Search

Summary:. The angular branch of the thoracodorsal artery and the periosteal branches of the circumflex scapular artery can be easily injured while harvesting a chimeric scapular flap. Thus, we reported the use of 3D printed scapular models using CT angiography to prepare inexpensive surgical guides from autoclavable dental silicone impressions for scapular flap harvest. Mandibular and scapular models were prepared using a 3D printer for 11 patients undergoing chimeric scapular flap transfer following mandibular resection. During preoperative simulation surgery, we molded dental silicone accordingly with scapular models to produce surgical cutting guides. Six men (54.5%) and five women (45.5%) were included. The average age of patients was 65.4 years. Fourteen bone units were reconstructed as three patients needed two bone segments (27.3%) whereas eight patients required reconstruction of one bone segment (72.7%). The mean flap harvest time and total surgical time were 52.1 min and 633.8 min, respectively. The mean duration for osteotomies and bone plate fixation was 26.2 min. The difference between the length of the preoperative surgical model (64.92 mm) and the postoperative 3D-CT measurements (64.48 mm) was not statistically significant (0.95 mm, P = 0.397). No injuries were caused to the angular and periosteal vessels. Four patients exhibited donor-site seroma (36.4%). The cost of the dental silicone for surgical guide was only $5 per patient. Dental silicone-based surgical guides help minimize the risk of vascular injury while harvesting chimeric scapular flaps. The osteotomies were performed with precision and in a time-efficient manner.

High-speed winding of paper web sometimes leads the winding system into unstable states, interlayer slippage of wound roll, paper breakage and so on, due to the excessive air-entrainment at the roll-inlet of nip contact region. These phenomena are more frequently observed on coated paper or plastic film comparing with newspaper, because the former allows little permeation of air and their surface roughness is small. Therefore, it is of vital importance to clarify the in-roll stress of wound roll considering the effect of air-entrainment. Generally, it is known that the amount of air-entrainment is affected by grooving shape of nip roll surface. In this paper, we focused on the grooving shape and investigated the relationship with the air-entrainment into two rolls being pressed each other and the grooving shape in order to achieve stable winding at high speed. We conducted experiments using small sized test machine. Entrained air-film thickness was evaluated applying the solution of the elasto-hydrodynamic lubrication for foil bearing with the consideration of nip profile at the grooved area. Air film thickness was measured to ensure the applicability of the above theory. Consequently, we found that the air film thickness can be estimated considering the effect of grooves on the nip roll surface, and that the validity of the above estimations was ensured from experimental investigations. Furthermore, it became to be able to propose the optimal shape of grooves on nip roll surface to maintain the stable winding at high speed and at large-diameter in reel.

Angiosarcoma is a rare malignant tumor of endothelial origin. It is an aggressive neoplasm with early metastasis and poor prognosis and accounts for approximately 2% of all soft tissue sarcomas. Primary tumors arising in the oral cavity account for only 1% of all angiosarcomas. Here, we report a rare case of metastatic angiosarcoma of the gingiva originating from a primary mediastinal lesion. The patient was an 83-year-old man who presented with a maxillary interincisor tumor; it was a painless mass with rounded superficial necrosis measuring 23 mm× 17 mm on the labial side and 20 mm× 17 mm on the palatal side. The histopathological diagnosis was of an epithelioid angiosarcoma. Imaging revealed lesions in the mediastinum, lungs, liver, and skin. The primary lesion was considered a mediastinal lesion. As the tumor had spread throughout the body, palliative therapy was administered. However, the patient's general condition deteriorated rapidly, and he died 3 weeks after the first visit. Identifying oral metastatic malignancies may result in detection of malignant tumors at other sites; thus, oral and maxillofacial surgeons must maintain a heightened awareness of angiosarcoma. [ABSTRACT FROM AUTHOR]

Abstract  High-speed transportation of paper web sometimes leads the web handling system into unstable state because of increase in the air-entrainment into the gap between a rotating roll and moving web or the nip region of winding system. In this paper, the property of the traction change with increase in the air-entrainment into the gap between a paper roll and web or the nip region of winding system was investigated experimentally and theoretically. The critical speed to avoid slippage between a roll and web was found to be estimable by applying and extending the concept of “effective” frictional coefficient with the consideration of air-entrainment, which is proposed by Good et al. (Proceedings of the fourth international conference on web handling, 1997), Hashimoto (Proc JSME 1999(5):183–184, 1999a) and so on, to the estimation of the traction force defined as the frictional force on a paper roll or at the nip region. Consequently, the web handling stability at high-speed was found to be predictable. [ABSTRACT FROM AUTHOR]