New approach of maxillary protraction using modified C-palatal plates in Class III patients

Effect of Different Mini Implant Assisted Rapid Palatal Expansion (MARPE) Designs on Maxillary Protraction in Skeletal Class III malocclusion: An FEM Study

Background

Four different designs of mini-implant-assisted rapid palatal expansion (MARPE) and protraction in nasomaxillary complex and mid-palatal sutures in late adolescent skeletal Class III malocclusion were compared using a three-dimensional finite element analysis.

Methods

A finite element model of skull and related sutures was constructed using the computed tomography scan of a 16-year-old female patient with skeletal Class III and ANB of -2°. Four appliance designs: Type I: MARPE with palatal force, Type II: MARPE with buccal force, Type III: Hybrid hyrax with palatal force, and Type IV: Hybrid hyrax with buccal force. Protraction vectors were and analyzed using Ansys software (ANSYS 2021 R2). The displacement pattern of the nasomaxillary structures and the stress distribution in the sutures were examined in all four appliance designs.

Results

All the appliance designs resulted in a forward movement of the maxilla, while Type I and III, which used palatal protraction force, caused the greatest forward displacement. In Type I, II, and III, along with forward movement, a clockwise rotation of maxilla was observed, while in Type IV, an anticlockwise rotation of maxilla was observed. Type I, II, and III resulted in higher stress distribution around the superior structures, while Type IV resulted in less stress distribution around the superior structures of maxilla.

Conclusion

The forward displacement was enhanced when palatal plates were used to protract the maxilla. The effective appliance design for skeletal class III with open bite case was Type I, II, and III and Type IV for deep bite cases.

Treatment effects of maxillary protraction with palatal plates vs conventional tooth-borne anchorage in growing patients with Class III malocclusion

INTRODUCTION

Evaluate the treatment effects of maxillary protraction using palatal plates and compare them to those with conventional tooth-borne anchorage in growing patients with Class III malocclusion.

METHODS

Forty patients were divided into 2 groups according to the type of anchorage used: group 1 (n = 20; mean age, 10.5 ± 1.6 years; palatal plates) and group 2 (n = 20; mean age, 10.0 ± 1.2 years; tooth-borne appliances). Lateral cephalograms were taken before and after maxillary protraction. Skeletal, dental, and soft-tissue variables were measured. For statistical analysis, paired and independent t tests were performed.

RESULTS

Group 1 showed maxilla advancement by 2.3 ± 1.0 mm compared with group 2 by 0.9 ± 0.6 mm, and group 2 indicated clockwise rotation of the mandible, but there was no such clockwise rotation in group 1 (P <0.001). Group 1 had a less lingual inclination of the mandibular incisors than group 2 (IMPA, -1.0° ± 3.8° vs -3.8° ± 2.8°; P <0.05). There was no difference in soft-tissue changes between the 2 groups.

CONCLUSIONS

A facemask with palatal plate induced maxillary advancement with less mandibular clockwise rotation and dental movement than conventional tooth-borne anchorage. This modality can be used efficiently for maxillary protraction in growing patients with Class III malocclusion.

Bone-anchored maxillary protraction (BAMP): A review

INTRODUCTION

Protraction therapy for maxillary deficiency in the treatment of skeletal class III malocclusion involves the use of facemask. Conventionally facemask has been anchored to the maxillary dentition, which is responsible for some of the counter-productive effects of facemask therapy including backward and downward rotation of the chin, increase in the lower anterior facial height, proclination of maxillary incisors, retroclination of mandibular incisors apart from mesialization of maxillary molars with extrusion and decreased overbite.

AIM

The aim of this article is to highlight the nuances of Bone-Anchored Maxillary Protraction (BAMP) including a literature review, which is comprehensive and narrative and comparing the different techniques involved such as type 1 BAMP versus type 2 BAMP and BAMP versus facemask.

MATERIALS AND METHODS

A computerized search was performed in electronic databases such as PubMed, PubMed Central, Cochrane, Embase, DOAJ, and Google scholar using key words such as "bone-anchored maxillary protraction" and "BAMP." The search was confined to articles in English published till March 2021. Forty-seven case-controlled, cross-sectional, retrospective and prospective studies, as well as systematic reviews and meta-analysis were included in this article, which were limited to human subjects. A hand search of the reference lists of the included articles was also carried out to include missed out articles.

CONCLUSION

To overcome these drawbacks, BAMP was introduced, which causes both maxillary protraction, restraint of mandibular growth with minimal dentoalveolar changes. BAMP is used widely nowadays in the treatment of skeletal class III malocclusion.

