Reconstruction after Resection of Undifferentiated Pleomorphic Sarcoma and Invasive Ductal Carcinoma in a Patient with Li-Fraumeni Syndrome.

This case exhibits a presentation of multiple primary malignancies in a patient with Li-Fraumeni syndrome, necessitating surgical excision and multistaged reconstruction. Due to Li-Fraumeni syndrome patients' predisposition to developing malignancies, management includes lifelong surveillance and aggressive treatment of cancers. Plastic surgeons can minimize damage to patient's quality of life by carrying out reconstruction in a thoughtful manner that maximizes function and considers a potential lifetime of future reconstructive needs.

Complications Following Tissue Expander-Based Reconstruction in Pediatric Burn Injuries: A Retrospective Analysis.

BACKGROUND: Tissue expansion has been widely used to reconstruct soft tissue defects following burn injuries in pediatric patients, allowing for satisfactory cosmetic and functional outcomes. Factors impacting the success of tissue expander (TE)-based reconstruction in these patients are poorly understood. Herein, we aim to determine the risk factors for postoperative complications following TE-based reconstruction in pediatric burn patients. METHODS: A retrospective review of pediatric patients who underwent TE placement for burn reconstruction from 2006 to 2019 was performed. Primary outcomes were major complications (TE explantation, extrusion, replacement, flap necrosis, unplanned reoperation, readmission) and wound complications (surgical site infection and wound dehiscence). Descriptive statistics were calculated. The association between primary outcomes, patient demographics, burn characteristics, and TE characteristics was assessed using the chi-squared, Fisher's exact, and Mann-Whitney U tests. RESULTS: Of 28 patients included in the study, the median [interquartile range (IQR)] age was 6.5 (3.3-11.8) years, with a follow-up of 12 (7-32) months. The majority were males [n = 20 (71%)], Black patients [n = 11 (39%)], and experienced burns due to flames [n = 78 (29%)]. Eleven (39%) patients experienced major complications, most commonly TE premature explantation [n = 6 (21%)]. Patients who experienced major complications, compared to those who did not, had a significantly greater median (IQR) % total body surface area (TBSA) [38 (27-52), 10 (5-19), P = 0.002] and number of TEs inserted [2 (2-3), 1 (1-2), P = 0.01]. Ten (36%) patients experienced wound complications, most commonly surgical site infection following TE placement [n = 6 (21%)]. Patients who experienced wound complications, compared to those who did not, had a significantly greater median (IQR) %TBSA [35 (18-45), 19 (13-24), P = 0.02]. CONCLUSION: Pediatric burn injuries involving greater than 30% TBSA and necessitating an increasing number of TEs were associated with worse postoperative complications following TE-based reconstruction.

Cervicofacial Pediatric Tissue Expansion: Aesthetic Unit-Based Algorithm.

BACKGROUND: Tissue expansion is a powerful tool for reconstruction of pediatric soft-tissue pathologies, but complication rates for children have been reported as high as 40%. Infection and implant extrusion lead to premature removal and delays in reconstruction. Expanding the head and neck is uniquely challenging because the confluence of facial aesthetic units must be respected. These challenges have prompted the senior author's creation of an aesthetic-unit based algorithm. METHODS: A retrospective study of pediatric patients who underwent cervicofacial tissue expander placement by the senior author (R.J.R) was performed over a 17-year period. Predictor variables included age, sex, race, indication, number of expanders placed at each operation, serial expansion, expander type, expander size, home versus clinic inflation, and prophylactic antibiotics. Univariate and multivariate analyses were performed to identify risk factors for complications. RESULTS: An aesthetic-unit based reconstructive algorithm is proposed. Forty-eight pediatric patients had 111 cervicofacial tissue expanders placed. Twenty expanders were associated with complications (18%) for surgical site-infection (12.6%), extrusion (4.5%), and expander deflation (6.3%). Expanders placed for congenital nevi (p=0.042) and use of textured expander (p=0.027) were significantly associated with decreased complications. When controlling for covariates, serial expansion of the same site was associated with increased rates of readmission (p=0.027) after having just one prior expander. Iatrogenic ectropion occurred in 13.5% of the study population; expanders with at least one complication during tissue expansion were significantly associated with incidence of iatrogenic ectropion (p=0.026). CONCLUSION: By using an aesthetic-unit based algorithm, reconstructive outcomes can be optimized for pediatric cervicofacial tissue expansion.

