Class II subdivision with skeletal transverse maxillary deficit treated by single-sitting bone-borne appliance

Accuracy of maxillary molar distalization with clear aligners in three-dimension: a retrospective study based on CBCT superimposition

BACKGROUND

To measure the actual moving direction and displacement of the root and crown of maxillary teeth before and after treatment in molar distalization cases using clear aligners(CAs).

MATERIALS AND METHODS

This retrospective study included 28 adult patients who received maxillary distalization treatment with CAs. The pre- and post-treatment CBCT were superimposed and the crown and root of all maxillary teeth were marked. Achieved and predicted three-dimensional displacement of maxillary teeth were then compared using the paired t test. Mixed-effect model was used to explore the influence of different staging design (one-molar distalization vs. two-molar distalization) and anchorage (TAD vs. Class II elastic vs. no extra anchorage management).

RESULTS

Labial displacement happened to the anterior teeth even the palatal displacement was prescribed. Body distalization of maxillary posterior teeth could not be fully achieved as predicted. The premolars and molars achieved greater distal tipping, buccal inclination, and less distal displacement than predicted. In buccal-palatal dimension, the greatest buccal tipping tendency happened to the 2nd premolar and decreased toward the distal portion of the aligner. In the mesial-distal dimension, the highest accuracy of molar distalization was found in the 2nd molars while the lowest in the 1st premolars. No significant difference was found between two molar distalization patterns. Extra anchorage management devices could not diminish the difference between the predicted and achieved displacement.

CONCLUSIONS

The achieved molar distalization displacement and anterior teeth retraction is not as good as expected using CAs. The anterior and posterior anchorage loss cannot be completely avoided despite extra anchorage management devices are adopted. The potential reason for the correction of class II malocclusion needs further exploration.

Compliance with Headgear Evaluated by Force- and Temperature-Sensitive Monitoring Device: A Case-Control Study

The aim was to objectively assess compliance in patients prescribed headgear and evaluate the impact of monitoring awareness, treatment duration, gender, and age on compliance levels. A total of 22 patients with Class II malocclusion wore the headgear integrated with the force and temperature sensitive Smartgear monitoring system (Smartgear, Swissorthodontics AG, Cham, Switzerland). Patients were instructed to wear the headgear for 13 h daily over a 3-month period. Randomly, 11 patients were informed that they monitored and 11 were not informed. Data were organized using Microsoft Excel and analyzed using R for statistical estimates, graphs, and hypothesis testing. Smartgear recorded an average daily compliance of 6.7 h. No statistically significant differences were found in cooperation between study group and control group over the 3 months of treatment, regardless of gender and age. However, there was slight greater cooperation in the first month than in the other months, and patients ≤10 years of age had almost 2 h more cooperation than their older counterparts. Moreover, the informed group exhibited an average of 1.1 more hours of cooperation per day than the uninformed group, which may carry clinical significance. This cooperation primarily occurred at night and was found to be statistically significant. Compliance among young patients typically remained lower than the prescribed level, regardless of their gender and psychological maturity. Although an awareness of monitoring does not seem to improve compliance, implementing such systems could still offer dentists a valuable means of obtaining objective information about their patients' adherence.

Palatal skeletal anchorage: multiple applications with a single appliance

Using a single bone-borne maxillary appliance with twofold mechanics, that is, rapid palatal expander and nonfrictional distalizing appliance (Pendulum) is a valuable option to treat young-adult patients with poor compliance. In this particular case, the same appliance was used to disinclude 2.3, eliminating reaction forces on the arch. Therefore, the first expansive phase was followed by the distalizing phase. After enough space was obtained for the recovery of tooth 2.3, a triple-looped titanium-molybdenum alloy (TMA) spring was used to perform canine orthodontic traction. The core concept is that digital planning and optimal positioning of two palatal mini-screws can ensure a bicortical anchorage which, in turn, enabled to tolerate the different orthodontic phases. As a matter of fact, a tooth-bone-borne anchorage was followed by a pure bone-borne anchorage with no lost of stability.

Aligner hybrid orthodontic approach to treat severe transverse divergence in an adolescent girl: A case report

OBJECTIVE

To resolve a complex Class II case with unilateral crossbite through an aesthetic approach, namely a hybrid orthodontic treatment combining aligners with miniscrews and auxiliaries.

MATERIALS AND METHODS

A 14-year-old hypodivergent female patient with dental Class II and posterior crossbite presented for orthodontic treatment. The patient refused conventional fixed multibracket treatment and was therefore prescribed aligners used in association with miniscrews and sectional lingual appliances. Pre- and post-treatment records and 2-year follow-up records are presented.

RESULTS

Treatment objectives, namely ideal occlusion and improved profile, were achieved in 12 months. Post-treatment panoramic radiography showed good root parallelism, and no sign of either crestal bone height reduction or apical root resorption. The patient was satisfied with the functional and aesthetic outcomes, which were stable at 2 years.

CONCLUSION

This case report illustrates that a hybrid aligner approach may be used to treat posterior crossbite and class II malocclusion with reduced treatment times, optimal oral hygiene and excellent aesthetics.

