Orthodontic treatment for deep bite and retroclined upper front teeth in children

The correlation analysis between incisal guidance angle and occlusal plane angles and temporomandibular joint morphology

OBJECTIVES

The correlations between the incisal guidance angle (IGA) and occlusal plane angles and temporomandibular joint (TMJ) morphology were investigated in adults with skeletal Class II division II malocclusion.

MATERIALS AND METHODS

CBCT images of 37 patients were analyzed. It included 19 cases of skeletal Class II division II malocclusion with low angle (study group) and 18 cases of skeletal Class I average angle (control group). The Invivo Dental 5 software was employed to acquire the data of the incisal guidance angle (IGA), occlusal plane angle (FH-OP), anterior occlusal plane angle (FH-AOP) and the TMJ measurement items.

RESULTS

The results of IGA, FH-AOP angle and FH-OP angle showed the study group > the control group (P < 0.05). There were statistically difference in the condylar mediolateral diameters, articular eminence inclination and height, and posterior joint spaces between two groups. No differences were revealed in the condylar anteroposterior diameters, the condylar inclination angle, condylar head width and height, condylar length, glenoid fossa depth and width between two groups. In the study group, IGA showed a moderate correlation with FH-AOP, a weak correlation with FH-OP and condylar mediolateral diameters. Meanwhile, there was a correlation between FH-AOP, FH-OP, and TMJ indicators.

CONCLUSIONS

The IGA was not only related to FH-AOP and FH-OP, but also to the condylar mediolateral diameters. In addition, there was a correlation between the occlusal plane angles and TMJ morphology in skeletal Class II division II low angle malocclusion.

CLINICAL RELEVANCE

For patients with skeletal Class II division II low angle malocclusion, adjusting the IGA and the occlusal plane angles could improve the esthetic appearance of the anterior teeth, occlusal function, and TMJ morphology.

Evaluation of the Best Method for Orthodontic Correction of Skeletal Deep Bites in Growing Patients: A Systematic Review

This review aimed to evaluate the currently available evidence regarding the best method of correcting deep bites in growing patients. In September 2023, a search was conducted electronically across the following databases: PubMed®, Web of Science™, Scopus®, Embase®, Google™ Scholar, and Cochrane Library. In this systematic review, randomized control trials (RCTs), controlled clinical trials (CCTs), and cohort studies of growing patients with deep bite malocclusion who received treatment with the primary objective of treating the deep bite were included. Risk of bias of the included studies was assessed using two different tools; one tool was applied for RCTs and the other one for the CCTs and cohort studies. One RCT, one CCT, and one cohort study were included (85 patients). The flat fixed acrylic bite plane was superior in terms of duration of treatment when compared to the inclined fixed acrylic bite plane and the utility arch with posterior intermaxillary elastics. Limited evidence indicates that the inclined fixed acrylic bite plane causes a significant increase in the lower incisor inclination and a significant increase in the angle between the mandible and the anterior cranial base (SNB). However, limited evidence indicates that the utility arch with posterior intermaxillary elastics causes a significant decrease in the angle between the maxilla and the anterior cranial base (SNA). Regarding the vertical skeletal changes, it was found that the three methods were comparable; in each case, the vertical dimension of the face increased because of a significant increase in the lower first molar height. There is a need for further studies to strengthen the evidence of the treatment efficacy of the employed methods, with more RCTs to be conducted in this regard.

Evaluation of Mandibular Projection in Class II Division 2 Subjects Following Orthodontic Treatment Using Clear Aligners

AIM

The purpose of this study was to evaluate the mandibular growth and/or projection following maxillary incisor proclination, overbite correction, and maxillary dentoalveolar expansion without the use of any class II mechanics, in growing class II division 2 patients treated with clear aligners.

MATERIALS AND METHODS

Before and after treatment cone-beam computed tomographic (CBCT) generated lateral and posteroanterior cephalograms of thirty-two patients with skeletal class II division 2, 16 in the treatment group and 16 in the untreated group, were reviewed to evaluate treatment-related changes. Upper incisors were proclined and protruded, as well as upper arch expansion and overbite correction were performed as part of their regular treatment. Cephalometric analysis was performed to evaluate skeletal and dental changes. Unpaired statistical t-tests were performed to determine if significant skeletal class II correction was achieved in the treatment group.

RESULTS

In the treatment group, after treatment, the upper incisors became more proclined and protruded, and the inter-molar width increased while the overbite was reduced compared to the control group. An increase in skeletal mandibular growth and forward projection was also observed, thus contributing to an improvement of the sagittal skeletal relationship as evidenced by ANB and Wits values compared to the control group.

CONCLUSION

A combination of upper incisor proclination, correction of deep overbite, and maxillary dentoalveolar expansion using clear aligners appears to contribute to an improvement of the skeletal class II relationship in growing patients with class II division 2.

