Evaluation of Change in Dento-Skeletal Vertical Dimensions using Two Retraction Methods: A Comparative Study

Introduction: The goal of Orthodontic treatment is toimprove the patient’s life through enhancement of Dentofacialfunctions and esthetics. Paradigms have started to shift inOrthodontic world since the introduction of mini-implantsin the anchorage armamentarium. So the present study wasundertaken to analyse and compare the amount of Intrusionin maxillary anterior teeth segment using one and twominiscrews, while paying an utmost attention to patientscomfort and esthetics during the treatment.Material and Methods: The sample consisted of 20 subjectswith deep overbite and complete root formation with increasedincisor show. Lateral cephlogram and P.A Cephalogram wererecorded before placement of implant. Sample was furtherdivided in to two groups, Group I (Implant group one implantis placed between maxillary central incisors and two implantsplaced between second premolar and first molar) and GroupII (Implant Group with Power arms, one implant is placedbetween maxillary central incisor and power arms fabricatedon first molar bilaterally). Clinical evaluation of intrusion wasrecorded on every six weeks.Results: The mean intrusion achieved is 0.28mm per 6weeks interval of time in both groups suggesting there is nodifference in amount of intrusion achieved in both groups withp value of 0.697 which is statistically non-significant. Changein Frankfort mandibular plane angle was observed with GroupI and Group II.Conclusion: On the base of study it was concluded thatimplant and power arm is better choice for intrusion inmaxillary anterior segment for correction of deep overbite andcorrection of gummy smile with minimal effect on posteriorsegment

Advance and review: miniscrew-assisted rapid palatal expansion / 中华口腔医学杂志

Rapid palatal expansion (RPE) is commonly used to correct transverse maxillary deficiencies and recognized as a reliable orthopedic procedure in children and adolescents. For adults, however, conventional RPE has been considered rarely successful and can produce undesirable dental effects. Along with the development of digital techniques and mini-implant anchorage, a novel method called miniscrew-assisted RPE (MARPE) has become available for the treatment of maxillary transverse deficiency in older patients recently. In this article, the biomechanical principles and indications of MARPE, the advances in device design, the clinical effects, the matters needing attention and limitations of this method, and the stability after expansion are discussed.

Morphometric analysis of the infrazygomatic crest zone in 84 mini-implants using cone-beam CT / 中华口腔医学杂志

Objective@#To investigate the soft and hard tissue morphology in the infrazygomatic crest zone by observing the cone-beam computed tomography (CBCT) scans in patients with mini-implants.@*Methods@#CBCT scans of 43 patients performed from January 2014 to December 2016 in the Department of Stomatology, Beijing Friendship Hospital, Capital Medical University, with 84 existing mini-implants in the infrazygomatic crest region were collected. The bone thickness and cortical bone thickness were measured in the palatal and buccal side of the mini-implant. The maxillary sinus membrane thickness, sinus septa, reverse fold, and the sinus opening angle were also determined and analyzed in the maxillary posterior region.@*Results@#The bone thicknesses in the buccal and palatal side of the existing mini-implant were 2.5 (1.5, 3.2) and 5.2 (4.0, 6.4) mm, respectively. However, the corresponding cortical bone thicknesses were only 2.1 (1.3, 2.8) and 1.5 (1.0, 1.9) mm, respectively. The prevalences of the septa and the reverse fold were 33% (28/84) and 45% (38/84), respectively. The sinus opening angle was the largest in the mid-coronal plane of the maxillary first molar (71.6°±15.6°). In the coronal plane located at 10 mm mesially, the angle was the smallest (46.1°±18.0°), and in this area, 20% (16/82) of the angle was less than 30°.@*Conclusions@#The outer cortical plate of the infrazygomatic crest along with the cortical plate of sinus floor could be related to the initial stability of mini-implant anchorage. The anatomic variation such as the reverse fold indicated thorough consideration of insertion depth and angle to avoid unexpected sinus injury.

Advances in studies on distal molar movement with temporary anchorage devices / 中华口腔医学杂志

Crowding and protrusion of the dentition are often the chief complaint of orthodontic patients. For patients with severe crowding or protrusion, orthodontist often improve their profile with premolar extraction treatment. However, for patients with mild crowding and protrusion, orthodontist usually achieve treatment objective using distal molar movement with temporary anchorage devices (TAD). The present article reviewed the advances in the use of TAD in total arch distalization, including therapeutic effect measured in three-dimensions, factors that affected distal movement and the stability of curative effect.

