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Different reconstruction techniques of the anterior and middle skull base as consequence of a defect after surgical treatment of neoplastic pathologies are described in the literature. The aim of the present study is to present our experience regarding the use of microvascular free flaps for reconstruction of the anterior or middle skull base after large defects caused by removal of malignant neoplasms. From 2000 to 2004, in the Department of Maxillo-Facial Surgery of the University of Rome "La Sapienza" and "Tor Vergata," 13 surgical procedures for reconstruction of anterior and middle skull base defects by free flaps were performed in 11 patients. Data on patient demographics, histopathology, location and size of defect, type of reconstruction, and postoperative complications were obtained from medical record charts. A safe soft tissue closure of the intracranial space was achieved in all patients. Defect repair was accomplished by revascularized transfer of rectus abdominis flaps in seven cases, latissimus dorsi muscle flaps in two patients, radial forearm flap in one case, and fibula flap in one case. There were two total flap losses; the secondary defect repair was accomplished in both cases by revascularized transfer of latissimus dorsi muscle flap. No donor site complications were observed in all the flaps. The mean operation time was 85 hours; patients were hospitalized for a mean period of 14 days. The method of choice for the reconstruction of anterior or middle skull base defect should be based upon careful evaluation of the single case and, particularly, the localization and entity of the residual defect. For defects that require large amounts of soft tissue, the latissimus dorsi free flap and the rectus abdominis free flap are the best appropriate choices for reconstructive procedures for anterior and middle skull base tumors.

Hemangiopericytoma is a rare vascular tumor featuring the uncontrolled proliferation of pericytes. This tumor tends to develop in subcutaneous tissue and skeletal muscle. The localization of hemangiopericytoma in the orbit is particularly rare. Clinical signs and symptoms are, in order of frequency, proptosis, perception of an intraorbital mass, pain, diplopia, reduction of visus, tumescence, and ecchymoses of the eyelids. Hemangiopericytomas have higher potential of relapse, local invasiveness, and the possibility of producing distant metastases. Surgery must be as radical as possible to avoid incomplete tumor resection and high frequency of relapse together with increased duration of the disease and a higher risk of malignant development. The current report is a study of two cases of hemangiopericytoma in the orbital cavity treated at the Unit of Maxillo-Facial Surgery of the University of "La Sapienza" in Rome. The present data demonstrate that complete en bloc excision of the mass with its capsule is important to avoid the risk of relapse. To this end, an appropriate first surgical treatment should be chosen so as to obtain a wide "surgical light" and complete view of the mass. In the reported cases, the use of a combined anterolateral approach was preferred to attack the tumor from different sides. Indeed, such an approach allows one to obtain optimal exposition of the orbital region and temporal and infratemporal fossae contemporaneously.

Internal carotid artery (ICA) reparative techniques are nowadays widely standardized in traumatic as well as degenerative pathological conditions; therefore, the greatest difficulty encountered in the treatment of lesions at the expense of the most distal segment of the ICA is not a result of the application of these techniques as much as the difficulty in obtaining adequate exposure of the vessel and a sufficiently wide surgical field. In the past, lesions localized more toward the skull were considered to be surgically unreachable. During the last 20 years, however, various techniques have been suggested and attempted for the exposure of this difficult area. This article suggests a type of approach already carried out by the Department of Maxillofacial Surgery of the University of Rome "La Sapienza" in collaboration with the II Department of Vascular Surgery of the same university, which offers the advantage of being of simple and rapid execution with minimum repercussions on the intrasurgical time required and guarantees an excellent exposure of the most distal tract of the ICA with an adequate widening of the surgical field.

Background: Comparison of renal osteodystrophy in predialysis and hemodialysis has been rarely reported. Distinct patterns of renal osteodystrophy could be found in these conditions. In addition the use of parathyroid hormone (PTH) and other markers for noninvasive diagnosis may result in different predictive values in predialysis and hemodialysis patients., Methods: 79 consecutive patients with conservative chronic renal failure and 107 patients on hemodialysis were studied. All patients were subjected to bone biopsy for histological and histomorphometric evaluation. The patients had no exposure to aluminium before dialysis and relatively low exposure while on hemodialysis., Results: In the predialysis patients, bone biopsies showed 9 cases of adynamic bone disease (ABD) and 8 cases of osteomalacia (OM), 50 patients with mixed osteodystrophy and 2 cases of hyperparathyroidism. Among the hemodialysis patients 12 cases had ABD, 3 cases OM, 30 mixed osteodystrophy, and 61 patients hyperparathyroidism. In the predialysis patients with chronic renal failure, bone aluminium was on average 4.5 mg/kg dry weight, while in dialysis patients the average value was 35.4 mg/kg dry weight. Discriminant analysis of low turnover osteodystrophy (ABD and OM) by intact PTH showed higher accuracy in dialysis than in predialysis patients. Correlation studies of intact PTH versus bone formation rate, osteoblast surface/bone surface and osteoclast surface/bone surface showed significantly steeper slopes in dialysis than in predialysis patients, which indicates that bone resistance to PTH is more marked in predialysis patients., Conclusions: The prevalence of ABD and OM in the geographic area investigated is lower than in other reports. Aluminium exposure does not seem to be the cause of low turnover osteodystrophy in the present population. The predictive value of intact PTH in the noninvasive diagnosis of renal bone disease is higher in hemodialysis patients than in predialysis patients. Predialysis chronic renal failure, when compared to the dialysis stage, seems to be characterized by resistance of bone tissue to PTH., (Copyright 2002 S. Karger AG, Basel)