CLINICAL SIGNIFICANCE

This study shows that unlocking the mandible by correcting a deep overbite, proclining upper incisors, and expanding the upper arch in growing class II division 2 patients can improve skeletal class II using clear aligners. How to cite this article: Mirzasoleiman P, El-Bialy T, Wiltshire WA, et al. Evaluation of Mandibular Projection in Class II Division 2 Subjects Following Orthodontic Treatment Using Clear Aligners. J Contemp Dent Pract 2024;25(4):295-302.

Three-dimensional spatial analysis of the temporomandibular joint in adult patients with Class II division 2 malocclusion before and after orthodontic treatment: a retrospective study

BACKGROUND

To investigate changes in the three-dimensional (3D) spatial morphology of the temporomandibular joint (TMJ) and condyle position in adult patients with Class II division 2 malocclusion using a 3D spatial measurement method and to investigate the similarities and differences in the effects of fixed appliance and clear aligner treatments on the TMJ.

METHODS

Cone-beam computed tomography (CBCT) data of 47 adult patients with Class II division 2 malocclusion (25, fixed appliance group; 22, clear aligner group) were collected before and after treatment. Mimics 21.0 was used to reconstruct the TMJ 3D model. Fourteen measurement items, such as the anterior, upper, and posterior joint spaces, were measured directly on the 3D model and compared.

RESULTS

Post-orthodontic treatment, the shape and position of the condyle changed in adult patients with Class II division 2 malocclusion. Reduction in the anterior joint space and increase in the posterior joint space after orthodontic treatment were significant in both fixed appliance and clear aligner treatments; the condyle moved forward to the center of the fossa. The superior joint space and depth of the glenoid fossa increased after clear aligner treatment, but there was no significant change after fixed appliance treatment.

CONCLUSIONS

The condylar shape and position in patients with Class II division 2 malocclusion changed significantly post-treatment, indicating that the condyle undergoes adaptive reconstruction during orthodontic treatment in these patients. These results provide a reference for diagnosis, design of treatment plan, and monitoring of treatment in orthodontic clinics.

Effectiveness of clear aligners in achieving proclination and intrusion of incisors among Class II division 2 patients: a multivariate analysis

BACKGROUND

The predictability of incisor movement achieved by clear aligners among Class II division 2 patients is poorly understood. The aim of this retrospective study was to determine the effectiveness of clear aligners in proclining and intruding upper incisors and its influencing factors.

METHODS

Eligible patients with Class II division 2 malocclusion were included. For clear aligner therapy, three types of incisor movements were designed: proclination, intrusion and labial movement. Pre-treatment and post-treatment dental models were superimposed. The differences between predicted and actual (DPA) tooth movement of incisors were analyzed. Univariate and multivariate linear regression were used to analyze the potential influencing factors.

RESULTS

A total of 51 patients and their 173 upper incisors were included. Actual incisor proclination and intrusion were less than predicted ones (both P < 0.001), while actual labial movement was greater than predicted one (P < 0.001). Predictability of incisor proclination and intrusion was 69.8% and 53.3%, respectively. Multivariate linear regression revealed that DPA of proclination was significantly positively associated with predicted proclination (B = 0.174, P < 0.001), ipsilateral premolar extraction (B = 2.773, P < 0.001) and ipsilateral canine proclination (B = 1.811, P < 0.05), while negatively associated with molar distalization (B = - 2.085, P < 0.05). The DPA of intrusion was significantly positively correlated with predicted intrusion (B = 0.556, P < 0.001) while negatively associated with labial mini-implants (B = - 1.466, P < 0.001). The DPA of labial movement was significantly positively associated with predicted labial movement (B = 0.481, P < 0.001), while negatively correlated with molar distalization (B = - 1.004, P < 0.001), labial mini-implants (B = - 0.738, P < 0.001) and age (B = - 0.486, P < 0.05).

CONCLUSIONS

For Class II division 2 patients, predicted incisor proclination (69.8%) and intrusion (53.3%) are partially achieved with clear aligner therapy. Excessive labial movement (0.7 mm) of incisors may be achieved. Incisor movement is influenced by predicted movement amount, premolar extraction, canine proclination, molar distalization, mini-implants and age.

Evaluation of efficacy of utility arch with inter-maxillary elastics for treating skeletal deep bite with retroclined upper incisors in the mixed dentition: a clinical randomized controlled trial

OBJECTIVES

To investigate the effectiveness of utility arch (UA) with inter-maxillary elastics compared with fixed anterior bite plane (FABP) for treating deep bite in brachy-facial children.

MATERIALS AND METHODS

This was a single-center, randomized controlled trial. Participants were children aged between 9 and 12 years with deep bite and a hypodivergent skeletal pattern. The sample was divided into the following two groups: (1) a UA group that was composed of patients with UAs with posterior inter-maxillary elastics and (2) an FABP group as a control. Outcomes were skeletal and dentoalveolar variables on cephalometric X-rays.

