Stainless Steel Reconstruction Plates Research Articles

Reconstruction Plate Fracture: Mechanism and Recent Advances

Reconstruction plates with or without bone grafts are used to restore mandibular continuity, form and function following segmental resection of mandible. Fracture of reconstruction plate is observed in 2.9 % to 10% of cases reported in the literature excluding other complications. In this case, we report the fracture of stainless steel reconstruction plate used without bone graft and its management using locking reconstruction plate with non vascularised iliac crest graft following removal of the fractured plate. Review of literature describing incidence, pattern and causes of reconstruction plate fracture and its management is discussed.

Follicular Ameloblastoma with Granular Changes Affecting Mandible & Maxilla - A Case Report

Ameloblastoma is defined as a benign but locally invasive neoplasm consisting of proliferating odontogenic epithelium lying in a fibrous stroma. Ameloblastomas are believed to have an epithelial origin, i.e. remnants of the dental lamina, remnants of Hertwig's root sheath (the epithelial remains of Malassez), epithelium of odontogenic cysts (particularly dentigerous cysts) and odontomas, the developing enamel organ and the basal cells of the surface epithelium of the jaws. Here we report a case of follicular cell ameloblastoma in a 45 years old female patient with a chief complaint of pain & swelling over the left side of face since 5 years. H & E stained sections showed stratified squamous hyperkeratotic epithelium with break in the continuity of the basement membrane. The underlying connective tissue contains numerous nests, strands, sheets & islands of dysplastic to atypical epithelial cells suggestive of malignancy in a fibro cellular stroma with little or no inflammatory cell infiltration. Hemimandibulectomy was done including condyle and coronoid process and the tumor mass. A 2.5 mm stainless steel reconstruction plate was fixed for the mandibular reconstruction. There was a marked resorption of the maxillary bone due to tumor expansion but maxilla was not involved directly into the tumor extension.

Mandibular Reconstruction using AO/ASIF Stainless Steel Reconstruction Plate: A Retrospective Study of 36 Cases

The study was aimed at esthetic and functional results as well as patient tolerance after reconstruction with reconstruction plate. The follow-up ranged from 1 to 4 years. A retrospective study of 36 patients who had mandibular reconstruction with AO/ASIF stainless steel reconstruction plates after oncologic resection was evaluated. The indications and postoperative outcomes were studied. At the end of study, 24 of 36 patients (67%) still had the plate in place. Around three (8%) plates were fractured. Nine (25%) plates got exposed leading to surgical intervention. Surgical results were satisfying, particularly when looking at delayed healing or long-term tolerance. Esthetic (79% rated results as good or acceptable) and functional results of this reconstruction were satisfying. We conclude by saying that reconstruction plate provides a solution for safe and rapid mandibular reconstruction for patients with poor prognosis or poor condition. This method also preserves the possibility of secondary reconstruction. The reconstruction plate may be a good clinical choice for safe and rapid mandibular reconstruction.

Psammomatoid juvenile aggressive ossifying fibroma of mandible

A female patient, aged 14 years, came to dental OPD, with a large swelling of the right mandibular region, progressing since 4–5 years. The swelling initially started with a small size and later it became a large swelling extending from left lower premolar region to right mandibular angle region. Inferiorly, the swelling was extending below the inferior border in the symphysis region. No paresthesia was experienced by the patient. There was quite a marked facial disfigurement of the right mandibular body and symphysis region extending to left side. No other bones were involved and no other abnormalities were found on general physical examination. The medical history was noncontributory. There was no family history of skeletal disease. The case was surgically treated by segmental resection of the mandible and reconstruction was done using stainless steel reconstruction plate. With the follow-up period of 1 year, there was no recurrence.

Bifocal Distraction to Regenerate Segmental Mandibular Defects Using a Custom Made Device: A Report of Two Cases

Mandibular reconstruction following tumor ablative surgery had been a challenge. It has gone through days of temporary stabilization with k-wire, stainless steel reconstruction plate to avascularized and vascularized bone grafts with varying degree of success and failure. Reconstruction with vascularized bone grafts, though most definitive, requires special expertise, expensive equipment, and long operative time. It also produces donor site morbidity and requires a significant learning curve. With the development of transport distraction techniques there has been a paradigm shift from "reconstructive" to "regenerative" surgery. The objective of this study was to identify the feasibility of an internal device for reconstruction of extensive mandibular defects. This article is to highlight a process of attempted mandibular regeneration in two cases using an indigenously designed distractor device. In individuals with extensive post ablative mandibular defects who were unwilling to have a secondary surgical site or were medically unfit for a long reconstructive procedure, the distraction technique can be used to reconstruct the lost mandibular structures. A satisfactory amount of regenerate was achieved using a bifocal distraction osteogenesis technique for extensive defects of the mandible. The custom made device which was used for this purpose was moderately satisfactory and requires further evaluation and refinement.

