Orthodontic Mini-implants Research Articles

Anchorage and Stability of Orthodontic Mini Implants in Relation to Length and Types of Implants

Anchorage and Stability of Orthodontic Mini Implants in Relation to Length and Types of Implants

A comparative evaluation of cytotoxicity and corrosion resistance between titanium and stainless steel orthodontic mini implants: An in vitro study

A comparative evaluation of cytotoxicity and corrosion resistance between titanium and stainless steel orthodontic mini implants: An in vitro study

Automatic Segmentation of the Jaws Used in Guided Insertion of Orthodontic Mini Implants to Improve Their Stability and Precision.

Background and Objectives: With the goal of identifying regions with bicortical bone and avoiding root contact, the present study proposes an innovative technique for the simulation of the insertion of mini orthodontic implants using automatic jaw segmentation. The simulation of mini implants takes place in 3D rendering visualization instead of Multi-Planar Reconstruction (MPR) sections. Materials and Methods: The procedure involves utilizing software that automatically segments the jaw, teeth, and implants, ensuring their visibility in 3D rendering images. These segmented files are utilized as study models to determine the optimum location for simulating orthodontic implants, in particular locations characterized by limited distances between the implant and the roots, as well as locations where the bicortical structures are present. Results: By using this method, we were able to simulate the insertion of mini implants in the maxilla by applying two cumulative requirements: the implant tip needs to be positioned in a bicortical area, and it needs to be situated more than 0.6 mm away from the neighboring teeth's roots along all of their axes. Additionally, it is possible to replicate the positioning of the mini implant in order to distalize the molars in the mandible while avoiding the mandibular canal and the path of molar migration. Conclusions: The utilization of automated segmentation and visualization techniques in 3D rendering enhances safety measures during the simulation and insertion of orthodontic mini implants, increasing the insertion precision and providing an advantage in the identification of bicortical structures, increasing their stability.

Mapping optimal orthodontic implant sites in the palate using cone-beam computed tomography.

To measure the palatal soft tissue thickness and cortical bone density to determine safe regions for the placement of orthodontic mini-implants and to examine the influence of sex and age on soft tissue thickness and cortical bone density. Cone-beam computed tomography images of 42 patients (22 males and 20 females), including 21 adults and 21 adolescents, were examined in this study. The palatal soft tissue thickness and cortical bone density were measured at the coronal planes between the premolars (P4-5), between the second premolars and first molars (P5-6), and between the first molars and second molars (P6-7). The thickness of the soft tissue revealed similar coronal planes, but the bone density varied. The mean thickness was 3.8 mm at 0°-60° and 1.5 mm at 60°-90°. P4-5 had the highest bone density (>600 HU), decreasing toward P6-7 (<600 HU). Bone density decreased from 90° to 0° coronally, whereas the soft tissue thickness increased. Age, sex, and their interaction affected bone and soft tissues. In general, areas with a high bone density tended to have thin soft tissue coronally, thus the preferred implant site tends to be more anterior to the P4-5 plane and closer to 60°-90°. Considering individual variances, mapping of the recommended regions for palatal mini-implants is suggested.

Surface Analysis of Orthodontic Mini-Implants after Their Clinical Use.

Temporary anchorage devices (TADs) are orthodontic mini-implants with remarkable characteristics that, once inserted, present mechanical retention (primary stability) without the process of bone osseointegration. However, interaction with the biological environment may cause changes in the morphology of the external surface of dental TADs. In this study, we used 17 TADs made of aluminum-vanadium titanium alloy, produced by two companies, which were analyzed through optical microscopy after being removed from the patients during orthodontic treatment. We evaluated the changes that appeared on the TADs' surfaces after their use in the biological environment, depending on the morphological area in which they were inserted. In our study, we found changes in the morphology of the implant surface, and especially deposits of biological material in all study groups. On all samples examined after clinical use, regardless of the period of use, corrosion surfaces in different locations were observed. Our obtained results support the idea that the biological environment is aggressive for mini-implant structures, always producing changes to their surface during their clinical use.