Morphology of Thin-Film Nafion on Carbon as an Analogue of Fuel Cell Catalyst Layers.

Species transport in thin-film Nafion heavily influences proton-exchange membrane (PEMFC) performance, particularly in low-platinum-loaded cells. Literature suggests that phase-segregated nanostructures in hydrated Nafion thin films can reduce species mobility and increase transport losses in cathode catalyst layers. However, these structures have primarily been observed at silicon-Nafion interfaces rather than at more relevant material (e.g., Pt and carbon black) interfaces. In this work, we use neutron reflectometry and X-ray photoelectron spectroscopy to investigate carbon-supported Nafion thin films. Measurements were taken in humidified environments for Nafion thin films (≈30-80 nm) on four different carbon substrates. Results show a variety of interfacial morphologies in carbon-supported Nafion. Differences in carbon samples' roughness, surface chemistry, and hydrophilicity suggest that thin-film Nafion phase segregation is impacted by multiple substrate characteristics. For instance, hydrophilic substrates with smooth surfaces correlate with a high likelihood of lamellar phase segregation parallel to the substrate. When present, the lamellar structures are less pronounced than those observed at silicon oxide interfaces. Local oscillations in water volume fraction for the lamellae were less severe, and the lamellae were thinner and were not observed when the water was removed, all in contrast to Nafion-silicon interfaces. For hydrophobic and rough samples, phase segregation was more isotropic rather than lamellar. Results suggest that Nafion in PEMFC catalyst layers is less influenced by the interface compared with thin films on silicon. Despite this, our results demonstrate that neutron reflectometry measurements of silicon-Nafion interfaces are valuable for PEMFC performance predictions, as water uptake in the majority Nafion layers (i.e., the uniformly hydrated region beyond the lamellar region) trends similarly with thickness, regardless of support material.

Cervical Necrotizing Fasciitis: A Severe Sequela of Open Mandibular Fracture and Delay in Treatment.

Cervical necrotizing fasciitis (CNF) is a rare condition in the United States, with very few cases reported as a sequela of mandibular fracture. The authors describe the case of a 40-year-old man with poor oral health and no significant past medical history who developed CNF following delayed treatment of an open mandibular fracture, leading to life-threatening septic shock, thrombophlebitis of the internal jugular vein, and septic emboli to the lungs. Successful management of this patient was accomplished by serial surgical debridement, the administration of broad-spectrum antibiotics, and hemodynamic support. Eventual reconstruction was performed with external fixation of the mandible fracture and split-thickness skin grafting for the left neck and chest wound. The authors recommend early treatment of open mandibular fractures for immunocompromised patients or patients with poor oral hygiene to avoid the rare but potentially fatal complication of CNF and highlight external fixation as a useful technique in select cases of complex mandibular fractures.

Surface to Perforator Index: Assessing the Importance of the Number of Perforators in Successful Harvesting of the Anterolateral Thigh Flap.

