The analysis of the therapeutic effect for 10 cases of type C extreme distal radial fracture in micro needle plate internal fixation / 中国骨伤

OBJECTIVE@#To analyze the clinical outcomes of mini-plate combined with wireforms in the treatment of Type C distal radial fractures with marginal articular fragments.@*METHODS@#This retrospective study included a total of 10 cases, including 5 males and 5 females, with 6 cases involving the left side and 4 cases involving the right side, of Type C distal radial fractures with marginal articular fragments. The age of the patients ranged from 35 to 67 years old. All patients underwent surgical treatment utilizing mini-plate combined with wireforms for internal fixation.@*RESULTS@#The follow-up period ranged from 6 to 18 months. Complete fracture healing was observed in all cases, with healing times ranging from 10 to 16 weeks. During the entire follow-up period, patients reported high levels of satisfaction with the treatment outcomes, and there were no incidences of incision infection, chronic wrist pain, or wrist traumatic arthritis. At the final follow-up assessment, the Mayo score for the wrist joint ranged from 85 to 95, with 7 cases rated as excellent and 3 cases as good.@*CONCLUSION@#Mini-plate combined with wireforms proves to be an effective fixation method for Type C distal radial fractures with marginal articular fragments. The early initiation of wrist joint exercises, strong fixation, maintenance of proper reduction, minimal complications, and high rates of excellent and good outcomes demonstrate the reliability and efficacy of this treatment approach.

Effects of different force directions of intra-oral skeletally anchored maxillary protraction on craniomaxillofacial complex, in Class III malocclusion: a 3D finite element analysis

ABSTRACT Introduction: The intra-oral skeletally anchored maxillary protraction (I-SAMP) has been found to be an effective treatment for skeletal Class III malocclusion. Objective: This in-silico study explored the influence of different force directions of intra-oral skeletally anchored Class III elastics on the changes in craniomaxillofacial complex, using finite element analysis. Methods: A 3-dimensional (3D) finite element model of the craniomaxillofacial bones including circummaxillary sutures was constructed with high biological resemblance. A 3D assembly of four miniplates was designed and fixed on the maxilla and mandible of the finite element model. The model was applied with 250g/force at the miniplates at three angulations (10°, 20°, and 30°) from the occlusal plane, to measure stress and displacement by using the ANSYS software. Results: The zygomaticotemporal, zygomaticomaxillary, and sphenozygomatic sutures played significant roles in the forward displacement and counterclockwise rotation of maxilla and zygoma, irrespective of the angulation of load application. The displacements and rotations of the zygomatico-maxillary complex decreased gradually with an increase in the angle of load application between miniplates from 10° to 30°. The mandible showed negligible displacement, with clockwise rotation. Conclusions: The treatment effects of I-SAMP were corroborated, with insight of displacement patterns and sutures involved, which were lacking in the previously conducted 2D and 3D imaging studies. The prescribed angulation of skeletally anchored Class III elastics should be as low as possible, since the displacement of zygomatico-maxillary complex increases with the decrease in angulation of the elastics.

RESUMO Introdução: A protração maxilar com ancoragem esquelética intrabucal (I-SAMP) tem sido considerada um tratamento efetivo para a má oclusão esquelética de Classe III. Objetivo: O presente estudo in silico avaliou, usando análise de elementos finitos, a influência de diferentes direções da força dos elásticos Classe III com ancoragem esquelética intrabucal nas mudanças no complexo craniomaxilofacial. Métodos: Um modelo de elementos finitos tridimensional (3D) dos ossos craniomaxilofaciais, incluindo as suturas circum-maxilares, foi construído, com alta semelhança biológica. Uma montagem 3D de quatro miniplacas foi projetada e fixada na maxila e na mandíbula do modelo de elementos finitos. O modelo foi aplicado com o uso de 250g/força nas miniplacas em três angulações (10°, 20° e 30°) em relação ao plano oclusal, para medir as tensões e os deslocamentos, usando o programa ANSYS. Resultados: As suturas zigomaticotemporal, zigomaticomaxilar e esfenozigomática desempenharam um papel significativo no deslocamento para anterior e na rotação anti-horária da maxila e do zigoma, independentemente da angulação na aplicação da força. Os deslocamentos e as rotações do complexo zigomático-maxilar diminuíram gradualmente com o aumento de 10° para 30° no ângulo de aplicação da força entre as miniplacas. A mandíbula apresentou deslocamento irrelevante, com rotação no sentido horário. Conclusões: Os efeitos do tratamento com I-SAMP foram corroborados, com um vislumbre dos padrões de deslocamento e das suturas envolvidas, que não existiam nos estudos com imagens 2D e 3D realizados anteriormente. A angulação dos elásticos Classe III ancorados esqueleticamente deve ser a menor possível, visto que o deslocamento do complexo zigomático-maxilar aumenta com a redução no ângulo dos elásticos.