Evaluation of Surface Morphology and Stress Distribution of Orthodontic Mini-implants in Maxilla: A Three-dimensional Finite Element Study

Objectives: Inaccurate design, insertion or loading of mini-implant may lead to disturbed bone turnover and subsequent implant failure. This study assesses the two commonly used types of implants and their bone stress pattern and determines which type of implant may be more patient-compatible. Method: The samples were categorized into four groups and analyzed by scanning electron microscopy to assess the surface morphology. Stress distribution was estimated using finite element method for which three-dimensional (3D) models of the maxilla and mini-screws were prepared. The implant was then inserted 5 mm from the alveolar crest onto the buccal cortical plate of maxilla between the second premolar and first molar within the platform of Ansys Workbench software. Two loads were applied: 5 Ncm and 2 N. Evaluation of von Mises stresses in the bone was estimated. Results: The study concluded that tapered stainless steel screws exerted greater stress on the bone than titanium screws in both situations. As the diameter increased from 1.3 mm to 1.5 mm, the mini-screw displacement and stress were less. Under 2 N force, the stress was distributed around the head and neck of the mini-implant and the cortical bone. Conclusion: The assessment of von Mises stress distributed around an orthodontic mini-implant under a constant load revealed that stainless steel mini-screws generated more stress than titanium mini-screws. It was observed that the majority of the stress and strain is tolerated by the cortical bone, not the cancellous bone. The diameter of mini-screw is more significant irrespective of material composition.

Investigating adhesion of primary human gingival fibroblasts and osteoblasts to orthodontic mini-implants by scanning electron microscopy

Miniscrews offer controlled anchorage and thus optimize tooth movement in orthodontic treatment. Nevertheless, failures such as soft tissue problems, instability due to loosening, partial osseointegration, or even device fracture can occur. While clinical technique can play a role in some of these problems, the manufacturer’s design and material choice influence how the implant interacts with the surrounding tissue. In some cases, the design and material may trigger unwanted bone and soft tissue responses. This in vitro study investigates how the implant surface affects cell adhesion and growth of human primary fibroblasts and osteoblasts on commercially available orthodontic TiAl6V4 miniscrews from three producers: tomas-pin SD N 08 (Dentaurum), OrthoEasy Pin (Forestadent), and Dual Top G2 (Promedia, Jeil Medical). Cell–implant interaction at the top, neck, and drilling part of the screws was assessed qualitatively by scanning electron microscopy. While both cell types adhered to and grew on all products, subtle differences in cell shape and spreading were detected, depending on the microstructure of the implant surface. This indicates that cell adhesion to implant surfaces can be controlled by manipulating the machining conditions.

Conventional versus Guidance-based Techniques: Orthodontic Mini-implants and Corticotomy

Conventional versus Guidance-based Techniques: Orthodontic Mini-implants and Corticotomy

Interdisciplinary treatment of a mutilated dentition with multiple missing teeth and horizontal impaction of a mandibular third molar using an orthodontic skeletal anchorage and dental implants-Case report.

This case report presents a female adult patient who exhibits poor oral hygiene, a mutilated dentition with multiple missing teeth, and skeletal asymmetry. Interdisciplinary treatment was necessary to maintain oral hygiene, treat caries, extract residual roots, and upright a horizontally impacted third molar using a miniplate. Additionally, orthodontic mini-implants were utilized as anchorage to improve sagittal relationship and space closing. Space management was completed with orthodontic treatment, followed by restoration of the multiple missing teeth with dental implants. Consequently, an esthetic smile and functional occlusion were achieved by interdisciplinary treatment using orthodontic skeletal anchorage devices and dental implants. Missing mandibular first molar spaces were closed with retraction of the anterior teeth and protraction of the mandibular second molars using orthodontic mini-implants. The mandibular right third molar, which should have erupted, was protracted with the second molar, while the horizontally impacted mandibular left third molar was uprighted using a miniplate and was protracted with an orthodontic mini-implant. The missing maxillary lateral incisors were replaced with the maxillary canines, and the maxillary canines were replaced with the maxillary first premolars. The missing maxillary right second premolar and first molar and left first and second molars were successfully restored with dental implants.

