Five years of experience using palatal mini-implants for orthodontic anchorage.

PURPOSE: The authors review 5 years of clinical experience using Straumann Orthosystem (Straumann, Basel, Switzerland) palatal mini-implants for orthodontic anchorage, describe clinical procedures, and give statistical results. MATERIALS AND METHODS: Diagnostic planning, surgical phase, and clinical procedure are described. The diagnostic planning was performed on lateral cephalogram in 13 cases; in 1 case, with an ectopically included upper canine, a computed tomography was requested. The Straumann Orthosystem kit includes a pure titanium implant with the healing cap, and a set of burs and instruments for the surgical insertion and removal. The sample comprised 14 adult patients (2 males and 12 females) requiring fixed orthodontic appliance for Class II malocclusion. Because of critical anchorage conditions they had received a palatal mini-implant as absolute anchorage during orthodontic treatment: 9 implants of 6.0 mm and 7 implants of 4.0 mm were positioned, primarily using a 2.5 mm transmucosal neck length. The orthodontic phase always started after 13 weeks of the insertion, in order to ensure osteointegration. RESULTS: In all cases, neither a perforation of the nasal cavity nor other surgical complication occurred. All implants have been successfully osteointegrated, except for 1 which has been lost for critical hygiene conditions. Two implants needed to be replaced because of tongue forces, which had been determined to interfere with the osteointegration immediately after surgery; this inconvenience was afterwards solved by the use of a resin splint. CONCLUSIONS: Palatal mini-implants revealed to be clinically easy to use and proved to be an efficient auxiliary device in orthodontics when absolute anchorage is needed.     

微型种植体支抗治疗安氏Ⅱ类1分类错殆畸形的临床应用

目的：探讨微钛钉种植体支抗在安氏Ⅱ类1分类错抬畸形矫治中的,临床应用及其与传统支抗的区别。方法：选择30例安氏Ⅱ类1分类拔牙矫治的上颌前突患者,拔牙模式均为拔除上颌2个第一前磨牙,随机分成试验组和对照组,各15例。实验组于上颌双侧第一磨牙和第二前磨牙牙根之间植入自攻微型种植体作为支抗,对照组常规制作上颌横腭杆加Nance弓和口外弓。分析2纽治疗前后x线头影测量指标变化。结果：所有病例矫治后,上前牙突度及轴倾度得到改善。实验组SNA、ANB、U1-sN、UI—L1、U1-NA、U1-PP、U6-PP的变化较对照组明显,2组间差异有统计学意义。结论：微种植体能提供稳定的支抗,最大限度避免支抗的丧失,能更有效地改善安氏II类1分类错拾畸形患者的面形和牙弓凸度。     

自攻型微螺钉种植体内收上前牙的临床研究

目的：评价自攻型微螺钉种植体作为正畸支抗内收上前牙的有效性。方法：从临床病例中选择30例矫治设计拔除4颗第一双尖牙、上颌强支抗的双颌前突患者,均采用自攻型微螺钉种植体作为支抗手段,植入部位选择在上颌第二双尖牙和第一磨牙牙根间的颊侧牙槽骨,植入4周后施加350g以内矫治力,观察微螺钉种植体的稳定性,并对30例患者治疗前后X线头颅侧位片进行测量,评价治疗效果。结果：微螺钉种植体5个月内的成功率为93.3%,稳定性高。30例双颌前突患者上前牙内收效果明显,获得了磨牙强支抗的效果。结论：微螺钉种植体能作为稳定的正畸支抗,能有效地内收上前牙,起到了加强磨牙支抗的效果。     

微小种植体支抗辅助螺旋扩弓器上颌快速扩弓效果的动物实验研究

目的：应用动物实验观察微小种植体辅助螺旋扩弓器上颌快速扩弓的效果，为临床使用微小种植体进行快速扩弓提供实验依据。方法：选取6个月龄雄性犬8只，随机分为两组，一组利用微小种植体作支抗，另一组按传统方法利用牙齿为支抗进行扩弓。两组实验犬均测量实验前后上颌同名中切牙、尖牙、第一磨牙之间的宽度；各组尖牙、第一前磨牙、第一磨牙牙齿倾斜角度，进行组间前后比较。结果：两组牙弓均能够有效地使上颌横向扩大，但实验组没有发生牙齿倾斜，对照组均观察到支抗牙的颊向倾斜。结论：使用微小种植体辅助螺旋扩弓器进行上颌快速扩弓能够有效地避免利用牙作支抗进行扩弓的缺陷，避免了支抗牙的颊向倾斜。     

