Posttreatment Stability Research Articles

Evaluating the Impact of Myofunctional Therapy on Orthodontic Treatment Outcomes

ABSTRACT Background: Myofunctional therapy has gained attention as a potential adjunct to orthodontic treatment, focusing on improving orofacial muscle function and balance. Despite its increasing popularity, the precise impact of myofunctional therapy on orthodontic treatment outcomes remains to be fully elucidated. Materials and Methods: A retrospective cohort study was conducted, involving 80 orthodontic patients aged 8–18 years, divided into two groups: Group A received orthodontic treatment alone, while Group B received orthodontic treatment combined with myofunctional therapy. Orthodontic treatment outcomes were assessed based on occlusal stability, facial aesthetics (evaluated through standardized photographs), and patient-reported satisfaction scores. Posttreatment stability of occlusion was assessed using the peer assessment rating (PAR) index, with lower scores indicating better occlusal outcomes. Results: The results indicated a significant improvement in orthodontic treatment outcomes among patients who received myofunctional therapy in addition to orthodontic treatment. Group B demonstrated a mean decrease of 25% in PAR index scores compared to Group A, indicating superior occlusal stability posttreatment. Facial aesthetics were also notably enhanced in Group B, with a higher percentage of patients achieving harmonious facial profiles than Group A. Additionally, patient satisfaction scores were significantly higher in Group B, with 85% of patients reporting high satisfaction levels, compared to 60% in Group A. Conclusion: Myofunctional therapy as an adjunct to orthodontic treatment has a positive impact on treatment outcomes, including improved occlusal stability, enhanced facial aesthetics, and increased patient satisfaction.

Post-treatment stability, survival time and periodontal health associated with vacuum-formed, bonded and rapid prototype retainers: A prospective clinical study

Background: New technologies have paved the way for newer fabrication techniques, such as rapid prototyping, which has gained popularity in the fabrication of several orthodontic appliances including retainers. Aim: To evaluate the stability, survival time and periodontal health associated with vacuum-formed retainers (VFRs), bonded retainers (BRs) and rapid prototype retainers (RPRs) over a period of 12 months in retention. Study design: Prospective clinical study. Methods: A total of 72 participants completing fixed orthodontic treatment were allocated to the following three groups by the investigators based upon their initial malocclusion, compliant and preferences: VFR; BR; and RPR. The primary outcome was Little’s Irregularity Index (LII). Other stability parameters, including arch length (AL), inter-canine width (ICW) and inter-molar width (IMW), were also assessed immediately after debonding (T0) and 12 months (T2) after debonding. In addition, survival time, and calculus index and gingival index (GI) were assessed. Results: LII showed a significant difference ( P = 0.00) between the groups and was increased in the VFR group (0.18 ± 0.22 mm) compared to the BR (0.03 ± 0.05 mm) and RPR (0.01 ± 0.03 mm) groups but was not clinically significant. The mean survival time of maxillary retainers was longest for the RPR group (220.63 days; 95% confidence interval [CI] = 194.1–247.16) but there was no significant difference between the three groups ( P = 0.43). The mean survival time of mandibular retainers was higher and the same for the VFR and RPR groups (240 days; 95% CI = 240–240) and there was no significant difference between the three groups ( P = 0.38). The calculus index score ( P = 0.00) was statistically significant between the groups, with an increased score for the BR group (0.33 ± 0.27) compared to the VFR (0.07 ± 0.16) and RPR (0.13 ± 0.22) groups. Similarly, the GI score ( P = 0.02) was statistically significant between the groups and was increased in the BR group (0.01 ± 0.19) compared to the VFR (−0.15 ± 0.18) and RPR (−0.06 ± 0.15) groups. The increase in calculus index and GI scores for the BR group were not clinically significant. Conclusion: There were no clinically significant differences between the three retainer groups in terms of stability, periodontal health and time to failure.