Comparison of double mini locking plate and anatomical locking plate in the treatment of comminuted olecranon fracture / 国际外科学杂志

Objective:To compare the efficacy of double mini locking plate and anatomical locking plate in the treatment of comminuted olecranon fracture.Methods:The clinical data of 46 patients who underwent comminuted olecranon fracture in the Xi′an Honghui Hospital Affiliated to Xi′an Jiaotong University from March 2017 to May 2020 were analyzed retrospectively. Among them, 21 cases were treated with double mini locking plate (double plate group) and 25 cases with anatomical locking plate (single plate group). The operation time, patient satisfaction, range of motion, return to work time, soft tissue stimulation to remove internal fixation, Mayo elbow performance score (MEPS), disabilities of arm, shoulder and hand score (DASH) of the two fixation methods were statistically compared. Measurement data with normal distribution were represented as ( ± s), and comparison between groups was conducted using the t test. Comparison between groups of count data was conducted using the chi-square test or Fisher exact probability. Results:All 46 patients were followed up for to (19.17±2.79) months. All fractures healed after operation. There was no significant difference in operation time, range of motion, patient satisfaction, MEPS and DASH scores among the two groups( P>0.05). The time of returning to work was (8.47±2.13) weeks in the double plate group and (9.78±1.98) weeks in the single plate group, and the difference was statistically significant ( P< 0.05). There were 9 cases of internal fixation due to soft tissue stimulation, 1 cases in double plate group and 8 cases in single plate group, and the difference was statistically significant ( P<0.05). Conclusions:Compared with anatomical locking plate, the treatment of olecranon fracture with double mini locking plate can effectively reduce soft tissue stimulation and promote patients to return to work early, and the operation time is not significantly prolonged, and the biomechanical advantage is obvious, the clinical effect is satisfactory and the postoperative function is good, so it is an effective treatment.

Una miniplaca de titanio en comparación a dos miniplacas de titanio para fracturas de ángulo mandibular favorables y aisladas / One miniplate or two mini plates in the fixation of favorable and isolated mandibular angle fractures

RESUMEN: Introducción: Las fracturas mandibulares producen serias comorbilidades, alteraciones en la función, calidad de vida entre otros. Existen distintas alternativas quirúrgicas en las fracturas favorables de ángulo mandibular, siendo las más utilizadas las técnicas de estabilización mediante miniplacas de titanio. No existe consenso sobre si es más efectivo y seguro utilizar una o dos miniplacas de titanio. Métodos: Realizamos una búsqueda en Epistemonikos, la mayor base de datos de revisiones sistemáticas en salud, la cual es mantenida mediante el cribado de múltiples fuentes de información, incluyendo MEDLINE, EMBASE, Cochrane, entre otras. Extrajimos los datos desde las revisiones identificadas, analizamos los datos de los estudios primarios, realizamos un metanálisis y preparamos una tabla de resumen de los resultados utilizando el método GRADE. Resultados y conclusiones: Identificamos 7 revisiones sistemáticas que en conjunto incluyeron 17 estudios primarios, de los cuales 3 son ensayos aleatorizados. Concluimos que el tratamiento de estabilización mediante una miniplaca de titanio probablemente disminuye el riesgo de paresia facial. Por otro lado, el uso de una miniplaca podría aumentar el riesgo de dehiscencia de la herida quirúrgica, disminuir el riesgo de reintervención quirúrgica y podría resultar en poca o nula diferencia en el riesgo de maloclusión, pero la certeza de la evidencia es baja. No está claro si el uso de una en comparación con dos miniplacas de titanio reduce el riesgo de infección y parestesia ya que la certeza de la evidencia disponible es muy baja.