Mandibular reconstruction after resection of benign tumours using non‐vascularised methods in a series of patients that did not undergo radiotherapy

AbstractAim: A case series analysis of 52 consequent subjects of immediate mandibular reconstruction after tumour resection using non‐vascularised methods, undertaken at U.P. King George's University of Dental Sciences and King George's Medical University, is being reported. To assess the success of reconstruction on subjective and objective evaluation based upon Mandibular Reconstruction Assessment Scale (MRAS) questionnaire.Methods: Patients with benign mandibular tumours irrespective of age, sex, site and socio‐economic status were included. Primary reconstruction was carried out after resection in two surgical units on surgeon's choice using stainless steel wire (6/52; 12%), stainless steel reconstruction plate (10/52; 19%) or titanium reconstruction plate (36/52; 69%) without bone graft (23/52; 44%) or with bone graft (29/52; 56%). Bone grafts were harvested from iliac crest (21/52; 40%), rib (2/52; 4%) and an additional pectoralis major myocutaneous flap with iliac crest bone graft (6/52; 12%) to provide cover to the reconstruction plate was also used.Results: The primary outcome measurements were wound healing, mouth opening, chewing efficiency, jaw movements, cosmetic achievement and speech on a five‐point scale, all of which improved significantly after surgery. The overall complication rate was 17%. Three patients (6%) had loosening of the screw, two (4%) showed dehiscence of the plate, two (4%) showed tumour recurrence and one (2%) had infection of the graft that was subsequently removed.Conclusion: Titanium reconstruction plates with iliac crest graft provided good result in the absence of microvascular reconstruction because of unavailable long operating time and lack of expertise. Long‐term satisfactory rehabilitation can be achieved using removable dentures or prosthesis on dental implants on the contraption provided by the non‐vascularised tissue despite non‐calcified bone visible on the skiagram.

Reconstruction of large defects postmandibulectomy for oral cancer using plates and myocutaneous flaps: a long-term follow-up

A series of 28 consecutive cases of mandibular reconstruction by means of reconstructive plates and myocutaneous flaps were reviewed. In all cases mandibular resection was indicated for treatment of squamous cell carcinoma of the oral cavity: 25 pelviglossomandibulectomies (resulting in large defects from the angle of the mandible), 2 Commando operations (resulting in lateral defects) and 1 anterior sectional mandibulectomy (resulting in an anterior defect). Tumour stages were T1–T2 (4 cases) and T3–T4 (24 cases). Success was defined as plate maintenance 6 months’ postoperatively/postradiotherapy. The overall success rate was 32.2%. Lateral–centre–lateral (L–C–L) defects had 32% success, L (lateral) defects had 50% success and in the single case of a C (centre) defect, the plate was not maintained. Stainless steel reconstruction plates showed a similar success rate as titanium plates (30% versus 34%). In cases not submitted to radiotherapy there were more maintained plates than in cases that received radiotherapy (45.5% versus 23.6%). Reconstruction plates are not effective in bridging large defects of the resected mandible. Only in selected cases that are not eligible for microvascular free flaps should plates and myocutaneous flaps be considered as an option for mandibular reconstruction.

Long-term functional outcome of mandibular reconstruction with stainless steel AO reconstruction plates

Mandibular continuity defects are usually reconstructed with bone grafts. However, factors associated with the tumour and the patient can still be reasons to choose reconstruction plates. The aim of this study was to find out the results of mandibular reconstructions with stainless steel AO reconstruction plates after a long follow-up period. The records of 36 patients were reviewed for personal data and the history of disease, treatment and complications. Patients with failed reconstructions were compared with those in whom the procedure had been successful. Patients and surgeons gave their opinion on the functional and cosmetic results. The mean follow-up was 39 months (range 4–99); 4 patients were withdrawn because they developed early recurrent disease and in 17 patients the reconstruction failed. We found no significant differences between the successful and the failed group. Fourteen patients could be evaluated for functional outcome, 10 of whom were totally or satisfactorily rehabilitated. Therefore, stainless steel reconstruction plates can be used in patients when other options are inappropriate.

