Mini-implants For Orthodontic Anchorage Research Articles

Narrow Diameter Dental Implants as an Alternative Treatment for Atrophic Alveolar Ridges. Systematic Review and Meta-Analysis.

To determine the marginal bone loss and the survival, success and failure rates of narrow dental implants, a systematic literature search was carried out in the MEDLINE (Pubmed), Cochrane, Scopus, and Scielo databases for articles published between 2010 and 2021. The exclusion criteria were: systematic reviews, case reports, expert opinions; animal studies; samples of less than 10 subjects; follow-up periods of less than 36 months; smokers of minimum 10 cigarettes/day; and articles about mini-implants for orthodontic anchorage. Meta-analyses were performed to assess marginal bone loss and implant survival, success, and failure rates. Fifteen studies were included: 7 clinical trials, 3 randomized clinical trials, 3 cohort studies, and 2 case series. The total number of subjects was 773, in whom 1245 implants were placed. The survival rate for the narrow diameter implants was 97%, the success rate 96.8%, and the failure rate 3%. Marginal bone loss was 0.821 mm. All these data were evaluated at 36 months. Based on the literature, it can be considered that there is sufficient evidence to consider small diameter implants a predictable treatment option. These show favorable survival and success rates and marginal bone loss. All of them are comparable to those of standard diameter dental implants.

Orthodontic correction of bialveolar protrusion by interproximal reproximation and water-soluble tubes bonded with deflection-based bonding technique: A case report

Orthodontic treatment with premolar extraction is usually performed to correct bialveolar protrusion. These methods require the use of stiff rectangular working archwire which requires lengthy alignment and leveling before insertion. In this case report, interproximal reproximation was performed instead of extraction. To establish clearance between the archwire and resin domes fixing the archwire, an archwire was inserted into a water-soluble tube before fabricating resin domes. This tube is solved away by the saliva. During fabrication of resin domes, the archwire was deflected intentionally reflecting the displacement of teeth from their ideal position. This can be called as deflection-based bonding (DBB) technique. DBB is different from conventional method of positioning the brackets on its ideal position and then inserting an archwire to align the brackets. Because the orthodontic force of the archwire comes from its deflection from passive configuration, deflecting an archwire as needed can move the teeth more predictably than just bonding brackets on its ideal position. Also, areas with good alignment before orthodontic treatment can be maintained simply by not deflecting the archwire during bonding in these areas. After initial alignment, interproximal reproximation was performed to create 4.8 mm space in the maxillary arch and 4.2 mm space in the mandibular arch. These spaces were closed using orthodontic mini-implant anchorage thus retracting the maxillary incisors 4 mm posteriorly accompanied with 0.7 mm and 0.3 mm distal movement of right and left molars. By using interproximal reproximation and water-soluble tube with DBB, mild bialveolar protrusion was successfully treated without extraction.

Experimental Study on the Stability Level Assessment of Mini-Implants for Orthodontic Anchorages

This paper presents some results of the experimental investigations that were aimed at assessing the primary stability of orthodontic mini-implant anchorage by measuring the tensile force with a special device adapted for traction in the axial direction and at a 45 degree angle, taking as variables bone characteristics (thickness and cortical bone density, thickness and density of the medulla). We used samples (pork ribs) whose characteristics were measured at computer tomography with a specialized software, in which there have been inserted orthodontic mini-implants with spherical head, round thread having different characteristics of shape and dimensions of the thread (length diameter, pitch). Experiments have provided information on the relationship between bone characteristics of samples and maximum traction force in the axial direction and at 45degree angle, as well as mini-implant primary stability.