ABSTRACT: Introduction: Mandibular fractures produce severe comorbidities, functional alterations, changes in the quality of life, among others. There are different surgical alternatives for favorable mandibular angle fractures; the most used is the stabilization techniques using titanium miniplates. There is no consensus on which it is more effective and safe; use one or two titanium miniplates. Methods: We searched in Epistemonikos, the largest database of systematic reviews in health, which is maintained by screening multiple information sources, including MEDLINE, EMBASE, Cochrane, among others. We extracted data from the systematic reviews, reanalyzed data of primary studies, conducted a meta-analysis and generated a summary of findings table using the GRADE approach. Results and conclusions: We identified seven systematic reviews that included 17 primary studies, in which three were randomized trials. We conclude that stabilization treatment with a titanium miniplate probably reduces the risk of facial paresis. On the other hand, the use of a miniplate could increase the risk of dehiscence of the surgical wound, decrease the risk of reoperation, and could result in little or no difference in the risk of malocclusion, but the certainty of the evidence is low. It is not clear whether the use of one compared to two titanium miniplates reduces the risk of infection and paresthesia since the certainty of the available evidence is very low.

Una Descripción General y Actualizada de Miniplacas y Minitornillos. Efectos Dentoalveolares y Esqueléticos / A General and Updated Description of Miniplates and Miniscrews. Dentoalveolar and Skeletal Effects

RESUMEN: En ortodoncia, las miniplacas se utilizan como dispositivo de anclaje temporal (TAD) para la realización de movimientos dentales que permiten el uso de fuerzas ortopédicas en ellos. En comparación con los mini tornillos, las miniplacas tienen la ventaja de una tasa de falla muy baja, pero la desventaja es que para la extracción se necesita el mismo acto quirúrgico que se realizó para la instalación. El objetivo de este estudio es realizar una revisión bibliográfica de las indicaciones de miniplacas en pacientes con mordidas abiertas, clase II y anomalías de clase III, y buscar cómo las miniplacas han mejorado los tratamientos de ortodoncia. La información principal se reunió buscando en PubMed con las palabras clave enumeradas a continuación. Afirmamos que las miniplacas están indicadas para la retracción en masa de la arcada, donde se observó que la fuerza de 150 g aplicada en los molares superiores es suficiente no solo para empujar los molares hacia atrás en una clase I corregida, sino también para iniciar la retracción de premolares, caninos e incisivos. En pacientes con mordida abierta, las miniplacas se definen como un método seguro, una alternativa rápida y menos costosa a la cirugía ortognática. Y en pacientes de las clases II y III se utilizan sin producir efectos dentoalveolares que sustituyan a los dispositivos extraorales como máscaras, con dispositivos intraorales y elásticos (BAMP).

ABSTRACT: In orthodontics, miniplates are used as a Temporary Anchoring Device (TAD) for the purpose dental movements, allowing the use of orthopedic forces. In comparison with mini-screws, miniplates have the advantage of a very low rate of failure. Nonetheless, their removal requires the same surgical procedure as during installation, which is an obvious disadvantage. The aim of this study is to review the indications of miniplates in patients with open bite, class II and class III anomalies, and review how miniplates improved orthodontics treatments. Information was obtained by a search in PubMed with the keywords listed below. Miniplates are indicated for retraction in mass of the arcade, where it was seen that the force of 150 g applied on maxillary molars, is sufficient not only to push the molars back into a corrected class I, but also to initiate retraction of premolars, canines, and incisors. In open-bite patients, mini plates, are achieved as a safe method, that is quick and a less expensive alternative to orthognathic surgery. Further, in class II and III patients they are used without producing dentoalveolar effects replacing extraoral devices as facemasks, with intraoral devices and elastics. (BAMP).

Meta-plate and mini-plate internal fixation for the treatment of anterior comminuted coronal plane Pilon fractures / 中国组织工程研究

