Constitutive model of viscoelastic dynamic damage for the material of gas obturator in modular-charge howitzer

In order to investigate the mechanical response behavior of the gas obturator of the breech mechanism,made of polychloroprene rubber(PCR), uniaxial compression experiments were carried out by using a universal testing machine and a split Hopkinson pressure bar(SHPB), obtaining stress-strain responses at different temperatures and strain rates. The results revealed that, in comparison to other polymers, the gas obturator material exhibited inconspicuous strain softening and hardening effects;meanwhile, the mechanical response was more affected by the strain rate than by temperature. Subsequently, a succinct viscoelastic damage constitutive model was developed based on the ZWT model, including ten undetermined parameters, formulated with incorporating three parallel components to capture the viscoelastic response at high strain rate and further enhanced by integrating a three-parameter Weibull function to describe the damage. Compared to the ZWT model, the modified model could effectively describe the mechanical response behavior of the gas obturator material at high strain rates. This research laid a theoretical foundation for further investigation into the influence of chamber sealing issues on artillery firing.

Obstructive Tumor of the Palate in the Old Person: A Case Report

Introduction: Pleomorphic adenoma or mixed salivary gland tumor is a heterogeneous benign tumor of the salivary glands. The most common site is the parotid gland. Its extra-parotid locations, particularly in the accessory salivary glands, are rarer. We report a case of a pleomorphic adenoma of the posterior palate which posed management problems. Observation: This is an 85-year-old patient who consulted for a tumor of the posterior palate that had been evolving for 3 years. The examination revealed a globular tumor of the posterior palate extending beyond the midline by approximately 7 cm in long axis, shooting towards the oropharynx and hindering breathing, speech and eating, indicating a life-saving tracheotomy. A CT scan of the facial area revealed a well-circumscribed tumor at the expense of the soft palate, with multiple sites of bone lysis. The biopsy performed was in favor of a pleomorphic adenoma. The patient underwent total surgical excision of a huge tumor on the palate. The aftermath of the operation was marked by a loosening of the sutures with an oronasal fistula requiring the creation of an obturator plate due to the patient’s refusal to have another operation. Conclusion: Large pleomorphic adenoma of the posterior palate is a rare entity that can cause respiratory problems and surgical difficulties. His prognosis is generally good.

Root Canal Treatment Outcome and Restorative Condition of Teeth Treated by Undergraduates—A Clinical and Radiographic Evaluation

Background: The aim was to evaluate the nonsurgical Root Canal Treatment (nRCT) outcome, the restorative condition and the relationship between the coronal restoration quality and the outcome of teeth endodontic treated by undergraduates at the University of Caxias do Sul School of Dentistry (UCS-SD), Brazil, between 2019 and 2021. Materials and Methods: Data from the endodontically treated cases were retrieved, and the patients were recalled for a follow-up appointment at the university. The endodontic diagnosis, radiographs, and the presence of definitive restorations were analyzed in the clinical records. During the follow-up appointment, endodontically treated teeth were classified as present or absent. The nRCT was classified as successful (complete or incomplete healing) or failure (uncertain or unsatisfactory healing). Coronal restoration was classified as absent or present. When it was present, it was classified as permanent or temporary, and its quality as adequate or inadequate restoration. The results were presented as percentages. Results: A total of 257 teeth were endodontically treated. The most prevalent diagnosis was Chronic Apical Periodontitis (33.33%) and the most commonly treated teeth were premolars (46.15%). A total of 52 (21%) treated teeth were clinically and radiographically reexamined. The success rate for the nRCT was 98.08%. About 61.54% of this sample had a definitive composite resin restoration. Conclusion: The nRCT success rate was high. Special attention should be given to the presence and quality of the definitive restoration. Clinical Implications: There was no statistically significant impact between the coronal restoration and the nRCT success (P > 0.05).

Is There Any Relationship between Total Hip Arthroplasty and Urinary Incontinent?