Correction of an adult Class III malocclusion through regaining of orthodontic space and an implant restoration

This case report describes the interdisciplinary treatment of a 23-year-old female with Class III malocclusion and a missing maxillary left second premolar. Treatment alternatives were discussed, and the selected treatment plan was presented to illustrate a way to gain space for the premolar implant restoration and correct Class III relationship through maxillary molar retraction followed by maxillary total arch protraction with a palatal temporary skeletal anchorage device. Esthetic anterior alignment and functional occlusal rehabilitation was achieved, and facial balance was maintained at the end of treatment. CLINICAL SIGNIFICANCE: Implant restoration in conjunction with regaining orthodontic space by a team of multidisciplinary dental specialists presents an effective treatment solution to permanent tooth agenesis. Class III malocclusion can be treated with a combination of maxillary protraction and mandibular retraction using temporary skeletal anchorage devices. The versatility of modified palatal C-plates presents greater clinical application when related side effects are controlled with solid understanding of their biomechanics.

A Simple Technique Using a Modified Nance Appliance as Anchorage for Maxillary Molar Distalization—Two Case Reports

Maxillary molar distalization to correct a dental Class II molar relationship and to create space to relieve crowding has been a long-lasting subject of debate in orthodontics. Generally, to distalize maxillary molars, an intra-arch distalization appliance is favored over an inter-arch appliance since it does not utilize mandibular dentition as an anchorage, so some unwanted side effects on mandibular incisors can be avoided. A variety of intra-arch appliances have been developed to distalize maxillary molars, such as the pendulum, Jones jig, first class appliance, distal jet, and modified C-palatal plate. Although they could achieve efficient molar distalization, the learning curve of proper appliance insertion and activation is relatively long. In addition, the appliances are not comfortable for the patients due to the bulky activation units, especially when the activation units are designed in the palatal area. The current manuscript describes a novel and effective maxillary intra-arch molar distalization appliance—a modified Nance appliance technique, which consists of: (1) palatally, a big acrylic button against the palatal rugae and connected to the premolars with wide mesh pads; (2) buccally, regular brackets on maxillary premolars and first molars with sectional round stainless steel archwires and open coil springs between the second premolar and first molar. Either bilateral or unilateral maxillary molar distalization can be achieved with this appliance, and the Class II elastics are not needed. It is simple to be fabricated, delivered, and activated, and it is comfortable for patients.

A comparative evaluation of midfacial soft tissue and nasal bone changes with two maxillary protraction protocols: Tooth-borne vs skeletal-anchored facemasks

OBJECTIVES

Greater advancement of the maxilla can be achieved with skeletal-anchored facemasks (SAFM) using miniplates than with conventional tooth-borne facemasks (TBFM). The purpose of this study was to compare the effects of TBFM and SAFM on midfacial soft tissue and nasal bone up to two years after treatment.

SETTINGS AND SAMPLE POPULATION

Sixty-seven growing patients with Class III malocclusions were treated with facemasks. They were divided into a SAFM group with 31 subjects (average age 11.1 years) and a TBFM group with 36 subjects (average age 11.0 years).

MATERIALS AND METHODS

Cephalometric analysis was conducted using linear and angular midfacial measurements. Lateral cephalograms were taken initially (T0), after treatment (T1) and at two years post-treatment (T2). Significance was assessed between the two groups.

RESULTS

Comparing changes in the midfacial area between the SAFM and TBFM groups during the traction period (T0-T1), angular measurements such as SNOr (1.34°), nasolabial angle (4.20°), nasal angles 1 and 2 (1.23°, 2.14°) and linear measurements such as Prn, Sn, A' distance (approximately 2 mm) increased significantly more in the SAFM group. Over the entire treatment period (T0-T2), the changes in SNOr (1.33°), nasolabial angle (6.54°), nasal angles 1 and 2 (1.45°, 2.99°) and Prn, Sn, A' distance (approximately 2 mm) remained significant (P < .05).

CONCLUSIONS

In the treatment of growing patients with Class III malocclusions with maxillary deficiency, it was possible to achieve significantly greater advancement in the midfacial area with SAFM treatment than with TBFM treatment. This significant difference was well maintained at two years post-treatment.

