Nonsurgical approach to Class I open-bite malocclusion with extrusion mechanics: a 3-year retention case report

Total arch extrusion with skeletal anchorage to improve inadequate maxillary incisor display in a case of vertical maxillary deficiency

Inadequate maxillary incisor display can negatively impact facial esthetics. Various treatment options exist depending on the underlying cause and severity of the condition. Skeletal anchorage was used to extrude the maxillary dentition and rotate the mandible backward, enhancing visibility of the maxillary incisors. An extrusion assembly was introduced to achieve orthodontic extrusion. Use of bite raisers and interarch elastics was also discussed. Treatment results demonstrated successful achievement of the treatment goals. In addition to optimal occlusion, the patient's facial profile improved with increased lip fullness. There was an increase in vertical facial height, and maxillary incisor display was significantly improved, resulting in a more pleasant smile. Two-year postretention records evidenced the stability of total arch extrusion to improve maxillary incisor display.

Dentoalveolar effects of skeletally anchored extrusion arch in anterior open bite patients: A prospective clinical trial

OBJECTIVE

The purpose of this prospective clinical trial was to explore the dental and soft tissue changes accompanying the use of skeletally anchored nickel-titanium (NiTi) extrusion arch in the correction of anterior open bite (AOB).

MATERIAL AND METHODS

Twenty female patients with a mean age of 16.5 ± 1.5 years and a mean dentoalveolar AOB of 2.38±0.7 mm participated in this study. All patients were treated with an maxillary 0.017×0.025-in NiTi extrusion arch, with the aid of miniscrews inserted between the maxillary second premolars and first molars bilaterally, to act as indirect anchorage. Three-dimensional digital models and lateral cephalometric radiographs were taken just before the insertion of the extrusion arch (T0) and after 10 months (T1). Paired-sample t-tests were used in analyzing the data, to evaluate the changes after treatment (T1-T0). A significance level of p < 0.05 was used.

RESULTS

AOB was successfully closed in all patients, with a 4.35 ± 0.61 mm increase in the overbite. Maxillary incisors significantly extruded (2.52 ± 1.02 mm) and significantly reclined (5.78 ± 0.77°), with a resultant decrease in the overjet of 1.58 ± 0.5mm. A significant intrusion of maxillary first molars with no change in their inclination was observed. The upper lip showed a significant retraction tendency to the E-plane, and a significant increase in the nasolabial angle was observed.

CONCLUSION

The skeletally anchored NiTi extrusion arch was an effective technique in treating AOB, with no adverse effects on the molars.

Root resorption followed by orthodontic treatment in individuals with anterior open bite. A complete vision focused on different treatment alternatives: A review

The aim of this review was to determine the incidence of different types of treatment and the prevalence of root resorption in incisors induced by orthodontic treatment in patients with open bite. Libraries and electronic databases were searched, with 322 articles being selected and 55 articles considered regarding PRISMA checklist. It has been shown that apical root resorption of the incisors is more frequent in patients with premolar extractions than in those treated without extractions, due to greater apical displacement during retraction of the anterior teeth in the space closure phase. On the other hand, it has been described that intrusion of posterior teeth is four times more likely to cause root resorption than extrusion movement, thereby increasing the risk of root resorption in posterior teeth compared to conventional orthodontic treatment not requiring molar intrusions. Finally, aligners, such as orthodontic treatments with fixed appliances, have not been shown to induce clinically significant root resorption in open bite individuals. Literature on root resorption in open bite treatments is scarce making difficult conclusions difficult. However, the amount of root loss in cases of open bite seems to be similar to that of individuals without open bite.

Three-dimensional evaluation of open-bite patients treated with anterior elastics and curved archwires

INTRODUCTION

One nonsurgical treatment method for a patient with open bite is to use curved nickel-titanium arches and anterior elastics. The aim of this study was to investigate the effects of this technique with cone-beam computed tomography.

METHODS

Eighteen open-bite patients' treatment records were used for this retrospective study. The treatment methods were identical for all patients, beginning with the levelling and alignment of the teeth and the placement of maxillary accentuated and mandibular reverse curved archwires with anterior elastics. Cone-beam tomography images were taken and analyzed 3 dimensionally. The paired-samples t test statistical analysis was performed.

RESULTS

A-point moved anteriorly (0.33 mm) and the SN-MP angle increased slightly (1.17°). Maxillary and mandibular incisors were extruded by 2.16 and 1.49 mm, respectively. Overbite increased (4.38 mm). There were no significant changes in the vertical parameters of the premolars and molars.

CONCLUSIONS

The open bite was eliminated by retraction and extrusion of the anterior teeth while maintaining the vertical positions of the molars.

Orthodontic Clockwise Rotation of Maxillomandibular Complex for Improving Facial Profile in Late Teenagers with Class III Malocclusion: A Preliminary Report

Objective

Orthodontic camouflage treatments improve occlusion but might worsen facial profile in patients with Class III malocclusion. It has been reported that surgical clockwise rotation of maxillomandibular complex (MMc) improves facial profile by reducing chin prominence and chin throat length in patients with Class III malocclusion. The purpose of this report was to illustrate two orthodontic techniques for clockwise rotation of the MMc in late teenagers with Class III malocclusion and preliminarily evaluate their clinical effects.

Patients and Methods

Six patients in late teenage with Class III malocclusion were included in this preliminary report. Bite raisers were first placed on the upper molars to open the bite and clockwise rotate the mandible. Intermaxillary elastics were then applied vertically between the upper and lower dentitions in 3 patients for bimaxillary extrusion (Technique-1) or between the upper dentition and the lower temporary anchorage devices (TADs) in another 3 patients (Technique-2) for upper dentition extrusion and closure of the anterior open bite. The three-dimensional cone-beam computed tomography images taken before and after orthodontic treatment were superimposed to evaluate the treatment effects of MMc clockwise rotation for both techniques.

Results

The Technique-1 extruded the upper and lower dentitions, rotated the mandible clockwise 2.01°, moved chin down 2.98 mm, and back −1.64 mm, although the mandible grew 2.47 mm during the treatment period. The Technique-2 extruded the upper dentition, rotated the mandible clockwise 0.90°, moved chin down 1.78 mm, but slightly forward 0.47 mm due to the mandible grew 2.50 mm and lower dentition was not extruded.

Conclusions

The orthodontic clockwise rotation of MMc is an effective technique for orthognathic camouflage. The applications of bite raisers and bimaxillary dentition extrusion could be more effective than single dentition extrusion with TADs in the mandible for clockwise rotation of MMc and improvement of occlusion and facial profile in late teenagers with Class III malocclusion. However, the comprehensive clinical effects and long-term stability need further clinical studies.