Resorbable Miniplates Research Articles

Management of mandibular fracture and lacerated wound due to machete trauma in children: case report

Introduction: The facial fractures in pediatric patients are rare, and they need an immediate treatment to recover the function and aesthetic to the young patients. Anatomic reduction along with rigid skeletal stabilization is mandatory until bone union has occurred. Special consideration about variation in anatomy and physiology of pediatric patients, as well as the particular stage of growth and dental development should be preferred. Case report: We present a case of 5 year old girl patient with fractures of the parasymphyseal and left angle of mandible horizontally and vertically unfavourable, with significant displacement and huge lacerated wound of the face caused by machete slashed. We successfully managed the pediatric complex mandible fractures by performing open reduction internal fixation using resorbable miniplates and gunning splint as intermaxillary fixation. Conclusion: Pediatric mandible fractures requiring ORIF are rare. The combination of intermaxillary fixation and resorbable fixation system is needed postoperatively because of the extensive fractures for adequate fixation and good outcomes.

A Comprehensive Review of Orthognathic Surgery: Fixation, Relapse, and Complications

Background: This study aims to investigate all papers on orthognathic fixation to better understand changes in operative techniques and fixation materials and to better compare relapse and complication rates. Methods: A PubMed search was conducted of “orthognathic” AND “fixation” in the title or abstract between 1989 and 2020. Results: Three reviewers independently screened 439 papers and extracted data from 166 included papers. Of these studies, 118 investigated sagittal split ramus osteotomies (SSRO), 96 LeFort osteotomies, 25 genioplasties, and 21 intraoral vertical ramus osteotomies (IVRO). The most used fixation materials in the maxilla were titanium miniplates with monocortical screws (n = 65), followed by resorbable miniplates (n = 10); in the mandible, the most common were titanium miniplates (n = 67) and titanium bicortical screws (n = 49). Wide variability was demonstrated in relapse rates by operation, fixation type, and relapse time-point studied. Meta-analysis revealed a significantly higher infection rate in SSRO versus LeFort ( P = .003) and, surprisingly, a trend toward higher relapse rate in titanium versus resorbable fixation at 6 months in SSRO setback ( P = .08). Conclusion: This study reports all the available data on relapse rates across techniques, with non-inferiority of bicortical screws versus miniplates.

Reduction cranioplasty for hydrocephalic macrocephaly: clinical observations and literature review

Reduction cranioplasty for extreme hydrocephalic macrocephaly is performed for acquiring motor skills (head holding, sitting, moving), aesthetic correction and social adaptation of children. The authors analyze literature data and describe 2 patients with congenital hydrocephalic macrocephaly who underwent shunting surgery followed by reduction cranioplasty in early age using resorbable mini-plates. Reduction cranioplasty decreased skull volume, improved social adaptation of children and ensured favorable aesthetic outcome.

Biomechanical evaluation of resorbable and titanium miniplates and of single and double miniplates for the treatment of mandibular condyle fractures

Mandibular condyle fractures are one of the most common facial bone fractures, and open reduction, which involves implanting miniplates to ensure rigid fixation of the fractured surfaces, is the standard treatment. The aim of this study was to compare the stress fields of resorbable and titanium miniplates and of single and double miniplates by taking the displacement between the fracture surfaces (interfragmentary displacement) into account. Three-dimensional mandible models were created based on computed tomography images from 10 patients. To simulate the common loading conditions that the mandible is exposed to during daily living, mastication and muscle forces were applied to each model. The von Mises stress distribution over the miniplates and the maximum displacements between the fractured surfaces were calculated using finite element analysis. The mean maximum stresses associated with the titanium miniplates were significantly higher than those associated with the resorbable miniplates (p<0.05). Moreover, the mean maximum interfragmentary displacements associated with the resorbable miniplates were higher than those associated with the titanium miniplates, but there was no significant difference (p>0.05). The stress and interfragmentary displacement results associated with the single and double miniplates (made of either of the two materials) were within the clinically acceptable limits.

