiome on the TADs from orthodontic patients. 29 TADs (15 failed TADs and 14 successful TADs) were used for 16S rRNA gene sequencing. A total of 135 TADs (62 failed TADs and 73 successful TADs) were collected to conduct metagenomic sequencing. Additionally, 34 verified samples (18 failed TADs and 16 successful TADs) were collected for quantitative real-time polymerase chain reaction analysis (qRT-PCR).

RESULTS

Successful and failed TADs demonstrated discrepancies in microbiome structure, composition, and function. Clear separations were found in β-diversity in 16S rRNA gene sequencing as well as metagenomic sequencing (p < 0.05). Metagenomic sequencing showed that Prevotella intermedia, Eikenella corrodens, Parvimonas spp., Neisseria elongata, and Catonella morbi were enriched in the failed groups. qRT-PCR also demonstrated that the absolute bacteria load of Prevotella intermedia was higher in failed TADs (p < 0.05). Considering functional aspects, the failed group showed enriched genes involved in flagellar assembly, bacterial chemotaxis, and oxidative phosphorylation.

CONCLUSIONS

This study illustrated the compositional and functional differences of microorganisms found on successful and failed TADs, indicating that controlling bacterial adhesion on the surface of TADs is essential for their success rate.

Comparison of in vivo failure of precipitation-coated hydroxyapatite temporary anchorage devices with that of uncoated temporary anchorage devices over 18 months

INTRODUCTION

The objective was to compare the stability of hydroxyapatite-coated (HA) temporary anchorage devices (TADs) with uncoated TADs.

METHODS

Maxillary arches of 92 patients with Class II Division 1 malocclusion requiring premolar extractions were randomly distributed to receive both types of Ti-6Al-4V alloy TADs by a single operator. TADs were replicas of each other except for the HA precipitation surface coating of the threaded part. TADs were placed between the roots of the first molar and the second premolar and were immediately loaded by a 300 g of force nickel-titanium spring for retraction of the anterior segment. The main outcome was the loosening of the TAD.

RESULTS

TADs of each type were placed in 92 patients. The patients were recalled monthly for 18 months; 10 TADs failed in the HA-coated group (11%), whereas 12 TADs (13%) failed in the uncoated group, with a statistically insignificant difference between the survivability of the TADs in the 2 groups (P = 0.67, log-rank). The Kaplan-Meier curve showed better survivability of the HA-coated TADs between the second and fifth months. The TADs placed on the left side (19.6%) failed significantly more than on the right side (4.3%) (P = 0.002) when placed by a right-handed operator in right-handed patients.

CONCLUSION

The premise that the HA-coated TADs will have a lower failure rate seems incorrect.

Microbiological Advances in Orthodontics: An Overview and Detailed Analysis of Temporary Anchorage Devices

Dental biofilm is the initiating factor of oral diseases, such as periodontitis and caries. Orthodontic treatment could alter the microbiome structure balance, and increase the risk of such diseases. Furthermore, fixed appliances can induce temporary changes in the microbiome community, and the changes that clear aligners bring are smaller by comparison. Temporary anchorage devices (TADs) are skeletal anchorages that are widely used in orthodontic treatment. Microorganisms affect the occurrence and development of inflammation surrounding TADs. At present, existing researches have verified the existence of plaque biofilm on the surface of TADs, but the formation of plaque biofilm and plaque composition under different stable conditions have not been fully understood. The development of high-throughput sequencing, molecular biology experiments, and metabonomics have provided new research ideas to solve this problem. They can become an effective means to explore the microbiome surrounding TADs.

Dynamics, Efficacies, and Adverse Effects of Maxillary Full-Arch Intrusion Using Temporary Anchorage Devices (Miniscrews): A Finite Element Analysis

Introduction

Absolute anchorages obtained from temporary anchorage devices (TADs, miniscrews) considerably facilitate dental movements and make some very difficult movements such as full-arch intrusions possible. Despite the significance of assessing strategies to fully intrude the arch using mini-implants, there is no study in this regard except a few case reports. Therefore, we simulated/tested 4 scenarios.