BACKGROUND: Pilon fractures usually happened during severe injury, associated with compression and comminution of metaphysis and soft tissue injury and primary articular cartilage damage in varying degrees The treatment is difficult and the prognosis is relatively poor. OBJECTIVE: To explore the clinical effect of application of meta-plate and mini-plate internal fixation for the treatment of anterior comminuted coronal plane Pilon fractures. METHODS: From January 2013 to June 2017, 17 patients of closed anterior comminuted coronal plane Pilon fractures were admitted in Department of Bone and Joint Surgery, Affiliated Hospital of Southwest Medical University. There were 7 males and 10 females, aged from 24 to 62 years, with an average age of 41.3 years. All patients signed the informed consent. This study was approved by the Hospital Ethics Committee. Preoperative CT scans and three-dimensional reconstruction confirmed that the main fracture line was in coronal plane and multiple fragments of distal tibial metaphysis were displaced obviously. According to Ruedi-Allgower classification, there were 3 cases of type and 14 cases of type III. Fracture fragments of articular surface were fixed with transverse metacarpophalangeal mini-plate and screws, and the distal tibial coronal fractures were fixed with anterior meta-plate. The ankle and hind foot score of the American Orthopaedic Foot and Ankle Society was used to evaluate the function after surgery. RESULTS AND CONCLUSION: (1) The 17 patients were followed up for 12 to 28 months. All incisions healed in the first stage without complications such as wound infection, skin necrosis, failure of internal fixation and neurovascular injury. Only one patient had redness on the edge of the incision after operation and healed after swelling reduction and dressing change. (2) Fractures healed within 3 to 6 months without delayed union or nonunion. (3) At the last follow-up, the American Orthopaedic Foot and Ankle Society ankle and hind foot score was excellent in 10 cases, good in 5 cases, and average in 2 cases. The excellent and good rate was 88%. (4) The application of transverse mini-plate and screws fixation can effectively support and fix the fracture fragments of articular surface. Combined with anterior meta-plate of distal tibia for the treatment of anterior comminuted coronal plane Pilon fractures can achieve good therapeutic effect, and strengthen biomechanical stability.

Finite element analysis of different fixation methods for mandibular defects reconstructing with fibula flaps / 中国组织工程研究

BACKGROUND: Segmental defect of mandible is often caused by tumor, trauma and other reasons. Simultaneous mandibular defect by vascularized fibular flap is the most important repair method at present. It is not only useful for the reconstruction with titanium plates, but also useful for small titanium plates for fixation. Clinical retrospective studies have shown that there is no significant difference in postoperative complication rate between patients with the two fixation methods, but relevant biomechanics studies are still lacking at present. OBJECTIVE: The three-dimensional finite element analysis was used to analyze the stress distribution and stability on mandibular segmental defects simulated fibular flaps grafted with reconstruction plates and miniplates fixation. METHODS: A healthy adult male with complete dentition was selected for CT scan and data were input into the computer to reconstruct the mandible and dentition model. Three types of 3D models were built for mandibular defects dependent on Jewer’s classification, including models H (loss of lateral mandible, mandibular angle, ascending branch of mandible, and condyles), L (loss of unilateral mandible) and C (loss of bilateral mandible chin). Mechanical distribution features and stability of fixation with reconstruction plates and miniplates were comparatively studied after fibular repair of mandibular segmental defects. RESULTS AND CONCLUSION: (1) The stress graphs showed that stress was mostly higher in surrounding areas of normal mandibles such as condyle, condylar neck, mandibular angle, molar and titanium screws. In particular, the stress was highest near mandibular angles. (2) For type-H defect, the great stress was generated near the mandibular angles when mandible was reconstructed with reconstruction plate, and the stress value was 185 MPa. The stress values approximately ranged from 117 to 135 MPa on type-H and type-L defects with miniplates. The maximum stress of fibula block was less than 30.4 MPa, and the maximum stress of titanium nail was 56.2 MPa. (3) The relative displacements approximately varied between 15 µm and 18 µm on the fracture sides after repair with type-H and type-L defects with miniplates and reconstruction plates. Almost no relative displacement was generated on the fracture sides after type-C mandibular defects. (4) Both titanium reconstruction plates and titanium miniplates could meet biomechanical requirements for fibular repair of H, C, and L defects.

Comparative Study of 3 Dimensional and Standard Miniplate in Management of Anterior Mandibular Fractures

Introduction: The aim of mandibular fracture treatment isto restore the pre-injury anatomic form and function, withparticular care to establish the occlusion. Of the varioustreatment modalities available, Champys miniplate fixation hasbecome the most widely used technique. The 3-dimensional(3D) plating for mandibular fracture treatment is relativelynew. This study was conducted to compare efficacy, stabilityand rigidity of 3-dimensional plates with that of 2mm titaniumminiplates in the surgical management of anterior mandibularfractures.Material and Methods: The study was conducted on 70patients with anterior mandbibular fractures (Symphysis andParasymphysis region). Patients were randomly divided intotwo groups, Group I (n=35) in which the patients underwentfixation by miniplates (2 nos) while in Group II (n=35), 3Dplates were used for fixation. The patients preoperative, intraoperative and post-operative clinical and radiological findingswere recorded in a proforma and were subjected to statisticalanalysis. Fisher’s Exact Test was used to compare the dataobtained from group I and group II patients.Results: Out of 70 patients, 77.14% corresponded to the agegroup of 15-30 years and 82.85% were males. Road trafficaccident (80) % was the leading cause of fracture. The timerequired to adapt and fix the miniplates was slightly more than3-D plates and results were statistically significant. Skeletaland occlusal stability was maintained in both group.Conclusion: There is no major difference in terms of treatmentoutcome in both systems, and both are equally effective inmandibular fracture treatment.