Comparative study on long-term stability in mandibular sagittal split ramus osteotomy: hydroxyapatite/poly-l-lactide mesh versus titanium miniplate

BackgroundResorbable devices have recently been adopted in the field of orthognathic surgery with controversies about their postoperative skeletal stability. Hence, we determined the long-term skeletal stability of unsintered hydroxyapatite/poly-l-lactic acid (HA/PLLA) mesh for osteofixation of mandibular sagittal split ramus osteotomy (SSRO), and compared it with that of titanium miniplate.MethodsPatients were divided into resorbable mesh and titanium miniplate fixation groups. A comparative study of the change in the mandibular position was performed with preoperative, 1-day, 6-month, and 2-year postoperative lateral cephalograms.ResultsAt postoperative 6 months—compared with postoperative 1 day, point B (supra-mentale) was significantly displaced anteriorly in the titanium-fixation group. Moreover, at postoperative 2 years—compared with postoperative 6 months, point B was significantly displaced inferiorly in the titanium-fixation. However, the HA/PLLA mesh-fixation group did not show any significant change with respect to point B postoperatively.ConclusionsThe HA/PLLA mesh-fixation group demonstrated superior long-term skeletal stability with respect to the position of mandible, when compared with the titanium-fixation group.

Bone healing after biodegradable mini-plate fixation.

To compare bone healing in mandibular vertical body osteotomies (MVBO) after fixation with a resorbable 2.0mm-profile fixation system in the first and third postoperative months in rabbits. Twenty hemimandibles of ten rabbits were divided into two groups according to duration of resorbable fixation-one or three months. The MVBOs were performed and one four-hole, resorbable, 2.0mm mini-plate fixation system was used on each side. The computed tomography (CT) scans, scanning electron microscopy (SEM), and histomorphometric outcomes of groups I and II were compared. Significant differences were found between the one- and three- month assessments in terms of newly formed bone ratio values (p<0.05). There was more new bone formation at the third month on both the CT and histomorphometric examinations. A better adaptation of the bone tissues to the resorbable mini-plate and screws was observed on SEM at three months. The resorbable mini-plates provided a fixation stable enough to allow immediate oral alimentation and callus formation in both groups.

COMPARATIVE EVALUATION OF THE MECHANICAL PROPERTIES OF RESORBABLE AND TITANIUM MINIPLATES USED FOR FIXATION OF MANDIBULAR CONDYLE FRACTURES

In this paper, comparative evaluation of the mechanical properties of resorbable and titanium miniplates, which are used for the fixation of the mandibular condyle fractures, was carried out using finite element analysis (FEA). To do so, first two-dimensional (2D) computed tomography (CT) images of mandibles recorded from 10 adult patients were converted into three-dimensional (3D) solid body models. Then these models were transferred to the finite element software. In the finite element stage of the study, a condyle fracture was created onto the mandible and double-titanium and double-resorbable miniplates were separately fixed to the mandible surface such that the fractured sites to be firmly attached. Stress distribution over the plates and interfragmentary displacements between adjacent surfaces, which stem from the clenching force applying to the mandible, were calculated using FEA. It was observed from the results that maximum tensile stresses occurred in the titanium miniplates were significantly higher than those obtained from resorbable miniplates (p &lt; 0.01). Higher maximum displacements between fractured surfaces were observed in the case of resorbable plate systems (p &lt; 0.01). Maximum stress and displacement values obtained from both titanium and resorbable plate systems were under clinically acceptable limits. According to results, resorbable plates showed a similar reliability with titanium miniplates in terms of withstanding various stress and strain deformations.

In vitro biomechanical evaluation of fixation methods of sagittal split ramus osteotomy in mandibular setback

