A Comparison of the Mechanical Measures Used for Assessing Orthodontic Mini-Implant Stability

The effect of surface roughening on the success of orthodontic mini-implants: A systematic review and meta-analysis

INTRODUCTION

Orthodontic mini-implants are a widely accepted treatment modality in orthodontics; however, the failure rate is moderately high. Surface roughening is the golden standard in conventional oral implantology, and this may prove beneficial for orthodontic mini-implants as well. The objective of this systematic review is to assess the effect of surface roughening on the success rate of orthodontic mini-implants in both adolescent and adult patients undergoing orthodontic treatment.

METHODS

Randomized studies comparing the success of surface-roughened and smooth, machined-surface orthodontic mini-implants were included. A literature search was conducted for 6 electronic databases (Pubmed/Medline, Embase, Cochrane, CINAHL, Web of Science, and Scopus), Clinical trial registry (https://www.

CLINICALTRIALS

gov), and grey literature (Google Scholar). A manual search of the reference lists of included studies was performed. Two authors independently performed the screening, data extraction, risk of bias, and quality assessments. The risk of bias was assessed with the Cochrane risk-of-bias 2.0 Tool. Data were synthesized using a random effect model meta-analysis presented as a forest plot. The certainty in the body of evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation tool.

RESULTS

A total of 4226 unique records were screened, and 6 of these were included in the quantitative analysis. Four additional articles were selected for a secondary outcome. A total of 364 orthodontic mini-implants were included in the primary outcome analysis. There was no statistically significant effect of surface roughening on the success of orthodontic mini-implants (odds ratio = 0.63 favoring roughened orthodontic mini-implants; 95% confidence interval, 0.35-1.14). The secondary outcome (ie, the overall failure rate of roughened orthodontic mini-implants) was 6% based on studies with high heterogeneity. Limitations of this study were the risk of bias, study imprecision, and possible publication bias, leading to a very low certainty in the body of evidence.

CONCLUSIONS

There is very low-quality evidence that there is no statistically significant effect of surface roughening on the success of orthodontic mini-implants in humans. The overall failure rate of surface-roughened orthodontic mini-implants was 6%.

FUNDING

No funding was received for this review.

REGISTRATION

This study was preregistered in the Prospective Register of Systematic Reviews (CRD42022371830).

Does molar distalization by the Beneslider have skeletal and dental impacts? A prospective 3D analysis

OBJECTIVE

The study aimed to clarify (1) the effect of the Beneslider distalization appliance on maxillary molars (M1+2), (2) the type of tooth movement, and (3) changes in skeletal parameters.

STUDY DESIGN

Dental distalization paths and transversal changes were measured according to the distance of the pterygoid vertical as well as on the virtualized 3D plaster model.

RESULTS

Distalization of the second premolar (P2; T1 - T2) was 2.51 mm (±1.81 mm; P < .001) combined with a distal tipping of 6.50° (±5.09°; P < .001), whereas for M1 a distalization of 3.49 mm (±1.10 mm) occurred with negligible tipping (0.73° ± 5.04°). No significant differences (T1 - T2) on sagittal and vertical skeletal variables were found within or between G1+2. In contrast, a significant increase in N-Sp' in G2 and in Sp'-Gn in G1+2 with consecutive Hasund index reduction was shown. Comparing T1 and T2, the device had an effect on the transversal development.

CONCLUSION

The Beneslider distalization appliance causes an effective distalization of M1+2, with slight second premolar tipping. No modification of skeletal parameters was recorded, but a relevant effect on Hasund index and the transverse was found.