Treatment strategies for vertical maxillary excess: Cases with and without anterior open bite

This comprehensive review investigates the treatment of vertical maxillary excess (VME) with and without anterior open bite (AOB) in seven unique case studies. These cases illustrate the implementation of advanced orthodontic techniques, such as miniscrew-assisted intrusion of the maxillary and mandibular arches. The multifaceted nature of AOB must be considered, highlighting the need for clear diagnostic criteria and an understanding of the long-term impacts of treatment strategies. The main goal of treatment is to reduce the vertical dimension of the maxillomandibular complex. A single miniscrew in the midpalatal region for the maxillary arch and two miniscrews in the buccal areas of the mandibular arch can be applied for the effective intrusion of the posterior teeth. The review then delves into the specific challenges and treatment modalities for managing VME without AOB, stressing the critical role of individualized intervention plans. Each case study demonstrates a different aspect of the treatment approach: from differential intrusion of molars to address esthetic concerns and functional issues to comprehensive strategies involving the intrusion of entire dental arches to correct severe malocclusions. The outcomes emphasize the importance of controlled orthodontic mechanics in achieving and maintaining optimal posttreatment stability. This review underscores the effectiveness of these treatment strategies in significantly improving facial profiles and dental function while highlighting the adjunctive use of myofunctional therapy and other retention techniques to prevent relapse. Collectively, these cases provide valuable insights into the tailored treatment of complex orthodontic conditions, offering guidance on achieving long-term success in clinical practice.

Comparison of transverse dimensional and incisor changes between wide and narrow orthodontic archwires: a randomized controlled trial.

To clinically compare the effects of broader archwires to standard archwires, using conventional brackets in both cases, on the transverse and incisor changes in maxillary and mandibular arches during leveling and alignment. Fifty-two patients presenting with crowding were allocated into two groups; one group received the broad Damon archwires while the other received standard 3M OrthoForm III Ovoid archwires. All participants were treated with conventional brackets using similar archwire sequences (0.014, 0.018, 0.016 × 0.022/0.016 × 0.025, 0.019 × 0.025 NiTi/CuNiTi archwires). Digital casts were obtained from alginate impressions before treatment (T0) and six weeks after inserting 0.019 × 0.025 NiTi archwires (T1). Pretreatment (T0) and post-alignment (T1) lateral cephalograms were obtained for each patient. The primary outcomes were the changes in the transverse arch dimensions and incisor inclination. The secondary outcomes were the horizontal and vertical linear changes in incisor position. Complete data were collected for 47 patients. There was a significant increase in arch width during treatment within each group, except for upper inter-molar width in 3M group (P = 0.071). Damon wire induced a statistically significant increase in maxillary inter-second premolar width (P = 0.042), and mandibular inter-first premolar (P = 0.043), inter-second premolar (P = 0.008) and inter-molar widths (P = 0.033) compared to 3M group. The increase in incisor proclination and the linear change in incisor position were significant within each group, with less mandibular incisor proclination (P = 0.004) and horizontal advancement (P = 0.038) in the Damon group. Damon archwires created a comparatively greater increase in the maxillary inter-second premolar width and the mandibular inter-first premolar, inter-second premolar, and inter-molar widths, and less proclination and horizontal advancement in mandibular incisors. The study provides invaluable evidence that using broad archwires with self-ligating brackets is the reason behind any greater expansion observed in this system rather than the unique mechanical and biological features exerted by the self-ligating system. Our results suggest that Damon archwire might be a better alternative compared to the narrower standard archwires that are usually used with conventional brackets, especially in the mandibular arch, in cases where mild to moderate crowding is planned to be resolved with a non-extraction approach. However, as arch expansion in the absence of posterior crossbites raises the question of long-term stability, the reported advantage of the use of wide wires should be interpreted with caution and should be considered in the retention phase, bearing in mind that achieving a good post-treatment occlusion is important for enhancing post-treatment stability.