Use of Orthodontic Mini-Implants in Conjunction with Elastics for Extrusion of Impacted Canines and Correction of Bimaxillary Protrusion.

Orthodontic extrusion of canines, although challenging, can yield excellent results without tooth extraction. Temporary anchorage devices (TADs), involving mini-implants in the alveolar bone, offer stable anchorage via biomechanics. This case report details orthodontic extrusion of bilaterally impacted maxillary canines using TAD mini-implants and elastics. The patient had bimaxillary protrusion, moderate crowding, deep bite, and vertical growth pattern, necessitating careful treatment planning. The combination of TAD mini-implants with Class-II elastics simplified biomechanics. The treatment achieved efficient results, maintained adjacent teeth positioning, and improved patient compliance.

The value of imaging investigation in designing of an experimental study of bone tissue dynamics in orthodontic mini-implants

The value of imaging investigation in designing of an experimental study of bone tissue dynamics in orthodontic mini-implants

The Influence of the Diameter of Orthodontic Mini-Implants on Primary Stability: Bending Tests-An In Vitro Study.

The objective of this study is to evaluate the influence of the diameter of Mini-Implants through bending force tests, taking into account primary stability after one and two insertions. Here, 40 Ti6AI4V alloy Mini-Implants of two different brands and diameters were divided into eight groups, half of which received one insertion in the artificial bone, and the rest received two. All were subjected to a constant bending force using an INSTRON-Electropuls E10000LT (Norwood, MA, USA) until fracture. The smaller-diameter Mini-Implants were less resistant to fracture, but both were able to withstand the necessary loads produced by orthodontic movements. As for the inserts, there were no statistically significant differences. There is an advantage to using 1.6 mm Mini-Implants over 2.0 mm ones, as a smaller diameter does not lead to fracture due to the forces used in orthodontic treatment. Having one or two inserts did not have a statistically significant effect.

Corrosion behavior of an ultrafine-grained Ti6Al4V-5Cu alloy in artificial saliva containing fluoride ions

Ti6Al4V alloy has been widely used in dental applications, such as orthodontic mini-implants. However, it has been reported that fluoride ions could obviously accelerate the corrosion of implant materials and affect their performance. This work aimed to improve the F− erosion resistance of Ti6Al4V alloy through the strategy of both Cu addition and grain refinement. As contrasted with Ti6Al4V alloy, both the coarse- and ultrafine-grained Ti6Al4V-5Cu alloys effectively mitigated the acceleration of the fluoride ions to the anode process, because Cu substituents blocked the continuous damage of FO· doped in the passive film. Furthermore, grain refinement enhanced the protective ability of the passive film, more oxides and less adsorption amount of fluorides presented in the passive film of ultrafine-grained Ti6Al4V-5Cu alloy than those of coarse-grained Ti6Al4V-5Cu alloy. Under the combination of Cu alloying and grain refinement, the ultrafine-grained Ti6Al4V-5Cu alloy is greatly appropriate for the fabrication of orthodontic devices.

Morphological evaluation of the nasopalatine canal using cone beam computed tomography and its clinical implications for orthodontic miniscrew insertion.

