scholarly journals Tyrosine-derived polycarbonate membrane in treating mandibular bone defects. An experimental study

2006 ◽  
Vol 3 (10) ◽  
pp. 629-635 ◽  
Author(s):  
Antti J Asikainen ◽  
Jukka Noponen ◽  
Christian Lindqvist ◽  
Mika Pelto ◽  
Minna Kellomäki ◽  
...  

This study was designed to evaluate the suitability of a novel bioabsorbable material in treating bone defects. A poly(desaminotyrosyl-tyrosine-ethyl ester carbonate) (PDTE carbonate) membrane (thickness 0.2–0.3 mm) was implanted into the mandibular angle of 20 New Zealand White rabbits to cover a through-and-through defect (12×6 mm). In group 1, the defects were left unfilled but covered with membrane and in group 2 the defects were filled with bioactive glass mesh and covered with membrane, too. Controls were left uncovered and unfilled. The animals were followed for 6, 12, 24 and 52 weeks, respectively. The material was evaluated by qualitative analysis of histological reactions and newly formed bone. We found that PDTE carbonate elicited a modest foreign body reaction in the tissues, which was uniform throughout the study. New bone formation was seen in all samples after six weeks. Group 1 had more new bone formation until 24 weeks and after this the difference settled. Based on findings of this study it was concluded that PDTE carbonate membranes have good biocompatibility and are sufficient to enhance bone growth without additional supportive matrix.

2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
Mikael Starecki ◽  
John A. Schwartz ◽  
Daniel A. Grande

Introduction. Autogenous bone graft is the gold standard in reconstruction of bone defects. The use of autogenous bone graft is problematic because of limited bone as well as donor site morbidity. This study evaluates a novel biomaterial as an alternative to autogenous bone graft. The biomaterial is amniotic membrane, rich in growth factors. Methods. Twenty-one adult male Sprague-Dawley rats were implanted with biomaterial using the rat critical size femoral gap model. After creation of the critical size femoral gap animals were randomized to one of the following groups: Group 1 (control): gap left empty and received no treatment; Group 2 (experimental): the gap was filled with commercially available bone graft; Group 3 (experimental): the gap was filled with bone graft plus NuCel amniotic tissue preparation. Results. The experimental groups demonstrated new bone formation compared to controls. The results were evident on radiographs and histology. Histology showed Group 1 controls to have 11.1% new bone formation, 37.8% for Group 2, and 49.2% for Group 3. These results were statistically significant. Conclusions. The study demonstrates that amniotic membrane products have potential to provide bridging of bone defects. Filling bone defects without harvesting autogenous bone would provide a significant improvement in patient care.


2013 ◽  
Vol 587 ◽  
pp. 404-411
Author(s):  
Ioan Cristescu ◽  
Lucian Marina ◽  
Daniel Vilcioiu ◽  
F. Safta ◽  
M. Istodorescu ◽  
...  

Antibiotic delivery systems used in the past have consisted primarily of impregnated cement beads that required routine removal once the antibiotic had eluded completely. With the development of collagen scaffolds that could be used to fill bony defects the antibiotic cold be delivered from the scaffold used to sustain local bone growth. Over the course of two years antibiotic loaded collagen scaffolds were used in the local treatment of 21patients suffering of complicated fractures including bone defects, infections or pseudoarthrosis, all of them of traumatic nature. At the time of the initial surgical debridement or at subsequent second look procedures once local tissue viability was observed the antibiotic loaded collagen scaffold was inserted in the tissue defect and never removed. Excellent results were obtained and the infection was brought under control by use of both surgical and antibiotic modalities. Bone grafting was used in 6 cases where the defects were extensive. Where there was less extensive bone destruction the scaffold was a good adjuvant in new bone formation. Use of antibiotic loaded collagen scaffolds is a reliable and effective means of local antibiotic delivery system combining both the new bone formation capacity of the scaffold to hold osteoblasts with the ability to deliver high doses of antibiotic in the local tissue environment and thus avoiding the systemic toxicity.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Sergio Alexandre Gehrke ◽  
Tiago Luis Eliers Treichel ◽  
Jaime Aramburú Júnior ◽  
Piedad N. de Aza ◽  
Juan Carlos Prados-Frutos