Use of Miniplate for Severe Comminuted Metadiaphyseal Fractures of the Distal Radius

PURPOSE: This study investigated the clinical and radiological outcomes of patients undergoing provisional fixation in conjunction with locking plate fixation. Miniplates were used as the reduction plates for the surgical treatment of severe comminuted metadiaphyseal fractures with an intra-articular fracture of the distal radius. MATERIALS AND METHODS: The radial length, radial inclination, volar tilt, and radial intra-articular step-off were measured preoperatively, postoperatively, and at one year after surgery in 12 patients (eight males, four females, mean age 55.4 years old). The patients underwent volar locking plate fixation with miniplate as a reduction plate for severe comminuted metadiaphyseal fractures with an intra-articular fracture of the distal radius. Clinical evaluations were conducted using the modified Mayo wrist score (MMWS). RESULTS: Bone union was achieved in all cases. The mean MMWS was 81.8 points, including two excellent, three good, and seven fair cases. Radiological improvements were observed in the average radial length (preoperative, 6.4 mm; postoperative, 11.8 mm), average radial inclination (10.2° to 22.4°), average volar tilt (−4.5° to 10.6°), and average radial intra-articular step-off (4.8–0.8 mm) (all, p0.05). CONCLUSION: Miniplate fixation can be an effective treatment option as a reduction plate for the treatment of distal radial fractures, which is challenging to reduce and maintain due to severely comminuted metadiaphysis fractures with the intra-articular fracture.

Evaluation of labial versus labio-inferior lines of osteosynthesis using 3D miniplate for fractures of anterior mandible: A finite element analysis with a pilot clinical trial / 中华创伤杂志(英文版)

PURPOSE@#The fractures of anterior mandible are subject to severe torsional forces due to muscles acting in opposite directions. 3D miniplate has been suggested as a good alternative by some researchers. However, finite element model (FEM) studies indicate that labio-inferior positioning of two miniplates perpendicular to each other offers better stability as compared to labial positioning. This study aims at combining the advantages of a single 3D miniplate and labio-inferior positioning of two conventional miniplates, which was assessed by finite element analysis along with a pilot clinical trial.@*METHODS@#Two FEM models were created using CT data of a 24-year-old patient with Angle class I occlusion: control model with labial plating and study model with labio-inferior plating. The models were processed with MIMICS® (materialise, Leuven, Belgium), CATIA® (Dassault Systemes) and finite element analysis softwares. Parameters adopted for analysis were (1) displacement (mm) of fracture fragments during each screw fixation, (2) lingual splay and post fixation stability of fracture fragments with masticatory load, and (3) stress distribution (MPa) across fracture fragments. Moreover, a pilot clinical trial including five patients with anterior mandible fracture was conducted. The fractures were managed by intraoral open reduction and 3D miniplate fixation in labio-inferior position. Intraoperative interfragmentary gap, post fixation lingual splay and radiographic fracture union and complications were assessed clinically.@*RESULTS@#Labio-inferior plating demonstrated less displacement (mm) of fracture fragments during screw fixation (0.059 vs. 0.079) as well as after application of masticatory load (1.805 vs. 1.860). Negligible lingual splay and less stress distribution (MPa) across fracture fragments (1.860 vs. 1.847) were appreciated in the study group as compared to control group. Clinical trial support the favorable outcome related to intraoperative and postoperative assessment parameters.@*CONCLUSION@#FEM analysis and clinical trial reveal better results with labio-inferior positioning of 3D miniplate when compared to labial positioning.