Effect of inserted angle on the stability of loaded microscrews / 中华口腔医学杂志

Objective@#To evaluate the effect of different insertion angles on the osseointegration of loaded microscrews in beagle jaws.@*Methods@#Forty-eight microscrews were inserted at four different angles (30°, 50°, 70° and 90°) into the interradicular zones between the mandibular first molar and third premolar in twelve beagles and the microscrews had been loaded with a force of 2 N immediately for 8 weeks. After microscrew-bone specimens fixed, the maximum output value (Fmax) of pull-out test was recorded and the histomorphological changes of hard tissue were observed. The bone-implant contact (BIC%) was quantitatively analyzed and the osseointegration of microscrew-bone interface was comprehensively evaluated.@*Results@#Both Fmax and BIC% values of microscrews were influenced by the insertion angles. The maximum value of Fmax was (385±23) N in the group with 50° angle, and the minimum value was (198±16) N in the group with 30° angle(P <0.05). The maximum value of BIC% was (59.1±6.0)% in the group with 70° angle, and the minimum value was (30.2±3.2)% in the group with 30° angle (P <0.05). Histomorphology observation revealed that in peri-screws region, the various degree of bone remodeling was found in different angle samples.@*Conclusions@#The insertion angles (50°and 70°) were favorable to the stability of the microscrew.

Effect of three types of rapid maxillary expansion: a three-dimensional finite element study / 中华口腔医学杂志

Objective@#To evaluate the transverse displacement, stress distribution and tendency of change in tooth, alveolar bone and mid-palatal suture using three kinds of rapid maxillary expansion methods.@*Methods@#Cone-beam CT image data was obtained by scanning skulls of a volunteer. Three-dimensional models of maxillary complex were re-established using Mimics and Geomagic Studio and models of Hyrax expander, Haas expander and miniscrew-assisted rapid palatal expander (MARPE) were established using ANSYS Workbench. Stress distribution, displacement and tendency of change in tooth, alveolar bone and mid-palatal suture were evaluated.@*Results@#Hyrax expander brought 0.105 mm lateral displacement of crown, 0.022 mm mid-palatal suture width increase, wedge opening and clockwise rotation tendency of maxilla. Haas expander created uniform stress distribution, 0.216 mm lateral displacement of crown, and 0.031 mm mid-palatal suture width increase. In MARPE model, the lateral displacement of crown was 0.267 mm, and mid-palatal suture width increased 0.315 mm. The maximum of mid-palatal suture expansion and stress distribution appeared in the middle region, and maxilla had tendency of counterclockwise rotation.@*Conclusions@#The lateral changes of teeth and bones brought by MARPE were the most significant. Haas expander had some advantages in comparison with Hyrax.

Impact of anchorage implant design factors on its primary stability / 中华口腔医学杂志

During the past decade, the anchorage implants have been widely used in the orthodontic treatment. Many scholars have studied the influence of different factors on anchorage implant's primary stability, including anchorage implant's material properties, structural design, surgical procedure, bone condition, loading force's magnitude and direction. This article is to review the influence of anchorage implant's shape, dimension, neck design and thread design on its primary stability.

The value of bone mineral density and bone resorption markers around the mini-screw implant in the orthodontic treatment / 中国基层医药

Objective To investigate the value of bone mineral density and bone resorption markers around the mini-screw implant in the orthodontic treatment.Methods 178 orthodontic patients were prospectively collected.According to the organization condition around the mini-screw implant loaded,all patients were assigned into stable group (n =160) and loose group (n =18).The levels of interleukin-1 β (IL-1 β) and matrix metalloproteinase-9 of the liquid around the mini-screw implant were detected at 1,2 and 3 months after loading.Moreover,the bone miner al density around the mini-screw implant before and after loading were studied as well.Results Compared with the stable group,the loose groups at 1,2 and 3 months after loading got significantly higher levels of IL-1β [(35.48 ± 4.39)pg/mL vs.(29.48 ±3.92)pg/mL,t =3.348,P =0.004;(41.45 ±5.39)pg/mL vs.(26.29 ±4.12)pg/mL,t =6.493,P =0.000;(54.39 ± 12.82) pg/mL vs.(23.58 ± 3.62) pg/mL,t =11.589,P =0.000].Compared with the stable group,the loose group at 1,2 and 3 months after loading got significantly higher levels of MMP-9[(5.68 ± 3.54) ng/mL vs.(1.74 ± 0.88) ng/mL,t =8.496,P =0.000;(6.84 ± 2.82) ng/mL vs.(1.25 ± 0.62) ng/mL,t =9.835,P =0.000;(9.84 ± 4.39) ng/mL vs.(1.21 ± 0.58) ng/mL,t =12.548,P =0.000].Compared with the sta ble group,the loose group got significantly lower levels of bone mineral density of maxillary bones around the miniscrew implant before and at 3 months after loading[(620.48 ±67.82) HU vs.(694.39 ±84.58)HU,t =2.459,P =0.015;(597.39 ± 58.93) HU vs.(693.59 ± 83.29) HU,t =2.909,P =0.008].Conclusion The decrease of bone mineral density around the mini-screw implant is related to the loosening of the mini-screw implant,and IL-1 β and MMP-9 of the surrounding fluid can reflect the peripheral inflammation.