AbstractThe objective of our in vivo study was to compare the effects of the osteotomy on the thermal alterations, the bone healing and count of polymorphonuclear cells, comparing the drill design (cylindrical or conical) using continuous or intermittent movement. Twelve rabbits were used, which were made four osteotomies (n = 2 per tibia) to simulate the surgical drilling sequence for the installation of a dental implant at 8 mm of length and regular diameter. Four groups were proposed: group G1, cylindrical drill with continuous movement; group G2, cylindrical drill with intermittent movement; group G3, conical drill with continuous movement; and, group G4, conical drill with intermittent movement. Thermal mean variation was 6.91 ± 1.4 °C in group 1, 4.30 ± 1.3 °C in group 2, 2.78 ± 0.6 °C in group 3, and 2.77 ± 0.7 °C in group 4. Whereas the mean area of new bone formation was 1.00 ± 0.3 mm2 in group 1, 1.48 ± 0.3 mm2 in group 2, 2.20 ± 0.4 mm2 in group 3, and 2.43 ± 0.4 mm2in group 4. The mean count of polymorphonuclear cells, in the group 1 was 62.4 ± 5.9 cells, group 2 was 50.7 ± 4.2 cells, group 3 was 44.4 ± 3.7 cells, and group 4 was 42.4 ± 3.7 cells. The conical drill sequence produced a significantly smaller increase in temperature during both techniques (continuous and intermittent), more effective new bone formation and a smaller number of polymorphonuclear cells. During the osteotomy for the installation of implants, the professional must take to consider the drill design to perform a less traumatic surgical technique, which can improve and facilitate the healing of peri-implant tissues.


2017 ◽  
Vol 34 (05) ◽  
pp. 307-314
Author(s):  
Ali Aliyev ◽  
Ömer Ekin ◽  
Ozan Bitik ◽  
Petek Korkusuz ◽  
Nilgün Yersal ◽  
...  

Background Reconstruction of craniofacial bone defects is a primary focus of craniofacial surgery. Although autogenous bone grafts remain as the gold standard, alloplastic materials have also gained widespread popularity due to their off-the-shelf availability, ease of use, and durability. In addition to replacing the missing bone, some of these alloplastic materials have also been found to induce new bone formation. Objectives In this study, the phenomenon of neo-osseous induction with bioactive glass was investigated for different implant-soft tissue configurations. Materials and Methods Thirty-two male, Wistar albino rats were divided into four equally numbered study groups. In group 1 (FP), adipofascial groin flaps were prefabricated with free periosteal grafts. In group 2 (FPB), adipofascial groin flaps were prefabricated with free periosteal grafts and bioactive glass. In group 3 (FB), adipofascial groin flaps were prefabricated with bioactive glass. In group 4 (control), adipofascial groin flaps were not prefabricated. Morphometric analyses of the prefabricated structures were performed using micro-CT. The histologic properties of the ectopic ossification were assessed by using a modified scoring system. Results Group 1 (FP) showed the greatest rate of mature lamellar bone formation. Group 2 (FBP) showed the greatest amount of bone density and volume. However, the addition of bioactive glass in group 2 (FBP) decreased the rate of mature lamellar bone formation when compared with group 1 (FP). Ectopic ossification was not observed in the control group. Conclusion Bioactive glass can be successfully used in the prefabrication of vascularized compound structures for the reconstruction of complex bone defects. However, interference with the periosteal induction of mature lamellar bone formation should be taken into consideration, especially in pediatric bone defects, which primarily rely on spontaneous osteogenesis through periosteal induction.


2021 ◽  
Vol 6 (1) ◽  
pp. 9-13
Author(s):  
Cynthia Chemaly ◽  
◽  
Mireille Kallassi ◽  
Rawad Samaran ◽  
Roy Abou Fadel ◽  
...  

Background: Chitosan is a natural biopolymer that has gained a special interest in bone regeneration in recent years. Objective: The objective of this study is to show the bone formation obtained following a transplantation of sponges of chitosan alone, chitosan combined with chondroitin sulfate or chitosan combined with chondroitin sulfate and collagen, in rat critical calvarial bone defects. Material and Methods: 12 Wistar rats were divided into 4 groups of 3 rats each. Critically sized bone defects were made in calvaria, and grafted by sponges of:collagen / chitosan / chondroitin (group 1), chitosan (group 2), chitosan / chondroitin sulfate (group3). Bone defects of group 4 remained empty for control. The animals were sacrificed 12 weeks after the surgery. Results: Histological analysis showed the formation of lamellar bone in the chitosan group. In the chitosan / chondroitin sulfate group, formation of a less mature bone than that of the chitosan group was also observed. However, the least bone formation was observed in the collagen / chitosan / chondroitin sulfate group. Histological sections showed the presence of fibrous tissue. The results for this group are similar to the control group. In groups 2 and 3, the materials appear completely resorbed while in group 1 the resorption of the matrix was incomplete. Conclusion: Despite the size of the sample, this study has shown that chitosan alone or in combination with chondroitin sulfate promotes bone formation. On the other hand, the combination chitosan / chondroitin sulfate / collagen showed a negative result.