A comparative evaluation of different compensating curves and power arm length during retraction of maxillary anterior teeth: A finite element study

Introduction: The strategic design of an appliance for anterior retraction by using orthodontic mini-implant anchorage and sliding mechanics must take into account the height of the power arm and compensating curve in archwire. This study was conducted to analyze the change in maxillary anterior teeth displacement and stress distribution using different compensating curves in the arch wire and varying power arm length in first premolar extraction case during sliding mechanics. Materials and Methods: 6 geometric models were created using ANSYS software. This geometric model was converted into a finite element model with the help of software HYPERMESH 11.0. Bilaterally mini-implants were placed in the bone between the roots of maxillary second premolar and first molar. Power arms were placed at two heights – 3 mm and 5.5mm. Compensatory curves were placed in the archwire (0, 3mm or 5mm) and a force of 150 gms was applied using NiTi coil springs bilaterally. Stresses in bone and tooth displacements were analyzed. Results: There was more bodily movement of the teeth using the longer power arms. Incorporating a compensatory curve further helped to reduce tipping. The tooth that showed most bodily movement was the lateral incisor followed by central incisor and least by the canine. There was increased intrusion of the incisors and extrusion of canine with increase in power arm height. Conclusion: Increase in power arm height causes an increased intrusive tendency and increased bodily movement during en masse retraction of anterior teeth using mini- implant anchorage. Incorporation of a 5mm compensatory curve further helps reduce the tipping tendency of the anterior teeth.

歯科矯正用アンカースクリュー除去後にこう鼻にて生じた気腫の1例

歯科矯正用アンカースクリュー除去後にこう鼻にて生じた気腫の1例

Three-dimensional evaluation of tooth movement in Class II malocclusions treated without extraction by orthodontic mini-implant anchorage.

ObjectiveThe aim of this study was to analyze tooth movement and arch width changes in maxillary dentition following nonextraction treatment with orthodontic mini-implant (OMI) anchorage in Class II division 1 malocclusions.MethodsSeventeen adult patients diagnosed with Angle's Class II division 1 malocclusion were treated by nonextraction with OMIs as anchorage for distalization of whole maxillary dentition. Three-dimensional virtual maxillary models were superimposed with the best-fit method at the pretreatment and post-treatment stages. Linear, angular, and arch width variables were measured using Rapidform 2006 software, and analyzed by the paired t-test.ResultsAll maxillary teeth showed statistically significant movement posteriorly (p < 0.05). There were no significant changes in the vertical position of the maxillary teeth, except that the second molars were extruded (0.86 mm, p < 0.01). The maxillary first and second molars were rotated distal-in (4.5°, p < 0.001; 3.0°, p < 0.05, respectively). The intersecond molar width increased slightly (0.1 mm, p > 0.05) and the intercanine, interfirst premolar, intersecond premolar, and interfirst molar widths increased significantly (2.2 mm, p < 0.01; 2.2 mm, p < 0.05; 1.9 mm, p < 0.01; 2.0 mm, p < 0.01; respectively).ConclusionsNonextraction treatment with OMI anchorage for Class II division 1 malocclusions could retract the whole maxillary dentition to achieve a Class I canine and molar relationship without a change in the vertical position of the teeth; however, the second molars were significantly extruded. Simultaneously, the maxillary arch was shown to be expanded with distal-in rotation of the molars.

Mini-implants for Orthodontic Anchorage: Surface Analysis after Redrilling and Sterilization – An in vitro Study

This study aimed to investigate, in vitro, possible alterations on mini-implants surface after retrieval and if the cleaning process and sterilization can predispose damages. Two commercial mini-implants were tested for deformations after drilling and removing in artificial bone four times. Samples were analyzed by scanning electron microscopy, and surface alterations verified through thread and pitches deformation. To alterations caused by insertion/removal and the cleaning process and sterilization were verified in different procedures: Insertions and sterilization, only insertions, and only sterilization. Photomicrographs were analyzed in order to compare the surface characteristics. Head deformation was verified qualitatively. For a quantitative analysis, distances between threads were measured across the active part of the mini-implants. No deformation was observed in both groups. The cleaning and sterilization processes did not provoke alteration in both groups. Nevertheless, the presence of synthetic bone was noted in some samples. The mean distances between implant threads were similar after all steps in all regions in both groups. The results suggest that the tested mini-implants can be retrieved without damage of its surface after four cycles of insertion, removal, and sterilization. Orthodontic mini-implant, Redrilling, Sterilization. Mini-implants can be retrieved without damage to its surface after four cycles of insertion, removal, and sterilization in the same patient without representing a biological concern.