Bone quality affects stability of orthodontic miniscrews

The objective of this study was to evaluate the effect of bone–miniscrew contact percentage (BMC%) and bone quality and quantity on orthodontic miniscrew stability and the maximum insertion torque value (ITV). Orthodontic miniscrews of five different dimensions and several bovine iliac bone specimens were used in the evaluation. Miniscrews of each dimension group were inserted into 20 positions in bovine iliac bone specimens. The experiment was divided into three parts: (1) Bone quality and quantity were evaluated using cone-beam computed tomography (CBCT) and microcomputed tomography. (2) The 3D BMC% was calculated. (3) The ITVs during miniscrew insertion were recorded to evaluate the stability of the orthodontic miniscrews. The results indicated that longer and thicker miniscrews enabled higher ITVs. CBCT was used to accurately measure cortical bone thickness (r = 0.939, P < 0.05) and to predict the bone volume fraction of cancellous bone (r = 0.752, P < 0.05). BMC% was significantly influenced by miniscrew length. The contribution of cortical bone thickness to the ITV is greater than that of cancellous bone structure, and the contribution of cortical bone thickness to BMC% is greater than that of cancellous bone structure. Finally, the higher is BMC%, the greater is the ITV. This study concludes that use of CBCT may predict the mechanical stability of orthodontic miniscrews.

Evaluation of clinical parameters for the stability of 2 types of miniscrews

INTRODUCTION

The purpose of this research was to compare insertion techniques and effects on mechanical and clinical parameters between 2 types of miniscrews.

METHODS

Forty-four consecutive patients whose orthodontic treatment involved the use of miniscrews (miniscrew A [MA] and miniscrew B [MB]) for anchorage were included in this study. Miniscrews were placed with predrilling or self-drilling; peak maximum insertion torque (MIT) and Periotest values were measured. Cone-beam computed tomography was performed after the insertion of miniscrews and root proximity determination; cortical bone thickness was also analyzed. Periotest values were measured after the application of orthodontic force.

RESULTS

Self-drilling produced higher Periotest values (P <0.01) for MA and higher MIT (P <0.01) for MB with closer root proximity (P <0.05). MB had higher MIT and Periotest values with drilling compared with MA (P <0.05); MB also showed closer root proximity (P <0.05). Successful miniscrews had lower MIT (P <0.05) for MB and lower Periotest values (P <0.01) for both MA and MB, with significantly more distant root proximity (P <0.01). Self-drilling produced higher Periotest values at the time of placement (P <0.01) and after 4 weeks (P <0.05) in MA. Drilling produced higher Periotest values for MB at the time of placement (P <0.05). MIT had positive correlations with Periotest values for MB with self-drilling (P <0.01) and with root proximity for MA with drilling (P <0.01). Periotest values had negative correlations with root proximity for MA and the MB group with drilling (P <0.01).

CONCLUSIONS

For miniscrews with larger diameters, higher MIT may result in more mobility (higher Periotest values). Drilling can avoid root contact and enhance primary stability, thus producing lower Periotest values.

A novel technique for measurement of orthodontic mini-implant stability using the Osstell ISQ device

OBJECTIVES

To develop and validate a method for application of the Osstell ISQ device in the assessment of mini-implant stability.

MATERIALS AND METHODS

An adaptor was developed for attachment of Osstell's SmartPeg onto a variety of orthodontic mini-implants. For validation of the adaptor, Benefit mini-implants were inserted into bone blocks that mimicked different stability conditions. The Osstell device was used to assess mini-implant stability with the adaptor (test measurement) and conventional SmartPeg attachment (gold-standard measurement). Implant stability quotient (ISQ) values were assessed for agreement, repeatability, and reproducibility.

RESULTS

Strong positive correlations were found between ISQ values obtained using the novel adaptor and the conventional attachment. Repeatability and reproducibility of ISQ values with the adaptor were similar to those obtained with the conventional attachment.

CONCLUSIONS

A method was developed and validated to assess the stability of orthodontic mini-implants using the Osstell system. The novel mini-implant adaptor provided repeatable and reproducible measurements of mini-implant stability, which agreed with those obtained using a conventional SmartPeg attachment. This adaptor permits noninvasive stability assessment of various designs of mini-implants, most of which are incompatible with the conventional SmartPeg attachment.