2021 ◽  
pp. 105566562199265
Author(s):  
Ishwarya Shradha Mamidi ◽  
Esperanza Mantilla-Rivas ◽  
Brynne A. Ichiuji ◽  
Md Sohel Rana ◽  
Karen I. Ramirez ◽  
...  

Objective: Oronasal fistula (ONF) is a known complication after primary palatoplasty (PP). Studies investigating the effect of perioperative antibiotics on fistula rates after PP are limited by inadequate sample size or reliance on self-reporting through national databases. In this study, the authors evaluated the association between single-dose perioperative antibiotics and postoperative fistula rates after PP at a single institution. Design: A retrospective study. Participants: Children younger than 2 years who underwent PP from April 2009 to September 2019 were included. Interventions: Patients were divided into 2 categories: Group 1 received a single intraoperative dose of IV antibiotic, while group 2 did not. Main Outcome Measure(s): Outcome measures included ONF formation, length of stay (LOS), and 30-day readmission rates. Multivariable firth logistic regression, quantile regression, and χ2 tests were performed. Results: Of the 424 patients, 215 and 209 patients were in groups 1 and 2, respectively. The overall ONF rate was 1.9% among all patients. Patients in group 1 experienced an ONF rate of 3.3%, while patients in group 2 had an ONF rate of 0.5%. After correcting for confounding variables, the difference in ONF rates was not statistically different ( P = .68). Median LOS was 35.7 hours and 35.5 hours ( P = .17), while the rate of readmission within 30 days was 4.7% and 2.4% for group 1 and 2, respectively ( P = .96). Conclusions: Administration of a single-dose perioperative antibiotic did not decrease fistula formation after PP, nor did it affect the patient’s LOS or 30-day readmission rate.


Biomedicines ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 952
Author(s):  
Fabien Bornert ◽  
François Clauss ◽  
Guoqiang Hua ◽  
Ysia Idoux-Gillet ◽  
Laetitia Keller ◽  
...  

One major limitation for the vascularization of bone substitutes used for filling is the presence of mineral blocks. The newly-formed blood vessels are stopped or have to circumvent the mineral blocks, resulting in inefficient delivery of oxygen and nutrients to the implant. This leads to necrosis within the implant and to poor engraftment of the bone substitute. The aim of the present study is to provide a bone substitute currently used in the clinic with suitably guided vascularization properties. This therapeutic hybrid bone filling, containing a mineral and a polymeric component, is fortified with pro-angiogenic smart nano-therapeutics that allow the release of angiogenic molecules. Our data showed that the improved vasculature within the implant promoted new bone formation and that the newly-formed bone swapped the mineral blocks of the bone substitutes much more efficiently than in non-functionalized bone substitutes. Therefore, we demonstrated that our therapeutic bone substitute is an advanced therapeutical medicinal product, with great potential to recuperate and guide vascularization that is stopped by mineral blocks, and can improve the regeneration of critical-sized bone defects. We have also elucidated the mechanism to understand how the newly-formed vessels can no longer encounter mineral blocks and pursue their course of vasculature, giving our advanced therapeutical bone filling great potential to be used in many applications, by combining filling and nano-regenerative medicine that currently fall short because of problems related to the lack of oxygen and nutrients.


Author(s):  
A H A Baazil ◽  
J G G Dobbe ◽  
E van Spronsen ◽  
F A Ebbens ◽  
F G Dikkers ◽  
...  

