Type of tooth movement during en masse retraction of the maxillary anterior teeth using labial versus lingual biocreative therapy in adults: A randomized clinical trial

En-masse maxillary anterior retraction to close the extraction space with fixed orthodontic appliances: A systematic review

OBJECTIVE

To evaluate the evidence on the treatment results and patients' reported outcomes of the en-masse maxillary anterior retraction technique.

MATERIAL AND METHODS

Web of Science™, MEDLINE (via PubMed®), and Scopus electronic databases and reference lists of relevant studies were comprehensively searched on September 24, 2024 with no time frame limitation but, with the language limited to English. Randomized clinical trials investigating en-masse retraction in orthodontic patients who needed maxillary first premolars extraction were selected using keywords to search the titles and abstracts before a detailed reading of each full text in the next steps. Primary outcomes included rate, duration, or amount of anterior retraction and anchorage loss while secondary outcomes included positional changes in the anterior and molar teeth, root resorption of the anterior teeth, and patients' experiences. The Cochrane Collaboration's risk of bias tool was used for risk of bias and quality assessment of the included studies.

RESULTS

There were 257 articles deemed potentially suitable for the review. Removing duplicates, careful reading the titles and abstracts, and applying the inclusion/exclusion criteria left 22 articles were included. The risk of bias assessment showed 3, 7, and 12 studies of "high", "some concerns" or "low" risk of bias respectively. En-masse retraction produced similar incisor retraction and anchorage loss in about half the time needed by the two-step mechanics. Corticotomy, micro-osteoperforation, and low level laser therapy showed positive results for accelerating en-masse retraction. while piezocision and platelet rich plasma did not. Root resorption of the incisors could increase when using mini-screws, especially infra-zygomatic mini-screws.

CONCLUSIONS

There is need for future RCT on the different outcomes done according to standardized methodologies. Corticotomy, micro-osteoperforation, and low-level laser showed positive results in accelerating en-masse retraction, but the clinical significance remains unclear. Rate of tooth movement was similar in piezocision, platelet-rich plasma, and the control groups. Mini-screws, especially infra-zygomatic mini-screws, increase the chance of root resorption, but the force system arrangement is crucial.

Combined anterior and posterior miniscrews increase apical root resorption of maxillary incisors in protrusion and premolar extraction cases

Objective

Miniscrews are commonly utilized as temporary anchorage devices (TADs) in cases of maxillary protrusion and premolar extraction. This study aimed to investigate the effects and potential side effects of two conventional miniscrew configurations on the maxillary incisors.

Methods

Eighty-two adult patients with maxillary dentoalveolar protrusion who had undergone bilateral first premolar extraction were retrospectively divided into three groups: non-TAD, two posterior miniscrews only (P-TADs), and two anterior and two posterior miniscrews combined (AP-TADs). Cone-beam computed tomography was used to evaluate the maxillary central incisors (U1).

Results

The AP-TADs group had significantly greater U1 intrusion (1.99 ± 2.37 mm, n = 50) and less retroclination (1.70° ± 8.80°) compared to the P-TADs (-0.07 ± 1.65 mm and 9.45° ± 10.68°, n = 60) and non-TAD group (0.30 ± 1.61 mm and 1.91° ± 9.39°, n = 54). However, the AP-TADs group suffered from significantly greater apical root resorption (ARR) of U1 (2.69 ± 1.38 mm) than the P-TADs (1.63 ± 1.46 mm) and non-TAD group (0.89 ± 0.97 mm). Notably, the incidence of grade IV ARR was 16.6% in the AP-TADs group, significantly higher than the rates observed in the P-TADs (6.7%) and non-TAD (1.9%) groups. Multiple regression analysis revealed that after excluding tooth movement factors, the AP-TADs configuration resulted in an additional 0.5 mm of ARR compared with the P-TADs group.

Conclusions

In cases of maxillary protrusion and premolar extraction, the use of combined anterior and posterior miniscrews enhances incisor intrusion and minimizes torque loss of the maxillary incisors. However, this approach results in more severe ARR, likely due to the increased apical movement and composite force exerted.

Finite element analysis of the effects of different archwire forms and power arm positions on maxillary incisors in en masse retraction using fixed lingual orthodontic appliances

Objective

This study aimed to investigate the effects of archwire form and power arm positions on maxillary incisors during lingual en masse retraction supported by miniscrew implants, using the finite element analysis method.

Methods

Sliding mechanics for lingual en masse retraction were simulated using the finite element method. Power arms were placed mesial and distal to the maxillary canine with straight and mushroom-shaped archwires. Miniscrews provided absolute anchorage for retraction force.

Results

When power arms were positioned mesial to the canine teeth, an increase in the intercanine distance was observed, while a decrease was noted when the power arms were distal to the canine tooth. Lateral incisors exhibited a greater torque loss, particularly when the power arm was mesial to the canine tooth. In the central incisors, the mushroom archwire resulted in intrusion, while the straight archwire showed an extrusion tendency. Movements in groups using the straight archwire were less controlled compared to those in groups using the mushroom archwire.

