Evaluation of factors affecting the success rate of orthodontic mini-implants by survival analysis

Success rate and factors affecting stability of infrazygomatic miniscrew implants: a systematic review and meta-analysis

BACKGROUND

The infrazygomatic miniscrew implants (IZC-MSI) serve as innovative temporary anchorage devices placed parallel to the roots of molars in the infrazygomatic crest region, leveraging their extra-radicular location to support the en masse distalization and intrusion of the maxillary dentition. The efficacy and stability of these screws are crucial for their application in contemporary orthodontic practices.

OBJECTIVES

This systematic review aimed to estimate the success rate and factors affecting the stability of IZC-MSI.

SEARCH METHODS

An electronic search was conducted on 7 February 2024 across the following databases: PubMed, Scopus, EMBASE, and Cochrane databases without any restriction on language and time of publication.

SELECTION CRITERIA

The review included clinical trials (both randomized and non-randomized) and retrospective cohort studies that utilized infrazygomatic miniscrew anchorage for orthodontic tooth movement in human participants.

DATA COLLECTION AND ANALYSIS

The proportion of success rate was calculated and factors affecting stability (patient and implant-related factors) such as age, sex, implant position, and loading characteristics were subjected to subgroup analysis and meta-regression. The quality assessment of studies was done using the Cochrane risk-of-bias tools for randomized (RoB 2.0) and non-randomized trials (ROBINS-I).

RESULTS

Fourteen studies (n = 1683 IZC-MSI) were included in the meta-analysis revealing a 92% success rate of IZC-MSI (C.I. 87%-95%; prediction interval: 66%-99%; I2 = 80%). Studies with sample size > 100 presented a 94% success rate (C.I. 91%-96%; I2 = 63%) and moderate heterogeneity. Meta-regression analysis revealed no significant relation between age and success rate. Significant heterogeneity was observed in the subgroup analysis of host-, implant- and other related risk factors affecting stability and limited correlation was found. The risk-of-bias assessment revealed high risk in five, moderate in five, and low in four studies.

CONCLUSIONS

IZC-MSI have shown a good success rate for their clinical application. Although some factors appear to influence IZC-MSI stability, the majority of them necessitate additional investigation due to the low quality of evidence. Furthermore, high-quality studies are needed to confirm the results of this meta-analysis and address other important factors such as operator's experience, insertion torque, and sinus penetration that could not be analysed due to limited data.

REGISTRATION

CRD42024469048.

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

AIM

The objective of the present study was to investigate success rates and associated factors affecting temporary anchorage device (TAD) failure in different biomechanical applications.

METHODS

A total of 180 TADs were used as a part of 82 patients' treatment plan (24 males and 58 females); their mean age was 21.41 years. Three types of TADs were used: 50 (3M ESPE, Neuss, Germany), 56 (Bone screw; Jeil Medical, Seoul, Korea), and 74 (Morelli, Sorocaba, Brazil). Eight maxillary and four mandibular sites were selected for insertion. Three different lengths (6, 8, and 10 mm) and three different diameters (1.5, 1.6, and 1.8 mm) were used. The force levels were set at 50, 100, 150, 200, and 250 g. Patient-, implant-, and operator-dependent factors were evaluated throughout the 266 days of function. Qualitative variables were described by proportions and percentages and analyzed using χ² test.

RESULTS

The overall success rate was 82.2%. The higher age group showed a significantly higher success rate. Oral hygiene showed a statistically-significant (P ˂ .05) difference between both success and failure groups. All other patient-related factors showed no significant differences. Regarding force levels used, the highest success rate was in 250 g and the lowest was in 100 g. There were no significant differences between both groups regarding other implant- and operator-related factors.

CONCLUSIONS

Temporary anchorage devices have a good success rate and are beneficial to be integrated in orthodontic treatment planning. Patient age, oral hygiene, and force level are the most significant factors affecting TAD success.