Bioabsorbable materials in orthopaedics

The applications of bioabsorbable implants in orthopaedic surgery have mainly been mandated from the need to eliminate implant removal operations. Although they have not gained widespread popularity among orthopaedic surgeons, they still represent an area of evolution. Considerable effort has been put into developing new bioabsorbable materials with fewer adverse effects. In this article an extensive review of the literature is presented emphasising on basic science and clinical applications of these materials. A review of the types of implants, the materials used, their biochemical properties, their adverse effects and some of the potential future applications is presented.     

多孔金属钽假体在骨缺损修复中的应用

目的对多孔金属钽假体治疗骨缺损的研究现状作一综述。方法广泛查阅多孔金属钽假体特性及其治疗各种骨缺损的相关文献,并进行综述。结果多孔金属钽假体凭其特性,在某些类型的骨缺损治疗中效果显著。结论多孔金属钽假体存在着自身优缺点,在符合其适应证的前提下使用可取得较好近期疗效,为临床骨缺损修复提供了种新参考,但远期疗效需进一步观察。     

微螺钉种植支抗稳定性的临床研究

目的：研究微螺钉加载正畸负荷后的稳定性。方法：本研究包括了15例成年患者，以植入上颌颧突的微螺钉作为前牙内收的颌内支抗。微螺钉植入2周后施力。加力前及加力后9个月分别拍摄X线头颅定位片，将头影测量片进行重叠，测量微螺钉的移位变化。结果：15例中6例患者的微螺钉伸出并移位（-0．5～1．5mm）。微螺钉头部平均向前移位0．4mm，有统计学意义（P〈0．05）。结论：微螺钉是一种稳定的支抗装置，但是在承载正畸负荷的过程中，并不保持绝对的稳定，部分微螺钉在正畸力作用下有移位。为了防止因微螺钉移位伤及临近的重要组织结构，建议微螺钉应植入在没有主要神经、血管通过的非齿槽骨区，或植入在齿槽间隔区，但微螺钉与牙根之间应留出2mm的安全距离。     

Schaftfreier Kopfersatz

Currently there are four manufacturers offering stemless implants for shoulder joint replacement. The first implant was introduced in 2004, the most recent in 2011. A total of almost 10,000?stemless implants have been used in shoulder arthroplasty since 2004. There are two different types of metaphyseal anchorage: in three implant systems, metaphyseal anchorage is obtained by impaction of a fin system. In one implant system, cage screw fixation is used. These two types of metaphyseal anchorage show different advantages and disadvantages. The cage screw system achieves an ideal fixation in sclerotic bone structure as often seen in posttraumatic conditions. Impaction using the fin system is particularly suitable in soft bone structure. An additional use of cancellous bone from the resected humeral head as spongiosaplasty improves stability of the implant. Regarding revision surgery, the different types of implants show varying advantages and disadvantages in terms of a secondary approach to the glenoid and the metaphyseal component. Because of the small number of cases and short observation period at the present time, none of the implant systems obtains the decisive superiority. In sclerotic bone, the cage screw system seems to be advantageous, whereas impaction using the fin system seems to be preferable in osteoporotic bone and conditions with a defect of the bone.     