Introduction: In my daily practice as a hip surgeon, I have observed some circumstances where urinary incontinence (UI) improves after total hip arthroplasty (THA). We investigated UI symptoms before and after THA at our facility and considered the factors that influence UI. Patients and Method: The subjects were 113 female patients who underwent primary THA in our facility. An anterior lateral approach was used in all cases. Using the International Consultation on Incontinence Questionnaire-Short Form (ICIQ-SF), we conducted an investigation into the presence of UI before and 2 weeks after THA. An improvement in UI was defined as a decrease of 1 point or more, a worsening is defined as an increase of 1 point or more. Results: The responses from the 113 subjects were analyzed. Of the 113 patients, prior to THA, UI was prevalent among 59 patients and was absent among 54 patients. In the group where UI was prevalent, it improved after THA in 50 patients (85%), remained unchanged in 5 (8%) and worsened in 4 (7%). In the group where UI was absent, 49 patients (91%) remained unchanged and UI appeared in 5 (9%). Compared with the non-prevalence group (62 patients), the prevalence group (50 patients) had a noticeable improvement rate of internal rotation of the surgical hip side (P Conclusion: UI greatly reduces the quality of life (QOL). In this study, there is a possibility that THA improves UI.

Comparison of modified percutaneous transhepatic variceal embolization and endoscopic cyanoacrylate injection for gastric variceal rebleeding

AIM:To compare the efficacy of modified percutaneous transhepatic variceal embolization(PTVE)with 2-octyl-cyanoacrylate(2-OCA)and endoscopic variceal obturation(EVO)with an injection of 2-OCA for prophylaxis of gastric variceal rebleeding. METHODS:In this retrospective study,the medical records of liver cirrhosis patients with gastric variceal bleeding who underwent either endoscopic 2-OCA(EVO) or modified PTVE using 2-OCA at Shandong Provincial Hospital from January 2006 to December 2008 were reviewed.Patient demographics,rebleeding rate,survival rate,and complications were compared between the two groups(PTVE and EVO).All results were expressed as mean±SD,or as a percentage.Quantitative variables were compared by two sample Student t tests, and qualitative variables were compared by the Fisher exact test or theχ 2 test(with Yates correction)where appropriate.A P value less than 0.05 was considered significant.Statistical computation was performed using SPSS 13.0 software. RESULTS:A total of 77 patients were included;45 patients who underwent EVO and 32 patients who received PTVE.During the follow-up(19.78±7.70 mo in the EVO group,vs 21.53±8.56 mo in the PTVE group) rebleeding occurred in 17 patients in the EVO group and in 4 patients in the PTVE group(37.78%vs 12.5%, P=0.028).The cumulative rebleeding-free rate was 75%,59%,and 49%in 1,2,and 3 years respectively for EVO,and 93%,84%,and 84%for PTVE(P=0.011). Cox analysis was used to identify independent factors that predicted rebleeding after treatment.Variables including age,gender,cause,Child-Pugh classification, size of gastric varices(GV),location of GV,and treatment methods were analyzed.It was revealed that Child-Pugh classification[risk ratio(RR)2.10,95%CI:1.03-4.28,P=0.040],choice of treatment(RR 0.25, 95%CI:0.08-0.80,P=0.019),and size of GV(RR 2.14, 95%CI:1.07-4.28,P=0.032)were the independent factors for predicting rebleeding.Follow-up computed tomography revealed that cyanoacrylate was retained in the varices and in the feeding veins of PTVE patients. During the follow-up,eight patients in the EVO group and four patients in the PTVE group died.The cumulative survival rates at 1,2,and 3 years were 93%,84%, and 67%respectively in the EVO group,and 97%, 88%,and 74%respectively in the PTVE group.The survival rates were not significantly different between the two groups(P=0.432).Cox analysis showed that the Child-Pugh classification was the most significant prognostic factor of survival(RR 2.77,95%CI:1.12-6.80,P=0.027).The incidence of complications was similar in both groups. CONCLUSION:With extensive and permanent obliteration of gastric varices and its feeding veins,PTVE with 2-OCA is superior to endoscopic 2-OCA injection for preventing gastric variceal rebleeding.

Proton pump inhibitor administration delays rebleeding after endoscopic gastric variceal obturation

AIM: To clarify the efficacy of proton pump inhibitors (PPIs) after endoscopic variceal obturation (EVO) with N-butyl-2-cyanoacrylate.