The purpose of this study was to compare different internal fixation techniques with resorbable or titanium fixation system used in sagittal split ramus osteotomy (SSRO) for mandibular setback.Synthetic polyurethane hemimandible replicas were used. The distal segment was repositioned in a 5-mm setback position. The hemimandibles were divided into the following eight groups: resorbable miniplate (A), titanium miniplate (B), resorbable hybrid; resorbable miniplate and bicortical screw (C), titanium hybrid; titanium miniplate and bicortical screw (D), resorbable mixed hybrid; resorbable bicortical screw and titanium miniplate (E), titanium mixed hybrid; titanium bicortical screw and resorbable miniplate (F), three resorbable bicortical screws (G) and three titanium bicortical screws (H). The compression loads were applied on the incisal edge. The compression loads (N) at 5- and 10-mm displacement were analyzed (P < 0.05).Miniplate groups (A and B) were significantly weaker than the other groups (C ∼ H). Group (H) had greatest biomechanical stability. There was no significant difference between group (D) and group (H) at 10-mm displacement. Group (G) showed a lower load than group (H) and group (D). There was no significant difference between the hybrid and mixed hybrid groups.It was concluded that additional placement of a bicortical screw, either titanium or resorbable with a miniplate may provide significantly better stabilization.

Segmental stability of resorbable P(L/DL)LA-TMC osteosynthesis versus titanium miniplates in orthognatic surgery

After two decades of the use of resorbable miniplates, new polymer compositions for resorbable osteosynthesis are still being developed to make the handling and outcome of operations even more predictable and give higher stability to the repositioned segments. This study investigates a new resorbable osteosynthesis system in orthognathic patients.50 patients were treated with P(L/DL)LA-TMC resorbable osteosynthesis and compared to a group of 50 patients treated with titanium miniplates. Segmental stability and relapse were measured comparing preoperative, postoperative and follow-up lateral cephalograms.Throughout this study, resorbables appeared to be as stable as titanium miniplates except in maxillary elongation and mandibular setback. Here, the titanium miniplates showed significantly higher stability than resorbable plates.P(L/DL)LA-TMC osteosynthesis seem to have less strength against compressive forces after maxillary elongation and they are less resistant to the forces the tongue exerts, pressing against the mandible after setback. It can therefore be concluded that the resorbable osteosynthesis can be used in the same situations as titanium miniplates except in maxillary elongation and mandibular setback.

Preliminary Experience With a Dynamic Resorbable Fixation Device for Craniosynostosis Surgery

The advent of resorbable osteosynthesis material has revolutionized craniomaxillofacial surgery. The need to provide rigid bony fixation in the surgical treatment of craniofacial deformities has inspired an ongoing evolution of surgical innovations and implants. Stability of the plates has been improved, but the duration of their stability remains an ongoing problem. In infant craniofacial fixation, it is important to provide initial stability, but after 4 to 6 weeks, this is no longer required as the brain is rapidly expanding. Surgery was performed on 10 patients with sagittal suture synostosis with conventional suture resection, remodeling, and fixation with resorbable miniplate (PolyMax-RAPID) struts held in position with modeled resorbable pockets affixed to the neurocranium with resorbable screws placed across the resected suture between June 2004 and September 2008. All the patients presented a satisfactory aesthetic result without complications after at least 1-year follow-up. We present a further innovative method of craniofacial fixation in infants using resorbable plates as floating struts providing stability and at the same time controlled dynamic expansion of the cranial vault guided by brain growth.

A comparative in fixation of the craniofacial skeleton using resorbable material

Background: Application of resorbable materials in craniofacial surgery offers many advantages compared with conventional materials such as titanium which is used in the reduction of incidence of complications like extrusion, intracranial migration or translocations of the implant, also there is no restriction on the skeletal growth as well as no distortion in plain radiographic and CAT scan studies. Materials and Methods: It was a prospective, sequential, comparative and open study carried out between October of 2002 and February of 2004 among patients of the Clinic of Craniofacial Surgery at ISSEMYM Medical Center in Metepec, Mexico. The patients were sequentially assigned either to group I in which LactoSorb ; (Biomet microfixation) resorbable screws and miniplates of 1.5 mm, 2.0 mm and 2.5 mm sizes (made up of 82% PLLA and 18% PGA) were used; and to group II in which titanium screws and miniplates of the same sizes were used. All patients were preoperatively documented with clinical examination, clinical photographs and CAT scan. Results: A total of 100 patients were included with 50 patients in each group. In group I, 40 patients (80%) with facial fractures were operated, of which 18 were simple maxillary fractures, 11 were fractures of orbitomalar complex, 7 panfacial fractures, 2 fractures of frontal sinus and 2 mandibular fractures; in 5 patients (10%) with malocclusion, some kind of orthognathic surgery was performed, 4 maxillary osteotomies and one maxillo-mandibular osteotomy were performed; and the remaining 5 patients (10%) were subjected to some advanced craniofacial surgery procedure, in one patient with Apert's syndrome a fronto-orbital advancement was performed, there were 3 patients with hypertelorism in whom orbital medialization was undertaken in two cases and facial bipartition in one; the remaining case was a Treacher Collins patient in which a orbital reconstruction using monocortical parietal bone was performed. In the age range of 6-55 years with an average of 30.5-year-old in these procedures, a total of 196 miniplates were placed. Conclusions: The results of our study confirm data reported by previous descriptive studies about the systems for resorbable fixation. We consider that the present method of resorbable fixation is a viable and safe option for the management of patients who require some type of fixation of the craniofacial skeleton.