A Case Study on Orthodontic-Surgical Management of Skeletal Class III Malocclusion in Adults: Clinical Approach and Outcomes

This article presents a case study illustrating the successful management of skeletal Class III malocclusion in an adult through an orthodontic-surgical approach. The clinical case outlines the entire process, from initial assessment to post-treatment outcomes, conducted within our service. Key steps include diagnostic planning using advanced tools such as 3D imaging and virtual surgery simulation. Pre-surgical orthodontic treatment was carefully planned to prepare dental and skeletal structures for surgical correction. Orthognathic surgery was performed precisely according to the established plan, followed by a post-surgical orthodontic phase to finalize occlusion. Short-term and long-term outcomes are evaluated, highlighting significant improvement in facial aesthetics, occlusal function, and post-treatment stability. This case study demonstrates the effectiveness of our integrated approach in managing skeletal Class III malocclusions in adults, underscoring the importance of interdisciplinary collaboration for optimal outcomes

Three-Dimensional Evaluation of Treatment Effects and Post-Treatment Stability of Maxillary Molar Intrusion Using Temporary Anchorage Devices in Open Bite Malocclusion.

Background: We investigated treatment outcomes and post-treatment stability in 10 patients with an anterior open bite and nonsurgical orthodontics. Methods: The patients underwent maxillary molar intrusion using temporary anchorage devices (TADs) to deepen the overbite due to mandibular autorotation. Lateral cephalograms and dental cast models were obtained before treatment (T0), immediately after it (T1), and >1 year after it (T2). Skeletal and dental cephalometric changes and three-dimensional movements of the maxillary dentitions were evaluated. Results: At T0, cephalometric analysis indicated that patients had skeletal class I with tendencies for a class II jaw relationship and a skeletal open bite. During active treatment (T0 to T1), the maxillary first molar intruded by 1.6 mm, the mandibular first molar extruded by 0.3 mm, the Frankfort-mandibular plane angle decreased by 1.1°, and the overbite increased by 4.1 mm. Statistically significant changes were observed in the amount of vertical movement of the maxillary first molar, Frankfort-mandibular plane angle, and overbite. Three-dimensional (3D) dental cast analysis revealed that the maxillary first and second molars intruded, whereas the anterior teeth extruded, with the second premolar as an infection point. In addition, the maxillary molar was tipped distally by 2.9° and rotated distally by 0.91°. Statistically significant changes were observed in the amount of vertical movement of the central incisor, lateral incisor, canine and first molar, and molar angulation. From T1 to T2, no significant changes in cephalometric measurements or the 3D position of the maxillary dentition were observed. The maxillary and mandibular dentitions did not significantly change during post-treatment follow-up. Conclusions: Maxillary molar intrusion using mini-screws is an effective treatment for open bite correction, with the achieved occlusion demonstrating 3D stability at least 1 year after treatment.

Posttreatment Stability Following Facemask Therapy in Patients with Skeletal Class III Malocclusion: A Systematic Review.

Skeletal class III malocclusion is a challenging condition that orthodontists frequently come across. The facemask (FM) is a device commonly used to treat this malocclusion. However, the stability of this orthopedic correction remains unclear, and collective documentation of the short-, mid-, and long-term stability after FM therapy is necessary. The aim of the systematic review was to assess posttreatment stability following FM therapy in patients with skeletal class III malocclusion. Through a predefined search strategy, electronic searching was conducted in PubMed, Latin American and Caribbean Health Sciences Literature (LILACS), Cochrane, Ovid, Embase, Scopus, and Web of Science until 30th June 2022. Eligible study selection, data extraction, and evaluation of the risk of bias were performed independently by two review authors according to the Cochrane tool for assessing the risk of bias in randomized trials (RoB 2.0 tool) and the Risk of Bias in Nonrandomized Studies-of Interventions (ROBINS-I) tool for nonrandomized trials. A total of 14 studies were finally considered eligible. The systematic review revealed that the maxillo-mandibular differential reverted to class III. The maxillary changes achieved were variable, with SNA angles ranging between -0.7° and 1.9°. Changes in the mandible were greater with an increase in the SNB angle ranging between 0.33° and 3.62°. The lower anterior facial height increased. The maxillary and mandibular incisors were proclined, and the overjet and overbite decreased. The soft tissue changes were insignificant. The effects of FM therapy were found to be stable in the short-term follow-up period. The long-term follow-up revealed that the effects of FM therapy remained stable for the maxilla. However, the mandible continued to grow in a horizontal and unfavorable direction until the adolescent growth spurt. The major variable that determines the long-term success of FM therapy is the amount and direction of mandibular growth during the adolescent growth spurt. More focus on restricting unfavorable mandibular growth and duration of retention is needed for post-FM therapy. PROSPERO (CRD42021218960). Raghupathy Y, Ananthanarayanan V, Kailasam V, et al. Posttreatment Stability Following Facemask Therapy in Patients with Skeletal Class III Malocclusion: A Systematic Review. Int J Clin Pediatr Dent 2023;16(6):897-907.