Maxillary protraction using customized mini-plates for anchorage in an adolescent girl with skeletal Class III malocclusion

The treatment of skeletal Class III malocclusion in adolescents is challenging. Maxillary protraction, particularly that using bone anchorage, has been proven to be an effective method for the stimulation of maxillary growth. However, the conventional procedure, which involves the surgical implantation of mini-plates, is traumatic and associated with a high risk. Three-dimensional (3D) digital technology offers the possibility of individualized treatment. Customized miniplates can be designed according to the shape of the maxillary surface and the positions of the roots on cone-beam computed tomography scans; this reduces both the surgical risk and patient trauma. Here we report a case involving a 12-year-old adolescent girl with skeletal Class III malocclusion and midface deficiency that was treated in two phases. In phase 1, rapid maxillary expansion and protraction were performed using 3D-printed mini-plates for anchorage. The mini-plates exhibited better adaptation to the bone contour, and titanium screw implantation was safer because of the customized design. The orthopedic force applied to each mini-plate was approximately 400-500 g, and the plates remained stable during the maxillary protraction process, which exhibited efficacious orthopedic effects and significantly improved the facial profile and esthetics. In phase 2, fixed appliances were used for alignment and leveling of the maxillary and mandibular dentitions. The complete two-phase treatment lasted for 24 months. After 48 months of retention, the treatment outcomes remained stable.

Displacement and stress distribution of the maxillofacial complex during maxillary protraction using palatal plates: A three-dimensional finite element analysis

Objective

The purpose of this study was to analyze initial displacement and stress distribution of the maxillofacial complex during dentoskeletal maxillary protraction with various appliance designs placed on the palatal region by using three-dimensional finite element analysis.

Methods

Six models of maxillary protraction were developed: conventional facemask (Type A), facemask with dentoskeletal hybrid anchorage (Type B), facemask with a palatal plate (Type C), intraoral traction using a Class III palatal plate (Type D), facemask with a palatal plate combined with rapid maxillary expansion (RME; Type E), and Class III palatal plate intraoral traction with RME (Type F). In Types A, B, C, and D, maxillary protraction alone was performed, whereas in Types E and F, transverse expansion was performed simultaneously with maxillary protraction.

Results

Type C displayed the greatest amount of anterior dentoskeletal displacement in the sagittal plane. Types A and B resulted in similar amounts of anterior displacement of all the maxillofacial landmarks. Type D showed little movement, but Type E with expansion and the palatal plate displayed a larger range of movement of the maxillofacial landmarks in all directions.

Conclusions

The palatal plate served as an effective skeletal anchor for use with the facemask in maxillary protraction. In contrast, the intraoral use of Class III palatal plates showed minimal skeletal and dental effects in maxillary protraction. In addition, palatal expansion with the protraction force showed minimal effect on the forward movement of the maxillary complex.

Lateral open bite and crossbite correction in a Class III patient with missing maxillary first premolars

Posterior and Class III elastics were used to correct lateral open bite and anterior crossbite in a 29-year-old man. His occlusion, smile esthetics, and soft tissue profile were significantly improved after 25 months of active orthodontic treatment combined with 4 anterior restorations.

Displacement and stress distribution by different bone-borne palatal expanders with facemask: A 3-dimensional finite element analysis

INTRODUCTION

The purpose of this study was to analyze displacement and stress distribution in the maxilla during maxillary expansion followed by protraction using bone-borne and conventional tooth-borne palatal expanders and a facemask via 3-dimensional finite element analysis.

METHODS

A finite element model of an adolescent skull was created, and 4 different types of appliances were integrated into it: facemask (type A); facemask with paramedian bone-borne expander (type B), facemask with palatal-slope bone-borne expander (type C), and facemask with conventional expander (type D). Expansion of 0.25 mm followed by 500 g of force per side was applied.

RESULTS

Type A showed anterior displacement of the dentition combined with downward displacement of posterior teeth and upward displacement of anterior teeth. The combination of protraction and expansion in type D showed the greatest anterior displacement. In types B and C, the expansion forces resulted in posterior displacement decreasing the net displacement of the combination. Stresses concentrated around the miniscrews in types B and C. In types A and D, stresses concentrated at the first premolar and first molar. Type B had the highest stresses followed by type C and then D.

CONCLUSIONS

The conventional tooth-borne expander (type D) enhanced the effect of maxillary protraction. Facemask alone (type A) resulted in more anterior displacement of the maxilla than the combination of facemask and bone-borne expanders (types B and C). The clinician should be aware of the initial stresses and movements from different expanders with facemask found in this study and confirm the movements in future clinical Class III studies.