Methods Of Rigid Fixation

Application of Anatomically Designed 2-Dimensional V Plate in Management of Mandible Fracture: A Pilot Study

Background

Mandible is the only mobile facial jaw bone and it aides in various functions such as phonation and mastication. Therefore, management of mandible fracture becomes inevitable due to its functional and anatomical importance. Fracture fixation methods and techniques have steadily evolved with various osteosynthesis systems. In this article, we discuss the management of mandible fracture using a newly designed two-dimensional (2D) hybrid V-shaped plate.

Purpose

In this paper, we have evaluated the efficacy of the newly developed 2D V-shaped locking plate in the management of mandibular fractures.

Method

We have assessed 12 cases of different mandibular fractures ranging from symphysis, parasymphysis, angle and subcondylar region. Treatment outcome was assessed both clinically and radiologically at regular intervals with various intraoperative and postoperative parameters.

Result

Results of this study suggest that fixation of mandible fracture with the 2D hybrid V-shaped plate facilitates anatomic reduction and functional stability and carries a low morbidity and infection rate.

Conclusion

The 2D anatomic hybrid V-shaped plate can be a suitable alternative to conventional miniplate and 3D plates as it offers satisfactory anatomic reduction and functional stability. Positioning the plate in relation to the mental nerve and plate adaptation along the angle region are much easier.

Comparison of Stability of Fracture Segments in Mandible Fracture Treated with Different Designs of Mini-Plates Using FEM Analysis

AIM

To compare the displacement gap of mandible fracture segments treated with different designs of mini-plates under various loading conditions.

MATERIALS AND METHODS

Fracture in the body of mandible was bridged with 15 different designs and configuration of titanium mini-plates. Bite forces were applied at 3 locations, ipsilateral fractured side, contra lateral side and incisor site. 3D finite element methods (FEM) model of mandible was generated using 10 nodal tetrahedral elements. A commercial FE solver was used to solve bone inter fragmentary displacement during loading.

RESULTS

Superior position of mini-plates produced better stability than inferior position. Positive bending moments can be reduced by larger plate in lower border in 2 plate system. Results of X mini-plate are comparable to 2 plate configuration. If length of middle portion of plate increased, stability decreased. Number of screws did not affect fracture stability.

CONCLUSION

Finite element methods analysis is used to determine the gap between mandible fragments which is otherwise impossible to measure clinically. The results obtained from this study offered us a choice of mini-plate design and configuration for clinical application.

Biomechanical analysis of the rigid fixation of zygoma fractures: an experimental study

In this experimental study, the goal was to test the sufficiency of actual fixation plates in zygomatic complex fractures and the efficiency of a modified plate at the zygomaticofrontal suture in a suitable model, which was designed for biomechanical study. To address this issue, a zygomatic fracture model produced by using a cadaveric cranium was simulated and the fractures were fixed by the actual and modified fixation materials. The force simulating masseter muscle pull was applied with the Lloyd material testing apparatus, and the rotation of the zygoma was determined using displacement transducers. In this study, there were three different experimental groups. Although miniplates at the zygomaticomaxillary buttress and microplates at the infraorbital rim were used in all three groups, three different plates (miniplate, microplate, and modified plate) were used at the frontozygomatic suture in these groups. Rotational displacement of the zygoma with the effects of simulated masseter muscle force was determined. According to the results obtained, microplates are not effective in stabilizing the frontozygomatic suture when the masseter muscle forces are within physiological range. Although miniplates stabilize zygomatic complex fractures, it was shown that modified microplates, which have no ondulation along the plate border, have a higher resistance to rotation than that of the conventional plates. The rotation angle at the instant of fracture with microplates was 4.59 degrees, and that with miniplates was 1.26 degrees. The maximum rotation angle with modified microplates was 0.32 degrees. Modified microplates designed for the fixation of fractures in the zygomatico-orbital region have been shown to be suitable in a well-designed experimental model and might be appropriate for clinical use.

Maxillofacial Fractures. Analysis of demographic distribution and treatment in 2901patients (25-year experience)

INTRODUCTION

The aim of this study was to analyse retrospectively the demographic distribution, treatment modalities, and complications of maxillofacial fractures in 2901 patients treated in this department in Southeast Anatolia between 1978 and 2002. In addition, the use of internal fixation was evaluated in an effort to determine whether there were changes in using internal fixation techniques.

PATIENTS AND METHODS

Two thousand nine hundred and one cases of facial trauma were assessed according to age, sex, and aetiology, in addition to the distribution of the fractures relating to facial bones and seasons.

RESULTS

It was found that facial fractures were most frequent in males (77.5%) and in the 0-10 year age group; they tended to be more frequent during summer (36.3%); and traffic accidents were the most common aetiological factor (38%). 77.9% of cases were treated with conservative methods, and 22.1% with one or more internal fixation techniques. The most favoured technique was miniplate osteosynthesis; the complication rate associated with internal fixation was 5.7%.

CONCLUSION

Currently there are many techniques to be used in treating maxillofacial trauma. However, the experience of the surgical team is also an important factor in achieving satisfactory functional and aesthetic results, and in minimizing complications.