Long-term skeletodental changes with early and late treatment using modified C-palatal plates in hyperdivergent Class II adolescents.

To compare skeletodental changes between early and late treatment groups using modified C-palatal plates (MCPP) and long-term retention outcomes in hyperdivergent Class II adolescents. Seventy-one hyperdivergent Class II patients were divided into four groups according to treatment modality and treatment timing: group 1, early treatment with MCPP (n = 16; 9.9 ± 0.9 years); group 2, late treatment with MCPP (n = 19; 12.3 ± 0.8 years); group 3, early treatment with headgear (HG; n = 18; 9.6 ± 0.8 years); and group 4, late treatment with HG (n = 18; 12.1 ± 1.2 years). Lateral cephalograms were taken and skeletal and dental variables were measured. For statistical analysis, paired t-tests, independent t-tests, and multiple regression were performed. The early MCPP group showed a more significant decrease in mandibular plane angle than the late MCPP group did, and vertical control was more efficient in the early group than in the late group. In the MCPP groups, both FMA and SN-GoGn were increased with late treatment but decreased with early treatment, and the difference was statistically significant (P < .01). The early-treatment MCPP group had a significant decrease in SN-GoGn of 0.6° compared with an increase of 1.7° in the early treatment HG group (P < .01). Posttreatment stability of both the early and late MCPP groups was maintained in long-term retention. Early MCPP showed more significant vertical control than late MCPP. However, there was no difference in long-term stability between early and late groups.

Comparison of posttreatment stability after total mandibular arch distalization with mini-implants and mandibular setback surgery.

To compare posttreatment stability in skeletal Class III patients between those treated by total mandibular arch distalization (TMAD) with buccal mini-implants and those by mandibular setback surgery (MSS). The samples included 40 Class III adults, 20 treated by TMAD using buccal interradicular mini-implants and 20 treated with MSS. Lateral cephalograms were taken at pretreatment, posttreatment, and at least 1-year follow-up, and 24 variables were compared using statistical analysis. Mandibular first molars moved distally 1.9 mm with intrusion of 1.1 mm after treatment in the TMAD group. The mandibular incisors moved distally by 2.3 mm. The MSS group exhibited a significant skeletal change of the mandible, whereas the TMAD group did not. During retention, there were no skeletal or dental changes other than 0.6 mm labial movement of the mandibular incisors (P < .05) in the MSS group. There was 1.4° of mesial tipping (P < .01) and 0.4 mm of mesial movement of the mandibular molars and 1.9° of labial tipping (P < .001) and 0.8 mm of mesial movement of the mandibular incisors in the TMAD group. These dental changes were not significantly different between the two groups. The TMAD group showed a slightly decreased overjet with labial tipping of the mandibular incisors and mesial tipping of the first molars during retention. Posttreatment stability of the mandibular dentition was not significantly different between the groups. It can be useful to plan camouflage treatment by TMAD with mini-implants in mild-to-moderate Class III patients.

Stability of anterior open bite cases treated with upper and lower extrusion arches in adults: a follow-up study.

