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Objectives: The objective of this study was to evaluate if there are any morphologic, positional, and volumetric differences in the temporomandibular joint (TMJ) of patients with unilateral posterior crossbite (UPC) compared to controls. Another objective was to analyse the discrepancy in the TMJ between the crossbite versus non-crossbite side in UPC versus right and left sides in controls. Additionally, this study aimed to evaluate the differences in the bone density at the masseteric insertion site at the angle of mandible in the UPC group and control group., Material and Methods: One hundred and thirty-two CBCTs were analysed with 66 patients in UPC group and 66 patients in control group (non-crossbite). Temporomandibular joint spaces - Anterior joint space (AJS), Superior joint space (SJS), Posterior joint space (PJS), Medial joint space (MJS), Middle joint space (MiJS), and Lateral joint space (LJS) were measured. Additionally, bone density at angle of mandible and volume of mandibular condyle were evaluated. The measurements were compared between the groups as well as between the crossbite and non-crossbite sides within the UPC group and between right and left sides within the control group. Furthermore, the associations between UPC and changes in TMJ regarding joint space availability, bone density, condylar head volume, and the effects of sex and age were evaluated using regression analysis., Results: It was observed that UPC group showed a greater condylar volume, than the control group. Additionally, a larger mean discrepancy was observed between the crossbite side and non-crossbite side within the UPC group concerning condylar volume than controls. Concerning age, condylar volume was observed to be larger in adults than children. Adults showed significantly greater bone density and condylar volume than adolescents. Concerning sex, it was observed that males showed a larger SJS (right), MiJS, LJS, and bone density at the mandibular angle than females., Conclusion: There is a difference in the TMJ parameters particularly condylar volume in patients with UPC compared to controls., (Copyright © 2024 CEO. Published by Elsevier Masson SAS. All rights reserved.)

Introduction: This study compared treatment efficacy for specific tooth movements between 2 clear aligner systems (Clarity [3M Oral Care Solutions, St Paul, Minn] and Invisalign [Align Technology, San Jose, Calif])., Methods: The study sample included 47 patients (7 males, 40 females; mean age, 36.57 ± 15.97 years) treated with Invisalign and 37 (4 males, 33 females; mean age, 34.30 ± 16.35 years) treated with Clarity aligners who completed their first set of aligners and had an initial refinement scan. Initial and predicted models were obtained from the initial simulated treatment plan. The first model of the refinement scan was labeled as achieved. SlicerCMF software (version 3.1; http://www.slicer.org) was used to superimpose the achieved and predicted digital models over the initial ones with regional superimposition on the relatively stable first molars. Nine hundred forty teeth in the Invisalign system were measured for horizontal, vertical, and angular movements and transverse width and compared with similar measurements of 740 teeth for the Clarity aligners. The deviation from the predicted was calculated and compared between both systems., Results: The deviation achieved from the predicted was significant between the groups for the mandibular interpremolar and intercanine widths (P <0.05). Clarity aligners significantly undercorrected rotations compared with Invisalign for the mandibular first premolars, mandibular canines, maxillary canines, and maxillary central incisors. There was no statistically significant difference between the groups for the achieved vs predicted movements in the horizontal and vertical planes (P >0.05)., Conclusions: The efficacy of clear aligner therapy systems (Clarity and Invisalign) in treating mild and moderate malocclusions was comparable. Deviation of the achieved movements from the predicted was greatest for rotational and vertical movements., (Copyright © 2023 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Objectives: To investigate aligner treatment protocols among orthodontists in the United States and Canada and assess the factors influencing clinician choices in aligner systems, treatment protocols, and targeted malocclusions for aligners., Materials and Methods: A validated online questionnaire was developed specifically for this research and consisted of three sections. Section 1 evaluated demographics and experience with aligners. Section 2 assessed patient selection and demands and clinician confidence in treating various malocclusions with aligners. Section 3 evaluated treatment protocols used by clinicians. The American Association of Orthodontists Partners in Research Program distributed the survey via e-mail to active members in the United States and Canada., Results: A total of 160 providers completed the survey. Aligners were used by 65.00% of respondents, with the Invisalign system the most popular (81.25%). Aligners were mostly used for adults (97.50%). Tipping was ranked as the easiest movement (1.79 ± 1.35). Extrusion (4.34 ± 1.53) and root movement (4.31 ± 1.27) were ranked as the most difficult. Most were confident treating mild (98.8%) and moderate (82.5%) crowded cases, spacing (96.9%), and anterior crossbite (85%). Of the providers, 58.12% recommended aligners to be changed weekly. Respondents who were confident addressing some of the severe malocclusions were more likely to use Invisalign., Conclusions: Invisalign is the most popular aligner system, and clinicians seem to be confident using it. Providers are aware of the pitfalls of aligners; they find it challenging to perform root movement and extrusion, and they seem confident treating mild to moderate malocclusions. They avoid complex cases with impactions and severe skeletal problems., (© 2023 by The EH Angle Education and Research Foundation, Inc.)