Conclusions

The archwire form and the position of the power arm affected the torque loss and vertical position of incisors during lingual en masse retraction supported by miniscrew implants. The most controlled movement was achieved with the combination of a power arm positioned distal to the canine tooth and a mushroom archform.

Friction versus frictionless mechanics during maxillary en-masse retraction in adult patients with Class I bimaxillary dentoalveolar protrusion: a randomized clinical trial

BACKGROUND

Extraction space closure is a challenging phase during orthodontic treatment that affects not only the total treatment duration but also the whole treatment outcome.

OBJECTIVE

To compare the efficiency of friction and frictionless mechanics during en-masse retraction of maxillary anterior teeth in adult patients with bimaxillary dentoalveolar protrusion.

TRIAL DESIGN

Two-arm parallel group, single-center randomized clinical trial.

MATERIALS AND METHODS

Thirty-two adult patients with bimaxillary protrusion were recruited and randomly allocated to two different retraction mechanics. A friction group, using NiTi coil springs and a frictionless group using closing T-loops for en-masse retraction. Randomization in a 1:1 ratio was generated by Microsoft Excel. The randomization numbers were secured in opaque sealed envelopes for allocation concealment. Retraction started in all patients following first premolars extraction using miniscrews as a source of indirect anchorage. Activation was done on a monthly basis until complete retraction of anterior segment. The rate of retraction, amount of anchorage loss, the dental, and soft tissue changes were analyzed on digital models and lateral cephalograms taken before retraction and after space closure.

BLINDING

The outcome assessor was blinded through data concealment during assessment.

RESULTS

Two patients were lost to follow up, so 30 patients completed the trial. The rate of anterior segment retraction was 0.88 ± 0.66 mm/month in the frictionless group compared to 0.72 ± 0.36 mm/month in the friction group which was statistically significant. Anchorage loss of 1.18 ± 0.72 mm in the friction group compared to 1.29 ± 0.55 mm in the frictionless group with no significant difference. Comparable dental and soft tissue changes following en-masse retraction were reported in both groups, with no statistically significant difference.

HARM

one patient complained of soft tissue swelling following miniscrew insertion, but the swelling disappeared after one week of using mouth wash.

LIMITATION

The study focused only on the maxillary arch.

CONCLUSION

Both mechanics have successfully achieved the required treatment objectives in patients with bimaxillary dentoalveolar protrusion. Frictionless group showed a faster rate of retraction than the friction group, which was statistically but not clinically significant.

TRIAL REGISTRATION

Clinicaltrials.gov with the identifier NCT03261024.

Rate of upper incisor retraction in Class II division 1 patients managed with palatal versus buccal miniscrew supported segmental orthodontics: Randomized parallel clinical trial

OBJECTIVE

This study was conducted to compare maxillary incisor retraction rates using buccal orthodontics with segmented arch approach supported by a buccal or palatal mini-screw in non-growing Class II Division 1 patients during a 3-month period.

PATIENTS AND METHODS

All patients between September 2018 and December 2021 with following criteria were included: non-growing class II division 1 protrusion, indication for premolar extraction, no or little crowding, normal overbite, no previous orthodontic treatment, no systematic disease, good oral hygiene, no periodontal problems or oral habits. Mini-implant was inserted buccally or palatally between upper second premolar and first molar bilaterally. Incisor retraction was manipulated by a 200-gram force through a nickel-titanium closed-coil spring extended from the mini-implant to the segmental design. Study casts were made before retraction and after every 4 weeks (T0: baseline, T1: 4 weeks, T2, 8 weeks, T3: 12 weeks). A repeated measures ANOVA was performed for total comparison of data (mm of retraction) on 3D casts. A pairwise t test with Bonferroni correction was used for comparison between two experimental periods for the same group. An independent samples t-test was also used for comparison between two groups for the same experimental period.

RESULTS

Of 30 patients meeting the eligibility criteria, only 28 were included with mean age 16±2.5 years. Repeated measures ANOVA revealed significant differences in incisor retraction between the time intervals for both buccal and palatal groups (P=0.001). In addition, the paired-sample t test indicated a significant difference between each time interval for both the buccal and palatal groups (P=0.001), except between T3 and T2 for the palatal group (P=0.09). The independent sample t-test revealed significant differences between the buccal and palatal groups at T1 (Mean: 0.55 [0.355-0.748],=0.001) and T2 (Mean: 1.4 [0.91-1.88], P=0.001); whereas no significant difference was found at T3 (Mean: 1.15 [0.67-1.63], P=0.945).

CONCLUSIONS

Anterior retraction using a segmental palatal model with mini-screws was effective regardless of the buccal or palatal situation of the minivis. Retraction of incisors with palatal miniscrews was significantly faster in the first two months.

