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OBJECTIVES@#This study aimed to construct the finite element model of the mandibular first molar with the invisible appliance and explore the dentition movement characteristics of the mandibular first molar when using micro-implant anchorage and different initial positions of the first molar.@*METHODS@#Models of the mandible, tooth, periodontal membrane, and invisible appliance were constructed using cone beam computed tomography (CBCT) data. The two groups were divided into the non-anchorage group and the micro-implant group (between the roots of the first molar and the second molar) based on whether the elastic traction of the micro-implant was assisted or not. The two groups were divided into the following conditions based on the starting position of the first molar: Working condition 1: the distance between the first molar and the second premolar was 0 mm; working condition 2: the distance between the first molar and the second premolar was 1 mm; working condition 3: the distance between the first molar and the second premolar was 2 mm; working condition 4: the distance between the first molar and the second premolar was 3 mm. The data characte-ristics of total displacement and displacement in each direction of dentition were analyzed.@*RESULTS@#In the non-ancho-rage group, all the other teeth showed reverse movement except for the first molar which was moved distally. Meanwhile, in the micro-implant group, except for a small amount of mesial movement of the second molar in wor-king condition 1, the whole dentition in other working conditions presented distal movement and anterior teeth showed lingual movement, among which the distal displacement of the first molar in working condition 4 was the largest. With the change of the initial position of the first molar to the distal, the movement of the first molar to the distal, the premolar to the mesial, and the anterior to the lip increased, while the movement of the second molar to the mesial decreased.@*CONCLUSIONS@#The micro-implant can effectively protect the anterior anchorage, increase the expression rate of molar distancing, and avoid the round-trip movement of the second molar. The initial position of the first molar movement is related to the amount of distancing and the remaining tooth movement.
Subject(s)
Finite Element Analysis , Molar , Bicuspid , Periodontal Ligament , Tooth Movement Techniques/methods , Orthodontic Appliances, RemovableABSTRACT
Objective To investigate the role of Power Arm in en-masse retraction of maxillary anterior teeth using clear aligner (CA) and micro-implant anchorage (MIA). Methods The three-dimensional (3D) model of maxillary anterior teeth by combined use of CA and MIA was established, and the 6 mm-height Power Arm, was attached to the canine or appliance. The initial displacement and the maximum von Mises stress of periodontal ligament under three loading conditions were analyzed, namely the force was loaded by CA+150 g retraction force at canine, CA+150 g retraction force on Power Arm at appliance, CA+150 g retraction force on Power Arm at canine. Results In sagittal direction, the crown and root displacement difference of maxillary central incisor was 129, 129, 133 μm，respectively. The crown displacement of the maxillary first molar was -23.3, -23.5, -26.8 μm, respectively. The maximum von Mises stress of periodontal ligament in central incisor was 48.4, 72.6, 40.0 kPa, respectively, and that of the first molar was 5.3, 10.5, 5.8 kPa, respectively. Conclusions It can not be testified that retraction of the 6 mm-height Power Arm at canine or appliance with 5 mm-height mini-screw has more advantages than retraction of the canine directly for more favorably controlling the torque of incisors, saving anchorage of posterior teeth and decreasing von Mises stress of the periodontal ligament.
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To evaluate the therapeutic effect of using micro-implant anchorage (MIA) to rotate the functional occlusal plane (FOP) counterclockwise. Forty skeletal class Ⅱ high-angle patients who had completed orthodontic treatment were enrolled, including 20 patients treated with MIA orthodontic system (MIA group) and the other 20 patients treated with traditional sliding straight wire appliance (control group). Cephalometric measurements on the lateral cranial radiographs before and after treatment were performed, all acquired data were statistically analyzed with SPSS 26.0. At the end of treatment, MIA group obtained better effect of FOP and mandibular plane counter-clockwise rotation than the control group. In the MIA group, the average change of FOP-frankfort horizontal plane (FH), FOP-SN and mandibular plane angle (MP-FH) angle was -4.5(-7.3, -3.7)°, (3.3)° and -1.7(-3.0, -0.9)°, respectively. In the control group, the average change of FOP-FH, FOP-SN and MP-FH angle was -0.1(-4.1, 3.0)°, (-0.1±5.1)° and -0.4(-2.4, 0.7)°, respectively. There was significant difference between the change of the two groups (all <0.05). Compared with the traditional sliding straight wire appliance, counterclockwise rotation of FOP can be more effectively reversed by using MIA orthodontic system, and the MP-FH can be reduced as well.
