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Biomedical subjects

L Trevisiol

Publications and source records attributed to L Trevisiol.

8 recordsLinked to original sources

Mandibular distraction of the body and ramus.

With the ever increasing interest in the field of osteodistraction techniques, the mandible is certainly the most studied anatomical site, both experimentally and clinically. Currently, the methods of mandibular distraction can be classified by position (intra- or extraoral), by the direction of distraction and by the site of application (toothborn, boneborn or hybrid fixation). To guarantee good results from the osteodistraction procedure, it is fundamental to have an accurate preoperative plan considering the correct classification and evaluation of the patient combined with a valid project regarding the direction of the distraction vector. One of the most important aspects to consider is the orientation of the distractor, especially if the defect to be corrected is three-dimensional. Regarding the correct planning of the operation, knowing the secondary effects of the distraction on the soft tissues, muscles and nerves, the temporomandibular joint and velopharyngeal functioning is of fundamental importance. It is worth considering particular situations in which osteodistraction is extremely helpful in maxillofacial surgery, for example in the construction of a neocondyle, in bone replacement during oncologic interventions, in obstructive sleep apnea correction and in hemi-mandibular reconstruction.

Humans↗

p63 expression in odontogenic cysts.

A total of 123 cases of odontogenic cysts, distributed as follows: 30 follicular (FC), 35 radicular (RC), 53 keratocysts, 1 glandular odontogenic and 4 calcifying odontogenic cysts, were analysed by immunohistochemistry for expression of p63, a component of p53 protein family. In RCs p63 positivity was not only in basal and parabasal layers but also in the intermediate layer and about 1/3 of cases displayed a percentage of stained cells comprised between 0 and <5%, and about 2/3 between >5% and <50%. In FCs positivity was confined to basal and parabasal layers of the epithelium and in the majority of FCs the stained cells were comprised between 0 and <5%. OKCs displayed the most intense and diffuse p63 labeling. In conclusion, these data suggest that p63 expression may be useful to identify cysts type with more aggressive and invasive phenotype supporting the hypothesis of a suprabasal proliferative compartment in OKCs.

DNA-Binding Proteins↗

Maxillary post-traumatic outcome correction literature review and our experience. Part I: maxillary bone non-unions-"poor bone positioning".

Still today, there is no classification of non-unions in maxillofacial traumatology. There is a broad spectrum of definitions that simultaneously describe the pathological conditions and functional implications determined by the anatomical location of the fractures and the time factor. In this article the authors describe a literature review about bone non-union classification. Weber, in 1973, introduced the term "pseudo-arthrosis" to describe an altered process of bone healing characterised by the presence of fibrous tissue interposed between the fracture segments, that was lined with cartilaginous tissue and joined by a capsule; Spiessl, in 1988, used the term "non-union" to define any alteration of the bone healing process after a time period of more than 6 months from the initial traumatic event; Rosen, in 1990, proposed a new classification of the modes of altered bone healing in fractures, distinguishing 5 categories: delayed consolidation, non-union, non-union vascular, non union avascular, pseudoarthrosis. The authors also talk about "poor bone positioning". This factor describes the incorrect anatomical position of the bone fragments despite perfectly normal healing according to Gruss. In this article they also discuss about the treatment of non-unions and the treatment of occlusal alterations caused by poor post-traumatic bone positioning.

Bone Plates↗

Maxillary post-traumatic outcome correction. Literature review and personal experience. Part II: loss of maxillary substance (free grafts of autologous bone).

Loss of maxillary substance following trauma varies significantly in relation to the dimensions, site and type of tissue involved. Anatomical maxillary interruptions, loss of dental elements and consequent bone re-absorption give rise to altered chewing, swallowing and speech functions. Treatment of pathological conditions over the years has seen the development of surgical protocols designed to achieve simultaneous aesthetic and functional restoration of the stomatognatic apparatus. The advent of osteointegrated implantology and continual progress in pre-prosthesis surgical techniques have undoubtedly revolutionised established approaches to prosthetic rehabilitation by introducing the concept of supported implant prostheses. The implantation protocols used are a safe and reproducible treatment method suitable for adequate anchorage of such prosthetic implants; the application of such protocols in any case is subordinated to the presence of adequate morpho-volumetric bone at the skeletal bases. Depending on the entity of maxillary loss of substance, the reconstruction methods we propose, in agreement with numerous other authors, are based on the use of free and free-revascularised autologous bone grafts or, even more recently, the application of osteogenetic distraction techniques. The purpose of this article is to evaluate treatment of loss of maxillary substance following trauma by means of non-revascularised free flaps. The use of free grafts of autologous bone is elective in patients presenting bone deficits less than 6 cm with and/or without upkeep of maxillary and mandibular cortical bone continuity but without compromise to the integrity and trophism of the soft tissues.

Bone Transplantation↗

Eagle's syndrome secondary surgical treatment. Report of a case.