To investigate the post-treatment stability of anterior open bite (AOB) cases treated with upper and lower extrusion arches in adults. 23 patients with AOB were treated with extrusion arches and evaluated for dentoskeletal changes using lateral cephalometric radiographs before treatment (T0), after treatment (T1), and 12 months post-treatment (T2). Patients received bondable tongue spurs and vacuum-formed retainers as post-treatment retention/stability measures for 12 months. Post-treatment stability was further assessed qualitatively by the Photographic Openbite Severity Index. All the cases showed positive overlap between the anterior teeth at the end of orthodontic treatment, and 20 of 23 treated patients attended the recall visit after 12 months. A total of 85% of the cases maintained positive overlap at least 1 year post-treatment, 10% showed edge-to-edge bite, and only 5% showed no overbite. Treatment of AOB in adults with extrusion arches proved to be stable 1 year post-treatment. Changes in the overbite after 1 year of follow-up were not significant.

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

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). 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 23patients: group Ex consisted of 10male and 13female patients (13.4 ± 1.6years old) with extraction of lower first premolars and group NonEx consisted of 11male and 12female patients (13.4 ± 3.9years old) without dental extractions. The patients' dental models and photographs were assessed at T0(pretreatment), T1(the end of active orthodontic treatment: 3.3 ± 1.0years in the Ex and 2.3 ± 0.8years in the NonEx group) and at T2(1year 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. 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 arelapse 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. Areduction of IMW was recorded in the Ex group (-1.89 ± 1.82 mm) during active treatment (P < 0.05), which remained stable 1year 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. Intergroup comparison revealed that ICW remained stable 1year posttreatment in the Ex group, whereas high relapse of ICW was recorded in the NonEx group. Furthermore, risk of arelapse of LII appears to be higher in cases with arelapse of the ICW.

The Influence of Occlusal Adjustment on Long-term Post-treatment Stability of Orthodontic Treatment

Objective: This study aimed to compare the long-term occlusal stability in patients treated orthodontically with and without occlusal adjustment. Material and Methods: This observational study followed the STROBE guidelines. The sample comprised 77 patients with class I malocclusion treated without dental extractions and without signs and symptoms of temporomandibular joint dysfunction (TMD), divided into two groups. Group 1 with occlusal adjustment comprised 37 patients, 16 males and 21 females, with mean initial, final, and post-retention ages of 18.33 (s.d.=3.96), 20.99 (s.d.=3.33), and 25.79 years (s.d.=3.34), respectively. The treatment time was 2.66 years (s.d.=1.57), and the time of post-retention evaluation was 4.80 years (s.d.=1.10). Group 2, without occlusal adjustment involved 40 patients, 21 males and 19 females, with mean initial, final, and post-retention ages of 18.07 (s.d.=3.03), 20.75 (s.d.=3.54), and 25.89 (s.d.=3.73) years, respectively. The treatment time was 2.68 years (s.d.=1.09) and the time of post-retention evaluation was 5.14 years (s.d.=1.36). The PAR and Little irregularity indices were measured in the initial, final, and post-retention dental casts. Intergroup comparison was performed using the independent t-test. Results: There was no statistically significant difference observed in the intergroup comparison of the PAR and Little irregularity indexes in all phases and periods evaluated. Conclusion: There was no significant difference found in the long-term post-treatment crowding and occlusal relapse between class I patients treated with orthodontic non-extraction with and without occlusal adjustment. The occlusal adjustment did not influence the alignment and occlusal post-retention stability.

Comparison of Posttreatment Stability Between Mandibular Setback Surgery-Early and Conventional Surgery in Class III Patients: A 4.6-Year Follow-Up.