INTRODUCTION: The use of perforator flaps has become more popular with improvement of surgical technique, technology, as well as understanding of microvascular anatomy. The selection of well-perfused angiosomes is critical to the successful outcome of patients undergoing free tissue transfer. The number of perforators that are needed is dependent upon the surface area of the flap being harvested; however, there have been no studies to assess the optimal surface area supplied by each perforator. We hypothesized that the smaller the surface area supplied by each perforator correlated with fewer flap-related complications in the harvesting of the anterolateral thigh (ALT) flap. METHODS: All ALT flaps harvested from 2015 to 2021 at our institution were retrospectively reviewed. The surface area of the flap harvested was calculated as A = πab, where a is the long radius and b is the short radius of the ellipse. The surface-perforator index (SPI) was calculated for each flap by dividing the surface area of the ALT flap by the number of perforators supplying the flap. Our primary outcomes were flap-related complications that included: partial flap loss, dehiscence, and venous congestion. RESULTS: A total of 106 patients were identified. Twenty-four patients (22.6%) developed perforator-related complications. An increasing SPI and SPI to body surface area were strongly associated with development of complications (adjusted odds ratio [95% confidence interval], adjusted p: 1.02 [1.01, 1.03], < 0.001and 1.23 [1.12, 1.42], p < 0.001). An SPI of greater than 150 cm2/perforator was associated with a higher probability of complications (p < 0.001). CONCLUSION: Flap-related complications are significantly related to the number of perforators supplying the flap. The smaller the surface area supplied by a single perforator correlates with significantly fewer flap-related complications. SPI is a new index that may be used as a predictive tool to aid in identifying flaps that may be more prone to complications in free tissue transfer.

Evaluation of modified frailty index for predicting post-operative outcomes after lower-extremity free-flap reconstruction.

BACKGROUND: Risk stratification for complex procedures such as microsurgical reconstruction of the lower extremities is an important part of preoperative planning and counseling. The aim of this study was to determine the effectiveness of the modified five-item frailty index (5-mFI) score, a validated tool for assessing risk in surgical patients, in predicting postoperative complications after lower extremity (LE) free flap reconstruction. METHODS: A retrospective review of the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was conducted from 2010 to 2020 on patients who underwent LE free-flap reconstruction. 5-mFI scores were calculated and patients were categorized as 5-mFI ≥2 or <2. The primary endpoint was the presence of 30-day overall complications. The secondary endpoints included 30-day readmission, need for reoperation, and need to discharge to a care facility. Comparisons were made using one-way analysis of variances, Pearson's chi-squared test, or Fisher's extract test. Multivariable logistic regression models were performed for sex, age, BMI, smoker status, operative time, and ASA classification. RESULTS: Total of 294 (61.6% males) patients were identified. Univariate analysis showed 5-mFI ≥2 had higher rates of overall complications (p = .043) and hematologic complications (p = .033). In this population, there were also higher rates of reoperation (p = .003) and discharge to care facility (p < .001). Multivariable regression models further substantiated that 5-mFI ≥2 was independently associated with increased overall complications [2.46, CI: 1.10-5.59, p = .031], hematologic complications [2.55, 1.02-6.35, p = .046], reoperation [4.55, 1.54-13.3, p = .006], and discharge to facility [2.86, 1.27-6.45, p = .011]. CONCLUSIONS: There is a strong association of 5-mFI ≥2 with adverse post-operative outcomes in male patients undergoing LE free-flap reconstruction. This can be a valuable adjunct in the counsel of patients for whom lower extremity salvage is feasible.

Breast reconstruction: Review of current autologous and implant-based techniques and long-term oncologic outcome.

Implant-based reconstruction is the most common method of breast reconstruction. Autologous breast reconstruction is an indispensable option for breast reconstruction demanding keen microsurgical skills and robust anatomical understanding. The reconstructive choice is made by the patient after a discussion with the plastic surgeon covering all the available options. Advantages and disadvantages of each technique along with long-term oncologic outcome are reviewed.

Concentration Scaling on Linear Viscoelastic Properties of Cellular Suspensions and Effects of Equilibrium Phase Behavior.