Management of open bite that developed during treatment for internal derangement and osteoarthritis of the temporomandibular joint / 대한치과교정학회지

This case report describes the orthodontic treatment performed for open bite caused by internal derangement (ID) and osteoarthritis (OA) of the temporomandibular joint (TMJ). A Japanese woman, aged 31 years and 11 months, referred to our department by an oral surgeon had an open bite with clockwise rotation of the mandible and degeneration of the condyle. The overbite was corrected through intrusion of the maxillary and mandibular molars using mini-screw implants to induce counterclockwise rotation of the mandible. Then, the mandibular second premolars were extracted and comprehensive orthodontic treatment was performed to establish a Class I molar relationship with distalization of the maxillary arch and to eliminate anterior crowding. Following treatment, her facial profile improved and a functional and stable occlusion was achieved without recurrence of the TMJ symptoms. These results suggest that orthodontic intrusion of the molars is one of the safer and less stressful alternatives for the management of open bite due to degeneration of the condyles caused by ID and OA of TMJ.

Estabilidad de los miniimplantes en Ortodoncia. "Biología ósea y Biomecánica" / Miniimplant stability in Orthodontics. "Bone Biology and Biomechanics"

El anclaje ha sido un aspecto crucial para la mayoría de los tratamientos de Ortodoncia. En las últimas dos décadas, el anclaje con miniimplantes ha aumentado el espectro de posibilidades para muchos tipos de tratamientos por presentar numerosas ventajas y pocas desventajas. Este artículo pretende hacer una revisión de literatura sobre los mecanismos de la biología ósea básica, como los aspectos mecánicos los activan y modulan; como se genera la estabilidad primaria y secundaria, como incide de manera crítica el porcentaje de éxito con el uso de los miniimplantes y como se ha estudiado esta interrelación por medio de modelos con elementos finitos.

Anchorage is crucial in most orthodontic treatments. During the last two decades, anchorage with mini-screw implants has increased the number of possibilities for many different types of orthodontic treatments. The aim of this paper is to present a literature review regarding how bone biology processes are elicited and modulated; how primary and secondary stability influence the success rate when mini-screw implants are used; and how this relation has been studied by means of the finite element method.

Comparison of success rates of orthodontic mini-screws by the insertion method / 대한치과교정학회지

OBJECTIVE: The aim of this study was to compare the success rates of the manual and motor-driven mini-screw insertion methods according to age, gender, length of mini-screws, and insertion sites. METHODS: We retrospectively reviewed 429 orthodontic mini-screw placements in 286 patients (102 in men and 327 in women) between 2005 and 2010 at private practice. Age, gender, mini-screw length, and insertion site were cross-tabulated against the insertion methods. The Cochran-Mantel-Haenszel test was performed to compare the success rates of the 2 insertion methods. RESULTS: The motor-driven method was used for 228 mini-screws and the manual method for the remaining 201 mini-screws. The success rates were similar in both men and women irrespective of the insertion method used. With respect to mini-screw length, no difference in success rates was found between motor and hand drivers for the 6-mm-long mini-screws (68.1% and 69.5% with the engine driver and hand driver, respectively). However, the 8-mm-long mini-screws exhibited significantly higher success rates (90.4%, p < 0.01) than did the 6-mm-long mini-screws when placed with the engine driver. The overall success rate was also significantly higher in the maxilla (p < 0.05) when the engine driver was used. Success rates were similar among all age groups regardless of the insertion method used. CONCLUSIONS: Taken together, the motor-driven insertion method can be helpful to get a higher success rate of orthodontic mini-screw placement.