Procedure-related complications in gastric variceal obturation with tissue glue

AIM To focus on procedure-related complications,evaluate their incidence,analyze the reasons and discuss the solutions.METHODS Overall,628 endoscopic gastric variceal obturation(EGVO) procedures(case-times) with NBC were performed in 519 patients in the Department of Endoscopy of the Third Affiliated Hospital of Sun Yat-Sen University from January 2011 to December 2016. The clinical data of patients and procedure-related complications of EGVO were retrospectively analyzed.RESULTS In the 628 EGVO procedures,sticking of the needle to the varix occurred in 9 cases(1.43%),including 1 case that used lipiodol-diluted NBC and 8 cases that used undiluted NBC(P = 0.000). The needle was successfully withdrawn in 8 cases. Large spurt bleeding occurred in one case,and hemostasis was achieved by two other injections of undiluted glue. The injection catheter became blocked in 17 cases(2.71%) just during the injection,and 4 cases were complicated with the needle sticking to the varix. Large glue adhesion to the endoscope resulted in difficulty withdrawing the endoscope in 1 case. Bleeding from multiple sites was observed in the esophagus and gastric cardia after the endoscope was withdrawn. Hemostasis was achieved by 1% aethoxysklerol injection and intravenous somatostatin. The ligation device stuck to the varices in two cases during the subsequent endoscopic variceal ligation. In one case,the ligation device was successfully separated from the esophageal varix after all bands were released. In another case,a laceration of the vein and massive bleeding were observed. The bleeding ceased after 1% aethoxysklerol injection.CONCLUSION Although EGVO with tissue glue is usually safe and effective,a series of complications can occur during the procedure that may puzzle endoscopists. There is no standard operating procedure for addressing these complications. The cases described in the current study can provide some reference for others.

Crucial anatomy and technical cues for laparoscopic transabdominal preperitoneal repair: Advanced manipulation for groin hernias in adults

Groin hernias include indirect inguinal, direct inguinal, and femoral hernias. Obturator and supravesical hernias appear very close to the groin. High-quality repairs are required for groin hernias. The concept of "tension-free repair" is generally accepted, and surgical repairs with mesh are categorized as "hernioplasties". Surgeons should have good knowledge of the relevant anatomy. Physicians generally focus on the preperitoneal space, myopectineal orifice, topographic nerves, and regional vessels. Currently, laparoscopic surgery has therapeutic potential in the surgical setting for hernioplasty, with laparoscopic transabdominal preperitoneal(TAPP) repair appearing to be a powerful tool for use in adult hernia patients. TAPP offers the advantages of accurate diagnoses, repair of bilateral and recurrent hernias, less postoperative pain, early recovery allowing work and activities, tension-free repair of the preperitoneal(posterior) space, ability to cover obturator hernias, and avoidance of potential injury to the spermatic cord. The disadvantages of TAPP are the need for general anesthesia, adhering to a learning curve, higher cost, unexpected complications related to abdominal organs, adhesion to the mesh, unexpected injuries to vessels, prolonged operative time, and as-yet-unknown long-term outcomes. Both technical skill and anatomical familiarity are important for safe, reliable surgery. With increasing awareness of the importance of anatomy during TAPP repair, we address the skills and pitfalls during laparoscopic TAPP repair in adult patients using illustrations and schemas. We also address debatable points on this subject.

Ileum perforation due to delayed operation in obturator hernia:A case report and review of literatures

A 83-year-old woman was admitted to our hospital because of intermittent abdominal colicky pain and vomiting for 26 h.The pain localized over the periumbilical area with radiation along the medial side of the thigh.Computed tomography scan with three-dimensional reconstruction revealed a loop of small bowel protruding into the left obturator canal. Incarcerated obturator hernia was diagnosed and emergency laparotomy was arranged immediately. Unfortunately,her family refused surgery because of her worsening condition.On the third evening after admission,the patient developed peritonitis and sepsis. Perforation of small bowel due to the incarceration was noted during laparotomy.Bowel resection and an endileostomy were performed.She recovered well despite of the complication of multiple organ dysfunction syndrome.Literature is reviewed,and the pathogenesis,clinical manifestation,imaging features and treatment are discussed.