Eagle's Syndrome is reported to be the symptomatic calcification of the stylohyoid complex. Calcification of the stylohyoid ligament is a relatively common finding in the general population, however only a small percentage of these people presents symptoms. According to the kind of symptoms described by the patients it is possible to recognise two syndromes: the classic one, which occurs after a tonsillectomy, and stylo-carotid artery syndrome, which is independent from a tonsillectomy. The only effective treatment in symptomatic cases is the surgical shortening of the styloid process. The case presented underlines the problems due to the persistence of the calcified caudal portion of the stylohyoid ligament after a first surgical removal. A second surgical treatment is suggested for a complete resection of the calcified ligament which was causing the symptomatology complained by the patient. This patient had previously undergone surgical shortening of the stylohyoid ligament after he was diagnosed as having Eagle's Syndrome, of the styloid-carotid artery type. After a stylohyoidectomy, he still suffered from dysphagia, neck pain and scratching sensation when swallowing. Further surgical treatment was necessary, with the aim of removing the caudal portion of the ligament, which was causing the patient's symptoms. An extra-oral approach was used and, after surgery, the patient was completely relieved of the symptoms. Conventional and three-dimensional CT were performed after surgery, they showed the complete absence of the left calcified stylohyoid ligament.

Adult↗

Fractures of the iliac crest following anterior and posterior bone graft harvesting. Review of the literature and case presentation.

Iliac crest is the most commonly used extra-oral donor site of autologous non-vascularized bone, because of the great amount of bone available and easy access. Bone grafting from the ileum, however, is not without complications. An extensive review of the literature focusing on fractures of the iliac crest and pelvic ring instability due to anterior and posterior bone graft harvesting is reported, and 1 case of anterior stress fracture of the iliac crest is described. Thirty-five of the 37 fractures described up to date in literature were divided in 2 groups depending on the region of bone graft harvesting. Twenty-four fractures - including our case - were related to bone graft harvesting from the anterior region, 12 were due to harvesting from the posterior region. Four out of 24 anterior fractures required further surgical treatment (16.6%). In 8 of the 12 fractures with pelvic ring instability due to posterior bone harvesting, 1 or more additional surgical procedures were performed in order to stabilize multiple fracture sites (66.6%). Anterior iliac crest fractures, even though painful, remain stable and heal spontaneously in most cases without further complications. On the contrary, fractures due to posterior iliac crest harvestings very often require complex surgical treatments and lead to significant disability, which can be permanent.

Fractures, Bone↗

Scatter factor receptor (c-Met) as possible prognostic factor in patients with oral squamous cell carcinoma.

This report was performed to study the biological role of c-Met in oral tumorigenesis by analyzing its expression in relation to clinicopathological features. Seventy-three cases of oral squamous cell carcinoma and 10 of normal mucosa were analysed for c-Met expression by immunohistochemistry. Normal oral squamous epithelium showed absent or low membranous positivity in the intermediate (malpighian-spinous) layer. Fifty-seven cases (78%) of carcinoma showed immunopositivity, with a prevalently membranous positivity and scattered areas also showing a cytoplasmic localization. Sixteen cases of carcinoma (22%) showed no positivity for c-Met. Among positive tumours, well-differentiated areas showed low or absent cytoplasmic positivity, while low-differentiated areas showed both membranous and cytoplasmic positivity. There was no statistically significant correlation between c-Met expression and sex, recurrence, staging or grading. The frequency of lymph node metastases was higher in c-Met-positive tumours (17/57, 29%) than in c-Met-negative ones (4/16, 25%). When analysed for prognostic significance, patients with negative/reduced c-Met expression had better survival rates than patients with high expression. The difference between survival rates was statistically significant (p<0.05). These data suggest that c-Met expression may be useful to identify cases of oral squamous cell carcinoma with a more aggressive and invasive phenotype.

Adult↗

Maxillary post-traumatic outcome correction. Literature review and personal experience. Part III: loss of maxillary substance (free flaps-distraction osteogenesis).

Revascularised free flaps retain dual vascularisation, both periosteal and medullary, undoubtedly present optimal survival and minimal re-absorption in view of the prevalence of osteogenetic rather than osteoclastic phenomena. A revascularised free bone flap involves the transfer of a certain amount of bone tissue, whether or not associated with a muscular, skin and/or facial component, with the features of an axial flap, dissecting the vascular stalk of the donor site and re-anastomosing both the arterial and the venous components on to recipient vessels in the site of the primary defect. The vessels in question measure only about 2-4 mm, so that micro-surgery techniques must be applied. For bone defects less than 6 cm, with upkeep of the mandibular or maxillary cortical bone and preservation of the soft tissues, with residual bone of at least 8 mm in height and 4 mm in thickness, alveolar distraction may represent a valid alternative to bone grafts, at the same time as ensuring an increase of the alveolar bone and intraoral soft tissues involved in the distraction process.

Humans↗