Stability of transverse dental arch dimension with passive self-ligating brackets: a 6-year follow-up study

Posttreatment stability following therapy using passive self-ligating brackets: extraction vs. nonextraction

PURPOSE

This study aimed to evaluate the effects of lower premolar extraction on posttreatment stability one year following fixed orthodontic treatment with passive self-ligating brackets (Damon system, Ormco, Orange, CA, USA).

METHODS

All patients were treated with fixed orthodontic appliances using passive self-ligating brackets (Damon). For retention, removable Hawley retainers were used. Two groups of patients were included in the study. Each group consisted of 23 patients: group Ex consisted of 10 male and 13 female patients (13.4 ± 1.6 years old) with extraction of lower first premolars and group NonEx consisted of 11 male and 12 female patients (13.4 ± 3.9 years old) without dental extractions. The patients' dental models and photographs were assessed at T0 (pretreatment), T1 (the end of active orthodontic treatment: 3.3 ± 1.0 years in the Ex and 2.3 ± 0.8 years in the NonEx group) and at T2 (1 year posttreatment). All lower casts were scanned and the following dental parameters were recorded and compared between the two groups: intercanine width (ICW), anterior arch width (AAW), intermolar width (IMW), Little's irregularity index (LII) and gingival recessions.

RESULTS

An increase in ICW (group Ex: 1.20 ± 2.51 mm and group NonEx: 0.84 ± 1.48 mm) by the end of active treatment (T1; P < 0.05), as well as a relapse regarding the ICW (group Ex: -0.1 ± 0.47 mm and group NonEx: -67% ± 0.38 mm) one year post-treatment (T2) were recorded in the samples. Relapse in the non-extraction group was statistically and clinically significant, whereas ICW values remained relatively stable in the extraction group during the posttreatment period (T1-T2). The irregularity index decreased during treatment (group Ex: -8.79 ± 6.36 mm and group NonEx: -5.24 ± 2.99 mm) and relapsed in both groups (group Ex: 0.57 ± 90 mm and group NonEx: 0.27 ± 0.53). The rate of relapse in LII was correlated to the relapse rate of ICW. A reduction of IMW was recorded in the Ex group (-1.89 ± 1.82 mm) during active treatment (P < 0.05), which remained stable 1 year posttreatment. AAW increased in both groups (group Ex: 2.77 ± 1.77 mm and group NonEx: 1.77 ± 2.04 mm) throughout active treatment and remained stable at T2.

CONCLUSION

Intergroup comparison revealed that ICW remained stable 1 year posttreatment in the Ex group, whereas high relapse of ICW was recorded in the NonEx group. Furthermore, risk of a relapse of LII appears to be higher in cases with a relapse of the ICW.

Self-Ligating Versus Conventional Brackets: A Narrative Review

Orthodontic treatment has seen remarkable progress, particularly in bracket technology, enhancing efficiency, comfort, and oral hygiene. Self-ligating brackets (SLBs) have emerged as an alternative to conventional brackets (CBs), with claims of lower friction, shorter treatment time, better periodontal health, and reduced chairside visits. However, clinical studies yield mixed results, sparking ongoing debate. This narrative review examines the differences between SLBs and CBs in biomechanics, treatment duration, patient comfort, periodontal health, clinical efficiency, cost-effectiveness, and long-term stability based on recent research. The findings suggest that while SLBs offer certain benefits, they do not significantly surpass CBs in key treatment outcomes.

Descriptive analysis of the cases published in the Align® Global Gallery

INTRODUCTION

Social media enhanced access to information, making it easier to share dental treatments.

OBJECTIVE

This study aimed to conduct a descriptive analysis of the clinical cases published on the Align® Global Gallery platform.

MATERIAL AND METHODS

A retrospective cross-sectional study of 1,582 cases was conducted, data extracted referred to the following basic information: case number; patient's age; reported gender; Invisalign® package modality; treatment time; aligner exchange protocol; total number of aligners per arch; type of retainers, and inclusion of initial and final panoramic and cephalometric radiographs.

RESULTS

The majority were young (mean age 24.6 years, SD = 11.6), female patients (69.1%) with Class I malocclusion (39.4%) and crowding (77.9%). Comprehensive treatment was common (66.5%), with an average treatment time of 18 months (SD = 8.56; 95% CI = 17.6-18.5), with the most frequently reported aligner exchange protocol being 7 days (49.5%), with an average of 50.6 aligners in the upper arch (SD = 26.9; 95% CI = 49.2-51.9), and 48.7 in the lower arch (SD = 26.1; 95% CI = 47.4-50.0). Arch expansion (66.9%) and interproximal reduction (59.7%) were common approaches, while extractions were rare (4.3%). In most cases, initial lateral cephalometric (80.4%) and panoramic (93.3%) radiographs were presented. However, the final radiograph count dropped, with lateral cephalometric at 69.2%, and panoramic at 82.2% of cases.

CONCLUSION

Cases in the Align®Global Gallery mostly feature Class I patients with crowded teeth, treated with expansion and interproximal reduction. The absence of standardized information and post-treatment data restricts the applicability of these findings to broader Invisalign® treatment trends.