Efectividad del anclaje esquelético temporal para el cierre de espacios: Revisión sistemática de literatura / Effectiveness of temporary skeletal anchorage for space closure:A systematic review

Introducción y Objetivo: El manejo del anclaje es fundamental para el éxito del tratamiento en ortodoncia fi ja, sin embargo no hay consenso acerca de la efectividad del anclaje esquelético para la retracción de los dientes anteriores. El objetivo fue evaluar la efectividad del anclaje esquelético para el cierre de espacios en el arco maxilar.Materiales y Métodos: Se realizó una revisión sistemática de literatura a partir de las bases de datos PubMed, Lilacs, Cochrane, Scielo. Se incluyeron ensayos clínicos controlados, donde el anclaje esquelético fuera utilizado para el cierre de espacios; tresrevisores analizaron los resúmenes y textos completos para considerar el cumplimiento de los criterios de inclusión y exclusión de manera independiente, en un formato de extracción de datos.Resultados: Se identifi caron 324 artículos, de los cuales 316 fueron rechazados después de la evaluación, de los ocho estudios inicialmente seleccionados, cinco fueron excluidos. Sólo tres estudios cumplieron con los criterios de inclusión. Se realizó un metanálisis con el método de efectos aleatorios para el movimiento mesial del molar superior, en el cual los dispositivos de anclaje esquelético temporal mostraron ser más efectivos en el control del anclaje en -2,72 mm (-4,10,- 1,33 IC95%) al compararlos con los métodos de anclaje ortodóntico convencional, esta diferencia fue estadísticamente signifi cativa. Conclusiones: El anclaje esquelético temporal parece ser más efectivo para controlar el movimiento mesial del molar durante el cierre de espacios, comparado con el anclaje ortodóntico convencional, sin embargo la evidencia científi ca en la literatura es escasa.

Introduction and Objetive: Anchorage management is essential for successful fi xed orthodontic treatment; however there is no consensus about the effectiveness of skeletal anchorage for anterior teeth retraction. The aim of this review was to evaluate the effectiveness of skeletal anchorage forspace closure in the maxillary arch. Materials and Methods: A systematic review of the literature was performed in PubMed, Cochrane, Lilacs, Scielo databases. Controlled clinical trials were included, where skeletal anchorage was used for space closure. Three reviewers examined the abstracts and full texts to determine fulfi llment of the inclusion and exclusion criteria independently in a data extraction form. Results: 324 papers, out of which 316 were excluded after the evaluation of title and abstract of the eight initially selected trials. Only three trials met the inclusion criteria.A meta-analysis was performed with a random effects method for the mesial movement of upper molars in which the temporary skeletal anchorage devices showed to be more signifi cantly moreeffective in controlling anchorage -2,7 mm (-4,10,-1,33 CI 95%) when compared to the conventionalanchorage control methods.Conclusions: Temporary skeletal anchorage seems to be more effective in controlling the movement of molars during mesial space closure, when compared to the conventional orthodontic anchorage although evidence in the literature is limited.

Ancoragem ortodôntica: o uso de miniimplantes / Orthodontics anchoring: the usage of mini-implants

A ancoragem é um príncipio importante para o sucesso do tratamento ortodôntico e seu controle é fundamental para a obtenção dos resultados desejados. Os recursos de ancoragem mais utilizados comumente são limitados e muitas vezes dependem da colaboração do paciente.A ancoragem por implantes tem a grande vantagem de serem mais estáveis, sendo utilizada para a movimentação de dentes individualmente ou em grupo. Para que seja alcançado um resultado adequado, o uso de implantes no tratamento ortodôntico depende de um planejamento conjunto entre o ortodontista e o implantodontista. O objetivo deste trabalho é fazer uma revisão da literatura da importância e utilização desses implantes no tratamento ortodôntico.

The anchorage is an important factor for the success of the orthodontic treatment and its control is basic for the attainment of the desired results. The more used intra and extra-buccal resources of anchorage are limited and many times depend on the contribution of the patient. The anchor for implants has the great advantage of being always stable, being used for the handling of individual teeth or in groups. The use of implants in therapy orthodontic depends on a planning between the orthodontist and the implantodontist for adequate prognosis to be achieved in the planning. The aim of this work is to make a literature review of the importance and use of the dental implants in orthodontic treatment.

Mini-implante: um novo conceito em ancoragem ortodôntica: [revisão] / Mini screws: a new concept in orthodontics anchorage: [review]

O mini-implante é um dispositivo utilizado pelos ortodontistas como um método de ancoragem, eliminando em grande parte a necessidade de cooperação dos pacientes e ampliando as possibilidades de tratamento em diversos tipos de movimentos ortodônticos. O presente trabalho teve como objetivo realizar uma revisão da literatura, discorrendo sobre as diversas aplicações clínicas do miniimplante, suas vantagens e desvantagens, o procedimento cirúrgico, demonstrar a técnica para localização exata do sitio de instalação do mini-implante e ainda relatar um caso clínico de paciente portadora de sintomatologia dolorosa da ATM, mordida cruzada e desvio da linha média, onde o plano de tratamento foi a utilização de mini-implante associado a barra transpalatina. De acordo com a literatura consultada pode-se concluir que o mini-implante é bastante efetivo como dispositivo de ancoragem.