Methods

Four maxilla models were created with different miniscrews/appliances: (1) two miniscrews were placed distal to laterals and one in the mid sagittal region. (2) Two mini-implants were inserted in mesial of canines and 2 others between bilateral first and second molars, plus another TAD in the midpalatal area, plus a transpalatal arch (TPA). (3) Two mini-implants were inserted between bilateral canines and first premolars and 2 others between bilateral first and second molars + TPA. (4) Two mini-implants were installed between lateral-and-canine and 2 miniscrews between second premolars and first molars + TPA. Intrusive forces (80 g anterior, 150 g posterior) were exerted using stainless-steel coil springs. Stresses/displacements were measured. Risk of external root resorption was evaluated.

Results

The highest amounts of incisor/molar intrusion were seen in model 1. Model 2 had fewer intrusions, but its control over undesired movements was greater. Model 4 drastically reduced molar intrusion and considerably increased premolar intrusion. Overall amounts of intrusion were highest in the first 2 models, marking them as proper candidates for cases needing greater intrusion extents. Model 2 may be useful when miniscrew loosening/failure is a concern, while model 1 is recommended when fewer miniscrews are allowed. Overall, the highest and lowest root resorptions might occur in models 1 and 4, respectively.

Conclusions

Each model showed certain efficacies/drawbacks and thus is recommended for a particular set of cases. Therefore, depending on the diagnosis and treatment plan, one or more of these scenarios might be desirable.

A Scoping Review about the Characteristics and Success-Failure Rates of Temporary Anchorage Devices in Orthodontics

This study synthesized the scientific evidence concerning the main characteristics of the Temporary Anchorage Devices (TADs) used in orthodontics and reported the success-failure rates during treatment. For that means, this scoping review collected articles from previous research. A complementary search was carried out in the databases PubMed-MEDLINE, Scopus, LILACS, and EMBASE, focusing on original studies published from 2010 to 2020. We analyzed the main characteristics of the publications. As a result, 103 articles were included. Most of the research was conducted among different groups, who needed TADs principally in the maxilla and an interradicular location between the second premolar and first molar. AbsoAnchor, Dentos Inc., Daegu, Korea, was the most used brand of TADs. The most common characteristics of the devices and biomechanics were a diameter and length of 1.6 mm and 8 mm, a self-drilled system, a closed technique for placement, immediate loading, and forces that ranged between 40 and 800 g. Of the studies, 47.6% showed success rates ≥90%. In conclusion, high success rates were found for TADs, and differences were found according to sociodemographic and clinical variables. The studies showed variability in methodological design, and scientific publications were concentrated in certain countries. We recommend further scientific research on TADs using more standardized designs.

Failure Rate of Orthodontic Mini-screw after Insertion using 3D Printed Guide versus Conventional Free Hand Placement Technique: Split Mouth Randomized Clinical Trial

AIM: The aim of the study is to assess the failure rate after mini-screw insertion using digital three-dimensional printed guide versus free hand placement technique through a well-designed split-mouth randomized clinical trial. METHODS: Forty-two patients with mean age (22.56 ± 3.47 years) indicated for upper first premolars’ extraction (Bimaxillary protrusion and Class II division 1) were included in the study. Their maxillary quadrants were randomized to receive mini-screws as means of anchorage. Pre-operative maxillary cone-beam computed tomography scan with ultra-low-dose protocol was imaged and the maxillary arch was scanned using intra-oral scanner to obtain stereo-lithographic format file for the maxillary arch. Using in vivo and Rapidform Geomagic Studio® _Softwares the mini-screws were planned to be inserted in the buccal inter-radicular space between the upper second premolar and first molar in both right and left sides. For the intervention sides; digital three-dimensional guides were designed and printed for mini-screw insertion. Failure of the mini-screws was assessed till 3 months of loading. RESULTS: There was no statistical significant difference in failure rate of mini-screws in both intervention (7.14%) and control sides (16.6%), with weak and moderate correlation between the root proximity and the mini-screws failure in intervention and control groups respectively. CONCLUSIONS: Using a digital three-dimensional printed guide for mini-screw insertion had no effect on the failure rate of the inserted mini-screws. REGISTRATION: ClinicalTrials.gov Identifier: NCT03653078.