Total intravenous general anesthesia with laryngeal mask airway for transurethral resection of bladder tumor

Objective： To observe the advantage of total intravenous anesthesia for transurethral resection of bladder tumor （TURBT）. Methods.. Sixty ASA Ⅰ-Ⅱ patients undergoing TURBT were randomly assigned to 2 groups. Spinal anesthesia with 0. 75% pure bupivacaine （8-12 rag） was applied to patients in Group Ⅰ （n= 30）. Patients in Group Ⅱ （n=30） received total intravenous anesthesia with continuous infusion of Propofol and Remifentanil ; and a laryngeal mask was used to ensure the airway and ventilation. BP, HR, SPO2 and pertinent side effects were monitored and recorded. Results ： The patients in group Ⅱ experienced more stable hemodynamics than those in group Ⅰ . Obturator nerve reflex was observed in 15 （50. 0%） patients in Group Ⅰ , but none （0%） in Group Ⅱ （P〈0. 01）. Conclusion.. Total intravenous anesthesia with laryngeal mask is a safe, reliable, controllable and simple manual for patient undergoing TURBT.

Conservative endodontic management using a calcium silicate bioceramic sealer for delayed root fracture:A case report and review of the literature

BACKGROUND The success rate of conservative endodontic management for root fracture varies greatly based on different methods used.It has been rarely reported that calcium silicate-based materials are applied in root fracture treatment.CASE SUMMARY A 38-year-old male patient presented with spontaneous pain from the upper left anterior teeth for 1 wk.The spontaneous pain was subsequently relieved,but pain on mastication persisted for 3 d.The patient had a dental trauma from a boxing match 15 years ago.Cone beam computed tomography showed that the maxillary left central incisor had oblique fracture lines and a radiolucent lesion around the fracture line.The tooth was diagnosed with an oblique root fracture with no healing and symptomatic apical periodontitis.In the following conservative endodontic management,the coronal and apical fragments of the canal both were chemo-mechanically prepared and obturated using a single cone gutta-percha with iRoot SP(Innovative BioCreamix Inc,Vancouver,Canada),a new calcium silicate-based bioceramic root canal sealer.At follow-ups at 1,6,12,and 24 mo,the patient was asymptomatic and the radiolucency around the fracture line was healing radiographically.CONCLUSION Conservative root canal treatment is an alternative treatment in some cases of oblique root fracture with no healing.The application of bioceramic sealers and single core obturation techniques may also be essential to obtain an excellent outcome.

Finite element analysis of stress distribution of obturator prostheses for acquired unilateral maxillary defects

Objective To assess stresses produced by different obturator prostheses. Methods Three-dimensional finite clement models of unilateral maxillary defects rehabilitated with different obturators were constructed. The different stresses were analyzed by three-dimensional finite element method under different load angle. Results The Von Mises stress values obtained for the remaining tissues adjacent to defect cavity were higher when rehabilitated by inferior hollow obturator in comparison with by superior hollow obturator. The maximum of Von Mises were higher when rehabilitated by resilient hollow obturator than by rigid hollow obturator. It was also observed that in the rigid type stress distribution contours formed in the remaining tissues adjacent to defect cavity, while in resilient hollow obturator prostheses the stress distributed mainly in the prosthesis itself. The oblique load shows the most maximum of Von Mises among all types of obturator prostheses. Conclusions A high lateral wall of an obturator may be more better in preserving the remaining structures than a shorter prosthesis lateral wall. A soft liner may be incorporated to reduce the pain of the residual maxillary structures and mucosa. When load on defect, higher stress would be generated to the residual maxillary structures. The adjustment of occlusual relationship is very important.

Bacterial entombment by intratubular mineralization following orthograde mineral trioxide aggregate obturation: a scanning electron microscopy study

The time domain entombment of bacteria by intratubular mineralization following orthograde canal obturation with mineral trioxide aggregate（MTA） was studied by scanning electron microscopy（SEM）. Single-rooted human premolars（n560） were instrumented to an apical size #50/0.06 using ProF ile and treated as follows： Group 1（n510） was filled with phosphate buffered saline（PBS）; Group 2（n510） was incubated with Enterococcus faecalis for 3 weeks, and then filled with PBS; Group 3（n520） was obturated orthograde with a paste of OrthoM TA（BioM TA, Seoul, Korea） and PBS; and Group 4（n520） was incubated with E. faecalis for 3 weeks and then obturated with OrthoM TA–PBS paste. Following their treatments, the coronal openings were sealed with PBS-soaked cotton and intermediate restorative material（IRM）, and the roots were then stored in PBS for 1, 2, 4, 8 or 16 weeks. After each incubation period, the roots were split and their dentin/MTA interfaces examined in both longitudinal and horizontal directions by SEM. There appeared to be an increase in intratubular mineralization over time in the OrthoM TA-filled roots（Groups 3 and 4）. Furthermore, there was a gradual entombment of bacteria within the dentinal tubules in the E. faecalis inoculated MTA-filled roots（Group 4）. Therefore, the orthograde obturation of root canals with OrthoM TA mixed with PBS may create a favorable environment for bacterial entombment by intratubular mineralization.