Outcome of orthodontic mini-implant loss in relation to interleukin 6 polymorphisms

Mini-implants (MIs) are used increasingly for orthodontic anchorage and their success may require some osseointegration, which is affected by the underlying host immune-inflammatory response. Interleukin 6 (IL-6) is a cytokine expressed during the host response after a trauma or infection. The aim of this study was to investigate the association of clinical characteristics and IL6 tag single nucleotide polymorphisms (which capture the information of the whole gene in terms of genetic variability) with the loss of MIs for orthodontic anchorage. A total of 487 patients were treated with orthodontic MIs between 2004 and 2010. After the application of inclusion and exclusion criteria, the sample comprised 104 patients with one or more MIs that had been in function for at least 6 months with no loss, and 31 patients who had lost one or more MIs. Allele A of rs2069843 and allele T of rs2069849 were suggestively associated with the loss of MIs for orthodontic anchorage and were in complete linkage disequilibrium, which means that one of them is sufficient to capture the same information. The location of installation (mandible) and the number of MIs installed per patient were also associated with the loss of MIs.

TADs와 R-jig를 이용한 상악 구치 원심 이동에 관한 3차원 유한요소 분석

Purpose: The purpose of this study was to investigate the differences of displacement pattern depending on type of sliding jig and application method during maxillary molar distalization with temporary anchorage devices (TADs). Materials and Methods: Maxilla with normal tooth size and arch shape was selected to create a 3-dimensional finite element model, which included the bracket, orthodontic main archwire, removable sliding jig (R-jig). The orthodontic mini-implant anchorage was set 8 mm superiorly from main archwire, buccally between the second premolar and first molar. The base experimental design was Condition 1, which was composed inch stainless steel (SS) of wire size of R-jig, 200 gm force, un-tied state. And the other designs varied to wire size of R-jig, magnitude of force. The results are as follows. Results: As the wire size of R-jig was increased, the deformation of R-jig was decreased. However, the displacement of second molar wasn`t different each other. As the force to second molar was increased, the more displacement of second molar was observed, and the more distal tipping movement, vetical displacement was observed. Conclusion: R-jig can get distal teeth movement in orthodontic treatment without side effects.

Does cortical thickness influence the primary stability of miniscrews?:A systematic review and meta-analysis

To investigate whether there is evidence to support the association between cortical thickness (CtTh) and the primary stability of mini-implants (MI). A search was performed including articles published until September 2013. The inclusion criteria comprised observational clinical studies conducted in patients who received monocortical MI for orthodontic anchorage and in vivo or ex vivo experimental studies performed to evaluate the primary stability of MI, studies that evaluated the association between CtTh and MI primary stability, CtTh measurement performed numerically, and MI primary stability evaluated by implant stability quotient value, Periotest value , pull-out strength, or insertion torque. Studies conducted exclusively in artificial bone or finite elements were excluded. Abstract and title reading identified 15 possible articles to be included. After reading the complete text, three were excluded. One article was found by hand searching and another excluded for an overlapping sample. Finally, 12 articles were selected. A positive correlation was found between primary stability and CtTh when studies that evaluated primary stability through PS were grouped (r = .409) and when studies that evaluated stability in humans were grouped (r = .338). There is a positive association between MI primary stability and CtTh of the receptor site. However, there is still a lack of well-designed clinical trials.

Evaluation of Optimal Implant Positions and Height of Retraction Hook for Intrusive and Bodily Movement of Anterior Teeth in Sliding Mechanics: A FEM Study

Introduction: The design of an appliance for retraction of six anterior teeth using orthodontic mini-implant (OMI) anchorage and sliding mechanics must take into account the position and height of the mini-implant and the height of the anterior retraction hook, we used finite element analysis to examine effective en masse retraction with orthodontic mini-implant anchorage and sought to identify a better combination of the above factors. Materials and methods: Base models were constructed from a measurements given in the Wheeler’s dental anatomy book. The center of resistance for the 6 anterior teeth in the base model was calculated. The working archwires were assumed to be 0.019 × 0.025 in stainless steel. The amount of tooth displacement after finite element analysis was measured. Results and conclusions: In low OMI (6 mm) anteriors showed tipping movement. Mid implant condition (8 mm) showed more of bodily movement during retraction as the force passes near or through the CRs of all the six anterior teeth. In high OMI (10 mm) and 0 mm ARH condition, all the six anterior teeth showed intrusion with retraction.

