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Objectives: The aims of this study were to test whether or not the application of an in situ-formed synthetic polyethylene glycol hydrogel (PEG) used as a biodegradable membrane for guided bone regeneration with a variety of graft materials and ambient oxygen or hyperbaric oxygen (HBO) environments would result in enhanced bone regeneration, and to observe the histologic and histomorphometric aspects of bone healing of the calvarial defects with and without a PEG membrane., Study Design: Thirty adult, skeletally mature, male New Zealand white rabbits were randomly divided into 3 groups of 10 animals each. Bilateral 15-mm-diameter critical-size defects were created in the parietal bones of each animal. Group 1 served as a control with unfilled bilateral calvarial defects, group 2 had bilateral calvarial defects filled with morcelized autogenous calvarial bone, and group 3 had bilateral calvarial defects filled with a biphasic calcium phosphate ceramic. One of the calvarial defects was randomly protected with a PEG resorbable liquid membrane in each animal. Five animals from each group underwent a course of HBO treatment (2.4 ATA 100% oxygen for 90 minutes 5 days a week for 4 weeks) and the other 5 served as control and did not receive any supplemental oxygen (normobaric). The animals were killed 6 weeks after their surgery, and their parietal bones were harvested. The specimens were analyzed with microscopic computerized tomography (microCT) scans and histomorphometrics., Results: The unfilled normobaric control bony defects did not heal, proving the critical-size nature of these defects. The presence of autogenous bone or bone ceramic in the defects increased the bone volume fraction and bone mineral density of the defects (P < .001). The presence of a membrane in the ungrafted and autogenous bone grafted defects resulted in a decrease in the corrected bone volume fraction (P = .002) but not in the bone ceramic grafted defects (P = .580). Bony healing of defects where the membrane was unsupported was compromised; the membrane did not maintain the desired bone regeneration volume with the unfilled and autogenous bone grafted groups. The PEG resorbable liquid membrane worked best with the bone ceramic material. HBO did not ameliorate the healing of the autogenous bone graft or ceramic filled defects in the 6-week time period of this study., Conclusions: Although the PEG resorbable liquid membrane is easy to use and forms an occlusive layer, caution is recommended when using the membrane over an unsupported defect. HBO did not ameliorate bony healing with the membrane at the early 6-week time point. The authors recommend future assessment with HBO at the 12-week time point., (Copyright 2010 Mosby, Inc. All rights reserved.)

There is continued interest in the development of new biomaterials. The application of new implantable biomaterials requires intense research and thorough evaluation. Much time and effort has been required to overcome the risks and problems associated with the bioabsorbable devices. For surgical bone fixation, these materials were investigated since the 1960's. Different polymer properties were explored to ensure adequate strength and biocompatibility. High-molecular-weight bioabsorbable polymers were initially used, followed by addition of reinforcement materials. The most recent materials are self-reinforced, small yet strong devices. The newer generations contain bioactive substances such as antibiotics and growth factors. Bioabsorbable materials are constantly changing as we try to adopt the principles of tissue engineering. Surgeons are using new techniques to exploit these polymers and their bioabsorbable properties. It is hoped that this multidisciplinary approach of surgery and research will continue to help the further evolution of biomaterial science.

Introduction: Tuberous sclerosis is a hamartoneoplastic syndrome, which may involve multiple organ systems. Oral hard tissue manifestations of the syndrome have been described in the literature only as recently as 1955. Patients who presented with clinical manifestations of tuberous sclerosis did not routinely undergo oral surveys to rule out 'lesions', and consequently data on 'lesions' in the maxillofacial complex is scant. Ten cases have been found in the English language literature, which describe maxillofacial 'lesions', which may be tumours, new growths, neoplasms or overgrowths occurring in patients diagnosed with tuberous sclerosis., Purpose: To review the literature for all maxillofacial lesions associated with tuberous sclerosis and to present an eleventh case of a patient with a maxillofacial lesion diagnosed as having tuberous sclerosis., Results: Eleven cases were found with maxillofacial fibroblastic lesions associated with tuberous sclerosis. These lesions were all fibrous benign neoplasms found in the maxillofacial bony complex., Conclusions: Maxillofacial fibroblastic lesions in tuberous sclerosis have various histopathological presentations, some of which may be difficult to differentiate. Consequently, close microscopic examination of these lesions is necessary so that adequate surgical treatment is provided., (Copyright 2002 European Association for Cranio-Maxillofacial Surgery. Published by Elsevier Science Ltd.)