Inflatable hollow obturator prostheses for patients undergoing an extensive maxillectomy:a case report

The presence of a large palatal or maxillary defect after partial or total maxillectomy for tumor, trauma or congenital deformation poses a challenge to prosthodontists, particularly when the use of an implant cannot be considered. This case report described the use of an air valve in a hollow silicone obturator to manufacture an inflatable obturator that could be extended further into undercut area to retain itself. The inflatable obturator exhibited adequate retention, stability and border sealing, thereby improving the masticatory, pronunciation and swallowing functions of patients. It may be a suitable alternative treatment option to an implant-retained obturator.

Obturator nerve impingement caused by an osteophyte in the sacroiliac joint:A case report

BACKGROUND Cases of obturator nerve impingement(ONI)caused by osteophytes resulting from bone hyperplasia on the sacroiliac articular surface have never been reported.This paper presents such a case in a patient in whom severe lower limb pain was caused by osteophyte compression of the sacroiliac joint on the obturator nerve.CASE SUMMARY A 65-year-old Asian man presented with severe pain and numbness in his left lower limb,which became aggravated during walking and showed intermittent claudication.The physical examination revealed that the muscle strength of the left lower limb had decreased and that the passive knee flexion test result was positive.Computed tomography(CT)and 3D reconstruction showed a large osteophyte located in the anterior lower part of the left sacroiliac joint.The results of electrophysiological examination showed peripheral neuropathy.A CT-guided obturator nerve block significantly reduced the severity of pain in this patient.According to the above findings,ONI caused by the osteophyte in the sacroiliac joint was diagnosed.This patient underwent an operation to remove the bone spur and symptomatic treatment.After therapy,the patient's pain and numbness were significantly relieved.The last follow-up was performed 6 mo after the operation,and the patient recovered well without other complications,returned to work,and resumed his normal lifestyle.CONCLUSION Osteophytes of the sacroiliac joint can cause ONI,which leads to symptoms including severe radiative pain in the lower limb in patients.The diagnosis and differentiation of this disease should attract the attention of clinicians.Surgical excision of osteophytes should be considered when conservative treatment is not effective.

Quantitative scintigraphic analysis of the apical seal in Thermafil/Topseal and Real Seal 1/Realseal filled root canals

AIM: To investigate the microleakage of two different root canal obturation systems, using the nuclear medicine approach.METHODS: Twenty-six single-rooted extracted teeth were selected. The crowns were sectioned to obtain 15-mm long root segments and each tooth was prepared using rotary Pro File instruments. The roots were divided into 2 experimental groups using Real Seal 1 and Real Seal sealer or Thermafil and Top Seal sealer as well as two control groups. On the 7th and the 28 th day the apices were submersed in a solution of 99 m TcPertechnetate during 3 h. The radioactivity was counted using a γ camera. RESULTS: The present study showed that none of the root canal-filled teeth was leakage free. The statistical analyses were made using Kruskal-Wallis and statistical significance was assessed using α = 0.05. Although apical leakage measured in counts per minute(cpm) in the Thermafil/Top Seal group was lower than in the Real Seal/Real Seal group(363 916 ± 180 707.7 cpm vs533 427 ± 414 020.6 cpm) on 7th day and(1 678 200 ± 567 217.4 cpm vs 2 240 518 ± 383 356.7 cpm) on 28 th day, there was no statistical difference(P > 0.05). In the Thermafil/Top Seal group and Real Seal 1/Real Seal group it was found that over time, the number of counts increased between 7 d and 28 d(363 916 ± 180 707.7 cpm vs 1 678 200 ± 567 217.4 cpm) and(533 427 ± 414 020.6 cpm vs 2 240 518 ± 383 356.7 cpm), respectively, with statistically significant differences(Thermafil/Top Seal group, P = 0.015 and Real Seal 1/Real Seal group, P = 0.036).CONCLUSION:Both carrier-based Realseal 1 and Thermafil techniques showed a similar sealing effect,but none of the materials was leakage free.