Functional outcome of Metacarpal Fracture managed with Miniplate and Screws

Background and Objectives: Early techniques of splint immobilization work well for simple metacarpal fractures. However, if significantly shorting, rotational deformity, and angulations occur, surgical treatment is required. The aim of this article was to study the functional outcome of metacarpal fractures treated by open reduction and internal fixation with mini plates and screw in low resource condition of Nepal.Material and Methods: This retrospective study was done over a period of one year 2012 to 2013 in Bir Hospital, Patan hospital and Shree Birendra hospital. The functional outcome after treatment was assessed by ability to perform acts of daily life and calculating American Society for Surgery of the Hand Total Active Flexion (ASSH-TAF).Results: Out of 30 patients twenty three were male (76.7%) and seven were female (23.3%). Among them, 7 patients (23.3%) showed union in 6 weeks. 18 Patients (60%)  had union in 4 weeks. 3 patients (10%) had at five weeks and 2 patients had union at 6 weeks. We observed ASSH-TAF score at 2 weeks, 1month, 3 months, and 6 months. Results showed 24 patients (80%) had excellent, 4(13.3%) had good and 2(6.7%) had poor result.Conclusion: The use of miniplate and screws is a reasonable option for treating in displaced metacarpal fracture as it provides a rigid, Secure an anatomical stable reduction, which is sufficient to allow early mobilization of the adjacent joints, hence the mini plate fixation is effective means of immobilization of fracture of metacarpal with less complication and excellent functional outcome.

Clinical efficacy of miniplates anchorage between the maxilla and the mandible for maxillary hypoplasia in cleft patients / 中华医学美学美容杂志

Objective To investigate the effects of titanium miniplates used for anchorage between the maxilla and the mandible for maxilly hypoplasia in cleft patients.Methods Miniplates were inserted into the infrazygomatic crests and between the canine and lateral incisor in the mandible on both the right and left sides in 6 subjects (mean age,11.3 years).Maxillomandibular elastics were attached between the upper and lower miniplates on each side.Cephalometric radiographs of each patient were evaluated at the beginning of treatment and at the end of active protraction treatment.Results A-point movement was increased mean 3.67 mm,SNA angle and ANB angle were increased by 2.75° and 3.1° respectively.Wit's appraisal was increased by 4.52 mm,and upper lip to E-plane was decreased mean 2.8 mm in a mean of 15 months and the significant difference was found (P＜0.05).Miniplates stability was excellent in all patients throughout treatment.Conclusions Remarkable advancement in the middle face and consequent fullness in the soft-tissue profile can be achieved by using titanium miniplates protraction for maxilly hypoplasia in cleft patients in the late mixed-dentition and initial stage of permanent dentition period.

Zygomatic miniplates for skeletal anchorage in orthopedic correction of Class III malocclusion: A controlled clinical trial / 대한치과교정학회지

OBJECTIVE: To evaluate the effects of facemask therapy, which was anchored from the zygomatic buttresses of the maxilla by using two miniplates, in skeletal Class III patients with maxillary deficiency. METHODS: Eighteen skeletal Class III patients (10 girls and 8 boys; mean age, 11.4 ± 1.28 years) with maxillary deficiency were treated using miniplate-anchored facemasks, and their outcomes were compared with those of a Class III control group (9 girls and 9 boys; mean age, 10.6 ± 1.12 years). Two I-shaped miniplates were placed on the right and left zygomatic buttresses of the maxilla, and a facemask was applied with a 400 g force per side. Intragroup comparisons were made using the Wilcoxon test, and intergroup comparisons were made using the Mann-Whitney U-test (p < 0.05). RESULTS: In the treatment group, the maxilla moved 3.3 mm forward, the mandible showed posterior rotation by 1.5°, and the lower incisors were retroclined after treatment. These results were significantly different from those in the control group (p < 0.05). No significant anterior rotation of the palatal plane was observed after treatment. Moreover, changes in the sagittal positions of the maxillary incisors and molars were similar between the treatment and control groups. CONCLUSIONS: Skeletally anchored facemask therapy is an effective method for correcting Class III malocclusions, which also minimizes the undesired dental side effects of conventional methods in the maxilla.