Concentration scaling on linear viscoelastic properties of cellular suspensions has been studied by rheometric characterisation of Phormidium suspensions and human blood in a wide range of volume fraction under small amplitude oscillatory shear experiments. The rheometric characterisation results are analysed by the time-concentration superposition (TCS) principle and show a power law scaling of characteristic relaxation time, plateau modulus and the zero-shear viscosity over the concentration ranges studied. The results show that the concentration effect of Phormidium suspensions on their elasticity is much stronger than that of human blood due to its strong cellular interactions and a high aspect ratio. For human blood, no obvious phase transition could be observed over the range of hematocrits studied here and with respect to a high-frequency dynamic regime, only one concentration scaling exponent could be identified. For Phormidium suspensions with respect to a low-frequency dynamic regime, three concentration scaling exponents in the volume fraction Region I (0.36≤ϕ/ϕref≤0.46), Region II (0.59≤ϕ/ϕref≤2.89) and Region III (3.11≤ϕ/ϕref≤3.44) are identified. The image observation shows that the network formation of Phormidium suspensions occurs as the volume fraction is increased from Region I to Region II; the sol-gel transition takes place from Region II to Region III. In combination with analysis of other nanoscale suspensions and liquid crystalline polymer solutions reported in the literature, it is revealed that such a power law concentration scaling exponent depends on colloidal or molecular interactions mediated with solvent and is sensitive to the equilibrium phase behaviour of complex fluids. The TCS principle is an unambiguous tool to give a quantitative estimation.

Literature Review: Robotic-Assisted Harvest of Deep Inferior Epigastric Flap for Breast Reconstruction.

INTRODUCTION: Robotic-assisted surgery is gaining popularity because of reported improvement in aesthetic outcomes while reducing the occurrence of complications compared with conventional surgical methods. Deep inferior epigastric perforator (DIEP) flap harvesting has a long track record as a viable procedure for autologous reconstruction of the breast. In this literature review, we describe the feasibility of using the robotic platform in DIEP flap harvest. METHODS: The Preferred Reporting Items for Systemic Reviews and Meta-Analysis methodology was to guide the literature review. PubMed and Scopus databases were searched from inception to June 6, 2022. The Medical Subject Heading terms and keywords used to conduct this search are as described: "Robotic AND deep inferior epigastric perforator AND Breast reconstruction." RESULTS: Seven publications, detailing a total of 56 robotic-assisted DIEP flap harvest procedures, were selected for review. Four publications used the transabdominal preperitoneal approach, whereas 2 exclusively used a totally extraperitoneal approach, and 1 compared the 2 approaches. The measured outcomes included technical feasibility of flap harvest in cadavers, viable flap harvest in live patients, harvest time and pedicle dissection time, pedicle length, fascial incision length, donor site pain, need for postoperative narcotic, donor site morbidity, and hernia formation. Overall, the reviewed articles demonstrated successful DIEP flap harvesting without the need for conversion to the conventional open procedure. Postoperative complications were minimal. Robotic DIEP flap harvest was shown to be safe and there were no reports of donor-site morbidity in the studies reviewed. The main advantages of the robotic approach include decreased postoperative pain and length of hospital stay, along with improved aesthetic outcomes. The main disadvantages are increased operative time and cost. CONCLUSIONS: Although at its current iteration, the robotic-assisted DIEP flap is feasible, it may not be practical in all settings. Furthermore, the true benefit of the robotic platform is yet to be determined, as more long-term studies are necessary.

Multiscale characterization reveals oligomerization dependent phase separation of primer-independent RNA polymerase nsp8 from SARS-CoV-2.

RNA replication and transcription machinery is an important drug target for fighting against coronavirus. Non-structure protein nsp8 was proposed harboring primase activity. However, the RNA primer synthesis mechanism of nsp8 is still largely unknown. Here, we purified dimer and tetramer forms of SARS-CoV-2 nsp8. Combined with dynamic light scattering, small-angle neutron scattering and thermo-stability analysis, we found that both dimer and tetramer become loosened and destabilized with decreasing salt concentration, and the dimer form is more stable than the tetramer form. Further investigation showed that nsp8 dimer and tetramer can undergo phase separation but exhibit different phase separation behaviors. Nsp8 dimer can form liquid-like droplets in the buffer with a low concentration of NaCl; phase separation of nsp8 tetramer depends on the assistance of RNA. Our findings on different phase separation behaviors of nsp8 dimer and tetramer may provide insight into the functional studies of nsp8 in coronavirus.