后牙区微型种植体支抗改善露龈微笑的临床效果观察

目的评价正畸治疗中使用后牙区高位微型种植支抗改善患者露龈微笑的临床疗效,探讨其临床适用性。方法 2011年8月-2013年5月在本院接受正畸治疗的患者中,选取双颌前突伴露龈微笑且设计拔除上颌两侧第一双尖牙的患者39例,搜集患者治疗前后X线头颅侧位片及患者微笑和侧貌像,并测量。结果采用后牙区高位种植体压低、内收上前牙,1-SN距和1-NA距的变化均有统计学意义（P〈0.01）,上唇突度和上下唇间距均有一定程度减小。结论应用后牙区高位微型种植体支抗,可明显压低上前牙改善露龈微笑,并且操作简单,适合临床长期推广应用。     

自攻型微钛钉支抗在矫治成人上颌前突中的临床应用

目的：探讨自攻型微钛钉矫治成人上颌前突的临床疗效。方法：应用自攻型微钛钉作为支抗矫治19例安氏Ⅱ类1分类上颌前突成年患者,拔除双尖牙并排齐牙列后,微钛钉植入上颌第一恒磨牙和第二前磨牙颊侧,2周后以每侧1.0～1.5N滑动内收前牙。通过前后X线头影测量分析,比较前牙内收情况和磨牙支抗的变化。结果：19例上颌前突均得到明显改善,切牙切缘平均内收7.49mm,切牙牙轴与SN交角平均减少17.94°,与NA交角平均减少12.46°,前牙覆盖平均减少了7.4mm,上颌切牙治疗前后差异有统计学意义（P〈0.05）。上颌第一磨牙平均前移0.38mm,上颌第一磨牙治疗前后垂直向移动差异无统计学意义,94.7%种植体保持了稳定。结论：自攻型微钛钉能够有效治疗上颌前突成年患者,改善侧貌,起到强支抗的作用。     

微型种植体支抗在青少年口腔正畸中的临床应用价值

评估微型种植体支抗用于青少年口腔正畸中的效果。方法 选取我院2019年5月-2020年5月 收治的100例青少年口腔正畸患者为研究对象,采用随机数字表法分为对照组与观察组,各50例。对照 组予以常规正畸治疗,观察组予以微型种植体支抗治疗,比较两组正畸效果、咀嚼功能及不良反应发生 情况。结果 观察组上中切牙凸距差、上中切牙倾角差大于对照组,磨牙移位小于对照组（P ＜0.05）; 观察组咬合力及咀嚼效率均高于对照组（P ＜0.05）;观察组不良反应发生率为8.00%,低于对照组的 28.00%（P ＜0.05）。结论 微型种植体支抗疗法用于青少年口腔正畸可获得满意的正畸效果,能够增强咀 嚼功能,安全性较好。     

Entwicklung neuer biodegradabler Implantate

The advantage of biodegradable implants is that they do degrade after they have fulfilled their function. Therefore, a second operation for removing metal implants is not necessary. Additionally, the healing process may be stimulated by the successive loss of the mechanical properties of the implant during degradation, corresponding with the increasing loading on the healing tissue. The most important materials are polylactide, polyglycolide and their copolymers, and polydioxanone. The mechanical properties of these polymers were improved by special fabrication techniques. Nevertheless, the materials have disadvantages relating to their stiffness and relaxation behavior. Therefore, their use has to be restricted to nearly unloaded situations. The degradation behavior of the materials can be controlled by the production of copolymers and by the molecular weight of the polymers. The degradation behavior cannot be predicted exactly in vivo, as it is influenced not only by the chemistry and the implant design but also by the localization of the implant in the tissue. In general, the biocompatibility of the polymers used today is good and the observed complication rate is very low. Osteolytic reactions, which can sometimes be observed, have no clinical consequences in most instances. The clinical applications comprise resorbable pins and screws for the fixation of small bony fragments, interference screws for the surgery of the anterior cruciate ligament, resorbable augmentation devices for ligaments and tendons, resorbable membranes for guided bone regeneration in maxillofacial surgery, and a lot more. Future developments are expected in the field of tissue engineering and drug release.     