The effect of social media on patient acceptance of temporary anchorage devices

OBJECTIVES

To investigate the relationship between the use of social networking sites (SNSs) on patient perceptions, acceptance, and expectations of treatment using temporary anchorage devices (TADs) and to compare differences between patients from the United Kingdom and Brazil.

MATERIALS AND METHODS

Cross-sectional questionnaires were administered to 39 participants at orthodontic practices in the United Kingdom and Brazil about patients' use of SNSs, exposure to TADs on SNSs, and thoughts on extractions, jaw surgery, or TADs as treatment options.

RESULTS

UK patients prefer for clinicians to have SNS profiles (P = .022). Most UK and Brazilian patients want to see their clinician's work online (76.7%) and use SNSs to get information about treatment options (76.6%). There was a statistically significant difference in Brazilian patients' acceptance of TADs as a treatment option compared with UK patients, particularly if it meant avoiding extractions (P = .002), avoiding jaw surgery (P = .004), or reducing treatment time (P = .010). Knowledge of TADs was greater in Brazilian patients (P < .001).

CONCLUSIONS

Patients use SNSs to obtain information about treatments and prefer clinicians to have social media accounts. Patients exposed to TADs on SNSs are more likely to accept them as an orthodontic treatment option. UK patients have less knowledge of TADs and are therefore less sure to consider TADs as an option. Brazilian patients are more confident in considering the use of TADs. Clinicians should consider increasing their social media presence to accommodate patients' expectations and acceptance of TADs.

Risk factors for orthodontic mini-implants in skeletal anchorage biological stability: a systematic literature review and meta-analysis

The reason of the biological stability loss of mini-implants is still a matter of discussion between dentistry professionals. The main objective of this systematic literature review and meta-analysis was to analyze the risk factors that prejudice this loss. A search was made in the electronic databases Pubmed, Scopus, Embase and Cochrane, in addition a manual search was made too in Grey Literature (Opengrey). No limits were set on the year of publication or language. The inclusion criteria were: studies in humans treated with fixed appliances with mini-implants, where the risk factors for secondary stability were evaluated for a minimum of 8 weeks. After eliminating duplicate studies and assessing which ones achieve the inclusion criteria, a total of 26 studies were selected for the qualitative synthesis, 18 of them were included in the quantitative synthesis. Common risk variables were compared in all of them. Analyzing the forest and funnel plots, statistically significant differences were obtained only for location, the upper maxilla having lower risk than the mandible with an odds ratio of 0.56 and confidence interval of 0.39 to 0.80. Prospective studies under controlled conditions should be required in order to obtain a correct assessment of the variables analyzed.

Effectiveness of anchorage with temporary anchorage devices during anterior maxillary tooth retraction: A randomized clinical trial

Objective

This study evaluated the efficiency of anchorage provided by temporary anchorage devices (TADs) in maxillary bicuspid extraction cases during retraction of the anterior teeth using a fixed appliance.

Methods

Patients aged 12 to 50 years with malocclusion for which bilateral first or second maxillary bicuspid extractions were indicated were included in the study and randomly allocated to the TAD or control groups. Retraction of the anterior teeth was achieved using skeletal anchorage in the TAD group and conventional dental anchorage in the control group. A computed tomography (CT) scan was performed after alignment of teeth, and a second CT scan was performed at the end of extraction space closure in both groups. A three-dimensional superimposition was performed to visualize and quantify the maxillary first molar movement during the retraction phase, which was the primary outcome, and the stability of TAD movement, which served as the secondary outcome.

Results

Thirty-four patients (17 in each group) underwent the final analysis. The two groups showed a significant difference in the movement of the first maxillary molars, with less significant anchorage loss in the TAD group than that in the control group. In addition, TAD movement showed only a slight mesial movement on the labial side. On the palatal side, the mesial TAD movement was greater.

Conclusions

In comparison with conventional dental anchorage, TADs can be considered an efficient source of anchorage during retraction of maxillary anterior teeth. TADs remain stable when correctly placed in the bone during the anterior tooth retraction phase.