Biomechanical analysis of distalization of mandibular molars by placing a mini-plate: A finite element study / 대한치과교정학회지

OBJECTIVE: The objective of this study was to analyze the patterns of tooth movements when distalization of mandibular molars using a mini-plate took place. A finite element analysis was applied to analyze patterns of tooth movements. METHODS: The model of the mandible and teeth were used to build a finite element analysis model, and a mini-plate was inserted in the mandibular ramus. Two different orthodontic forces were established for displacement of mandibular molars. Orthodontic forces were applied at the level of the bracket and at the level of the cemento-enamel junction in the mandibular canine respectively. RESULTS: orthodontic forces at the level of the cemento-enamel junction resulted in a greater biomechanical bodily movement in distalization of the mandibular molars compared to when the orthodontic forces were applied at the level of the bracket. Applying orthodontic forces to the cemento-enamel junction also resulted in unwanted greater extrusive movements in distalization of the mandibular molars compared to the bracket level. CONCLUSIONS: With considering the mode of orthodontic teeth movement, applying different vertical orthodontic forces for distalization of mandibular molars can lead to more effective distalization of teeth.

Mini-plate fixation of ulnar coronoid process fracture via anteromedial approach / 中华创伤杂志

Objective To investigate the clinical efficacy of mini-plate fixation for ulnar coronoid process fracture via anteromedial approach.Methods A retrospective review was made on 28 cases of ulnar coronoid process fracture treated with open reduction and mini-plate fixation from April 2010 to December 2014.There were 18 males and 10 females,with age range of 21-60 years (mean,34.3 years).Causes of injury were falls in 21 cases and traffic accidents in 7 cases.According to the O' Driscoll classification,there were 14 cases of type Ⅰ,11 cases of type Ⅱ and 3 cases of type Ⅲ.Time from injury to operation was 2-10 d (mean,3.7 d).Reduction loss,fracture healing time and complications were documented.Elbow function was evaluated at the last follow-up by Mayo elbow performance score (MEPS) and Broberg & Morrey score.Results All cases were followed up for 12-25 months (mean,15.1 months).Restricted elbow activity was initiated one week after operation.Bone united in mean 10.6 weeks (range,8-14 weeks).No nerve injury or fracture redisplacement occurred.At the final follow-up,mean flexion was (124 ± 15)° (range,90°-140°),mean extension loss was (18 ± 20) °(range,0°-50°),mean pronation was (65 ± 18)°(range,40°-85°),and mean supination was (63 ±16)°(range,35°-85°),showing significant difference in comparison with the preoperative measure (P＜0.05).According to the MEPS,the results were excellent in 17 cases,good in 8,fair in 2 and poor in 1.According to the Broberg & Morrey score,the results were excellent in 16 cases,good in 8,fair in 3 and poor in 1.Conclusion Through anteromedial approach,mini-plate fixation of the ulnar coronoid process fracture provides rigid fixation,which benefits joint stability and bone union,and allows early functional exercise.

Transbuccal versus transoral approach for management of mandibular angle fractures: a prospective, clinical and radiographic study

OBJECTIVES: We compared the transbuccal and transoral approaches in the management of mandibular angle fractures. MATERIALS AND METHODS: Sixty patients with mandibular angle fractures were randomly divided into two equal groups (A, transoral approach; group B, transbuccal approach) who received fracture reduction using a single 2.5 mm 4 holed miniplate with a bar using either of the two approaches. Intraoperatively, the surgical time and the ease of surgical assess for fixation were noted. Patients were followed at 1 week, 3 months, and 6 months postoperatively and evaluated clinically for post-surgical complications like scarring, infection, postoperative occlusal discrepancy, malunion, and non-union. Radiographically, the interpretation of fracture reduction was also performed by studying the fracture gap following reduction using orthopantomogram tracing. The data was tabulated and subjected to statistical analysis. A P-value less than 0.05 was considered significant. RESULTS: No significant difference was seen between the two groups for variables like surgical time and ease of fixation. Radiographic interpretation of fracture reduction revealed statistical significance for group B from points B to D as compared to group A. No cases of malunion/non-union were noted. A single case of hypertrophic scar formation was noted in group B at 6 months postsurgery. Infection was noted in 2 patients in group B compared to 6 patients in group A. There was significantly more occlusal discrepancy in group A compared to group B at 1 week postoperatively, but no long standing discrepancy was noted in either group at the 6 months follow-up. CONCLUSION: The transbuccal approach was superior to the transoral approach with regard to radiographic reduction of the fracture gap, inconspicuous external scarring, and fewer postoperative complications. We preferred the transbuccal approach due to ease of use, minimal requirement for plate bending, and facilitation of plate placement in the neutral mid-point area of the mandible.

