Maxillary and mandibular dentoalveolar expansion with an auxiliary beta-titanium arch

Comparison of maxillary transversal changes between auxiliary beta-titanium expansion arch and miniscrew-assisted rapid palatal expansion

OBJECTIVE(S)

This study compared buccal bone thickness, dental inclinations and maxillary transverse width dimensions changes between auxiliary beta-titanium expansion arch (AEA) and miniscrew-assisted rapid palatal expansion (MARPE).

MATERIALS AND METHODS

The sample consisted of 29 patients, aged between 18 and 40 years, with transverse maxillary deficiency and treated without extractions, divided into two groups: group AEA: comprised 13 individuals (initial mean age: 29.23 ± 9.13 years) treated using auxiliary beta-titanium expansion arch; group MARPE: comprised 16 patients (initial mean age: 24.92 ± 7.60 years) treated with miniscrew-assisted rapid palatal expansion. Buccal bone thickness, dental inclinations and transverse width dimensions (dental, nasal base and jugular) were measured in cone-bean computed tomographies at pre- and post-treatment stages. The variables were compared using the independent t-test.

RESULTS

The buccal bone thickness was similar for both groups at the post-treatment stage. The second premolars were significantly more buccal inclined in the AEA group and the right maxillary first molars in the MARPE group. The intercanine and intermolar distances were statistically significantly greater in the MARPE group. Changes in dental arch transverse dimensions were significantly greater for the MARPE group.

CONCLUSION

Both treatment protocols corrected the maxillary transverse discrepancy; however, MARPE provided greater correction.

The Practitioner’s Eye: The Ricketts Technique Elements in Non-Extraction Treatment Camouflaging Skeletal Class III with Bite Asymmetry—A Case Series Presentation

The study presents four cases of camouflage treatment of skeletal Class III with occlusal asymmetry in adult patients. Cephalometric analysis was performed using two different reference lines, S-N and FH. The treatment was carried out without the use of additional fixed appliances, no extraoral elastics for maxillary protection, and no extraction of teeth in the mandible. In addition to the characteristic elements and archwires taken from the Ricketts technique, NiTi, TMA, Wilcock archwires, Class III asymmetric intraoral elastic and criss-cross as well as individualized biomechanical systems were used. It has been proven that mild and moderate skeletal Class III with occlusal asymmetry can be treated with orthodontic camouflage, without additional fixed appliances for expansion or protraction of the maxilla. Moreover, it has been shown that it is possible to effectively treat this defect without extracting the teeth in the mand.

Modified Arnold expander: an alternative for mandibular arch expansion

Introduction:

Due to the anatomical constraints of the mandible, mandibular dental arch usually serves as a guideline to determine the required changes in the maxillary transverse dimension. The Schwarz appliance and the Lip Bumper are the traditional orthodontic appliances for mandibular arch expansion in patients with borderline amounts of crowding, and/or transverse discrepancy. However, they often require patient cooperation, which may be a concern for orthodontists in daily practice.

Objectives:

This article illustrates a simple fixed orthodontic device as an alternative to achieve mandibular arch expansion in patients with moderate tooth-size/arch-length discrepancy. The four reported cases refer to 8 to 10-year-old patients in the mixed dentition, with an Angle Class I or Class II malocclusion, transverse deficiency in both arches, moderate crowding and/or posterior crossbite, combined with compromised smile aesthetics. The patients were treated with rapid maxillary expansion (RME) using Hass expander appliance and the modified Arnold expander (MAE).

Conclusion:

This low-cost compliance-free orthodontic appliance provided dentoalveolar decompensation by means of uprighting the posterior teeth, with minimal or no adjustments during treatment. The final results were achieved in only three to four months, and fulfilled all treatment objectives, such as an increase in the arch perimeter and width, and a better teeth alignment.

Controlled Molar Inclination during Maxillary Dental Expansion Using a Straight Rectangular Archwire

Purpose

The purpose of this study was to examine whether the amount of transversal dental expansion, controlled using a straight rectangular beta-titanium alloy (TMA®) wire, has an influence on changes in maxillary first molar inclination.

Materials and Methods

Twenty patients requiring bilateral maxillary dental arch expansion were treated using a 0.018”-slot preadjusted edge-wise fixed appliance. Once leveled and aligned, the maxillary dental arches were expanded using a 0.016” × 0.022” straight TMA® wire. Changes in arch width and maxillary first molar inclination were assessed before (T0) and after (T1) expansion using three-dimensional scanned models. Mann–Whitney U-test, Wilcoxon signed-rank test, and Kruskal–Wallis test were used, where appropriate, to compare changes between and within groups.

Results

Intermolar width expanded at a rate of 0.8 ± 0.3 mm/month, and first molar buccal crown tipping occurred at 2.1° ± 1.2° (P < 0.05). Changes in inclination between minor expansion (1.0–2.5 mm) and moderate expansion (2.6–4.0 mm) groups were not statistically significant (1.8 ± 0.5 vs. 2.2 ± 1.2; P > 0.05).

Conclusions

Use of a straight rectangular TMA® wire in conjunction with a fixed orthodontic appliance successfully expanded the maxillary dental arch. The amount of expansion had no effect on molar inclination.