Ultrasound-aided resorbable osteosynthesis of fractures of the mandibular condylar base: an experimental study in sheep

We evaluated the osteosynthesis of condylar fractures using resorbable mini plates and ultrasound-aided insertion of pins clinically and histologically. Stability was greater than that with resorbable screws because of the fusion of pin and plate. Long term evaluation showed complete resorption of the polymeric osteosynthesis material.

Pediatric Craniofacial Osteosynthesis and Distraction Using an Ultrasonic-Assisted Pinned Resorbable System

Resorbable osteosynthesis is an important tool in pediatric craniofacial surgery. A prospective clinical study was carried out to evaluate the Sonic Welding resorbable osteosynthesis system. Twenty pediatric patients with craniosynostosis were operated on for craniofacial reconstruction. The techniques used were the same than usual (fronto-orbital remodeling or advancement). During the process of osteosynthesis, similar resorbable miniplates were used, but for fixation, only 2 steps were necessary (drilling and welding), tapping being unnecessary. Clinically, the hold of the pins in the bone seemed stronger, and less-than-usual osteosynthesis materials were necessary. Clearly, the pins were able to hold in a very thin bone in which no screws could hold. Subjectively, the satisfaction of the surgeon was greater owing to the avoidance of the tapping step. On follow-up, resorption took place with an initial swelling effect, like with another pure polylactic acid material. The good resistance of pins suggests that, in such a system, the resorbable plate becomes the weak point.

Comparative evaluation of ten different condylar base fracture osteosynthesis techniques

The aim of this study on the mandibles of minipigs was to compare the biomechanical stability of different methods of osteosynthesis that are used in the operative treatment of fractures of the base of the condyle. Ten different systems of osteosynthesis were used to fix 164 fractures, which were tested by a two-point bending test after repositioning and fixing. This stress test was applied in four directions: lateral to medial, anterior to distal, distal to anterior, and medial to lateral. The Eckelt lag screw, one or two 2.0 mm miniplates, one miniplate with bar (KLS Martin), minicompression plates (Medicon), zygoma compression plates (Medartis), condylus fracture plates (Medartis), square 4-hole plates (KLS Martin), and either one or two resorbable 4-hole miniplates (Resorb-X, Martin) were used for osteosynthesis. A total of 164 tests were done using a universal test machine that measured forces until the osteosynthesis failed. Advantages in mechanical load capacity were also measured for the Eckelt lag screw when force was applied from medial to lateral. Fixation with one resorbable miniplate was not functionally stable. Irrespective of the direction of force applied, two miniplates were the most stable technique. There were pronounced differences depending on the direction of force applied. The results suggest that treatment with a single resorbable miniplate is not functionally stable.