Methods of Anterior Torque Control during Retraction: A Systematic Review

Background: There are various methods of controlling the inclination of the incisors during retraction, but there is no evidence as to the advantages of some methods over others. The purpose of this systematic review and meta-analysis was to determine the effectiveness of the methods used to control torque during anterior teeth retraction. Methods: In accordance with the PRISMA guidelines, the main research question was defined in the PICO format [P: patients with complete permanent dentition; I: the maxillary incisor torque after (I) and before I retraction with straight-wire appliance and different modes of torque control; O: statistically significant differences in torque values of the upper incisors after orthodontic treatment]. The MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials databases were searched for keywords combining: retraction orthodontics, torque control orthodontics, torque orthodontics, inclination orthodontics, torque control retraction. The articles were subjected to risk of bias and quality analyses with the ROBINS-I protocol and the modified Newcastle–Ottawa QAS, respectively. Meta-analyses were performed with both fixed- and random-effects models. Results: 13 articles were selected in which total number of 580 subjects took part. In all studies, incisors were retroclined during retraction by 2.46° (mean difference), which was statistically significant. Considering the articles separately, the differences in torque between the study group and the control group were statistically significant in six articles. The Q statistic was 36.25 with p = 0.0003 and I2 = 66.9%, which indicated a high level of study heterogeneity. Conclusion: Both properly performed corticotomy and en-masse retraction using orthodontic microimplants seem to be the most effective and scientifically validated methods of torque control. Further high-quality research is needed to perform better quality analyses and draw more reliable conclusions.

Root proximity of the anchoring miniscrews of orthodontic miniplates in the mandibular incisal area: Cone-beam computed tomographic analysis

Objective

This outcome analysis study evaluated the actual positions of the orthodontic miniplate and miniplate anchoring screws (MPASs) and the risk factors affecting adjacent anatomic structures after miniplate placement in the mandibular incisal area.

Methods

Cone-beam computed tomographic images of 97 orthodontic miniplates and their 194 MPASs (diameter, 1.5 mm; length, 4 mm) in patients whose miniplates provided sufficient clinical stability for orthodontic treatment were retrospectively reviewed. For evaluating the actual positions of the miniplates and analyzing the risk factors, including the effects on adjacent roots, MPAS placement height (PH), placement depth (PD), plate angle (PA), mental fossa angle (MA), and root proximity were assessed using the paired t-test, analysis of variance, and generalized linear model and regression analyses.

Results

The mean PDs of MPASs at positions 1 (P1) and 2 (P2) were 2.01 mm and 2.23 mm, respectively. PA was significantly higher in the Class III malocclusion group than in the other groups. PH was positively correlated with MA and PD at P1. Of the 97 MPASs at P1, 49 were in the no-root area and 48 in the dentulous area; moreover, 19 showed a degree of root contact (19.6%) without root perforation. All MPASs at P2 were in the no-root area.

Conclusions

Positioning the miniplate head approximately 1 mm lower than the mucogingival junction is highly likely to provide sufficient PH for the P1-MPASs to be placed in the no-root area.

Evaluation of interradicular space, soft tissue, and hard tissue of the posterior palatal alveolar process for orthodontic mini-implant, using cone-beam computed tomography

INTRODUCTION

To investigate the anatomy of the posterior palatal alveolar process, which is often used for placement of the orthodontic mini-implant (OMI), and to suggest simple guidelines for safe placement of OMI.

METHODS

Cone-beam computed tomography (CBCT) scans of 60 patients (30 men, 30 women; age range, 18-39 years; average age, 25.8 years) was used to measure the palatal interradicular distance, the palatal bone thickness, and the palatal soft-tissue thickness. Measurements were performed on the area from the maxillary canine to the maxillary second molar based on the vertical distance apical from the cementoenamel junction. The CBCT data were analyzed by Bonferroni correction for multiple testing and the multivariable mixed linear model.

RESULTS

The palatal interradicular distance was the widest between the second premolar and the first molar and the narrowest between the first and second premolars. The palatal bone thickness at interdental sites was the thickest between the first and second premolars and the thinnest between the first and second molars. The interdental palatal soft-tissue thickness from the canine to the second premolar was thicker than any other area. There were minor measurement differences between genders and positive correlations between vertical distance from the cementoenamel junction plane and all of the parameters.

CONCLUSION

In this study, we evaluated the anatomy of the posterior palatal area using CBCT scans of adult patients. The data will provide guidelines to the clinicians before OMI placement in the posterior palatal alveolar process.

Critical issues concerning biocreative strategy in contemporary temporary skeletal anchorage device orthodontics: A narrative review

Biocreative Orthodontic Strategy (BOS) is designed to establish a physiologically stable occlusion in harmony with masticatory and TMJ function and healthy supporting tissues with strategic use of temporary skeletal anchorage devices (TSADs). This narrative review surveys current research that demonstrates how BOS with TSADs uses a target approach to overcome the limitations experienced with conventional orthodontic treatment. A narrative review article including research on TSADs orthodontics in the permanent dentition. This review is a brief survey of five BOS principles for contemporary TSAD orthodontics: elegant selection of TSADs, bracket prescription to enhance TSAD orthodontics, antero-posterior dimension control, transverse dimension control and airway control issues. Severe malocclusion and craniofacial dysmorphology can be treated with Biocreative Orthodontic Strategy with a minimum number of TSADs. In order to achieve successful treatment outcome using TSADs, it is critical to understand the key diagnosis and treatment principles of BOS and how to develop a target approach for the tooth and bone movement.