Abstract Objective This study aimed to compare the necessary scutum defect for transmeatal visualisation of middle-ear landmarks between an endoscopic and microscopic approach. Method Human cadaveric heads were used. In group 1, middle-ear landmarks were visualised by endoscope (group 1 endoscopic approach) and subsequently by microscope (group 1 microscopic approach following endoscopy). In group 2, landmarks were visualised solely microscopically (group 2 microscopic approach). The amount of resected bone was evaluated via computed tomography scans. Results In the group 1 endoscopic approach, a median of 6.84 mm3 bone was resected. No statistically significant difference (Mann–Whitney U test, p = 0.163, U = 49.000) was found between the group 1 microscopic approach following endoscopy (median 17.84 mm3) and the group 2 microscopic approach (median 20.08 mm3), so these were combined. The difference between the group 1 endoscopic approach and the group 1 microscopic approach following endoscopy plus group 2 microscopic approach (median 18.16 mm3) was statistically significant (Mann–Whitney U test, p < 0.001, U = 18.000). Conclusion This study showed that endoscopic transmeatal visualisation of middle-ear landmarks preserves more of the bony scutum than a microscopic transmeatal approach.


Author(s):  
A. V. Syrkina ◽  
I. E. Pashkova ◽  
A. R. Monakhov ◽  
O. V. Silina ◽  
E. V. Chekletsova ◽  
...  

Background. In young children, the most common liver disease leading to transplantation is biliary atresia. Liver transplantation has fundamentally improved the survival rate of children with biliary atresia. Studies on developmental outcomes in children are mostly limited to small samples; there are no such studies in the Russian Federation.Objective: to determine the cognitive outcomes in children undergoing one-stage or two-stage surgical treatment of biliary atresia.Materials and Methods. 83 children were divided into groups: 36 children underwent transplantation without previous surgical interventions (group 1), 47 children underwent the Kasai palliative portoenterostomy (group 2). Inclusion criteria: 24 months of age or younger at the moment of transplantation, no medical history of neurological pathology. All children were examined before transplantation and at 1, 3, 6 and 12 months after liver transplantation. Psychomotor development was assessed using the Griffiths Psychomotor Development Scale for children under 24 months (translated by E.S. Keshishian), the Griffiths Intellectual Development Scale for children aged 2 to 8 years, and the Modified Checklist for Autism in Toddlers, Revised, for children 16-30 months old.Results. All children had developmental delays at the time of transplantation. Up to 50% of the children had signs of cachexia, with a shoulder circumference of less than 3 percentile. Only two children showed obvious hepatic encephalopathy in the form of depressed consciousness. After liver transplantation, 94% of group 1 children recovered their preoperative psychomotor development levels, and only 68% in group 2 made these gains. At 3 and 6 months after transplantation, about 80% of group 1 children showed normal psychomotor development, whereas in group 2, only 61% did. By 12 months after liver transplantation, the difference between the groups was more evident: 83.3% of group 1 children and only 53.2% of group 2 children were developing according to age. The difference between the groups was statistically significant (p < 0.05).Conclusion. Children who received one-stage treatment of biliary atresia and underwent liver transplantation have better neuropsychological development within a year after surgery than children with two-stage surgical treatment.


2021 ◽  
Vol 25 (1) ◽  
pp. 473-479
Author(s):  
Jagar Doski ◽  
Berivan Jamal

Background and objective: The accelerated protocol of Ponseti method was suggested to shorten the period of treatment of the conventional one for the cases of talipes equinovarus deformity. This study aimed to compare the accelerated protocol of Ponseti method in the treatment of clubfoot deformity with the conventional one. Methods: A prospective comparative study was conducted for infants less than six months with congenital talipes equinovarus deformity. The patients were randomized to either Group 1 (casts changed every week, conventional protocol of Ponseti method) or Group 2 (twice weekly, accelerated one). Pirani score was used to assess the severity of the deformity at presentation, at time of last cast removal, and at the last follow up visit (6th months). Results: The patients included were 48 cases with 79 feet. Group 1 (39 clubfeet) had a mean Pirani score of 5.6 (± 1.15) at presentation, which dropped to 0.47 (± 0.41) when the last cast was removed. In Group 2 (40 clubfeet), it dropped from 5.57 (± 0.83) to 0.77 (± 0.01). The result of each treatment protocol was significant, but the difference between them was not significant. Five cases (three patients aged more than three months) of Group 2 needed eight casts to reach an acceptable position of correction. The difference between the mean number of casts applied in Group 1 (5.09) and Group 2 (5.82) was statistically not significant. However, the difference between the mean number of days spent in the cast was significant. The complications occurred in 12 out of 79 feet, with no statistically significant difference between both groups. Conclusion: The accelerated protocol of Ponseti method for treating clubfoot deformity is as effective and as safe as the conventional one. It shortens the time required to complete the treatment program. Those who present lately (beyond the age of three months) may require an additional number of casts. Keywords: Clubfoot; Congenital talipes equinovarus; Ponseti; Accelerated; Cast.


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