COMBINED TEMPOROPARIETAL FASCIA AND THIN SILICON SHEET AS INTERPOSTIONAL ARTHROPLASTY FOR THE MANAGEMENT OF TMJ ANKYLOSIS- AN EXPERIENCE BASED ON SINGLE INSTITUTIONAL STUDY

Introduction: Temporomandibular joint ankylosis is a debilitating condition leading to problems in mastication, speech, digestion, oral hygiene and even facial appearance. The basic techniques for surgical correction of ankylosis include the gap arthroplasty, joint reconstruction or interpositional arthroplasty. The treatment of TMJ ankylosis poses a significant challenge because of technical difficulties and a high incidence of recurrence. Material and Methods: 21 patients of temporomandibular joint ankylosis admitted from 2015 to 2018 in the Department of Plastic Surgery, SMS Hospital, Jaipur. . Diagnosis was based on history and clinical assessment supplemented with orthopantomogram (OPG) and computer tomographic scans. Mouth opening is measured as interincisoral distance using a scale. Intraoperatively, silicon sheet is sutured with the distal part of flap using non absorbable suture in half overlapped fashion with an overlapped portion across the joint space. Preoperative photograph is taken in all patients and serial post operative photograph were taken during their regular follow up Results: 21 patients were part of the study (14 males and 7 females). 16 of our patients were post traumatic. Their age ranged from 7 to 55 years. The disease was unilateral in 19 cases and bilateral in 2 cases. The pre-op interincisal mouth opening ranged from 0 to 9 mm. The intra-operative interincisal mouth opening ranged from 28 to 46 mm. There was no immediate complication and no incidence of facial nerve injury. One patient with bilateral congenital TMJ ankylosis had recurrence. Five patients were lost after the initial 1-year follow-up. Conclusion: Use of combined temporoparietal fascia with thin silicon sheet as interpositional arthroplasty provides extra protection in cases of TMJ ankylosis and thereby decreasing the incidence of its recurrence Keyword: Ankylosis, TMJ, Interpositional arthroplasty

Evaluation of the extent of damage to the esophageal wall caused by press-through package ingestion

Press-through package (PTP) is the most common accidentally ingested foreign body in Japan. Accidental ingestion of PTP can result in esophageal damage. An approach for evaluating the risk of esophageal injury has not been established. Therefore, we used porcine esophageal tissue and silicone sheets to establish a method for assessing the risk of esophageal damage on accidental PTP ingestion. We pathologically evaluated porcine lower esophageal tissue using a scratch tester. Using porcine esophageal tissue, scratch tests were performed with 4 test objects and pathological damage was compared. It was assumed that each object was accidentally ingested. The objects were polyvinylidene chloride (PVDC)-coated polyvinyl chloride (PVC) PTP, soft PThPa, round PTP, and a disposable scalpel. The porcine esophagus was replaced with a silicon sheet, and an automatic friction machine was used for quantitative evaluation. The silicon sheet was scratched using HHS 2000 with 750-g load at 50 mm/min. We investigated the frictional force exerted on the surface for each of the objects. The degree of damage (depth) was the highest for the disposable scalpel, followed by PVDC-coated PVC PTP, while the degree of damage (depth) was the lowest for soft PThPa and round PTP. The mean frictional forces on the silicon sheet were 524.0 gf with PVDC-coated PTP, 323.5 gf with soft PThPa, 288.7 gf with round PTP, and 922.7 gf with the disposable scalpel. We developed approaches to qualitatively and quantitatively evaluate the risk of esophageal damage after accidental PTP ingestion. Our findings indicate that the risk of gastrointestinal damage after accidental PTP ingestion is low with soft PTP and round PTP.

Comparison of subdermal and perforator delay techniques on a rat flap model

ABSTRACT Background: In this study, we investigated the subdermal and perforator delay phenomena as a method to improve flap survival. Materials and Methods: In this experimental study, we used 24 rats in three groups. In the control group, the dorsal flaps were elevated and reinserted back to their place. In the experimental groups, we practiced the delay phenomena with two different techniques. In the first experimental group, cranial and lateral side incisions were performed; however, the flaps were not cut-off from the underlying fascia. In the second experimental group, we placed a silicon sheet under the planned flap to cut-off the circulation from the perforator vessels. Four weeks after the delay procedure, the flaps were raised completely and reinserted back to their place. Results: The average of necrotic area in the control group was 21.9% (±7.70). There was no necrosis in both experimental groups (P < 0.0001). Histological examination revealed that collagen density in both of the experimental groups was increased in comparison to the control group, it has only been found a significant first experimental group (P = 0.0315). We have not found any significant difference in lymphocyte density between the groups. Angiographic imaging has showed an increase in the vascular density in the flaps of the first experimental group. Conclusion: We believe that both of these delay techniques can be adapted to clinical applications and used safely to increase flap survival.

Silicon Steel Sheet Vibration Model Based on the Magnetostrictive Properties

Magnetostriction of transformer core plays a dominated role in the vibration of transformer equipment. In order to simulation the magnetostrictive effect, a equivalent magnetostrictive force model is introduced in this paper. Elongation-based models are used to deduce the magnetostrive force. Elongation-based models employ experimental data from magnestrictive elongation to bulid the relation between magnestrictive strain and magnetic flux density, and can be used for harmonic analysis. Magnetostrictive force on single slicion sheet is deduced by strain energy density and energy conservation principle. The force is applied on the single silicon sheet model to analysis the deformation caused by magnetostriction.

Effect of Fe on the Microstructure and the Thermal Storage Performances of High-Silicon Aluminum Alloy

The influence of Fe on microstructure and the expansion coefficient and thermal conductivity of Al-30 wt.% Si alloy was studied. Results show that the primary silicon morphology and size changed significantly after joining the Fe, by angular blocky primary silicon sheet or plate into small pieces and then into a polygonal large lump, edge and angle are passivated. As the content of Fe is 0.3 wt.%, material expansion coefficient and high thermal conductivity. Later, with the increase of the content of Fe, alloy point defect and line defect, surface defect and large area defect increase, the thermal conductivity of materials and inflation performance declined. When the content of Fe is 0.1 wt.%, materials with high thermal conductivity and low thermal expansion coefficient, the heat storage performance impact is minimal.