PRELIMINARY FINDINGS OF A POTENZIATED PIEZOSURGERGICAL DEVICE AT THE RABBIT SKULL

The number of available ultrasonic osteotomes has remarkably increased. In vitro and in vivo studies have revealed differences between conventional osteotomes, such as rotating or sawing devices, and ultrasound-supported osteotomes (Piezosurgery®) regarding the micromorphology and roughness values of osteotomized bone surfaces. Objective: the present study compares the micro-morphologies and roughness values of osteotomized bone surfaces after the application of rotating and sawing devices, Piezosurgery Medical® and Piezosurgery Medical New Generation Powerful Handpiece. Methods: Fresh, standard-sized bony samples were taken from a rabbit skull using the following osteotomes: rotating and sawing devices, Piezosurgery Medical® and a Piezosurgery Medical New Generation Powerful Handpiece. The required duration of time for each osteotomy was recorded. Micromorphologies and roughness values to characterize the bone surfaces following the different osteotomy methods were described. The prepared surfaces were examined via light microscopy, environmental surface electron microscopy (ESEM), transmission electron microscopy (TEM), confocal laser scanning microscopy (CLSM) and atomic force microscopy. The selective cutting of mineralized tissues while preserving adjacent soft tissue (dura mater and nervous tissue) was studied. Bone necrosis of the osteotomy sites and the vitality of the osteocytes near the sectional plane were investigated, as well as the proportion of apoptosis or cell degeneration. Results and Conclusions: The potential positive effects on bone healing and reossification associated with different devices were evaluated and the comparative analysis among the different devices used was performed, in order to determine the best osteotomes to be employed during cranio-facial surgery

Hard Tissue Engineering

Peer reviewe

Incidence of lymph node metastases after piecemeal laser-surgical and en bloc cold steel resection of auricular VX2 carcinoma. A comparative study.

The CO2 laser surgery has become a widely used clinical treatment in otorhinolaryngology. In advanced neoplastic disease of the head and neck it is often difficult and even impossible to expose well the whole tumor through the surgical laryngoscope. In such cases the tumor is usually divided with the CO2 laser in several parts, which are excised separately. This approach seems opposed to the basic principles of oncologic surgery, where the tumor should not be touched in order to avoid local recurrences or metastatic spread. The proponents of the piecemeal resections refer back to few morphological and clinical studies, which show no evidence of increased incidence of metastases after the piecemeal resection. On this background the aim of the present study was to compare the piecemeal laser surgical complete (R0) resection with cold steel complete (R0) en bloc resection of tumors in an animal model. For both surgical approaches the incidence of local recurrences, regional and distant metastases had to be compared. After randomization to the both study arms in 143 male New Zealand White rabbits a VX2 squamous cell carcinoma was induced on the auricle. On day 8 a complete resection of the tumour was performed: for the first group - with cold steel resection en bloc; for the second group the cancer was transected by the CO2 laser following which it was removed in two pieces - piecemeal laser-surgical resection. On the 42nd postoperative day all animals were sacrificed and subjected to evaluation of the tumoral spread. Compared on the incidence of LN metastases the two therapeutic groups showed significant differences. Twenty-five percent of the animals with en bloc cold steel had metastases to regional lymph nodes, whereas forty-seven percent of the laser piecemeal group had metastatic nodal involvement. The incidence of distant metastases was similar for both study groups - 12.3% for the en block resection group and 7.7% for the piecemeal laser resection group. In this experimental setting the piecemeal laser surgical resection achieved better local results, but lead to more metastases (mainly lymphatic ones), than the cold steal en bloc resection. However, it is unlikely that tumor cells disseminated from the resection line itself caused this difference, as the vessels here were occluded by the laser. Mechanisms, which could explain the observed difference include dissemination through the walls of the intratumoral or peritumoral lymphatics. Piecemeal laser resection may decompress intratumoral pressure and release intra and peritumoral lymphatics, causing a flood of tumor emboli. Changes in the permeability and the lymph/blood flow caused by the local laser heat could have similar effect. Additionally mechanical trauma to the tumor mass itself or explosion-like tumor cell spread into the lymphatic network due to the applied laser energy could also precipitate metastases

Tissue Engineering in Oral and Maxillofacial Surgery : From Lab to Clinics

Regenerative medicine aims at the functional restoration of tissue malfunction, damage or loss, and can be divided into three main approaches. Firstly, the cell-based therapies, where cells are administered to re-establish a tissue either directly or through paracrine functions. Secondly, the often referred to as classical tissue engineering, consisting of the combined use of cells and a bio-degradable scaffold to form tissue. Thirdly, there are material-based approaches, which have made significant advances which rely on biodegradable materials, often functionalized with cellular functions (De Jong et al. 2014). In 1993, Langer and Vacanti, determined tissue engineering as an “interdisciplinary field that applies the principles of engineering and the life sciences toward the development of biological substitutes that restore, maintain, or improve tissue function”. They published this definition in Science in 1993. Tissue engineering has been classically thought to consist of three elements: supporting scaffold, cells and regulating factors such as growth factors (Fig. 1). Depending on the tissue to be regenerated, all three vary. Currently, it is known, that many other factors may have an effect on the outcome of the regenerate. These include factors enabling angiogenesis, physical stimulation, culture media, gene delivery and methods to deliver patient specific implants (PSI) (Fig. 2). During the past two decades, major obstacles have been tackled and tissue engineering is currently being used clinically in some applications while in others it is just taking its first baby steps.Peer reviewe