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Humans , Cephalometry , Dental Occlusion , Malocclusion, Angle Class II/therapy , Mandible , Maxilla , Treatment OutcomeABSTRACT
The study was design to investigate the clinical effect of Micro implant system in Italy on immediate mandibular implant-supported overdenture. A total of 192 patients with mandibular edentulous treated in our hospital were randomly divided into 2 groups in which the control group consisted of 96 patients treated with immediate mandibular implant-supported overdenture by Xive implant system, while the observation group included 96 cases treated with the overdenture by Italy Micro implant system. Patients were followed up for 1 year and then the states of implant-borne overdentures, marginal bone resorption around alveolar bone, the compatibility of implant restorations with adjacent teeth, adverse events and satisfaction degree were compared between the groups. According to the results of 1-year follow-up, the resorption around alveolar bone of the observation group was significantly higher than that of the control group (p<0.05). In the observation group the differences in labial gingival margin position, gingival color and texture were significantly better (p<0.05) as compared to control group. The incidence of adverse events was notably lower (p<0.05). The Italy Micro implant system has significant curative effect on mandibular implant-supported overdentures with good compatibility of the implant restorations with adjacent teeth and low incidence rate of adverse reactions, so it is worthy of clinical application and spreading.
O estudo foi desenvolvido para investigar o efeito clínico do sistema de implantes de B&B na Itália na prótese total imediata apoiada em implante mandibular. Um total de 192 pacientes com desdentação mandibular, tratados em nosso hospital foram divididos aleatoriamente em 2 grupos, nos quais o grupo controle consistia em 96 pacientes tratados com overdenture imediato apoiado por implante mandibular pelo sistema de implante Xive, enquanto o grupo de observação incluiu 96 casos tratados com o sobredentadura pelo sistema de implantes Itália B&B. Os pacientes foram acompanhados por 1 ano e, em seguida, foram comparados os estados de sobredentaduras implanto-suportadas, reabsorção óssea marginal ao redor do osso alveolar, compatibilidade das restaurações do implante com dentes adjacentes, eventos adversos e grau de satisfação. De acordo com os resultados do seguimento de 1 ano, a reabsorção ao redor do osso alveolar do grupo de observação foi significativamente maior que a do grupo controle (p <0,05). No grupo de observação, as diferenças na posição da margem gengival labial, cor gengival e textura foram significativamente melhores (p <0,05) em comparação ao grupo controle. A incidência de eventos adversos foi notavelmente menor (p <0,05). O sistema de implantes B&B da Itália tem um efeito curativo significativo nas sobredentaduras mandibulares suportadas por implantes, com boa compatibilidade das restaurações dos implantes com dentes adjacentes e baixa taxa de incidência de reações adversas, por isso é digno de aplicação clínica e disseminação.
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Denture, OverlayABSTRACT
BACKGROUND: Maxillary skeletal expander is a non-surgical expansion technique of the maxilla. It is different from the traditional maxillary rapid expander, micro-implant assisted rapid palatal expansion, and surgically assisted rapid palatal expansion. It provides new ideas and methods for the correction of maxillary transverse deficiency, and especially for adult patients with the growth finished, provides an efficient and minimally invasive bone expansion. OBJECTIVE: To review the application and advantage of the maxillary skeletal expander in the treatment of maxillary transverse deficiency, providing scientific reference for the clinical therapeutic schedule in such patients. METHODS: A computer search for Cochrane Library, PubMed, Embase, Web of Science, CNKI, WanFang Database, and CBM databases was performed for Chinese and English literature related to the maxillary expansion device published before May 31st, 2019. RESULTS AND CONCLUSION: The maxillary skeletal expander is an effective method for correcting the maxillary transverse deficiency, and the expansion of the arch is not limited by age. This device also has a good outcome in bone expansion for adults. The maxillary skeletal expander expands the entire mid-face structure, causing the mid-sacral suture to be parallel, followed by ruptured palatine suture, increased width between the zygomatic bones, as well as the entire nasal cavity involving the upper nasal bone area is widened. This device also causes less adverse reactions, for example, the teeth are inclined buccally and the height of the alveolar bone is reduced.