This retrospective study aims to compare long-term stability between the mandibular setback surgery-early (MSE) approach, involving minimal orthodontics, and the mandibular setback conventional surgery (MCS) approach, involving sufficient orthodontics, in Class III patients with mandibular prognathism. Among 210 patients who underwent orthognathic surgery, a total of 40 subjects were enrolled based on standardized inclusion criteria: only mandibular surgery, <5 mm setback difference between right and left of the mandible, orthodontics with fixed appliances, and more than 2 years of follow-up after treatment. These patients were allocated to the MSE (n = 20) and MCS groups (n = 20) according to the duration of presurgical orthodontics. Changes in cephalometric measurements were compared between the MSE and MCS groups before surgery (T0), 1 month after surgery (T1), at the end of treatment (T2), and posttreatment retention (T3). The MSE and MCS groups had a mean presurgical orthodontic duration of 2 and 9.5 months, respectively. From T1 to T2, the MSE group showed a significantly larger forward movement of the mandible than the MCS group (2.1 versus 0.7 mm; P < 0.001). In addition, from T2 to T3 (average 4.6 years), the MSE group presented anterior relapse of 0.6 mm in the mandible, but there were no statistically significant intergroup differences. Although the MSE group showed greater postsurgical forward mandibular relapse than the MCS group, the two groups exhibited similar skeletal and dental stability during the posttreatment retention.

EXTRACTIONS IN ORTHODONTICS: LITERATURE REVIEW

Tooth extractions for orthodontic purposes has been a topic discussed for over a hundred years and, currently, the criteria that determine the choice of this form of treatment go beyond the analysis of models and the position that the teeth are in the bone base. The aim of this study was to analyze the indications for extractions, which teeth are extracted most frequently, and post-treatment stability. The study was developed from an electronic search in PubMed/Medline and Google Scholar databases. Articles published over a 10-year period were selected that addressed extractions in the treatment plan. Duplicate articles in both databases and those that did not address the topic of Extractions were excluded. 468 articles were found in PubMed and 152 in Google Scholar, 472 were excluded, 153 articles were examined, reaching the selection of 37 articles and, of these, only 12 were used for the development of this work. The extractions are indicated in cases of dental and skeletal discrepancies, protrusion or biprotrusion and ortho-surgical treatments. The main teeth to be extracted are the maxillary premolars due to their location in the arch and post-treatment stability was similar to cases where extractions are not chosen in the treatment plan.

Adhesion Properties and Stability of Non-Polar Polymers Treated by Air Atmospheric-Pressure Plasma.

Atmospheric-pressure plasma (APP) has advantages for enhancing the adhesion of polymers and has to provide uniform, efficient treatment, which also limits the recovery effect of treated surfaces. This study investigates the effects of APP treatment on polymers that have no oxygen bonded in their structure and varying crystallinity, aiming to assess the maximum level of modification and the post-treatment stability of non-polar polymers based on their initial structure parameters, including the crystalline-amorphous structure. An APP reactor simulating continuous processing operating in air is employed, and the polymers are analyzed using contact angle measurement, XPS, AFM, and XRD. APP treatment significantly enhances the hydrophilic character of the polymers, with semicrystalline polymers exhibiting adhesion work values of approximately 105 mJ/m2 and 110 mJ/m2 for 0.5 s and 1.0 s exposure, respectively, while amorphous polymers reach approximately 128 mJ/m2. The maximum average oxygen uptake is around 30%. Short treatment times induce the roughening of the semicrystalline polymer surfaces, while the amorphous polymer surfaces become smoother. The polymers exhibit a limit to their modification level, with 0.5 s exposure being optimal for significant surface property changes. The treated surfaces remain remarkably stable, with the contact angle only reverting by a few degrees toward that of the untreated state.