Bone reconstruction of extensive maxillomandibular defects in adults

Reconstruction of significant maxillomandibular defects is a challenge that has been much discussed over the last few decades. Fundamental principles were developed decades ago (bone bed viability, graft immobilization). Clinical decision-making criteria are highly relevant, including local/systemic factors and incision designs, the choice of material, grafting technique, and donor site morbidity. Stabilizing particulated grafts for defined defects—that is, via meshes or shells—might allow significant horizontal and vertical augmentation; the alternatives are onlay and inlay techniques. More significant defects might require extra orally harvested autologous bone blocks. The anterior iliac crest is often used for nonvascularized augmentation, whereas more extensive defects often require microvascular reconstruction. In those cases, the free fibula flap has become the standard of care. The development of alternatives is still ongoing (i.e., alloplastic reconstruction, zygomatic implants, obturators, distraction osteogenesis). Especially for these complex procedures, three-dimensional planning tools enable facilitated planning and a surgical workflow

Improving the peri-operative management of patients undergoing free tissue transfer for head and neck malignancy

Abstract The cohort of patients with oral malignancy is typically of advanced age with significant comorbidity. The causative factors for such malignancies, such as tobacco and alcohol, are also those which result in cardiovascular disease. As a result patients undergoing ablative and reconstructive surgery, with free tissue transfer, are at considerable risk of peri-operative morbidity and mortality from both primary and secondary disease. Free flap failure has a significant impact upon patient outcome, with resultant delayed discharge, and increased morbidity and mortality. By optimising co-morbidity and peri-operative factors such as fluid balance, nutrition, coagulation and blood pressure support, the complications of complex surgery are reduced. The collective objectives of this thesis were to determine methods, by both routine and novel approaches, to enhance patient care following ablative and reconstructive surgery for head and neck malignancy. As a result of these investigations, fluid optimisation with LiDCO monitoring, which derives stroke volume from the blood pressure waveform, is advocated in patients undergoing ablative and reconstructive surgery. Peri-operatively when blood pressure cannot be maintained with fluids alone and pressor support is required, low dose noradrenaline is considered the optimal agent in view of the improvements in flap perfusion and reliable elevation of mean arterial pressure. Careful anticoagulation prescribing should be undertaken, with anti-Xa monitoring of low molecular weight heparin to ensure adequate response, in combination with thromboelastography to identify patients most at risk of thrombotic flap complications. This thesis has made original contributions to the literature in the peri-operative management of patients undergoing free tissue transfer following ablative surgery for head and neck malignancy in terms of pressor support, coagulation, nutrition, fluid management and hospital admission route. Collectively these recommendations may improve patient outcome with significant long term benefits for both patients and the NHS

Management of bone defects with Bio-oss

Introduction: The defects in the alveolar bone might appear as a result of congenital malformations, traumatic injuries, periodontal disease, surgical traumas, chronic periapical changes and tumors from benign or malignant origin. The aim of this study was to provide solid and healthy area with application of Bio-Oss in the defect. Materials and methods: Based on the clinical diagnosisestablished by previously taken history, clinical examination and radiographic images oral-surgery interventions was made. To realize the aim of this work, augmentative material was implicated in the bone defects made in the patients after removal of follicular cyst, chronic periapical lesion, and parodontopathia. During the first and seventh day of the interventions, the patients have been followed through from aspect of possible development of local and general complications after the oral-surgery intervention. After period of one, three and six mount control x-ray was made. Results: Obtained results confirmed that: volume of the socket and defect of the bone was kept, fast revascularization was achieved, bone formation and slow resorption of the augmentative material was achieved, and period of normal healing without infection was also achieved. Conclusions: The augmentative materials used for treatment of bone defects besides their basic chemical and physical characteristics referring to their solubility in the body fluids, the transformation, modulation and resorption must be completely safe or secure, i.e. not to bring any risk of infection, immunological risk, physiological intolerance or inhibition of the process of restitutio ad integrum. In our study Bio-Oss was confirmed as augmentative material who had this characteristics. Keywords: bone defect, resorption of the bone, augmentative material, Bio-Os

A Textbook of Advanced Oral and Maxillofacial Surgery

The scope of OMF surgery has expanded; encompassing treatment of diseases, disorders, defects and injuries of the head, face, jaws and oral cavity. This internationally-recognized specialty is evolving with advancements in technology and instrumentation. Specialists of this discipline treat patients with impacted teeth, facial pain, misaligned jaws, facial trauma, oral cancer, cysts and tumors; they also perform facial cosmetic surgery and place dental implants. The contents of this volume essentially complements the volume 1; with chapters that cover both basic and advanced concepts on complex topics in oral and maxillofacial surgery