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Objective: To evaluate the biomechanical effects of combined use of miniscrew and clear aligner in different kinds of loading condition on the en-mass retraction of maxillary anterior teeth. Methods: 3 D finite element models of the maxillary bone with miniscrews and clear aligner were reconstructed using the method of reverse engineering with CBCT data of an adult patient who had maxillary first premolars extracted. The orthodontic force was loaded by (1) clear aligner, (2) clear aligner and 1. 47 N force of retraction at appliance and (3) clear aligner and 1. 47 N force of retraction at canine, respectively. Results: Under the working condition of (1), (2) and (3), in sagittal direction, the displacement difference of crown and root of the maxillary central incisor was 1. 12 E-02 mm, 1. 29 E-02 mm and 9. 62 E-03 mm respectively, the displacement of the first molar crown was-2. 49 E-02 mm, -2. 09 E-02 mm and-2. 00 E-02 mm respectively; in vertical direction, extrusion of the maxillary central incisor was 1. 77 E-03 mm, 2. 93 E-03 mm and 6. 53 E-04 mm respectively. Conclusion: The working condition (3) is more advantageous to control the torque of incisors and to save the anchorage of posterior teeth, and more effective to control the extrusion of the incisors.
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Objective@# To study the remodeling of alveolar bone after retraction of the maxillary incisors assisting with micro-implant anchorage in adult patients with maxillary protrusion by CBCT.@*Methods@#Forty patients who were treated with extraction of the maxillary first premolars with microimplant anchorage meeting the inclusion criteria were selected. The CBCT data before and after treatment were collected, and the Dolphin Imaging 3D measurement software was used to measure and analyze the height and thickness of the alveolar bone of the 80 upper central incisors and the 80 lateral incisors.@*Results @#After retraction of the incisors assisting with microimplant anchorage, the labial alveolar bone height of the maxillary central incisors decreased (0.11 ± 0.33) mm, and the lingual alveolar bone height of the maxillary central incisors decreased (0.85 ± 1.23) mm. The labial alveolar bone height of the maxillary lateral incisors decreased (0.18 ± 0.42) mm, and the lingual alveolar bone height of the maxillary lateral incisors decreased (1.13 ± 1.14 ) mm. The reduction in the lingual alveolar bone height was greater than that of the labial side, and the difference was statistically significant (P < 0.05). The labial alveolar bone thickness of the maxillary central incisors increased (the root cervix, the root media and the root apex), and the difference was statistically significant (P < 0.001). The labial alveolar bone thickness of the maxillary lateral incisors also increased (P < 0.05), while the lingual alveolar bone thickness and the total alveolar bone thickness of the maxillary central and lateral incisors decreased (P < 0.001). @*Conclusion@#In adults with maxillary protrusion, the microimplant was used to assist the reduction of the anterior teeth. The alveolar bone height of the maxillary incisors was reduced, and the palatal alveolar bone height decreased more than that of the labial side. The alveolar bone of the labrum was thickened, and the palatal alveolar bone thickness and the total alveolar bone thickness of the maxillary incisors were reduced after treatment.