Effective en-masse retraction design with orthodontic mini-implant anchorage: A finite element analysis

The strategic design of an appliance for correcting a bialveolar protrusion by using orthodontic mini-implant anchorage and sliding mechanics must take into account the position and height of the mini-implant, the height of the anterior retraction hook and compensating curve, and midline vertical traction. In this study, we used finite element analysis to examine effective en-masse retraction with orthodontic mini-implant anchorage and sought to identify a better combination of the above factors. Base models were constructed from a dental study model. Models with labially and lingually inclined incisors were also constructed. The center of resistance for the 6 anterior teeth in the base model was 9 mm superiorly and 13.5 mm posteriorly from the midpoint of the labial splinting wire. The working archwires were assumed to be 0.019 x 0.025-in or 0.016 x 0.022-in stainless steel. The amount of tooth displacement after finite element analysis was magnified 400 times and compared with central and lateral incisor and canine axis graphs. The tooth displacement tendencies were similar in all 3 models. The height of the anterior retraction hook and the placement of the compensating curve had limited effects on the labial crown torque of the central incisors for en-masse retraction. The 0.016 x 0.022-in stainless steel archwire showed more tipping of teeth compared with the 0.019 x 0.025-in archwire. For high mini-implant traction and 8-mm anterior retraction hook condition, the retraction force vector was applied above the center of resistance for the 6 anterior teeth, but no bodily retraction of the 6 anterior teeth occurred. For high mini-implant traction, 2-mm anterior retraction hook, and 100-g midline vertical traction condition, the 6 anterior teeth were intruded and tipped slightly labially.

Palatal Bone Density in Adult Subjects: Implications for Mini-Implant Placement

To evaluate palatal bone density to allow for better selection of palatal implant anchorage sites. Computed tomographic (CT) images were obtained from 15 males and 15 females (mean age, 27 years; range, 23-35 years). Bone density was measured in Hounsfield units (HU) at 80 coordinates at regular mediolateral and anteroposterior intervals along the midpalatal suture. Bone densities ranged from 805 to 1247 HU. A significant difference between male and female groups was noted, although no difference was found between left and right sides of individual palates. Palatal bone densities showed a tendency to decrease laterally and posteriorly. The midpalatal area within 3 mm of the midsagittal suture had the densest bone in the entire palate. Results suggest that mini-implants for orthodontic anchorage may be effectively placed in most areas with bone density equivalent to the palatal area if they are placed from 3 mm posterior to the incisive foramen and 1 to 5 mm to the paramedian side.

Bone density at interradicular sites: implications for orthodontic mini‐implant placement

Implant stability is primarily related to local bone density; Few studies have evaluated interradicular bone density related to mini-implant placement for orthodontic anchorage. Therefore, this study evaluated bone density differences between interradicular sites. Computed tomographic (CT) images were obtained from 14 males and 14 females (mean age 27 years, range 23-35 years). Bone density in Hounsfield units (HU) was measured at 13 interradicular sites and four bone levels. Bone densities in most areas were higher than 850 HU. Statistically significant differences in bone density were detected at different levels and sites. Bone densities in both maxilla and mandible significantly increased from the alveolar crest toward basal bone in posterior areas, while the opposite was observed in anterior areas. There were statistically significant differences in bone densities between the maxilla and mandible in posterior areas. Bone densities progressively increased from anterior to posterior areas in the mandible. The results suggest that mini-implants for orthodontic anchorage may be effective when placed in most areas with equivalent bone density up to 6 mm apical to the alveolar crest. Site selection should be adjusted according to bone density assessment.

