Stability of aligned maxillary anterior teeth after orthodontic treatment: amount of changes with different retention methods and without retention

Well-aligned anterior teeth are the major reason for the patients seeking orthodontic treatment, and keeping teeth aligned and stable afterwards is a goal for the orthodontist and the patient. Relapse after treatment is a common problem, and it is defined as when teeth go back to their previous positions. Removable or fixed retainers have been used to avoid relapse after treatment. It has been common practice to use removable retention to retain anterior teeth in the maxilla. However, in recent decades, it has become increasingly common to retain with bonded retainers. Almost all previous studies on retention devices in the maxilla were based on removable retainers. Consequently, there existed knowledge gaps and lack of short-term and long-term studies on the capability to maintain the stability of the maxillary anterior teeth with bonded retainers. Hence, the reason for the papers in this study. In addition, it is not known if retentionis needed in all orthodontic patients or if there are patients, based on their initial malocclusion and individual variations, who may not need retention after treatment. The research questions addressed in this thesis thus originate from knowledgegaps and clinical needs concerning retention strategies after orthodontic treatments. To provide strong clinical evidence, randomised controlled trials (RCT) as well as intention to treat (ITT) methodology has been assessed. The results are expected to be beneficial for the patients who will be offered the most effective retention strategy for maxillary anterior teeth based on patients’ preferences. In Paper I and II, 45 and 27 adolescents’ patients were collected from the Orthodontic Clinic in Mariestad, Sweden. At the time when Paper Iand II were conducted, there were no studies that had evaluated the longterm effect of bonded retainers in the maxilla. In two RCTs, Paper III and IV, 90 and 63 adolescents’ patients were collected from the Orthodontic Clinic in Växjö, Region Kronoberg, Sweden. Paper I: The aim was to investigate the amount and pattern of relapse of maxillary anterior teeth previously retained with a bonded retainer. Paper II: The aim was to investigate the amount and pattern of changes of maxillary anterior teeth seven years post-retention, which previously were retained with a bonded retainer. Paper III: The aim was to evaluate post-treatment changes in the irregularity of the maxillary six anterior teeth and single tooth Contact Point Discrepancy (CPD) of three different retention methods. Paper IV: The aim was to evaluate whether retention is needed after orthodontic treatment for impacted maxillary canines and with moderate pre-treatment irregularity in the maxilla. Key findings in Paper I • The contact relationship between the laterals and the centrals is the most unstable contact. Canines are the most stable teeth. • There was no difference in the relapse pattern between rotational displacements and labiolingual displacement. Key findings in Paper II • There was a strong correlation between irregularity at one- and seven-years post-retention. Stable cases one-year post-retention were stable and unstable cases deteriorated with time. Key findings in Paper III • All three retention methods showed equally effective retention capacity and all the changes found in the three groups were small and considered clinically insignificant. Thus, the null hypothesis was confirmed. All three methods can be recommended. Key findings in Paper IV • Changes between the retention and the non-retention group were statistically but not clinically significant. Since satisfactory clinical results one-year post-treatment were found in the non-retention group, retention does not appear always to be needed. • Most of the changes occur within the first 10-week period after treatment with no retention. Key conclusions and clinical implications Both removable and bonded retainers are effective for holding teeth inposition and can be used for preventing the relapse. It can be enough toretain with bonded retainer 12-22 instead of 13-23. It might be possibleto avoid retention in selected cases in the short-term, but a longer evaluationperiod is needed.

Fixed Lingual Retainer Positioner: A narrative review

Retention is one of the most critical phase of Orthodontic treatment . Angle stated that "the problem involved in retention are greater than the difficulties being encountered in the treatment, and tests the utmost skill of the operator. The various retention appliances available include Removable retainers and bonded retainers. Removable retainers have their own advantages and disadvantages, but they need patient’s compliance to wear them.Fixed retainers consist of a length of orthodontic wire that is bonded on the lingual aspect of tooth .The major advantages of bonded retainers includes invisibility, no patient compliance required and long term retention. Bonding of a lingual retainer is a challenging and technique sensitive procedure because it requires long working time and has a risk of contamination from saliva and moisture, leading to bond failure as it is difficult to adaptation of the retainer wire and further stabilization of contoured retainer wire in the oral cavity during bonding. If retainer wire can be effectively stabilized over the lingual surface of tooth prior to bonding, bonding becomes a simple process. Various methods used to stabilize lingual retainer before bonding involves use of separators (Kesling and elastomeric separators), materials like resin, memosil, glue etc or use of metal Stablizers in form of W,V or use of wires . The objectives of this article is to compile the different retention techniques used to stabilize the lingual retainer wire for bonding altogether at one place. Keywords: Retainers, lingual aspect, Bonding, Stablization

Orthodontic Bonded Retainers: a Narrative Review

Indefinite retention is now considered essential to prevent relapse after orthodontic treatment. Compliance with removable retainer wear is suboptimal and appears to decline with time post-treatment. As a result, use of bonded retainers may become more commonplace in the future. In this narrative review, the characteristics of bonded retainers are outlined and a summary of the evidence from randomized clinical trials regarding their effectiveness is provided. Guidance is also offered regarding care and maintenance. CPD/Clinical Relevance: All general dental practitioners (GDPs) should be familiar with types of bonded retainers, evidence relating to their effectiveness and the GDP's role regarding their care and maintenance.

Lingual bonded retainers: A case series of complications and resolutions

Objective: The objective of the study was to describe the types, causes, and recommendations for the prevention/ management of complications related with lingual bonded retainers (LBRs) during the retention period. Materials and Methods: The retention protocol was a combined use of the LBRs made from 0.0175 multistrand wire and bonded on the maxillary and mandibular anterior teeth by DuraLay resin transfer method and a removable retainer at both arches for nighttime wear. Nine cases, which did not show bonding failure or fracture of LBR, were described to explain the complications including unexpected tooth movements and gingival problems. Results: The types of complications were spacing, loss of alignment, change in transverse position, angulation or torque of the crown, gingival recession, and black triangle. There are three possible causes for these complications: (1) Active force generated by LBR, which was not passively fabricated or bonded, (2) deformation of LBR induced by heavy biting force or traumatic occlusion, and (3) untwisting force of strand in round flexible multistrand wire. These complications can be prevented or managed by (1) fabrication of LBR on a working model to make it passive, (2) use of a jig to position LBR during bonding to avoid deformation by finger pressure, (3) supplemental use of a removable retainer for nighttime wear, (4) early detection of bonding failure, deformation, or fracture of LBR, and (5) immediate removal of LBR and use of a new removable retainer for resolution of complications. Conclusion: Clinicians should check the existence of these complications from the start of retention and inform the patient of the possibility of retreatment.