Root proximity of the anchoring miniscrews of orthodontic miniplates in the mandibular incisal area: Cone-beam computed tomographic analysis.

OBJECTIVE: This outcome analysis study evaluated the actual positions of the orthodontic miniplate and miniplate anchoring screws (MPASs) and the risk factors affecting adjacent anatomic structures after miniplate placement in the mandibular incisal area. METHODS: Cone-beam computed tomographic images of 97 orthodontic miniplates and their 194 MPASs (diameter, 1.5 mm; length, 4 mm) in patients whose miniplates provided sufficient clinical stability for orthodontic treatment were retrospectively reviewed. For evaluating the actual positions of the miniplates and analyzing the risk factors, including the effects on adjacent roots, MPAS placement height (PH), placement depth (PD), plate angle (PA), mental fossa angle (MA), and root proximity were assessed using the paired t-test, analysis of variance, and generalized linear model and regression analyses. RESULTS: The mean PDs of MPASs at positions 1 (P1) and 2 (P2) were 2.01 mm and 2.23 mm, respectively. PA was significantly higher in the Class III malocclusion group than in the other groups. PH was positively correlated with MA and PD at P1. Of the 97 MPASs at P1, 49 were in the no-root area and 48 in the dentulous area; moreover, 19 showed a degree of root contact (19.6%) without root perforation. All MPASs at P2 were in the no-root area. CONCLUSIONS: Positioning the miniplate head approximately 1 mm lower than the mucogingival junction is highly likely to provide sufficient PH for the P1- MPASs to be placed in the no-root area.

Treatment of 2 impacted molars in a large dentigerous cyst (expansile cystic lesion) with combined orthodontic and surgical therapy.

Nonmineralized cysts and cyst-like lesions that frequently occur in the mandible include ameloblastomas, odontogenic keratocysts, and dentigerous cysts. They have specific features of well-demarcated, unilocular, and radiolucent lesions that are often associated with tooth impaction. Although it rarely occurs, these cysts can become extremely large. Furthermore, cyst enlargement causes additional symptoms that can challenge the success of tooth recovery through orthodontic treatment. This clinical report presents the successful eruption of 2 impacted molars in a large dentigerous cyst treated with marsupialization and orthodontic traction using an orthodontic miniplate anchorage over a 4-year treatment period.

Application of the 2-piece orthodontic C-implant for provisional restoration with laser welded customized coping: a case report.

This article presents the application of laser welding technique to fabricate an orthodontic mini-implant provisional restoration in missing area after limited orthodontic treatment. A 15-year-old boy case is presented. Two-piece orthodontic C-implant was placed after regaining space for missing right mandibular central incisor. Due to angular deviation of implant, customized abutment was required. Ready-made head part was milled and lingual part of customized abutment was made with non-precious metal. Two parts then were laser welded (Master 1000, Elettrolaser Italy, Verona, Italy) and indirect lab composite (3 M ESPE Sinfony, St. Paul, MN, USA) was built up. The patient had successful result, confirmed by clinical and radiographic examinations. Before the patient is ready to get a permanent restoration later on, this provisional restoration will be used. This case shows that a two-piece orthodontic C-implant system can be used to maintain small edentulous space after orthodontic treatment.

Evaluation of stability of surface-treated mini-implants in diabetic rabbits.

Introduction. The purpose of this study was to investigate effects of surface treatment of mini-implants in diabetes-induced rabbits by comparing osseointegration around mini-implants. Methods. Twelve New Zealand white rabbits were divided into two groups (alloxan-induced diabetic group and control group). A total of 48 mini-implants were placed after four weeks of diabetic induction. 24 mini-implants were surface-treated with SLA (sandblasted with large grit, and acid etched) and the remaining 24 mini-implants had smooth surfaces. Four weeks after placement, 32 mini-implants were removed from 4 control and 4 diabetic rabbits. Insertion and removal torques were measured. The remaining 16 mini-implants from the two groups were histomorphometrically analyzed. Results. Maximum insertion torque showed no difference between diabetic and control groups, but total insertion energy was higher in control group. In surface-treated mini-implants, maximum removal torque was higher in both diabetic and control groups. Bone-implant contact (BIC) was increased in the control group when compared to the diabetic group. Surface-treated group had higher BIC than smooth surface group in both control and diabetic groups. However, there was no significantly statistical difference. Conclusions. Type 1 diabetes mellitus and surface treatment method of mini-implant affected primary stability of mini-implants. In addition, the use of orthodontic mini-implants in a diabetic patient is likely to show results similar to the healthy patient.