Necrotizing Soft Tissue Infection of Abdominal Wall after Lipoabdominoplasty: Complication following Medical Tourism.

Necrotizing soft tissue infection (NSTI) is an acute life-threatening complication of cosmetic surgery. We present a case study of a 48-year-old woman diagnosed with NSTI of the abdominal wall following liposuction, abdominoplasty, and ventral hernia repair performed in Latin America. In the operating room, bowel perforation at the hepatic flexure was observed requiring emergent fascial debridement, bowel resection, and broad-spectrum antibiotics. She required multiple washouts and split-thickness skin grafts. Complications such as NSTI are possible after lipoabdominoplasty and are prevalent in cosmetic medical tourism, due, in part, to varying institutional standards and accreditations, and in some cases lack of consistent adherence to set standards. Complications after medical tourism contribute a significant burden to medical staff and the healthcare system in patients' home countries. Patient education by their surgeons and plastic surgery societies should be prioritized. It is important for domestic emergency physicians, plastic surgeons, and other care providers to understand complications postcosmetic surgery to promote timely management.

Perioperative Tissue Oximetry-driven Fluid Resuscitation Improves Flap Perfusion in Autologous Free Tissue Breast Reconstruction.

Introduction: The use of tissue oximetry for monitoring following free tissue transfer has become a common practice to facilitate early detection of poor flap perfusion. We hypothesized that T stat readings may guide fluid administration in the postoperative period and improve perfusion in patients undergoing autologous breast reconstruction. Methods: Patients undergoing free flap breast reconstruction from 2015 to 2018 were reviewed. Mean percutaneous oximetry readings of the first four postoperative days were recorded. The mean change at 24 hours from the original reading was calculated (∆TO). The study population was divided in two groups based on whether administration of intravenous fluids (IVFs) was increased/maintained (group 1) or decreased (group 2) after postoperative day 1. Results: A total of 120 patients were identified. The mean age was 53, and mean BMI was 33. Overall, patients for whom fluid administration was decreased experienced an increase in their tissue perfusion, while patient who received a bolus or maintained the same rate of IVF experienced a decrease. Patients who had a negative ∆TO experienced a statistically significant difference between groups 1 and 2 at 24 and 72 hours (-4 versus +3 and -11 versus +13, respectively). For patients with a positive ∆TO, although decreasing fluids resulted in higher readings, it did not reach statistical significance at 24 or 72 hours (0 versus +2 and +4 versus +6, respectively). Conclusions: In patients undergoing free tissue breast reconstruction, tissue oximetry readings may be used as a novel guide for postoperative fluid management.

Palmar Venous Malformation: A Case Report of a Rare Occurrence and a Treatment Algorithm.

Palmar venous malformations are not well described in the surgical literature and are a therapeutic challenge due to the intricate anatomy of the hand. We present the case of a 19-year-old right-handed female patient from Mexico who was referred to us with a right palmar lesion present since birth, previously diagnosed as a venous malformation. The patient reported that she had undergone sclerotherapy 10 years before in addition to a prior aborted attempt at excision. Venous palmar malformations are rare occurrences. Although an individualized approach is important, the development of an algorithm may assist in the standardization of the treatment of this pathology to preserve the hand's functional status.

Resolution of a Cystic Endodontic-Periodontal Lesion Utilizing Combined Apicoectomy and Guided Tissue Regeneration: A Case Report.