Stability of Class II malocclusion treatment with Class II elastics

The objective of this study was to compare the long-term cephalometric stability after successful therapy of nonextraction Class II malocclusion with elastics and with headgear. The sample comprised 43 patients with Class II malocclusion and was divided into 2 groups. The elastic group (EG) consisted of 20 patients treated with fixed appliances associated with Class II elastics, and the headgear group (HG) consisted of 23 patients treated with fixed appliances and extraoral headgear. Pretreatment, posttreatment, and long-term posttreatment lateral radiographs were evaluated; t tests were used to compare the long-term posttreatment changes between the groups. The groups were matched regarding initial age, time of long-term posttreatment evaluation, initial malocclusion severity, quality of treatment result, and all pretreatment cephalometric variables. Intergroup comparisons of long-term posttreatment changes showed that the HG group presented significantly greater mandibular protrusion, occlusal plane angle decrease, and maxillary molar mesialization. However, long-term posttreatment stability was similar in overjet, overbite, and molar relationships. Nonextraction Class II malocclusion treatment with elastics or extraoral headgear have similar long-term posttreatment stability.

The development of a novel Orthodontic Alignment Index and its use to evaluate the effect of residual overjet on the stability of the alignment of the maxillary anterior dentition

BackgroundIt is thought that achieving a normal overjet may help to stabilise the alignment of the maxillary anterior dentition. Little’s Irregularity Index is limited in assessing discrete post-orthodontic changes, fails to account for reciprocal rotations and is not sensitive to dental changes in three planes. A more holistic tool for the assessment of post-treatment change is therefore required.AimTo compare the post-treatment stability of maxillary anterior dental alignment in subjects treated either to a Class I incisor relationship or an increased overjet (> 4 mm) following fixed appliance-based orthodontics using a novel measurement tool.Materials and methodsThe Orthodontic Alignment Index (OAI) was developed and validated using a panel of 63 raters. The new index accounts for a range of weighted features including contact point displacement, spacing, reciprocal rotations, inclination, angulation and vertical discrepancy. A retrospective cohort study was undertaken at the Institute of Dentistry, Queen Mary University of London. Recruitment took place over a 4-year period. All participants had removable retainers in the maxillary arch only. The stability of maxillary anterior teeth was assessed using Little’s Irregularity Index (LII) and the OAI. Subjects were recruited at least 12 months following completion of dual-arch fixed appliance-based treatment.ResultsEighty-two participants were included with a positive correlation observed between LII and OAI at the 12-month post-treatment review with a 1-mm increase in LII associated with a 2-point increase in the OAI (P < 0.001). Limited relapse was observed in both groups: normal overjet group (OAI = 1.28; LII = 0.52); residual overjet group (OAI = 0.88; LII = 0.47). Median regression analysis failed to identify a significant association between an increased overjet at debond and the alignment of the maxillary anterior segment when assessed with OAI (P = 0.389) and LII (P = 0.577). Furthermore, age, gender, extraction protocols and retention regime were not predictive of post-treatment change.ConclusionsUsing a novel index (OAI) and LII, there was limited post-treatment relapse in alignment of the maxillary anterior dentition over a 12-month period. Based on this retrospective evaluation, achieving a normal overjet at the end of treatment may have little bearing on the post-treatment stability of maxillary anterior alignment at 12 months.

Relapse in class II orthognathic surgery: a systematic review

ObjectivesRelapse after orthognathic surgery seems to depend on diverse factors. Proffit et al. postulated in 2007 a “hierarchy of stability” (Head Face Med 6:66, 2007), ranking posttreatment stability after various orthognathic procedures, but no systematically reviewed evidence was provided. Therefore, the aim of this review was to investigate the extent of class II relapse in orthognathic surgery of Angle class II patients depending on the surgical procedure used.Materials and methodsSeven databases were searched for randomized and controlled clinical trials to compare relapse in surgical procedures for Angle class II patients. After duplicate study selection, data extraction and risk of bias assessment were performed with the ROBINS-I tool as well as data synthesis by frequency distribution, followed by assessment of the quality of evidence with GRADE.ResultsFour non-randomized cohort-studies with a total of 132 patients were included. Bimaxillary procedures as well mandibular advancement procedures proved to be highly stable. Single jaw interventions at the maxilla achieved mostly stable results at sagittal dimension and problematic stability in the vertical dimension. However, there were only limited data available with low quality of evidence.ConclusionsLimited existing evidence of low quality partly support the postulated hierarchy of stability of Proffit et al. (Head Face Med 6:66, 2007) and indicates that a surgical correction of class II dysgnathia with bimaxillary procedures and mandibular advancement seems to be highly stable. However, additional studies are needed to address the relation between relapse and surgical orthognathic intervention.Trial registration PROSPERO 2019 CRD42019144873.