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SUMMARY: Micro-implant stability has always been the focus of orthodontic clinical research.In the experiment, the morphological changes of bone tissue around the micro-implants in self-tapping and assisting implantation were investigated to explore the effect of different implantation on the osseointegration of micro-implants in order to provide some theoretical basis for clinical practice. Six adult male Beagle dogs were selected,three implants were implanted into the left and right maxillary bone of Beagle dogs at the 0th, 4th and 6th week, respectively. One side to self-tapping implantation, the opposite side to assisting implantation. At the 8th week of the experiment, the animals were sacrificed and the micro-implant-bone tissue specimens with the healing time of 8w, 4w and 2w were obtained.The specimens were stained with Toluidine Blue (TB) and photographed under 100X, 200X microscope. Morphology of microimplant- bone interface cells was observed under light microscope. In self-tapping group, there were some fibrous tissues surrounding the micro-implants at the 2th week, the formation of osteoblasts and osteoid was observed at the 4th week, the wavy and lamellar bone tissues were seen at the 8th week.In assisting group,more collagen fibers were deposited around the micro-implant at the 2th week, there were a large number of osteoid-like cells, and the collagen was gradually replaced by the bone tissue at the 4th week, the osteoblasts were active and the osteoblasts were linear arrange and form a laminate bone at the 8th week.Whether implanted self-tapping or assisted implantation, micro-implant-bone interface reconstruction can occur. If the clinical need for early loading force, micro-implant try to choose selftapping implantation. By appropriately prolonging the healing time, the initial stability of the micro-implant under assistive implantation can be improved.
RESUMEN: La estabilidad del microimplante siempre ha sido el foco de la investigación clínica en ortodoncia. En este trabajo se investigaron los cambios morfológicos del tejido óseo alrededor de los microimplantes autorroscantes y se ayudó a la implantación para explorar el efecto de diferentes implantes en la osteointegración de microimplantes con el fin de proporcionar alguna base teórica para la práctica clínica. Se seleccionaron seis perros Beagle machos adultos, y se colocaron tres implantes en los huesos maxilares izquierdo y derecho en la 0ª, 4ª y 6ª semana, respectivamente. De un lado se colocó el implante autorroscante, y del otro lado el implante asistido. En la octava semana, se sacrificaron los animales y se obtuvieron las muestras de microimplante-hueso con el tiempo de cicatrización de 8, 4 y 2 semanas. Las muestras fueron teñidas con azul de toluidina (TB) y fotografiadas bajo aumento de 100X, y microscopio de 200X. La morfología de las células de la interfaz microimplante-hueso se observó bajo microscopio óptico. En el grupo autorroscante, había tejido fibroso que rodeaba los microimplantes a la 2ª semana, se observó la formación de osteoblastos y osteoide a la 4ª semana y de tejido óseo ondulado y lamelar a la 8ª semana. En el grupo asistido, se depositaron más fibras de colágeno alrededor del microimplante en la 2ª semana, hubo un gran número de células similares a osteoide, y el colágeno fue reemplazado gradualmente por el tejido óseo en la 4ª semana; los osteoblastos estaban activos y se ubicaron linealmente formando un hueso laminado en la 8ª semana. Ya sea que el implante sea con autoasistencia o con implantación asistida, puede ocurrir la reconstrucción de la interfaz microimplante-hueso. Si existe la necesidad clínica de una fuerza de carga temprana, el microimplante de elección sería la implantación autorroscante. Al prolongar apropiadamente el tiempo de curación, se puede mejorar la estabilidad inicial del microimplante bajo implantación asistida.
Subject(s)
Animals , Male , Dogs , Dental Implantation , Orthodontic Anchorage Procedures , Maxilla/anatomy & histology , Maxilla/surgery , OsseointegrationABSTRACT
Objective @# To investigate the clinical effects of micro implant anchorage nail and Ni-Ti coilspring to lower the elongation molar. @*Methods@#60 patients with the first maxillary molar elongation were divided into 2 groups. 30 of them were treated with micro implant anchorage nail and Ni-Ticoil spring to lower the molar (observation group), and the other 30 patients were treated with segmental arch to lower the molar (control group). The average lowering time, depth and pain degree of the 2 groups were compared. @*Results@#The average lowering time was faster and the overage lowering depth was greater in the observation group than that in the control group; the slight pain rate in the observation group was significantly higher than that in the control group (P<0.05), while the ratio of moderate pain and severe pain was significantly lower than that in the control group (P<0.05).@*Conclusion@# To lower the elongation molar with micro implant anchorage nail and Ni-Ti coilspring might have shorter course and less pain.