Comparison of the apical seal on filled root canals with Topseal^®vs MTA Fillapex^®sealers: A quantitative scintigraphic analysis

This study investigated the microleakage of two different root canal obturation systems, using the nuclear medicine approach, with sodium pertechnetate 99mTc. Twenty six single-rooted extracted teeth were selected. The crowns were sectioned to obtain15 mmlong root segments and each tooth was prepared using rotary ProFile? instruments. The roots were divided into 2 experimental groups and two control groups. Twenty root canals were filled, using Thermafil? and Topseal? or MTA Fillapex? as a sealer. On the 7th and the 28th day the apices were submersed in a solution of 99mTc-Pertechnetate during 3 hours. The radioactivity was counted using a gamma camera. Although apical leakage on the 7th day in the Topseal group was reduced compared with RealSeal1, with a statistical significant difference (p = 0.057), on the 28th day, the MTA Fillapex increased the sealing properties (p = 0.017).

Combined Sciatic, Femoral, and Obturator Nerve Blocks for Ankle Surgery in a Patient with Severe Pulmonary Hypertension—A Case Report

We report a patient with severe pulmonary arterial hypertension (PAH) undergoing tibio-talo-calcaneal fusion due to Charcot joint. Despite the advancement in the management of PAH, the risks of anesthesia, surgery, and postoperative morbidity and mortality still remain high. A 46-year-old female was presented with severe PAH and end stage renal disease requiring hemodialysis three times a week. Ultrasound-guided sciatic, femoral, and obturator nerve blocks were performed with 0.5% levobupivacaine 15 ml, 10 ml, and 5 ml, respectively. All the blocks were successful, and the patient underwent uneventful anesthesia and surgery. In addition, the postoperative pain control lasted for 15 h and the patient was discharged on POD 5 without any complications. Therefore, ultrasound-guided sciatic, femoral, and obturator nerve blocks are valuable alternative to the general or neuraxial anesthesia in patients with severe pulmonary hypertension.

Obturator hernia-a rare etiology of lateral thigh pain:A case report

BACKGROUND Lateral thigh pain is a common complaint in patients visiting a pain clinic.Herein,we describe the case of a patient with lateral thigh pain caused by an obturator hernia.CASE SUMMARY An 83-year-old woman visited the emergency room with suddenly aggravated right lateral thigh pain.Magnetic resonance imaging of the thigh revealed no abnormal findings in the lateral thigh area.However,an obturator hernia between the pectineus and obturator externus muscles was observed by chance.Retroperitoneal computed tomography revealed a herniated small bowel with an incarceration point at the right obturator canal and a dilated loop of the small bowel upstream.Ultrasonography of the right inguinal region revealed a distended bowel loop in the right pectineus muscle.CONCLUSION Our report provides clinicians with information that an obturator hernia can cause lateral thigh pain.

Old unreduced obturator dislocation of the hip:A case report

Obturator dislocation is a rare type of hip dislocation,accounting for about 2%-5%of all hip dislocations.The occurrence of old unreduced obturator dislocation is even more infrequent,with only 17 cases reported in nine studies,most of which were from the 1950s to 1980s in developing countries.CASE SUMMARY A 38-year-old woman from Hunan Province,China presented with stiffness of the left hip in abduction,flexion,and external rotation after falling from a 2-meter-tall tree onto her left knee 1.5 mo prior.Pelvic radiograph and computed tomography revealed obturator dislocation of the left hip accompanied by impaction fracture at the superolateral aspect of the left femoral head without associated acetabulum fracture.Open reduction was performed,resulting in restoration of the concentric alignment of the left hip.After surgery,6-wk skin traction was applied and the patient was kept in bed for an additional 2 wk.At 3 mo after surgery,the patient reported experiencing some pain,which did not affect the function of the affected limb,and some movement restriction but no abduction deformity or claudication was present.An X-ray showed that the left hip was homocentric,and there was no sign of posttraumatic arthritis or avascular necrosis.CONCLUSION Open reduction may be an effective treatment strategy for the rare condition of old unreduced obturator dislocation with short neglect time.