RESULTS

A total of 28 patients (13 boys, 15 girls) with a mean age of 10.66 years were enrolled. The treatment duration was 8.16 months in the UA group and 7.22 months in the FABP group. After treatment, the angle between the anterior cranial base and the mandible in the vertical plane increased significantly (P = .000) in both groups (about 1.97 degrees in the UA group and 2.75 degrees in the FABP group). Overbite decreased significantly in both groups (-2.1 m in the UA group and -3.64 m in the FABP group), but it decreased less significantly in the UA group than in the FABP group. The upper incisors flared significantly after treatment with both appliances (6.6 degrees in the UA group and 5.9 degrees in the FABP group).

CONCLUSIONS

Treatment of deep bite in children with a horizontal growth pattern by each of the appliances used in this study is effective. The mandible showed minor, significant backward rotation after treatment. The overbite decreased less in the UA group than in the FABP group.

Retention: taking a more active role

Retention may be particularly challenging after the correction of specific malocclusion features, such as tooth rotations, open bite and expansion, which are all inherently unstable. In this article, some indications for active retention are reviewed by highlighting a variety of clinical techniques and appliances. Active retention is discussed in relation to preservation of tooth alignment and in the three planes of space: sagittal, vertical and transverse. In some situations, an active retention regimen may be helpful to minimise or counteract relapse after orthodontic treatment and to improve patient satisfaction during the typically lengthy post-treatment period.

Controlling incisor torque with completely customized lingual appliances

PURPOSE

To test the null hypothesis of no significant deviation between the center of rotation (C_ROT) and the center of resistance (C_RES) during space closure in Angle class II division 2 subjects achieved using a completely customized lingual appliance (CCLA) in combination with class II elastics and elastic chains.

METHODS

This retrospective study included 29 patients (male/female 11/18; mean age 15.6 [13-27] years) with inclusion criteria of an Angle class II/2 occlusion of least of half of a cusp, maxillary dental arch spacing, completed CCLA treatment (WIN, DW Lingual Systems, Bad Essen, Germany) in one center with a standardized archwire sequence and use of class II elastics and elastic chains only. Maxillary incisor root inclination was assessed by X‑ray superimpositions of the maxilla at the beginning (T1) and the end (T3) of CCLA treatment. Using Keynote software (Apple®, Cupertino, CA, USA), the incisor's C_ROT was assessed with the point of intersection of the incisor axes (T1; T3) following vertical correction of overbite changes. C_RES was defined at 36% of the incisor's apex-incisal edge distance.

RESULTS

The null hypothesis was rejected: the mean C_ROT - C_RES difference was 52.6% (p < 0.001). The mean C_ROT was located at 88.6% (min-max 51-100%) of the incisor's apex-incisal edge distance. Although 6.9% of C_ROT were located between the C_RES and the alveolar crest, the vast majority (93.1%) were assessed between the alveolar crest and the incisal edge, or beyond.

CONCLUSION

CCLAs can create upper incisor palatal root torque even in cases in which lingually oriented forces applied incisally to the center of resistance of the upper incisors counteract these intended root movements.

Systematic reviews in orthodontics: Impact of the PRISMA for Abstracts checklist on completeness of reporting

INTRODUCTION

This study evaluated and compared the completeness of reporting of abstracts of orthodontics systematic reviews before and after the publication of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) extension for Abstracts Checklist (PRISMA-A).

METHODS

Abstracts of systematic reviews and meta-analyses in orthodontics published in PubMed, Latin American and Caribbean Health Sciences Literature, and the Cochrane Database of Systematic Reviews databases before March 23, 2018, that met the predefined inclusion and exclusion criteria, were evaluated using the 12 items of PRISMA-A, scoring each item from 0 to 2. Abstracts were classified into 2 groups: before and after publication of the PRISMA-A checklist. Three calibrated evaluators (intraclass correlation coefficient and kappa > 0.8) assessed the scores for compliance with the checklist. The number of authors, country of affiliation of the first author, performance of meta-analysis, and topic of the article were recorded. A regression analysis was performed to assess the associations between abstract characteristics and the PRISMA-A scores.

RESULTS

Of 1034 abstracts evaluated, 389 were included in the analysis. The mean PRISMA-A score was 53.39 (95% CI, 51.83-54.96). The overall score for studies published after the publication of the checklist was significantly higher than for studies published before (P ≤ 0.0001). The components returning significantly higher scores after publication of PRISMA-A were title (P = 0.024), information from databases (P = 0.026), risk of bias (P ≤ 0.0001), included studies (P ≤ 0.0001), synthesis of results (P ≤ 0.0001), interpretation of results (P = 0.035), financing and conflict of interest (P ≤ 0.0001), and registration (P ≤ 0.0001). These results showed the positive effect of PRISMA-A had on the quality of reporting of orthodontics systematic reviews. Nevertheless, the poor adherence revealed that there is still need for improvement in the quality of abstract reporting.

CONCLUSIONS

The quality of reporting of abstracts of orthodontic systematic reviews and meta-analyses increased after the introduction of PRISMA-A.