INTRODUCTION: Endodontic-periodontal combined lesions pose a treatment challenge for clinicians, especially when the lesion is persistent and does not show signs of healing after initial endodontic treatment. This case report describes interdisciplinary management of a non-healing combined endodontic-periodontal lesion related to a peri-apical cyst, through a combined approach of apicoectomy and guided tissue regeneration (GTR) with enamel matrix derivative (EMD). Most documented cases have been treated in a sequential manner, with minimal literature present on the effects of a combined approach utilizing EMD for the treatment of these lesions. CASE PRESENTATION: A 72-year-old male patient presented with an endodontic-periodontal lesion at tooth #31 initially treated with nonsurgical root canal therapy. The lesion was not responsive to initial endodontic treatment. The patient was informed of questionable prognosis, however wished to save the tooth. Tooth #31 was treated via a combination approach of apicoectomy with bioceramic putty retrograde filling, followed by GTR of the defect using allograft, EMD, and resorbable barrier membrane. The lesion was biopsied and diagnosed as a periapical cyst. Clinical and radiographic examination at 1 year showed resolution of lesion, reduction in probing depths, and good bone fill of the defect. CONCLUSION: Traditionally, endodontic-periodontal lesions, which were not responsive to initial therapy, would be given a questionable prognosis and be extracted. This case demonstrates that non-healing, peri-apical lesions may be cystic in nature and effectively managed utilizing a combined approach, with apicoectomy and GTR with EMD, to produce a stable outcome.

Full versus Baby Dose Aspirin for Antithrombotic Prophylaxis in Free Tissue Transfer: Does Size Matter?

The postoperative prophylactic use of aspirin is a common practice among plastic surgeons after free tissue transfer. The use of baby aspirin (81 mg) has become more popular due to previously published literature in other fields. We hypothesized that a full dose daily aspirin is nonsuperior to a baby dose daily aspirin in preventing arterial thrombosis in free tissue transfer. Methods: All patients undergoing free tissue transfer of the extremities from 2008 to 2020 were retrospectively reviewed. They were divided into two groups based on the postoperative dose of aspirin administered (full versus baby dose). The decision to administer full or baby dose was based on the surgeon's preference. Primary outcome was revision of the arterial anastomosis. Secondary outcomes included flap complications. Results: A total of 183 patients were identified. Out of those, 78 patients received full dose aspirin postoperatively, whereas 105 received a baby dose of aspirin. Patients who received baby aspirin did not have a higher incidence of returning to the operating room for revision of their arterial anastomosis [7.6% versus 7.7%; adjusted odds ratio, 0.93 (95% confidence interval, 0.28-3.11); adjusted P, 0.906]. No differences were found between the two groups in complete and partial flap loss, wound dehiscence, or infection. None of the patients experienced any aspirin-related gastrointestinal complications. Conclusions: In patients undergoing free tissue transfer, thrombosis of the arterial anastomosis is rare. Administration of a full dose of aspirin postoperatively was not superior to a baby dose of aspirin in preventing arterial-related complications.

Contemporary Management of Zygomaticomaxillary Complex Fractures.

Zygomaticomaxillary complex fracture is one of the most commonly treated facial fractures. Accurate reduction and stable fixation of the zygoma are required to restore facial symmetry and projection and avoid functional sequalae from changes in orbital volume. Achieving optimal outcome is challenging due to the complex three-dimensional anatomy and limited visualization of all affected articulations of the zygoma. This article provides an updated overview of the evaluation and management of zygomaticomaxillary complex fractures based on available evidence and clinical experience at our center. The importance of soft tissue management is emphasized, and approaches to internal orbital reconstruction are discussed. While evidence remain limited, intraoperative imaging and navigation may prove to be useful adjuncts in the treatment of zygomaticomaxillary fractures.

The Efficacy of Schwann-Like Differentiated Muscle-Derived Stem Cells in Treating Rodent Upper Extremity Peripheral Nerve Injury.