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Objective:To investigate the changes of occlusal plane in the process of retracting maxillary anterior teeth with different vertical traction force.Methods:The three dimensional finite element model of maxillary anterior teeth en-masse retraction by micro-implant was constructed with cone beam CT scanning and MIMICS and ANSYS software.Then the movement tendency of tooth and the changes of the maxillary occlusal plane was calculated when the vertical traction force was 0,0.5,0.75 and 1 N in the process of en-mass retraction,respectively.Results:Lingual tipping of anterior teeth,distal tipping of the first molar and the maxillary occlusal plane clockwise rotation by the retraction forces were observed.With the vertical traction force increasing,lingual tipping of anterior teeth and distal tipping of the first molar were decreased,and the occlusal plane clockwise rotation was prevented.Conclusion:The upper dentition movement and occlusal plane rotation can be changed effectively by the vertical traction with different force.When retract anterior teeth,0.5-0.75 N vertical traction force is beneficial to prevent clockwise rotation of the maxillary occlusal plane.
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OBJECTIVE: The aim of this study was to compare the initial stability as insertion and removal torque and the clinical applicability of novel orthodontic zirconia micro-implants made using a powder injection molding (PIM) technique with those parameters in conventional titanium micro-implants. METHODS: Sixty zirconia and 60 titanium micro-implants of similar design (diameter, 1.6 mm; length, 8.0 mm) were inserted perpendicularly in solid polyurethane foam with varying densities of 20 pounds per cubic foot (pcf), 30 pcf, and 40 pcf. Primary stability was measured as maximum insertion torque (MIT) and maximum removal torque (MRT). To investigate clinical applicability, compressive and tensile forces were recorded at 0.01, 0.02, and 0.03 mm displacement of the implants at angles of 0°, 10°, 20°, 30°, and 40°. The biocompatibility of zirconia micro-implants was assessed via an experimental animal study. RESULTS: There were no statistically significant differences between zirconia micro-implants and titanium alloy implants with regard to MIT, MRT, or the amount of movement in the angulated lateral displacement test. As angulation increased, the mean compressive and tensile forces required to displace both types of micro-implants increased substantially at all distances. The average bone-to-implant contact ratio of prototype zirconia micro-implants was 56.88 ± 6.72%. CONCLUSIONS: Zirconia micro-implants showed initial stability and clinical applicability for diverse orthodontic treatments comparable to that of titanium micro-implants under compressive and tensile forces.
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Animals , Alloys , Foot , Fungi , Polyurethanes , Titanium , TorqueABSTRACT
Objective:To study the effects of fluor-hydroxyapatite (FHA) coating titanium alloy on the osseointegration and peri-implantitis of orthodontic micro-implant.Methods:Titanium of FHA alloy (FHA group) and titanium alloy(control group) orthodontic micro-implants were respectively planted into buccal alveolar bone in mandibular premolar area of rabbits.Scanning electron microscope was used to observe the osseointegration around the micro-implants.ELISA was employed to detect TNF-α in the gingival crevicular fluid around the implants.Results:The FHA-coating titanium alloy orthodontic micro-implants led to higher bone density,smaller marrow cavity,and lower TNF-α level and shorter lasting period of TNF-α over-expression than the controls (P ＜ 0.05).Conclusion:The FHA-coating titanium alloy orthodontic micro-implant has better histocompatibility and may inhibit peri-implantitis.
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Micro-implant anchorage was used for orthodontic intervention of 3 patients with buccal impacted maxillary canine,good clinical outcome was obtained.The micro-implant anchorage may provided a new approach for the treatment of this kind of teeth.
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An adult patient with skeletal crossbite and mandibular deviation was treated by mandibular molar distalization using micro-im-plant and intermaxillary traction.After treatment,the facial contour of the patient was improved,the Class Ⅰ molar and cuspid relationship was achieved.