Primary stability of self-drilling and self-tapping mini-implant in tibia of diabetes-induced rabbits.

Objective. This study aimed to evaluate effects of type 1 diabetes mellitus and mini-implant placement method on the primary stability of mini-implants by comparing mechanical stability and microstructural/histological differences. Methods. After 4 weeks of diabetic induction, 48 mini-implants (24 self-tapping and 24 self-drilling implants) were placed on the tibia of 6 diabetic and 6 normal rabbits. After 4 weeks, the rabbits were sacrificed. Insertion torque, removal torque, insertion energy, and removal energy were measured with a surgical engine on 8 rabbits. Remaining 4 rabbits were analyzed by microcomputed tomography (micro-CT) and bone histomorphometry. Results. Total insertion energy was higher in self-drilling groups than self-tapping groups in both control and diabetic groups. Diabetic groups had more trabecular separation in bone marrow than the control groups in both SD and ST groups. Micro-CT analysis showed deterioration of bone quality in tibia especially in bone marrow of diabetic rabbits. However, there was no statistically significant correlation between self-drilling and self-tapping group for the remaining measurements in both control and diabetic groups. Conclusions. Type 1 diabetes mellitus and placement method of mini-implant did not affect primary stability of mini-implants.

Virtually fabricated guide for placement of the C-tube miniplate.

INTRODUCTION: This paper introduces a virtually planned and stereolithographically fabricated guiding system that will allow the clinician to plan carefully for the best location of the device and to achieve an accurate position without complications. METHODS: The scanned data from preoperative dental casts were edited to obtain preoperative 3-dimensional (3D) virtual models of the dentition. After the 3D virtual models were repositioned, the 3D virtual surgical guide was fabricated. A surgical guide was created onscreen, and then these virtual guides were materialized into real ones using the stereolithographic technique. RESULTS: Whereas the previously described guide required laboratory work to be performed by the orthodontist, our technique is more convenient because the laboratory work is done remotely by computer-aided design/computer-aided manufacturing technology. Because the miniplate is firmly held in place as the patient holds his or her mandibular teeth against the occlusal pad of the surgical guide, there is no risk that the miniscrews can slide on the bone surface during placement. The software program (2.5-dimensional software) in this study combines 2-dimensional cephalograms with 3D virtual dental models. This software is an effective and efficient alternative to 3D software when 3D computed tomography data are not available. CONCLUSIONS: To confidently and safely place a miniplate with screw fixation, a simple customized guide for an orthodontic miniplate was introduced. The use of a custom-made, rigid guide when placing miniplates will minimize complications such as vertical mislocation or slippage of the miniplate during placement.

En-masse retraction dependent on a temporary skeletal anchorage device without posterior bonding or banding in an adult with severe bidentoalveolar protrusion: seven years posttreatment.

This report describes a novel concept of en-masse retraction with temporary skeletal anchorage devices in place of posterior bonding or banding. The patient was a Korean woman, aged 24 years 4 months, with a Class II Division 1 malocclusion with severe mandibular anterior crowding. Both molars showed decalcification of the cervical areas. Partial osseointegration-based C-implants and C-tube plates were placed bilaterally between the maxillary second premolars and the first molars and in the posterior mandible. These temporary skeletal anchorage devices were used as independent appliances for full retraction of the maxillary and mandibular anterior teeth 3-dimensionally without the assistance of posterior bonded appliances. The posterior occlusion was not changed during treatment, and Class I occlusal relationships with optimal overjet and overbite were achieved. The 7-year posttreatment records showed a stable result.

Corticotomy-assisted decompensation for augmentation of the mandibular anterior ridge.

INTRODUCTION: This article introduces a technique combining corticotomy and orthodontic forces, or accelerated osteogenic orthodontics, for use in patients with a Class III occlusion and a thin alveolus who will undergo orthognathic surgery. METHODS: Two adults with Class III malocclusion undergoing anterior decompensation for mandibular setback surgery were selected. The first patient was treated with accelerated osteogenic orthodontics and conventional decompensation. The second patient was treated with accelerated osteogenic orthodontics and decompensation with a temporary skeletal anchorage device in concert with guided tissue regeneration. Decortication of bone was performed to the mandibular teeth with a low-speed round bur and piezosurgery. After hemostasis, bone graft material was placed into the decorticated area. In the severely thin alveolar ridge, a rigid scaffold was applied for immobilization of graft material. After approximation of the flap, an immediate orthodontic force was applied to the teeth to initiate rapid tooth movement. RESULTS: Rapid tooth movement into predetermined positions for orthognathic surgery was accomplished in all mandibular anterior teeth. Preoperative 3-dimensional imaging showed dehiscences on the facial aspects of the mandibular anterior teeth. Postoperative imaging demonstrated coverage of the denuded roots with radiodense material. CONCLUSIONS: The accelerated osteogenic orthodontic technique is a safe and effective treatment option for mandibular anterior decompensation treatment of these patients. When combined with a temporary skeletal anchorage device and bone augmentation, this technique facilitated the decompression of the mandibular anterior teeth in severely compromised dentitions.