Short-term and long-term effects of orthopedic biodegradable implants

Presently, orthopedic and oral/maxillofacial implants represent a combined $2.8 billion market, a figure expected to experience significant and continued growth. Although traditional permanent implants have been proved clinically efficacious, they are also associated with several drawbacks, including secondary revision and removal surgeries. Non-permanent, biodegradable implants offer a promising alternative for patients, as they provide temporary support and degrade at a rate matching tissue formation, and thus, eliminate the need for secondary surgeries. These implants have been in clinical use for nearly 25 years, competing directly with, or maybe even exceeding, the performance of permanent implants. The initial implantation of biodegradable materials, as with permanent materials, mounts an acute host inflammatory response. Over time, the implant degradation profile and possible degradation product toxicity mediate long-term biodegradable implant-induced inflammation. However, unlike permanent implants, this inflammation is likely to cease once the material disappears. Implant-mediated inflammation is a critical determinant for implant success. Thus, for the development of a proactive biodegradable implant that has the ability to promote optimal bone regeneration and minimal detrimental inflammation, a thorough understanding of short- and long-term inflammatory events is required. Here, we discuss an array of biodegradable orthopedic implants, their associated short- and long- term inflammatory effects, and methods to mediate these inflammatory events.     

Patient‐Specific Orthopaedic Implants

Patient‐specific orthopaedic implants are emerging as a clinically promising treatment option for a growing number of conditions to better match an individual's anatomy. Patient‐specific implant (PSI) technology aims to reduce overall procedural costs, minimize surgical time, and maximize patient outcomes by achieving better biomechanical implant fit. With this commercially‐available technology, computed tomography or magnetic resonance images can be used in conjunction with specialized computer programs to create preoperative patient‐specific surgical plans and to develop custom cutting guides from 3‐D reconstructed images of patient anatomy. Surgeons can then place these temporary guides or “jigs” during the procedure, allowing them to better recreate the exact resections of the computer‐generated surgical plan. Over the past decade, patient‐specific implants have seen increased use in orthopaedics and they have been widely indicated in total knee arthroplasty, total hip arthroplasty, and corrective osteotomies. Patient‐specific implants have also been explored for use in total shoulder arthroplasty and spinal surgery. Despite their increasing popularity, significant support for PSI use in orthopaedics has been lacking in the literature and it is currently uncertain whether the theoretical biomechanical advantages of patient‐specific orthopaedic implants carry true advantages in surgical outcomes when compared to standard procedures. The purpose of this review was to assess the current status of patient‐specific orthopaedic implants, to explore their future direction, and to summarize any comparative published studies that measure definitive surgical characteristics of patient‐specific orthopaedic implant use such as patient outcomes, biomechanical implant alignment, surgical cost, patient blood loss, or patient recovery.     

Preclinical animal study and clinical trail of modified extraoral craniofacial implants.

We report on our experience using a new endosseous implant designed to provide sufficient retention to various types of facial prostheses. In a preclinical animal experiment implants (N=12, 4 x 3.5 mm) were placed in the frontal calvarial region of nine adult pigs. The animals were sacrificed at 2, 4 and 8 weeks to evaluate the implant incorporation microradiographically. The clinical outcome and patient satisfaction of implant-retained prostheses were evaluated in a group of 10 patients with facial defects by using clinical assessment and standardized questionnaires for patients and relatives. In the prospective clinical study 33 identical modified implants for extraoral anchorage were placed for the fixation of various prostheses in the midfacial (eye, nose) and ear regions in the course of a clinical trial and observed over a follow-up period of 34 months. The bone-implant contact in the animal experiment reached 31% (+/-2) at 2 weeks, 39% (+/-1) after 4 weeks and 51% (+/-5) at 8 weeks. In the clinical trial, no implants were lost and all implants remained osseointegrated as confirmed clinically and radiographically, providing a stable prosthetic restoration. The analysis of the questionnaire indicates an improvement of the quality of life of patients with respect to aesthetic and psychological well-being. The results demonstrate that extraoral implants not only achieve sufficient osseointegration but also show good clinical handling and easy fixation possibilities for prosthetic anchorage.     