The morphology of the nasopalatine canal is crucial in the planning of prosthetic restorations in the anterior region of the maxilla, as well as in the placement of orthodontic mini-implants. The aim of this study was to assess the morphology of the nasopalatine canal using cone beam computed tomography (CBCT) scans of patients from the University Dental Clinic in Krakow, Poland, to define the position of the canal in relation to common sites of palatal median microimplant placement, and to investigate potential correlations between the anatomy of the canal and age and gender of the patients. A total of 120 CBCT images were used to assess the anatomy of the nasopalatine canal in 3 planes of space. The bone thickness anterior to the nasopalatine canal and the distance between the distal margin of Stenson's foramen and the predicted midpalatal microimplant position were also measured. The most frequently observed canal type in the coronal plane was the Y-shaped canal, which was present in 60.8% of patients. The nasopalatine canal was classified as cone-shaped in 31.7% of the scans, cylindrical in 28.3%, hourglass-shaped in 27.5%, and banana-shaped in 12.5%. The mean length of the nasopalatine canal was 11.58 mm. The mean width of the canal was 2.89 mm at the nasal fossa level, 1.94 mm in the middle, and 5.09 mm at the palatal level. The mean bone thickness anterior to the nasopalatine canal was 9.07 mm at the level of the nasal opening, 6.84 mm at the level of the oral opening, and 7.32 mm in the middle. The mean distance between the distal margin of Stenson's foramen and the predicted midpalatal microimplant position varied from 0 to 11.94 mm, with a mean of 2.49 mm. Given the variety of nasopalatine canal forms and dimensions, detailed analysis of CBCT scans is essential prior to the placement of implants and microimplants.

ANALYZING DEVICES AND METHODS FOR ASSESSING THE PRIMARY STABILITY OF ORTHODONTIC MINI-IMPLANTS

When disruptions occur in the mechanisms regulating the eruption of lower jaw molars, it becomes necessary to artificially extract and reposition them within the dentition. Various treatment methods are employed for this purpose, with the primary approach involving traction fixed to teeth or other anchorage elements and bone supports. Skeletal support is preferred to minimize resistance from orthodontic appliances when applying force to the patient's teeth. The utilization of mini-implants for anchorage demonstrates a relatively high success rate, though instances of failures and complications are not unheard of. Potential issues such as stability loss and mini-implant displacement may necessitate relocation or adjustments to treatment strategies, posing challenges for both practitioners and patients. Unlike dental implants, where secondary stability often dictates treatment success, primary stability holds paramount importance for orthodontic mini-implants. Investigating primary stability parameters can significantly impact treatment strategy selection and orthodontic mini-implant loading timelines. Focusing solely on mini-implant torque during placement is inadequate, as it fails to comprehensively gauge real stability. Moreover, the available range of torque indicators for orthodontic mini-implant placement is limited, typically ranging from 5ncm to 10 ncm. Furthermore, the selection of specialized devices for measuring primary stability is limited and necessitates meticulous evaluation.

A Three-dimensional Finite Element Study of Stress and Strain Distribution around Orthodontic Mini-implants of Varying Geometry

A Three-dimensional Finite Element Study of Stress and Strain Distribution around Orthodontic Mini-implants of Varying Geometry

Heat Treatment's Vital Role: Elevating Orthodontic Mini-Implants for Superior Performance and Longevity-Pilot Study.

Ten self-drilling mini-implants sourced from two distinct manufacturers (Jeil Medical Corporation® and Leone®) with dimensions of 2.0 mm diameter and 10 mm length were tested. They were separated into two material groups: Ti6Al4V and 316L. Using the CETRUMT-2 microtribometer equipment, indentation testing was conducted employing a diamond-tipped Rockwell penetrator at a constant force of 4.5 N. Slight differences were observed in the elastic modulus of the Ti6Al4V alloy (103.99 GPa) and stainless steel 316L (203.20 GPa) compared to natural bone. The higher elastic moduli of these materials indicate that they are stiffer, which could potentially lead to stress-shielding phenomena and bone resorption. Heat treatment resulted in significant changes in mechanical properties, including elastic modulus reductions of approximately 26.14% for Ti6Al4V and 24.82% for 316L, impacting their performance in orthodontic applications. Understanding the effects of heat treatment on these alloys is crucial for optimizing their biomechanical compatibility and longevity in orthodontic treatment. To fully evaluate the effects of heat treatment on mini-implants and to refine their design and efficacy in clinical practice, further research is needed.