The prognosis for maxillary malignancies with posterior extension to the pterygo-maxillary and infratemporal fossae is worse than for those with anterior-inferior extrinsication. Maxillectomy using only an anterior approach does not enable enblock, radical resection of such tumors. Many different approaches to the infratemporal fossae have been described in the literature. The authors use a double infratemporal and transfacial approach. Between 1990 and 1998 this approach was used on 65 patients with malignant maxillary tumors. There was one post-operative death due to myocardial infarction. There were only 9 cases of temporal infection, and all were resolved. There were no cases of necrosis of either the temporal muscle or the revascularized flaps. The cases included the following tumors: spinocellular and anaplastic carcinoma (21 cases); adenoid-cystic carcinoma (16); adenocarcinoma (4); sarcoma (18); other malignant tumors (6). There were 29 primary tumors while the remaining 36 were recurrences from prior treatment. Using the UICC-AICC 1987-92 staging system there were 22 cases of T3 and 43 T4. Using the 1997 system there were 35 T3s and 30 T4s. Resection was radical in 54 cases while in the remaining 11 there were micro or macroscopic limitations at the rhinopharyngeal level and/or at the orbit apex. The NED survival percentages were: T3 59.2%; T4 28% (using the 1987-92 system) while they were T3 45.7% and T4 26.7% (using the 1997 system). In the 41 patients with carcinoma (spinocellular, anaplastic, adeno and adenoid-cystic) the NED survival percentages were: T3 54.5%; T4 23.4% (using the 1987-92 system) while they were T3 45% and T4 19% (using the 1997 system). The NED survival percentage was 41.4% for primary tumors and 36.1% for recurrences. These results lead one to conclude that this surgical technique permits good results with T3-T4 maxillary malignancies. The prognosis for recurrences is worse than for primary tumors and the prognosis for sarcoma is better than for carcinoma. The UICC-AICC staging systems are valid for prognostic purposes. The current analyses indicate that the 1987-92 system is slightly more suitable than the 1997 system. In fact, there were 13 patients which the 1987-92 system had classified as T4 and which the 1997 system had reclassified as T3. In all these cases the prognosis was more similar to that of T4 than T3.

The authors analyze the functions of the synovial membrane and the chemical-physical properties of synovial fluid. In particular they evaluate the role played by synovial fluid in the complex mechanism of the temporomandibular joint. Every single part that belongs to the temporomandibular joint, together with the stomatognathic apparatus, plays a specific and particular role according to the dynamics and to the preservation of the correct temporomandibular joint physiology. The physiological postural and functional relationship between the various parts of the temporomandibular joint is guaranteed by a number of biomechanical restrictions that lead and influence the regular execution of the articular movements. The most involved biomechanical restrictions in the temporomandibular joint are the temporomandibular ligament, the lateral disc ligament, the bilaminar zone or retrodiscal tissue, the synovial membrane, and the synovial fluid.

The temporo-mandibular-joint is a highly particular and complex anatomical entity in terms of both its structure and functions, which include the opening, closing, protrusion and lateral movement of the jaw. On the base of some papers previously published on the anatomy and physiology of the Temporo-Mandibular-Joint, the Authors have studied the functional dynamics of the TMJ. The correct postural and functional relationships between the various components of the joint are controlled by a series of biomechanical restrictions that guide and condition its movements. The role of biomechanical restriction played by such articular components, influences decidedly the therapeutical treatment aimed to the resolution of the Temporo-Mandibular joint pathology. In this article, the authors examine and analyze the role of the Temporo-Mandibular ligament, Disk Lateral Ligament, Articular disk, Retrodiskal Zone and of the Synovial Fluid in the functional dynamics of the Temporo-Mandibular-Joint.

The time-course of damage and repair in the bronchial epithelium of the mouse was studied morphometrically after a single inhalation of trichloroethylene (TCE). Mice were exposed for 30 min to 500, 1000, 2000, 3500, or 7000 ppm of TCE under controlled conditions and sacrificed after 2 and 24 h, and 2, 5, and 7 days. At all TCE concentrations, the damage consisted of dilation of endoplasmic reticulum and was selective for nonciliated cells throughout the bronchial tree. Damage was quantitatively evaluated by counting the percentage of vacuolated cells. Injury was maximal 24 h after exposure and was significantly (p less than 0.05) higher in bronchi with a diameter smaller than 0.4 mm (67.0% +/- 8.5%) in comparison with larger bronchi (34.0% +/- 13.2%). Cell turnover was studied by autoradiography after [3H]thymidine injection. Following TCE inhalation, the percentage of [3H]thymidine labeled cells, which in the controls was virtually zero, increased to a maximum of 13.5% +/- 6.8% (average at all doses) 48 h after treatment and then rapidly decreased to baseline values at 7 days (0.2% +/- 0.1%). Repair of some cells occurred after 24 h, and at 48 h the percentage of vacuolated cells decreased and became significantly related (p less than 0.01) to the administered TCE dose (2.4% +/- 1.4% and 21.2% +/- 6.0% average in the 500 and 7000 ppm groups, respectively). Repair of bronchial epithelium took place by both recovery of less damaged cells and proliferation of residual nonciliated cells, leading to restoration of the normal ratio between ciliated and nonciliated cells.