Reconstruction of mandibular continuity defects with stainless steel reconstruction plates

Reconstruction of mandibular continuity defects with stainless steel reconstruction plates

Rigid Fixation of Vascularized Bone Grafts in Mandibular Reconstruction

To evaluate the nature of complications and complication rates with the use of three different reconstruction plates for the rigid fixation of vascularized bone grafts in oromandibular reconstruction. We conducted a case series of 95 patients over a 6-year period, with a minimum follow-up of 6 months and a maximum follow-up of 66 months. Academic tertiary referral medical center. Forty-eight patients had vascularized bone grafts fixated to native mandible with AO stainless steel reconstruction plates; 25 patients, with AO titanium plates; and 22 patients, with titanium hollow screw reconstruction plates (THORPs). Types of vascularized flaps, mandibular defects to be reconstructed, and use of radiation therapy were similar among the three groups. The surgical approach involved oromandibular reconstruction with a vascularized bone graft rigidly fixated with a reconstruction plate. Clinically and radiographically noted complications and resultant treatment. In the grafts fixated with AO stainless steel reconstruction plates, three plate fractures, seven instances of loose screws, eight plate exposures, and two cases of nonunion occurred. No cases of plate fracture or nonunion occurred in the titanium or THORP groups. One titanium plate and two THORPs were exposed during the study period. One instance of loose screws occurred in the titanium group; none in the THORP group. Seventy-four percent of those complications occurred within 12.4 months (the mean follow-up time of the THORP group). The incidence of complications in the stainless steel group was significantly greater than that in the titanium or THORP groups. No statistically significant increase in the rate of complications was noted when radiation therapy was used as a component of treatment. To our knowledge, this is the first study to compare three different reconstruction plates for fixation in vascularized bone reconstruction of the mandible. AO THORPs are now used almost exclusively to rigidly fixate vascularized bone grafts because of their advanced design and their potential for osseointegration and because fewer screws are necessary to attain adequate fixation than with conventional AO reconstruction plates.

Rigid fixation of comminuted mandibular fractures

Treatment of comminuted mandibular fractures has traditionally involved closed reduction with external fixation in an effort to avoid stripping periosteum from the bony segments. The purpose of this study was to evaluate retrospectively the success rate of rigid fixation used to treat 16 consecutive comminuted fractures of the mandible in 15 patients. The comminuted fractures were as follows: symphysis and body, 10; angle, 3; and ramus, 3. In 13 cases, AO stainless steel reconstruction plates were applied, with a minimum of three 2.7-mm tapped bone screws in each of the two stable segments. In most cases additional screws were placed into the comminuted fragments to stabilize them. In two patients, the mandibular ramus was comminuted (one case bilaterally), which made it impossible to place a large plate. These fractures were stabilized with multiple titanium miniplates (2.0 mm, tapped). All patients' fractures healed to a bony union without bone grafting. The mean maximum incisal opening at longest follow-up was 40 mm (range, 20 to 50 mm). All patients had a satisfactory facial form and none required further surgery for facial recontouring or malocclusion. Complications were observed in three patients. Two patients (13%) developed infections. Both infections were caused by loose hardware and responded to removal of the hardware and did not require any other treatment. One mandible refractured during manipulation after coronoidectomy to treat mandibular hypomobility, a sequellae of a gunshot wound that traversed both mandibular rami. This fracture healed after plate removal and a course of maxillomandibular fixation without bone grafting. This study suggests that rigid fixation of comminuted mandibular fractures is a viable treatment that satisfies the necessity for reestablishment of form and function with minimal morbidity.