Posttraumatic craniofacial reconstruction using combined resorbable and nonresorbable fixation systems

The facial skeleton consists of high-stress-bearing buttresses and low-stress-bearing curved surfaces. The buttresses are like trusses made of beams, struts, and columns. They resist tensile, compressive, and shear loading. The thin, curved, planar surfaces provide for the support and partitioning of the soft tissue. The trusses are strong and one-dimensional whereas the planes are weak and two-dimensional. Ideally, strong one-dimensional fixation systems should be used for the former; weaker, two-dimensional systems should be used for the latter. The authors report their clinical experience of using such combined approaches to the treatment of facial fractures using rigid, titanium mini-plates and screws for the buttresses and polymeric resorbable meshes for the curved planes. For an 11-month period (August 2000 to June 2001), nine patients (7 males and 2 females) with a mean age of 33.7 years were treated in this fashion. The resorbable meshes were deployed for the reconstitution of the orbital walls and the anterior wall of the maxillary sinus. No enophthalmos, globe dystopia, or diplopia occurred during the short mean follow-up of 10 months (4-17 months). There were no infections or sterile abscess formations. This type of combined use of fixation systems appears to be safe and effective. More patients and more extensive follow-ups are obviously needed.

Alloplastic implantation

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Define an alloplastic material and know the differences between an alloplast and other types of implants available for surgical use. 2. Determine the biologic response to alloplastic implantation and the material and host characteristics that contribute to long-term reconstruction success with their use. 3. Review the criteria for choosing a specific alloplastic material for a reconstruction site and the principles of surgical technique for its proper placement. 4. Evaluate the various alloplastic material types that are currently available for surgical use and be able to discuss several physical properties of each as they relate to handling and clinical implantation. 5. Discuss the complication of alloplastic infection, its pathogenesis, preoperative and intraoperative measures for its avoidance, and the postoperative management of its occurrence.

An evaluation of the Würzburg titanium miniplate osteosynthesis system for mandibular fixation

We present an 8-year experience with the Würzburg noncompression titanium miniplate system for the rigid fixation of the mandible during elective head and neck cancer surgery in a consecutive series of 100 patients. One half of the miniplates were used to fix mandibulotomies undertaken for surgical access. The remaining half were in patients undergoing reconstruction of segmental mandibular defects, the vast majority (92%) with vascularised bone grafts. One to four variously shaped miniplates were used per patient (mean = 1.5), plate size ranging from 4 to 40 holes. Fifteen patients (15%) developed complications which included 3 mandibular osteoradionecrosis, 8 broken, 5 infected, and 4 exposed plates. Three of the eight fractured plates were associated with nonunion. In this study, the main advantages of titanium miniplate fixation, namely case of application, decreased fixation time and malleability, were accompanied by a level of morbidity which, while comparing well with alternatives, may necessitate a reappraisal of this technique of fixation.

An audit of mandibular fractures treated by intermaxillary fixation, intraosseous wiring and compression plating

As the principles of rigid internal fixation and compression osteosynthesis were adopted by maxillofacial surgeons during recent years the time-honoured methods of intermaxillary fixation and intraosseous wiring have gradually been abandoned. We have reviewed our cases of mandibular fractures operated on in recent years and the changing trends in treatment.

Retention of asymptomatic bone plates used for orthognathic surgery and facial fractures

Over the past three decades there has been an improvement in biomaterials that has virtually replaced the use of stainless steel with titanium and its alloys. Based on the possibility of causing corrosion, toxicity, hypersensitivity, and stress protection, stainless steel should not be considered as a permanent implant in maxillofacial fixation. However, because of their superior corrosion resistance, noncarcinogenicity, hyposensitivity, nontoxicity, and excellent tissue compatibility, titanium and Ti-6Al-4V may be retained as permanent implants in maxillofacial fixation. The stress protection offered by such devices, and the possible complications associated with their removal, also support this concept. Finally, the costs incurred in removal do not justify the benefits derived.

A comparative study of miniplates used in the treatment of mandibular fractures

The purposes of this study were to investigate the differences in mechanical properties of major miniplating systems used for noncompression miniplate osteosynthesis of mandibular fractures and to determine whether these properties influence treatment outcome. The study was conducted in two parts. First, six of the major miniplate systems currently used at the Royal Adelaide Hospital were subjected to bending tests at the University of Adelaide Engineering Department to quantify the relative stiffness of each plate. Second, a prospective sample of patients presenting with mandibular fractures was analyzed. These patients were treated with a variety of the miniplating systems. The results of treatment as a whole were compared to identify any direct benefit consequent on the miniplate selected. While significant differences in stiffness were identified between the plating systems, no significant differences in treatment outcome were identified, between the noncompression plates employed. Since no observable benefits have been identified by choice of miniplate, selection should be based on surgical preference, biocompatibility, CT compatibility and unit cost. Because of the variations in materials, design, properties, CT compatibility, and unit cost, it is important not to regard all miniplates as equal and interchangeable.