Novel application of the 2-piece orthodontic C-implant for temporary crown restoration after orthodontic treatment.

INTRODUCTION: This article reports the use of an orthodontic mini-implant for a temporary crown restoration in a small edentulous space after limited orthodontic treatment. METHODS: Two clinical cases are presented: a 23-year-old woman and a 14-year-old boy. In the adult patient, a 2-piece orthodontic C-implant (Cimplant, Seoul, Korea) was placed in a 3-mm wide edentulous space to build up a temporary crown restoration after a short orthodontic treatment to regain space for a missing mandibular right permanent lateral incisor. In the boy, a C-implant was placed in the space resulting from an avulsed maxillary right permanent lateral incisor to prevent aggressive alveolar bone resorption after dental trauma. Both patients were followed for more than 4 years of retention to evaluate the stability of the temporary crown restoration built up on the orthodontic mini-implants. RESULTS: Both patients had successful long-term results, confirmed by clinical and radiographic examinations. Both were pleased with the results and plan to retain the orthodontic mini-implant temporary crown restoration until they are ready for a permanent restoration later. CONCLUSIONS: A 2-piece orthodontic C-implant system can be used to maintain edentulous space after active orthodontic treatment.

Resistance to immediate orthodontic loading of surface-treated mini-implants.

OBJECTIVE: To test the hypothesis that there is no difference in the stability and resistance to orthodontic forces of immediately loaded sandblasted and acid-etched (SAE) mini-implants and those of machined-surface implants of the same size and shape. MATERIALS AND METHODS: Two types of mini-implants were used in the tibiae of 44 rabbits; some had an SAE surface and some had machined surfaces. Orthodontic loading of 150 g was applied immediately after placement. The success rates and maximum removal torque values (RTVs) of 412 mini-implants were recorded and compared immediately after placement, 3 days after placement, and 1, 6, and 10 weeks after placement. The RTV data were analyzed using multiple regression analysis to evaluate differences with respect to surface treatment, loading, and loading periods (P < .05). Multiple comparisons using the Scheffé method were performed to evaluate the RTVs for the subsequent loading periods. RESULTS: Thirteen mini-implants failed during the experimental period. The SAE group had a higher RTV than the machined group, and there was significant difference in RTVs in accordance with loading periods (P < .001). However, there was no significant RTV difference between loaded and unloaded mini-implants. CONCLUSIONS: The hypothesis was supported. Both SAE mini-implants and machined mini-implants can be loaded immediately and experience similar success rates. RTVs were higher for the SAE mini-implants than for the machined mini-implants. The latter finding suggests that, for immediate loading, SAE mini-implants may provide more stable retention than machined mini-implants.

Clinical application of accelerated osteogenic orthodontics and partially osseointegrated mini-implants for minor tooth movement.

INTRODUCTION: This article illustrates a new treatment system combining accelerated osteogenic orthodontics and osseointegrated mini-implants for minor tooth movement in severely compromised conditions. The procedures, advantages, efficacy, and indications of this method are discussed. METHODS: Three patients who needed minor tooth movement and orthodontic mini-implant treatment were recruited to use this combined technique; 1 required molar intrusion, and 2 required molar uprighting. C-Implant (diameter, 1.8 mm; length, 8.5 mm) were placed, and, after 5 weeks of healing, decortication of bone was performed near the malpositioned teeth by using a low-speed round bur. Bleeding was controlled, and the bone graft material was placed into the decorticated area. After the flap was secured, an immediate strong orthodontic force from the C-implant was applied to the teeth to start rapid tooth movement. RESULTS: Only a few orthodontic attachments were necessary, and the teeth moved rapidly to a good occlusal relationship without root resorption. CONCLUSIONS: The combination of accelerated osteogenic orthodontics and a partially osteointegrated mini-implant (C-Implant) was a safe and effective treatment choice. The C-implant's surface allows partial osseointegration, so it can resist a force moment without loosening and withstand the heavy forces associated with the accelerated osteogenic orthodontics protocol.