Efficiency of maxillary total arch distalization using temporary anchorage devices (TADs) for treatment of Class II-malocclusions: A systematic review and meta-analysis

To evaluate the treatment effects and post-treatment stability of the maxillary total arch distalization using TADs during the non-extraction treatment of class II malocclusions. Study involved an electronic search followed by hand searching for randomized and non-randomized clinical studies about maxillary total arch distalization using TADs. After data extraction and risk of bias assessment, meta-analysis was performed for dental, skeletal and soft tissue changes using the Generic-inverse variance approach by use of the mean difference and random-effect model. In total, 1788 articles were identified, 88 full texts were screened and 22 studies were found eligible; 17 of them were included in the quantitative analysis. The means of distalization/distal tipping of the maxillary first molar were 4mm/3.17° in adults, 3.95mm/1.61° in adolescents after treatment with the Modified C-Palatal plate (MCPP), while they were 2.44mm/2.91° with the inter-radicular mini-screws. Both MCPP's treatment in adults and inter-radicular mini-screws resulted in significant intrusion of U6 (1.64 and 0.75mm, respectively), while insignificant extrusion of U6 was resulted in adolescents treated by MCPP. MCPP appliances resulted in palatal inclination/extrusion of maxillary incisors U1 (6.77°/2mm in adults, 7.46°/3.14mm in adolescents). In contrast, inter-radicular mini-screws resulted in less palatal less amount of palatal inclination/insignificant intrusion of U1 (2.42°/0.14mm). MCPP treatment also resulted in significant changes in the skeletal measurements (SNA, ANB, occlusal and mandibular planes). Insignificant differences were found between subgroups in the retraction amount of maxillary incisors, as well as the upper and lower lips. In the follow-up of adolescents treated with MCPP, a significant amount of mesial movement, mesial tipping, and extrusion (2.94mm, 2.84°, and 3.94mm, respectively) was found. However, skeletal and occlusal corrections of the Class II relationship were maintained. Maxillary total arch distalization using TADs can be an effective and stable treatment procedure. However, RCTs or prospective cohort studies are highly recommended to establish a clinical evidence regarding their efficiency.

Posttreatment stability of an anterior open-bite by molar intrusion compared with 2-jaw surgery - a retrospective study.

This study aimed to compare post-treatment stability in patients with anterior open-bite (AOB) between those treated surgically (orthognathic 2-jaw surgery) and non-surgically (molar intrusion using orthodontic miniscrews). All subjects had initial overbite (OB) < -1mm and lateral cephalograms taken before treatment (T0), immediately after AOB correction (T1), after orthodontic treatment (T2), and at least 1year after treatment (T3). The non-surgical group was enrolled retrospectively; then, the surgical group was matched by OB, sex, and age to the non-surgical group (n = 21 each). Changes in cephalometric measurements during treatment (T1-T0), finishing (T2-T1), and retention (T3-T2) periods were compared between two groups. OB increased by 4.5-5.1mm during the treatment period with 3.3mm upward movement of the maxillary first molar (U6) in both groups. Changes in OB were not significantly different between the groups: 0.5-0.9mm increase during the finishing period but 1.0mm decrease during the retention period (P > 0.05). U6 moved 0.5mm downward in non-surgical group and 0.1mm upward in the surgical group during the finishing period, and 1.0mm and 0.4mm downward in the non-surgical and surgical groups, respectively, during the retention period. Post-treatment stability of AOB was similar for surgical and non-surgical methods (76.8 - 78.7%), although U6 moved more downward in the non-surgical group than in the surgical group. AOB without severe skeletal deformity can be treated by either molar intrusion or orthognathic surgery with similar treatment outcome and stability.