The mini screws are devices used by orthodontists as a method of anchorage, largely eliminating the need for patient cooperation and expanding the possibilities for treatment in various types of orthodontic movements. This study aimed to conduct a review of the literature, discussing the various clinical applications of the mini screw, their advantages and disadvantages, surgical procedures, demonstrate exact localization technique of the installation site mini screw and also report a case of a patient with symptoms of TMJ pain, cross bite and deviation midline, where the treatment plan was the use of mini-implants associated with transpalatal bar. According to the literature and after completion of the case, one can conclude that the mini screw was quite effective as a method of anchorage the correction of midline.

Insertion and removal torques according to orthodontic mini-screw design / 대한치과교정학회지

OBJECTIVE: This study was designed to analyze the primary and secondary stability characteristics of orthodontic mini-screws of tapered design when compared with the cylinder mini-screw. METHODS: A total of 48 mini-screws were placed into the buccal alveolar bone of the mandible in 6 male beagle dogs. Comparison was made between tapered and cylinder type mini-screws (Biomaterials Korea, Seoul, Korea). Maximum insertion torque (MIT) was measured using a torque sensor (Mark-10, MGT 50, USA) during installation, and maximum removal torque (MRT) was recorded after 3 and 12 weeks of loading. RESULTS: Taper mini-screws showed a higher MIT value of 22.3 Ncm compared with cylinder mini-screw showing 13.6 Ncm (p < 0.001). The MRT of the taper mini-screw showed a significantly higher value of 9.1 Ncm than those of cylinder mini-screw of 5.7 Ncm at 3-weeks after installation (p < 0.05). However, there was no difference in the MRT value between the taper and cylinder mini-screws at 12 weeks of loading. CONCLUSIONS: These results showed that the high insertion torque of the taper mini-screw design increases initial stability until 3 weeks of loading, but does not have any effect on the secondary stability at 12 weeks of loading.

Evaluation of insertion of torque and pull-out strength of mini-screws according to different thickness of artificial cortical bone / 대한치과교정학회지

OBJECTIVE: The purpose of this study was to evaluate the mechanical performance of mini-screws during insertion into artificial bone with use of the driving torque tester (Biomaterials Korea, Seoul, Korea), as well as testing of Pull-out Strength (POS). METHODS: Experimental bone blocks with different cortical bone thickness were used as specimens. Three modules of commercially available drill-free type mini-screws (Type A; pure cylindrical type, Biomaterials Korea, Seoul, Korea, Type B; partially cylindrical type, Jeil Medical, Seoul, Korea, Type C; combination type of cylindrical and tapered portions, Ortholution, Seoul, Korea), were used. RESULTS: Difference in the cortical bone thickness had little effect on the maximum insertion torque (MIT) in Type A mini-screws. But in Type B and C, MIT increased as the cortical bone thickness increased. MIT of Type C was highest in all situations, then Type B and Type A in order. Type C showed lower POS than Type A or B in all situations. There were statistically significant correlations between cortical bone thickness and MIT, and POS for each type of the mini-screws. CONCLUSION: Since different screw designs showed different insertion torques with increases in cortical bone thickness, the best suitable screw design should be selected according to the different cortical thicknesses at the implant sites

Histomorphometric characterization of osseointegration after implantation of dental mini-screw / 实用口腔医学杂志

Objective:To study the osseointegration after implantation of dental mini-screw under unloaded condition by histomorphometric observations.Methods:30 titanium mini-screws were used. 3 titanium implant miniscrews were implanted into each tibia of 10 New Zeland White rabbits at a distance of 10 mm between 2 mini-screws. 2 animals were sacrificed immediately,1,2,4 and 8 weeks after operation respectively.Samples of the screws with surrounding bone tissue were examined by HE staining.Results:Progressive changes were observed in the implant-bone interface.1 and 2 weeks after operation collagen fibers, locally absorbed areas and cancellous bones with loose connective tissues were found.4 weeks after operation compact cortical bone was observed.8 weeks after operatoin lamellar bone and second remodeling were found.Conclusion:Osseointegration between implanted mini-screw and bone tissue may complete in 8 weeks in rabbit tibia.