Mandibular Reconstruction With a Recombinant Bone-Inducing Factor: Functional, Histologic, and Biomechanical Evaluation

Bone morphogenetic protein-2 (BMP-2) is a human recombinant bone-inducing factor that stimulates bone formation within 14 days. Twenty-six dogs underwent reconstruction of 3-cm full-thickness mandibular defects. After stabilizing the defects with stainless steel reconstruction plates, test implants composed of inactive dog bone matrix carrier and human recombinant BMP-2 were placed in defects of 12 animals (group 1). Control implants (carrier without BMP-2) were used in 10 animals (group 2), and no implants were placed in mandibular defects of four animals (group 3). Animals were killed at 3 and 6 months. The reconstructed segments were evaluated by roentgenography, analysis of functional stability, histology, histomorphometry, and analysis of biomechanical strength using three-point bend testing. In group 1, reconstruction plates were removed at 10 weeks because stiff, noncompressible mineralized bone formed across the defects, allowing the animals to chew a solid diet. The defects from groups 2 and 3 showed minimal, if any, bone formation and remained grossly unstable, prohibiting plate removal or advancement to a solid diet. Histomorphometric analysis at 6 months revealed that 68% of the group 1 implants were replaced by mineralized bone, whereas mineralized bone occupied less than 4% of the implants in groups 2 and 3. Biomechanical testing at 6 months revealed that the average bending strength of the reconstructed hemimandibles (expressed as a percentage of the contralateral hemimandible) was 27% for group 1 and 0% for group 2. The biomechanical strength of the defects reconstructed with BMP-2 increased significantly from 3 to 6 months and was related to degree of mineralization and thickness of bone bridging the defect.

Healing Large Segmental Defects in Dogs and Sheep with Recombinant Human Bone Morphogenetic Protein (rhBMP-2)

ABSTRACTHuman recombinant BMP-2 is known to induce cartilage and bone in a rat subcutaneous site. Here we demonstrate that BMP-2 can induce therapeutic bony union in segmental bone defects in three different animal models: internally fixed defects in sheep femur (2.5 cm) and dog mandible (3.0 cm). In each model, inactive bone matrix from the same species as the test animal was prepared by acid demineralization and extraction in guanidinium chloride. Human recombinant BMP-2 was reconstituted with the bone matrix and inserted in the defect site. Inactive matrix served as the negative control. Healing was monitored weekly by x-ray, At the final time points, specimens were evaluated for union by biomechanical testing and for bone formation by histology. In the first model, a 3 cm mandibular defect in dogs was made and stabilized with a stainless steel reconstruction plate. Animals were terminated at 3 and 6 months. In the second model, an osteoperiosteal defect was created by excising a 2.5 cm midshaft segment from the femur of a skeletally mature sheep. The gap was stabilized by an anterolateral fixation plate. Animals were sacrificed at 12 weeks postoperation. In both studies, BMP-2 mixed with inactive carrier induced bony union judged by radiography, biomechanical testing, and histology; by the same criteria, the defect implanted with the carrier matrix alone did not unite.The ability of demineralized bone to induce cartilage and bone formation in ectopic sites was described by Urist [1]; this activity was named bone morphogenetic protein (BMP). The in vivo progression of demineralized bone to bone has been well-studied [1,2]. After initial proliferation of mesenchymal cells in the first five days after implantation, a cartilage model forms at days 5–10. The cartilage mineralizes and hypertrophies, and is gradually replaced by bone. The newly formed bone then continues to remodel, so that in rats a thin ossicle of bone surrounding bone marrow has formed by day 21. The therapeutic potential of a material which could induce bone formation and replace bone graft is very high, and demineralized bone or partially purified protein prepared from demineralized bone has been used to repair large bony defects in animal models and in human therapy.More recently, some of the individual components of the bone morphogenetic activity have been isolated and characterized from bovine bone [3]. Extensive biochemical purification and molecular cloning have demonstrated that there are at least 7 distinct proteins present in bone. Molecular cloning of the bone morphogenetic proteins (BMPs) 2 through 7 demonstrated that they are related and all are members of the transforming growth factor/inhibin family of genes [4,5,6]. There may also be additional factors involved in cartilage and bone induction, as other investigators have described components different from these [7,8]. Expression of the recombinant human BMP-2, BMP-3, BMP-4, BMP-5, and BMP-7 in mammalian cells, followed by purification, allowed the demonstration that an individual BMP is sufficient to induce cartilage and bone in an ectopic site. A detailed study in rats of BMP-2-induced bone formation showed that the progression seen with the recombinant protein is the same as observed with demineralized bone or highly purified bone-derived, bone-inductive proteins [9].With this background of rhBMP-2-induced ectopic bone formation, this study demonstrates the efficacy of BMP-2 in healing a bony defect. Using allogeneic bone as a matrix, rhBMP-2 shows efficacy in healing large defects in dog mandible and sheep femur.