Three-dimensional finite element analysis of a newly designed onplant miniplate anchorage system / 华中科技大学学报（医学）（英德文版）

The purpose of this research was to evaluate the structural stress and deformation of a newly designed onplant miniplate anchorage system compared to a standard anchorage system. A bone block integrated with a novel miniplate and fixation screw system was simulated in a three-dimensional model and subjected to force at different directions. The stress distribution and deformation of the miniplate system and cortical bone were evaluated using the three-dimensional finite element method. The results showed that the stress on the plate system and bone was linearly proportional to the force magnitude and was higher when the force was in a vertical direction (Y-axis). Stress and deformation values of the two screws (screw 1 and 2) were asymmetric when the force was added along Y-axis and was greater in screw 1. The highest deformation value of the screws was 7.5148 μm, much smaller than the limit value. The load was decreased for each single miniscrew, and the ability of the new anchorage system to bear the load was also enhanced to some degree. It was suggested that the newly designed onplant miniplate anchorage system is effective, easily implanted and minimally invasive.

Treatment effects of mandibular total arch distalization using a ramal plate / 대한치과교정학회지

OBJECTIVE: The purpose of this study was to evaluate treatment effects after distalization of the mandibular dentition using ramal plates through lateral cephalograms. METHODS: Pre- and post-treatment lateral cephalograms and dental casts of 22 adult patients (11 males and 11 females; mean age, 23.9 ± 5.52 years) who received ramal plates for mandibular molar distalization were analyzed. The treatment effects and amount of distalization of the mandibular molars were calculated and tested for statistical significance. The significance level was set at p < 0.001. RESULTS: The mandibular first molar distalization at the crown and root were 2.10 mm (p < 0.001) and 0.81 mm (p = 0.011), respectively. In the evaluation of skeletal variables, there was a significant increase in the Wits appraisal (p < 0.001). In the evaluation of the soft tissue, there was no significant effect on upper lip position, but the lower lips showed a significant retraction of 2.2 mm (p < 0.001). CONCLUSIONS: The mandibular molars showed a significant amount of distalization accompanied by limited extrusion and mesiobuccal rotation of the crowns. A ramal plate may be a viable device for mandibular total arch distalization in Class III patients who are reluctant to undergo orthognathic surgery.

Evaluation of the treatment of unfavourable mandibular angle fracture by internal fixation via two different approaches / 实用口腔医学杂志

Objective:To evaluation of the treatment of unfavourable mandibular angle fracture by internal fixation with two different approachs.Methods:46 patients with unfavourable mandibular angle fracture were treated by internal fixation with titanium miniplate through transoral approach group(n =20)and extraoral approach group(n =26)respectively.Postoperative clinical and radiological data including wound healing,difficulty in function and malocclusion were analysed 1 0 days,3 months and 6 months after operation. Results:Postoperative infection occurred in 2 cases in extraoral group,and 1 of them developed as ostomylitis which recovered gradu-ally in 1 year.Surgical site infection was observed in 2 cases in transoral approach group,which was resolved with appropriate course of antibiotics and wound care.Conclusion:Unfavourable mandibular angle fracture can be effectively treated by titanium miniplate via intraoral or extraoral approach.

The Result of Open Reduction and Mini-Plate Fixation for Displaced Talar Neck Fracture

PURPOSE: We evaluated the complications, radiological and clinical results after operative treatment using a mini-plate for fixation of displaced talar neck fractures. MATERIALS AND METHODS: There were 20 cases of displaced talar neck fractures from May 2006 to December 2011; we performed a retrospective chart review of 15 patients treated by open reduction and internal fixation using a mini-plate who had more than 2 years of follow-up. According to Hawkin's classification, there were 7 cases of type II fractures and 8 cases of type III fractures. During postoperative 12-16 weeks we checked magnetic resonance imaging. The assessment of clinical results was based on the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot scale. RESULTS: Mean union period was 11.6 weeks (10-15 weeks). Nonunion and malunion did not occur in all cases. The mean AOFAS score was 88.2 points (80-97 points). There were 5 cases of avascular necrosis. Of these, there were 3 cases of body collapse and 4 cases of post-traumatic arthritis. In the statistical analysis, there was no correlation between the elements including gender, Hawkin's classification and union rates and clinical results. CONCLUSION: Mini-plate fixation of a displaced talar neck fracture is thought to be a good technique, with a low rate of malunion and also showed satisfactory results in radiological and clinical assessment.