Poster 178: Stability of the Maxilla After Superior Repositioning With the Total Maxillary Alveolar Osteotomy

Statement of the ProblemThe purpose of this study was to investigate the postoperative stability of the maxilla following the total maxillary alveolar osteotomy (TMAO) with rigid internal fixation.Materials and MethodsThe maxilla was osteotomized using buccal access. Two parallel horizontal osteotomies were placed facially from the piriform aperture to the maxillary tuberosity. The inferior osteotomy was placed 5mm above the apices of the front teeth, whereas the superior osteotomy was placed below the floor of the nose. After the intrusion of the dento-alveolar segment with removal of horseshoe-shaped bone block, fixation with four titanium or resorbable miniplates was made.Method of Data AnalysisIn order to assess the postoperative maxillary movement pattern in 51 patients (mean age 23.1) with both vertical maxillary excess and so-called gummy smile, lateral cephalograms were obtained immediately preoperatively, and 1 day, 1 year, and 2 years after surgery. The changes in point A of the maxilla were examined on the cephalograms.ResultsNo apparent postoperative complications were found. At 1-year and 2-year follow-up, no significant postoperative relapse in the examined point of the maxilla was found in the horizontal (0.5±0.6 mm, 0.4±0.4 mm mean anterior movement, respectively) and vertical (0.2±0.4 mm, 0.2±0.4 mm mean anterior movement, respectively) direction.ConclusionThese results suggest that TMAO might be a reliable and useful technique for superior repositioning of the maxilla with alveolar height excess and gummy smile. Statement of the ProblemThe purpose of this study was to investigate the postoperative stability of the maxilla following the total maxillary alveolar osteotomy (TMAO) with rigid internal fixation. The purpose of this study was to investigate the postoperative stability of the maxilla following the total maxillary alveolar osteotomy (TMAO) with rigid internal fixation. Materials and MethodsThe maxilla was osteotomized using buccal access. Two parallel horizontal osteotomies were placed facially from the piriform aperture to the maxillary tuberosity. The inferior osteotomy was placed 5mm above the apices of the front teeth, whereas the superior osteotomy was placed below the floor of the nose. After the intrusion of the dento-alveolar segment with removal of horseshoe-shaped bone block, fixation with four titanium or resorbable miniplates was made. The maxilla was osteotomized using buccal access. Two parallel horizontal osteotomies were placed facially from the piriform aperture to the maxillary tuberosity. The inferior osteotomy was placed 5mm above the apices of the front teeth, whereas the superior osteotomy was placed below the floor of the nose. After the intrusion of the dento-alveolar segment with removal of horseshoe-shaped bone block, fixation with four titanium or resorbable miniplates was made. Method of Data AnalysisIn order to assess the postoperative maxillary movement pattern in 51 patients (mean age 23.1) with both vertical maxillary excess and so-called gummy smile, lateral cephalograms were obtained immediately preoperatively, and 1 day, 1 year, and 2 years after surgery. The changes in point A of the maxilla were examined on the cephalograms. In order to assess the postoperative maxillary movement pattern in 51 patients (mean age 23.1) with both vertical maxillary excess and so-called gummy smile, lateral cephalograms were obtained immediately preoperatively, and 1 day, 1 year, and 2 years after surgery. The changes in point A of the maxilla were examined on the cephalograms. ResultsNo apparent postoperative complications were found. At 1-year and 2-year follow-up, no significant postoperative relapse in the examined point of the maxilla was found in the horizontal (0.5±0.6 mm, 0.4±0.4 mm mean anterior movement, respectively) and vertical (0.2±0.4 mm, 0.2±0.4 mm mean anterior movement, respectively) direction. No apparent postoperative complications were found. At 1-year and 2-year follow-up, no significant postoperative relapse in the examined point of the maxilla was found in the horizontal (0.5±0.6 mm, 0.4±0.4 mm mean anterior movement, respectively) and vertical (0.2±0.4 mm, 0.2±0.4 mm mean anterior movement, respectively) direction. ConclusionThese results suggest that TMAO might be a reliable and useful technique for superior repositioning of the maxilla with alveolar height excess and gummy smile. These results suggest that TMAO might be a reliable and useful technique for superior repositioning of the maxilla with alveolar height excess and gummy smile.