Objective: The objectives of the study were to evaluate the survival rates for lower lingual retainers (LLRs) and to establish a correlation between patients' treatment-related factors (age, sex, malocclusion, appliance used for treatment, teeth bonded, retention protocols) to the survival of LLRs., Materials and Methods: A total of 765 subjects [474 females and 291 males: mean age = 24.29 ± 10.67 years] between 2013 and 2022 were included. A customized data collection form was utilized to gather the data from the electronic health record (EHR) of subjects. Patient-related factors, crowding or spacing, deep bite or open bite and duration of treatment were extracted from patients' files. Kaplan-Meier estimator was used for the survival function, whereas Cox proportional hazards regression models were used to associate risk factors with retainer survival., Results: 328 (42.9%) subjects had their LLRs failed, and the survival period was on average 17.37 ± 22.85 months. On the other hand, the follow-up period for the retainers that did not fail was on average 47.19 ± 23.66 months. 192 (28.3%) subjects had segment failure (retainer detached from 3 teeth or less), while 51 (7.5%) subjects had failures in more than 3 teeth (complete). None of the evaluated clinical variables were significantly associated with LLRs failure except for the bite category (P = .013) and the appliance used for treatment (P < .001)., Conclusion: Success rate for LLRs was 57.1% over 47.19 months, failure rate was 42.9% over 17.37 months. The presence of deep bite and treatment with aligners were significantly associated with increased failure rate., (© 2022 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Over the past two decades clear aligner-based treatment has received remarkableattention from the orthodontic profession and more so from general practitioners.Different companies have emerged using vigorous advertisement to promote theirproducts mainly to patients and clinicians through social media. A variety of concepts,methods, and adjuncts have been introduced to enhance the efficacy andeffectiveness of clear aligners. However, the accuracy of tooth movement (vspredicted) with aligners still hovers around 50%. Fixed appliances fare much better onaccuracy and predictability of treatment. Why is there a discrepancy betweenexpected and actual outcomes? This paper utilizes 'first principles' and the existingevidence to unravel some of the key drawbacks of aligner-based therapy. Severalshortcomings in the biomechanical properties of aligner material (thermoplastics) thataffect clinical performance are discussed. Based on the first principles of alignerbiomechanics, this paper provides clinical insights for improving predictability and effectiveness of aligner therapy., (Published by Elsevier Inc.)

Class III malocclusion when accompanied with transverse and vertical maxillomandibular discrepancies such as posterior crossbite and vertical open bite leads to complicated orthodontic treatment. Proper diagnosis and treatment planning are important in such patients for a successful orthodontic outcome. A common treatment approach for patients with class III malocclusion is to wait for the completion of growth and plan orthognathic surgery in conjunction with orthodontic treatment. However, performing no treatment and waiting for growth to be completed during teen years could lead to negative effects on the patient's self-esteem. In such cases, a non-surgical option with skeletal anchorage could be used to correct the malocclusion without surgical intervention. This case report shows that in patients with severe class III malocclusion, skeletal anchorage can be used for the correction of anterior crossbite with intermaxillary elastics., (Copyright © 2021 CEO. Published by Elsevier Masson SAS. All rights reserved.)

Aim: The aim is to present the treatment of an 11-year-old, hyperdivergent, Class II division I, female patient with a history of enlarged adenoids and severe arch length discrepancies., Methods: The malocclusion was treated by upper right molar distalisation and first premolar extractions. Accurate diagnosis, meticulous treatment planning and an unexpectedly favourable growth pattern lead to a highly satisfactory outcome., Results: There was a significant improvement in facial profile, overjet and occlusion. A significant decrease in the mandibular plane angle was recorded, without the use of any extra-oral appliance., Conclusion: The treatment results remained stable after six years of retention following maintenance of the favourable growth pattern.

Vertical dimension control with fixed appliance mechanotherapy has always been a matter of concern in moderate to severe high-angle patients with severe proclination of the anterior teeth. Extrusion of the posterior teeth is an inevitable sequela of conventional mechanics in such patients, especially if they are adults. This article reports on 3 patients who were treated with mini-implants (diameter, 1.3 mm; length, 8 mm) placed between the roots of the second premolar and the first molar for en-masse retraction of the anterior teeth. The biomechanical force system that developed not only maintained absolute anchorage, but also provided effective control over the posterior dentoalveolar dimension so that dramatic improvement in facial esthetics could be achieved. Small but significant autorotation of the mandible was noted; this led to increased chin prominence in all 3 patients. With accurate diagnosis and treatment planning, mini-implant anchorage can be a possible alternative to orthognathic surgery in similar borderline patients., (Copyright (c) 2010 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.)

Introduction: The purpose of this randomized controlled trial was to quantify the treatment effects of en-masse retraction of anterior teeth with mini-implants as anchor units in bialveolar dental protrusion patients undergoing extraction of all 4 first premolars., Methods: A total of 40 patients (mean age, 17.5 years; SD, 3.2 years) were randomly assigned either to group 1 (G1), anterior space closure with mini-implants as anchor units, or group 2 (G2), anterior space closure with conventional methods of anchorage (without mini-implants). Skeletal, dental, and soft-tissue changes were analyzed in both groups on lateral cephalograms taken before retraction and after space closure., Results: Student paired and unpaired t tests were used to analyze the treatment changes in the 2 groups. For the skeletal parameters, a statistically significant decrease in the facial vertical dimensions was seen in G1, but the variables in G2 showed no significant differences (P >0.05). Anchorage loss, in both the horizontal and vertical directions, was noted in G2, whereas G1 showed distalization (anchorage gain) and intrusion of molars. Although the soft-tissue response was variable, facial convexity angle, nasolabial angle, and lower lip protrusion had greater changes in G1. No differences were found in the amount of upper lip retraction between the groups (P >0.05)., Conclusions: Mini-implants provided absolute anchorage to allow greater skeletal, dental, and esthetic changes in patients requiring maximum anterior retraction, when compared with other conventional methods of space closure. The treatment changes were favorable. However, no differences in the mean retraction time were noted between the 2 groups.