A clinical example of the treatment of a patient using a hybrid device for rapid palatal expansion

While using a clinical case as an example, in this article we described the usage of an expanding appliance based on palatal orthodontic mini-implants for the upper jaw.

Influence of the Curve of Spee on Tooth Displacement Patterns: A Finite Element Analysis at Varying Implant Heights.

Background Monocortical mini-screw-type temporary anchorage devices (TADs), or mini-screws, have significantly impacted orthodontic treatment strategies, especially in severe crowding and protrusion cases. These devices offer flexibility in placement sites, but the chosen location can considerably influence tooth displacement patterns. Key factors include the 'line of force' and the biomechanical properties of orthodontic tools. By analyzing tension distribution and three-dimensional displacements, the finite element method (FEM) provides a thorough means to comprehend these patterns. The Curve of Spee (COS) is a crucial factor potentially affecting displacement. Objective This study aimed to leverage finite element analysis (FEA) to understand the impact of varying mini-implant heights (10 mm, 13 mm, and 16 mm) on the displacements of different tooth types under a consistent force of 150 gm and compare these displacements both in the presence and absence of the COS. Materials and methods A CAD model of the jaw and teeth was developed using CT scan data and a Rexcan III 3D White Light Scanner. This model was meshed in Altair HyperMesh using tetrahedral elements, resulting in a Finite Element Model. The model incorporated various components, including teeth, the periodontal ligament (PDL), alveolar bone, brackets, a titanium mini-screw, and an archwire measuring 0.019 x 0.025 inches. Unique material properties were assigned to the PDL, and the assembly accurately replicated the clinical alignment of the archwire and brackets. Subsequently, stress and strain analyses were conducted on the model using the FEM. Results The displacement patterns of various teeth at implant heights of 10 mm, 13 mm, and 16 mm under a 150-gm force were analyzed in relation to the COS. Notably, for the central incisor, the COS significantly affected displacements in the Y and Z directions. Similarly, the Lateral Incisor and Canine exhibited marked changes in the Z direction with the presence of the COS. The Second Premolar's apex displacement showed significant variation due to the COS, while the First Molar displayed notable changes in the X direction. Generally, the presence of the COS either maintained or slightly increased Z-directional displacements across teeth, particularly at the apices. Conclusion The presence of COS significantly influences tooth displacement patterns when using mini-screws at different implant heights. Central incisors, lateral incisors, and canines are particularly sensitive to changes in the Z direction with the COS. The biomechanical analysis emphasizes the importance of considering COS in treatment planning for optimal results with mini-implants in orthodontics.

Evaluation of Optimal Insertion Sites and Angles for Orthodontic Mini-Implants at the Anterior Nasal Spine Region Based on Cone-Beam Computed Tomography

Background: To infer the optimal angulation and height level of mini-implant insertion in the anterior nasal spine (ANS) region from alveolar bone depth (BD) and labial cortical bone thickness (CBT) through cone-beam computed tomography (CBCT), the influences of sex, age, and growth pattern on BD, CBT, and the starting point of the ANS were examined. Material and methods: BD and CBT were measured on CBCT median sagittal images at specific angles (0, 15, 30, 45, and 60 degrees) to simulate the angulation of insertion. The height level of the first axial image with obvious bone ridge was recorded as the start of ANS. Results: The average height of ANS start was 9.42 mm from the alveolar bone crest between the central incisors. The variations in height level and insertion angle combined, or either of them individually, significantly influenced BD and CBT, demonstrating overall decreasing trends (p &lt; 0.001). BD was not influenced by sex, age, or growth pattern (p &gt; 0.05). However, CBT was found to be correlated with sex and growth pattern, while the height level of ANS start was associated only with growth pattern, particularly in hypodivergent patients (p &lt; 0.05). Conclusion: The recommended insertion height level is 14–16 mm from the alveolar bone crest and the recommended angulation is 30–45°. An innovative inequity in the relationship between a certain height level and the insertion angulation is proposed.