Powder metal-made orthopedic implants with porous surface for fixation by tissue ingrowth

Powder metal-made orthopedic implants with a porous coating provide an effective means for implant fixation by tissue ingrowth. Additionally, the use of metal alloy powders for forming porous surfaces offers the advantage of uniform coatings on complex part shapes. With proper processing, implants with strong, porous surface layers and good substrate mechanical properties can be formed. The in vivo tests have demonstrated the need for initial implant stability to achieve bony ingrowth. Animal studies indicate an optimum pore size range of 50-400 mu, and human hip prostheses with pores in this range appear to function well. A porous surface integrated with a compatible implant design avoids undesirable bone remodeling with these types of implants.     

微螺钉支抗种植体在口腔正畸患者中对其牙齿美学效果的影响

探究对口腔正畸患者采用微螺钉支抗种植体治疗的临床效果。方法 选取2017年7月 12日-2022年7月12日于我院行口腔正畸治疗的82例患者为研究对象,按照随机数字表法分为对比组和研究 组,每组41例。对比组采用常规正畸支抗治疗,研究组采用微螺钉支抗种植体治疗,比较两组牙齿美学效 果、咀嚼功能、临床疗效及并发症发生情况。结果 两组治疗后PES评分、WES评分均高于治疗前,且研究 组高于对比组（P ＜0.05）;两组治疗后咀嚼功能优于治疗前,且研究组优于对比组（P ＜0.05）;研究组 治疗总有效率为97.56%,高于对比组的80.49%（P ＜0.05）;研究组并发症发生率为4.88%,低于对比组的 24.39%（P ＜0.05）。结论 微螺钉支抗种植体在口腔正畸患者中的应用效果确切,可有效提高牙齿美学效 果,有利于改善患者的咀嚼功能,且治疗后并发症发生风险较低,安全性较高。     

Clinical outcome after spinal fusion with a rigid versus a semi-rigid pedicle screw system

Several biomechanical studies have evaluated the quality of fusion obtained with a rigid versus a semi-rigid pedicle screw implant. Some studies indicate that increased rigidity of the implant system results in an increased strength of the fusion mass. Other reports have underlined the risk of stress shielding due to rigid implant systems. Based on these findings some authors have recommended the use of a semi-rigid system. There are, however, few studies focusing on any possible difference in clinical outcome between the two different types of implant systems. Questionnaires were sent to 89 patients who had undergone primary spinal fusion with either a rigid or a semi-rigid pedicle-screw-based implant system. In every case the diagnosis was spondylolisthesis or degenerative lumbar disease. The questionnnaires were analysed using forward stepwise logistic regression analysis. Eighty (90%) of the questionnaires were returned. There was a mean follow-up of 4 years (range 2–8 years). It was not possible to demonstrate any difference in clinical outcome between patients undergoing lumbar fusion with a rigid implant system and those given a semi-rigid system. The overall patient satisfaction rate was 69%, with no difference between the two types of implant. No difference in clinical outcome between the two types of implant was found. Considering the fact that the primary goal of spinal fusion procedure is to obtain a solid fusion mass, biomechanical tests favour the used of a rigid pedicle screw system. This fact combined with the fact that early mobilisation is possible with rigid implants justifies the use of rigid implant systems, although no difference in clinical outcome could be demonstrated in this study.     

Forearm bone-anchored amputation prosthesis: a case study on the osseointegration

Background and purpose Bone-anchored titanium implants have been used for anchorage of amputation prostheses for more than one and a half decades. Histo-logical and ultrastructural analyses were performed on a forearm amputation prosthesis after being in use for more than 11 years.

Material, methods and results The implant was retrieved from the ulnar bone after a fatigue fracture of the titanium implant, and was clinically stable at the time of removal. The histological findings showed a large amount of bone within the threads and a high degree of apposition of mineralized bone to the implant surface. Ultrastructural analysis of thin samples prepared by focused ion-beam microscopy revealed an electron-dense layer at the interface and direct apposition of crystalline hydroxyapatite at the implant surface.

Interpretation Our observations in this retrieval study provide a structural correlate to the functional properties and clinical results of amputation prostheses.     

Effects of low-intensity laser therapy over mini-implants success rate in pigs

Lasers in Medical Science - The success rate of miniscrews when used as temporary orthodontic anchorage is relatively high, but some factors could affect its clinical success such as inflammation...