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A volunteer was scanned by spiral CT,the Dicom format images were imported into Mimics software to reconstruct 3-D mandibular model,then optimized by Geomagic and meshed in Ansys software. A good geometric precise three-dimensional finite element model was constructed. The displacement of dentition was similar with clin-ical situation by computer.
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Objective:To compare 2 position implant-supported molar distalization systems in clinical application.Methods:25 pa-tients with Class II and mild to moderate crowding dentition were included,18 females and 7 males,aged 15 to 29 years old(22.58 on average ).All the patients were treated with non-extraction method by distalizing the upper molar with micro-implant anchorage.In ex-perimental group(n =12)the micro-implants were inserted on infrazygomatic crest above the maxillary first molar mesial buccal root. In control group(n =13)the micro-implants were inserted on buccal alveolar bone between maxillary second premolar and maxillary first molar.In both groups micro-implants were inserted to distalize the maxillary molars.The displacement patterns of maxillary inci-sors and molars were measured and compared.Results:Successful primary micro-implant placement was obtained in 87.5%(21 /24) of the implantation in control group and 100%(26 /26)in experimental group.The distal movement(mm)of the molars in control and experiment group was 2.29 ±0.96 and 2.91 ±0.96 respectively(P >0.05).Experimental group showed significant intrusive displace-ment of the molars.Horizontal incisor displacement in experimental group was more than that in control group.Conclusion:Micro-im-plant inserted in infrazygomatic crest may facilitate intrusion and distalization of the maxillary molar and incisor.
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Objective To investigate the clinical application and effect of micro-planting nail anchorage in orthodontics.Methods Fifty-six patients with oral orthodontic were randomly divided into two groups.29 patients in the observation group were used micro-planting nail anchorage,27 patients in the control group were used the strong non-implant anchorage.Results The reduction of upper incisor inclination and distance in observation group was significantly higher than control group.In another hand,displacement of molars in observation group was significantly lower than control group,the difference was significant(t =9.714,4.491,17.172,all P ＜0.05).Conclusion Micro planting nail can provide the ideal anchorage and orthodontic treatment,and it has the advantages of easy and flexible operation,and it can be instantly afterburner,reliable quality,worthy of clinical application and promotion.
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10.3969/j.issn.2095-4344.2013.24.011
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Objective To examine the effects of fixed appliance and micro-implant on the improvement of facial profile in patients with protruding.Methods 30 protruding cases were treated by fixed appliance and micro-implant.Cephalometric data before and after treatment were measured and analyzed to assess the effects.Results The upper incisors were retracted 6.5 mm.The upper lip was retracted 3.8 mm.The lower incisors were retracted 5.8 mm.The lower lip was retracted 5.6 mm.UL-E was retracted 3.21 mm.LL-E was retracted 3.67 mm.NLA was changed from 86.7°to 103.7°.The U1-SN,U1-Y,L1-MP,L1-Y,UL-Y,LL-Y,UL-E,LL-E,and NLA demonstrated significant differences between pre-and post-treatment.Conclusions Fixed appliance and micro-implant might retract the anterior teeth and lead to an improvement of facial profile.
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Objective To study the stability of micro-implant orthodontic anchorage(MA)with different pitch in the case of immediate loading.Method Employing 3D finite element analysis method,the stress and dis-placement distribution on the bone interface of MIA with different pitch(0.3 mm、0.5 mm、0.7 mm and 1.0 mm,respectively),which was 1.47 N loaded vertically in the major axis direction,were analyzed.Result The pitch affected the stress distribution significantly,because the maximum stress increased with the pitch decreasing and the impact of pitch on stress distribution on neck and central locations of MIA were different;to decrease the pitch could reduce the max displacement of the jaw,but the impact of pitch on displacement distribution of MIA was not significant.Condusions In the case of immediate loading.MIA with pitch 0.5 mm-0.7 mm is suggested to be selected as orthodontic anchorage in the clinic.