BACKGROUND: There is a pressing need to identify alternative mesenchymal stem cell sources for Schwann cell cellular replacement therapy, to improve peripheral nerve regeneration. This study assessed the efficacy of Schwann cell-like cells (induced muscle-derived stem cells) differentiated from muscle-derived stem cells (MDSCs) in augmenting nerve regeneration and improving muscle function after nerve trauma. METHODS: The Schwann cell-like nature of induced MDSCs was characterized in vitro using immunofluorescence, flow cytometry, microarray, and reverse-transcription polymerase chain reaction. In vivo, four groups (n = 5 per group) of rats with median nerve injuries were examined: group 1 animals were treated with intraneural phosphate-buffered saline after cold and crush axonotmesis (negative control); group 2 animals were no-injury controls; group 3 animals were treated with intraneural green fluorescent protein-positive MDSCs; and group 4 animals were treated with green fluorescent protein-positive induced MDSCs. All animals underwent weekly upper extremity functional testing. Rats were euthanized 5 weeks after treatment. The median nerve and extrinsic finger flexors were harvested for nerve histomorphometry, myelination, muscle weight, and atrophy analyses. RESULTS: In vitro, induced MDSCs recapitulated native Schwann cell gene expression patterns and up-regulated pathways involved in neuronal growth/signaling. In vivo, green fluorescent protein-positive induced MDSCs remained stably transformed 5 weeks after injection. Induced MDSC therapy decreased muscle atrophy after median nerve injury (p = 0.0143). Induced MDSC- and MDSC-treated animals demonstrated greater functional muscle recovery when compared to untreated controls (hand grip after induced MDSC treatment: group 1, 0.91 N; group 4, 3.38 N); p < 0.0001) at 5 weeks after treatment. This may demonstrate the potential beneficial effects of MDSC therapy, regardless of differentiation stage. CONCLUSION: Both MDSCs and induced MDSCs decrease denervation muscle atrophy and improve subsequent functional outcomes after upper extremity nerve trauma in rodents.

Solvent-Assisted Fractionation of Oligomeric Cellulose and Reversible Transformation of Cellulose II and IV.

Oligomeric cellulose with an average degree of polymerization of 7.68 and a polydispersity of 1.04 has been fractionated using solution processes. Three fractions have been obtained through initial dissolution, subsequent crystallization, and solvent precipitation, respectively. The resulting oligocellulose fraction has an average degree of polymerization of 7.70 and a polydispersity of 1.01, respectively. Cellulose IV2 crystals form in the oligocellulose fraction, and reversibly transform to II and back to IV using simple solvents.

The additive effect of clonidine to lidocaine on postoperative pain management after root canal treatment on mandibular molars with symptomatic irreversible pulpitis: A prospective randomised double-blind clinical trial.

CONTEXT: Postoperative pain control has been a common challenge to clinicians in endodontics. AIMS: This double-blind randomized clinical trial assessed the efficacy of clonidine added to lidocaine for postoperative pain following endodontic treatment of mandibular molars with symptomatic irreversible pulpitis (SIP). METHODS: One hundred participants with lower molars experiencing SIP were recruited and randomly assigned to two groups. 1.8 mL of 2% lidocaine with either epinephrine (1:80,000) or clonidine (15 µg/mL) was administered to each group via an inferior alveolar nerve block. A Heft-Parker Visual Analog Scale was used to rate preoperative pain and at 6, 12, 24, 36, 48, and 72 h following endodontic treatment. Their postoperative analgesic consumption was recorded. STATISTICAL ANALYSIS USED: The analgesic efficacy was analyzed by Chi-square test, paired t-test, and repeated measures ANOVA (P < 0.05). RESULTS: Early postoperative pain was significantly lower in the lidocaine/clonidine group than the lidocaine/epinephrine group (6 h: P = 0.038; 12 h: P = 0.031). The lidocaine/clonidine group consumed a significantly lower amount of analgesics (P = 0.048). CONCLUSIONS: The administration of clonidine added to lidocaine may reduce early postoperative pain and consumption of analgesics following endodontic treatment in lower molars with SIP.