Comparison of Strains Produced by Titanium and Poly D, L-Lactide Acid Plating Systems to In Vitro Forces

To determine if a specific resorbable plating system provides similar fixation, in terms of strain distribution under load, to a titanium system when the Champy technique is applied for the treatment of a mandibular angle fracture. A formalin-fixed cadaver mandible was harvested just before the study. A bicortical osteotomy was then made using a diamond disc extending in an oblique direction in the area of the angle. It was then passively fixated with a 4-hole 2.0-mm miniplate. Two stacked rosette strain gauges were bonded to the mandible on either side of the fracture. Each rosette had 3 strain gauges arranged in specific degrees relative to each other. The mandible was then placed on a dynanometer and 30 lb loads were delivered on the ipsilateral molar. Static resistance was placed in the condylar neck region to simulate the glenoid fossa. Loading was repeated 10 times with a period of 3 minutes between loads. Measurements were recorded for each strain gauge after loads were in place for 30 seconds. The same process was repeated using a 4-hole 2.1-mm resorbable miniplate. The strains were then used to calculate the maximum and minimum strains for each rosette. Hooke's law was used to calculate the principal stresses. Differences were observed between the strain gauges for each individual plating system. There was variability within the resorbable plate measurements as shown by the standard deviation. Using the REML ANOVA test, a significant difference was found between the 2 materials. In this in vitro study, there were significant biomechanical differences observed between a 2.0-mm titanium miniplate and a 2.1-mm resorbable miniplate when used to treat a mandibular angle fracture following Champy's principles. Based on our finding, both systems cannot be used interchangeably for the treatment of mandibular angle fractures under the same clinical conditions.

Resorbable poly- l-lactide plates and screws for the treatment of mandibular condylar process fractures: a clinical and radiologic follow-up study

Purpose The purpose of this study was to determine whether a resorbable poly- l-lactide (PLLA) miniplate system could be used to treat mandibular condylar process fracture. Patients and methods Fourteen patients (12 males, 2 females, aged 23.1 ± 5.7 years) who had mandibular condylar process fractures treated with PLLA implants were recalled for follow-up clinical and radiologic examinations at 3 years. Results Mouth opening recovered to more than 35 mm and occlusion was stable in all patients. There was no facial asymmetry 3 months postoperatively. Two patients had mild chronic postoperative tenderness at the implantation site; however, there was no wound infection. All fractured mandibular condyles showed anatomic good reduction and long-term stability with the use of resorbable miniplates and screws. Bone healing was satisfactory in all patients, and there was no evidence of abnormal resorption of the condylar process. The screw holes remained evident after 3 years. Screw holes in 2 patients showed enlargement on radiographic examination. Conclusion The PLLA miniplate system provides reliable stability when used for the fixation of mandibular condylar process fractures.

Reconstruction of the frontal calvarian continuity in a child using a freeze-preserved autogenous bone graft

Today, extended craniofacial defects in childhood can be treated by using modern techniques of bone banking and osteosynthesis, of particular importance when the restoration needs to consider calvarial growth. This is a report of an 8-year-old boy whose right frontal bone was removed during primary multidisciplinary trauma care. The bone was stored at a tissue bank using sterilization and freeze-dried preservation. Nine months later the graft was replaced and fixed with resorbable miniplates. Postoperatively no complications were observed and the (auto)graft has taken well. There was symmetrical craniofacial growth as well as a good aesthetic result three years after reconstruction.

The resorbable miniplate system lactosorb in a growing cranio-osteoplasty animal model

In the surgical treatment of craniosynostosis and craniofacial dysostosis in the growing child, passive intraosseous translocation (PIT effect) with intracranial displacement of metal plates and screws may be a problem. In an animal experiment, a possible PIT effect using resorbable PLA/PGA miniplates (Lactosorb, W. Lorenz, FL, USA) following cranio-osteoplasty were investigated in four young Göttingen minipigs. In addition to the mechanical properties, the processes of degradation and of sub- vs supraperiosteal application of the miniplates were evaluated. During degradation the resorbable PLA/PGA miniplates performed like metal plates as they also displayed passive intraosseous translocation in the growing animal model. However, in the experimental PLA/PGA miniplating the internal calvarial bone was not affected. Degradation took 12-18 months and was not delayed by bony incorporation. Mechanical properties proved to be sufficient in craniofacial surgery. Supraperiosteal plating delayed the PIT effect during the first 3 months after surgery. In the growing skull resorbable plates seem to be a promising therapeutic approach. However, prior to a general recommendation results of long-term clinical studies have to be evaluated.