Predictability of crowding resolution in clear aligner treatment

BACKGROUND

To assess the predictability of crowding resolution and the efficacy of different strategies to gain space during clear aligners treatment.

METHODS

A total of 10 clinicians were randomly recruited using the Doctor Locator by Align Technology (California). For each clinician, four consecutive patients treated with aligners and manual stripping were selected for a total of 40 subjects. Thus, 80 arches were collected and uploaded on the Orthoanalyzer software for arch measurements. The data were gained on the starting arch form (T0), on the virtual arch developed with digital planning (vT1), and on the arch form achieved at the end of the aligner sequences (T1). The following parameters were scored: Little's Irregularity Index, transversal arch diameters, (intercuspid, interpremolar, and intermolar width), incisor position/arch length, and enamel interproximal reduction (IPR).

RESULTS

For all the measurements, statistically significant differences were found at different stages. The predictability of crowding resolution was very high, ranging from 87% in the upper arch and 81% in the lower one. Among the different strategies to gain space, variations in sagittal incisor position were predictable, with a value of 70% both in the upper and lower arch. Conversely, changes in arch diameters were less reliable varying between 49 and 67% in the lower arch and 59-83% in the upper one. Moreover, IPR was the least accurate procedure, wavering at 49% in the upper arch and 42% in the lower arch.

CONCLUSIONS

The predictability of crowding resolution during treatment with aligners was high. However, the virtual arch forms obtained at the end of digital planning (vT1) did not correspond with the arch forms at the end of the aligner sequences (T1). The IPR was the least predictable strategy to gain space, being, perhaps, an operator-dependent procedure.

Class II treatment of transverse maxillary deficiency with a single bone-borne appliance and hybrid clear aligner approach in an adult patient: A case report

This case report describes the successful orthodontic treatment of a 22-year-old female patient affected by Class II malocclusion, maxillary skeletal transverse deficiency, ectopic maxillary left lateral incisor, and mild mandibular crowding. Due to her adult skeletal age, a bone-borne appliance was applied in order to obtain both purely skeletal rapid maxillary expansion and bilateral molar distalization. After accurate matching between the pretreatment cone-beam computed tomography scan and digital models, 4 self-drilling miniscrews were inserted palatally using a computer-aided design and computer-aided manufacturing (CAD/CAM) surgical template to guide their correct and safe placement, and a bone-borne appliance was fitted. After this first phase, the hybrid clear aligner approach was used to obtain alignment, levelling, and arch coordination, with the use of a partial lingual fixed appliance on the maxillary incisors.

Space closure by miniscrew-assisted mesialization of an upper third molar and partial vestibular fixed appliance: A case report

This case report demonstrates how the use of skeletal anchorage and appropriate orthodontic biomechanics can be used to resolve even complex cases, reducing unwanted dental movements and allowing the use of a partial vestibular appliance. It describes the complete mesialization of the left upper third molar and space closure following extraction of tooth UR7, due to vertical fracture one year after previous endodontic therapy for caries. This therapeutic choice was conditioned by the need not to alter the good pre-existing interarch relationships, and above all by the patient's request to be treated conservatively, and therefore not to undergo prosthetic implant rehabilitation. The use of orthodontic miniscrews and the careful application of orthodontic biomechanics, based on both direct and indirect anchorage, enabled the treatment objectives to be achieved in a reasonable period of time with reduced treatment costs.

Resolution of lower second molar impaction through miniscrew-supported biomechanics: A proposal for a simplified classification

Two case reports are presented showing how the strategic use of skeletal anchorage via orthodontic miniscrews manages to solve the complex problems of orthodontic disimpaction of second mandibular molars with excellent anchorage control and reduction of the adverse effects common to the use of conventional methods. The temporary anchorage device (TAD)-mediated biomechanics used can be categorized as both "pulling from the distal side" and "pushing from the mesial side" techniques in which both direct and indirect anchorage mechanics were employed. Each of these mechanics has its advantages and disadvantages, which must be weighed and considered on a case-by-case basis. Based on the force application side and the type of anchorage, a simplified classification of TADs supported biomechanics for the recovery of fully or partially impacted second molars is proposed.

Clear Aligners: Between Evolution and Efficiency-A Scoping Review

In recent years, clear aligners have diversified and evolved in their primary characteristics (material, gingival margin design, attachments, divots, auxiliaries), increasing their indications and efficiency. We overviewed the brands of aligners used in Italy and reviewed the literature on the evolution of clear aligners based on their characteristics mentioned above by consulting the main scientific databases (PubMed, Scopus, Lilacs, Google Scholar, Cochrane Library). Inclusion and exclusion criteria were established. The data were collected on a purpose-made data collection form and analyzed descriptively. From the initial 580 records, 527 were excluded because they were not related to the subject of the review or because they did not meet the eligibility criteria. The remaining 31 studies were deemed comprehensive for the purpose of the review, although the "gingival margin design" feature and "auxiliaries" tool are not well represented in the more recent literature. Current knowledge on invisible aligners allows us to have a much clearer idea of the basic characteristics of aligner systems. There remains a need to deepen the use of systems other than Invisalign™ to give greater evidence to aligners that are very different based on the characteristics analyzed here and that are very widespread on the market.