Evaluation of orthodontic mini-implant anchorage in premolar extraction therapy in adolescents

Evaluation of orthodontic mini-implant anchorage in premolar extraction therapy in adolescents

Evaluation of orthodontic mini-implant anchorage in premolar extraction therapy in adolescents

The purpose of this study was to determine the success rate, positional stability, and patient evaluation of orthodontic mini-implants (OMIs). Thirteen patients (8 girls, 5 boys; average age, 14 years 10 months) were treated with 82 OMIs measuring 1.6 mm in diameter and 6 mm in length placed in the buccal alveoli (1 unloaded OMI and 1 loaded OMI per quadrant). The right or left side of each arch was randomly selected for immediate loading with up to 250 g of direct force; the contralateral side was loaded 3 to 5 weeks later. Serial impressions, clinical observations, and orthodontic maintenance were performed until adequate space closure was achieved. The overall OMI success rate was 70.73%. As calculated with a mixed-model analysis, there was no statistically significant difference between the success rates of immediately loaded OMIs (80.0%) and delayed loaded OMIs (80.95%). The combined success rate for loaded OMIs (80.49%) was significantly higher than that of unloaded OMIs (60.98%). Patients' motivation for OMI treatment was primarily the desire to avoid headgear. Using a 100-mm visual analog scale, the patients indicated average scores of 54.77 for the amount of pain during OMI placement and 27.10 for the amount of pain during OMI removal. OMIs are a predictable, effective, and well-tolerated anchorage source for adolescents. Neither the timing of force application nor the force itself precipitated failure of the OMIs. Orthodontic forces can be applied immediately to OMIs. Various anatomic and behavioral conditions unique to adolescents and a clinical learning curve can affect the success rate of OMIs.

A descriptive tissue evaluation at maxillary interradicular sites: Implications for orthodontic mini‐implant placement

Few studies have evaluated interradicular anatomy for hard and soft tissue thickness. Because interradicular sites are common regions for mini-implant placement for orthodontic anchorage, the purpose of this study was to provide a guideline to indicate the best location for mini-implants as it relates to the thickness of cortical bone and soft tissue, and to the height of the attached gingival field. CT images from 15 men and 15 women (mean age 27 years, range 23-35 years) were used to evaluate the buccal interradicular cortical bone thickness from and mesial to the central incisor to the 1st molar. To record soft tissue depth at the site of assessment for cortical bone thickness, the mucosa was pierced with a #15 endodontic K-file until the attached rubber stop rested on the mucosa. The height of attached gingiva was measured at the mid-aspect of each tooth using a caliper. There were no significant differences in cortical bone thickness within interradicular sites except for the 2nd premolar/1st molar site. There were also no significant differences in soft tissue thickness within interradicular sites except for the lateral incisor/canine and 2nd premolar/1st molar sites. The height of attached gingiva was greater in the anterior compared to the posterior region and was shortest in the premolar region. Given the limits of this study, mini-implants for orthodontic anchorage may be well placed with equivalent bone-implant contact anywhere within the zone of attached gingiva up to 6 mm apical to the alveolar crest with adequate interradicular space.

Bone thickness of the palate for orthodontic mini-implant anchorage in adults

The palate is a suitable site for the placement of orthodontic mini-implants. This study was conducted to assess the bone thickness of the palate to provide a more reliable guide for mini-implant placement. Computed tomographic records of 18 adults (9 men, 9 women) 18 to 35 years old (mean age, 26.8 +/- 4.0 years) were used to measure the bone thickness of the midpalatal area and its vicinity posterior to the incisive foramen. Bone thickness was measured at 80 coordinates at regular mediolateral and anteroposterior intervals along the midpalatal suture. After the mean, minimum, and maximum values were obtained for the entire group and for the male and female groups, mediolateral and anteroposterior comparison was done, and the differences between sexes were evaluated. Individual variations were so great that high-resolution computed tomographic images are recommended for safety. Significant differences were seen between the male and female groups. The midpalatal area within 1 mm of the midsagittal suture had the thickest bone available in the whole palate. The thickness tended to decrease laterally and posteriorly. Maps of mean palatal bone thickness were made for visual comparison of placement locations and for selection of the mini-implant length. When a mini-implant could deviate from the midpalatal area by more than 1 mm, we recommend placing it not far posteriorly or using a shorter mini-implant.