Faculty Bibliography

OBJECTIVES/OBJECTIVE:To evaluate and compare the outcomes of shear (S) and microtensile (μT) bond strength tests of CAD/CAM fiber-reinforced composite (FRC) to dentin. Aging with either fatigue or thermocycling were conducted for comparison with baseline microtensile group. METHODS:CAD/CAM FRC (Trinia, Bicon LLC, Boston, USA) blocks were milled to 3-mm diameter cylinders for shear and to blocks (5×5×5mm) for μT. Sixty extracted human molars were flattened to obtain dentin surfaces and randomly divided in four groups (n=15): (1) SC: samples tested in shear 24h after bonding; (2) μTC: samples tested in μT 24h after bonding); (3) μTF: samples submitted to mechanical fatigue prior to μT test, and; (4) μTT: thermocycling prior to μT test. Bonding system was applied onto the FRC material (Cera-Resin Bond, CRB, Shofu Dental, Kyoto, Japan). A conventional three-step adhesive system (All-bond 3, Bisco, Schaumburg, USA) was use with a self-cure resin cement (C&B resin cement, Bisco, Schaumburg, USA). Bond strength tests were conducted at 0.75mm/min and data analyzed using Weibull distribution (p<0.05). RESULTS:Weibull contour plots showed a significantly lower characteristic strength (η) and Weibull modulus (m) for SC (η=6.9MPa and m=1.4) compared to μTC (η=20.9MPa and m=4.5). Fatigued and thermocycled μT groups presented significantly reduced characteristic strength (η=3.1MPa and η=4.1MPa, respectively) compared to μTC. Weibull modulus was significantly reduced only for SC and μTF groups compared μTC. Failure predominantly occurred at the cement/FRC interface. SIGNIFICANCE/CONCLUSIONS:FRC bonded to dentin samples presented lower Weibull modulus and characteristic bond strength when immediately tested in shear compared to microtensile. Aging through thermocycling or mechanical fatigue significantly reduced the characteristic strength in microtensile testing, with the majority of failures emerging between restoration material and cement interface.

Technical success has been achieved in several forms of vascularized composite allotransplantation, including hand, face, penis, and lower extremity. However, the risks of lifelong immunosuppression have limited these procedures to a select group of patients for whom nontransplant alternatives have resulted in unsatisfactory outcomes. Recent reports of facial allograft failure, and subsequent reconstruction using autologous tissues, have reinforced the idea that a surgical contingency plan must be in place in case this devastating complication occurs. Interestingly, backup plans in the setting of vascularized composite allotransplantation consist of the nontransplant alternatives that were deemed suboptimal in the first place. Moreover, these options may have been exhausted before transplantation, and may therefore be limited in the case of allograft loss or reamputation. In this article, the authors describe the surgical and nonsurgical alternatives to hand, face, penis, and lower extremity transplantation. In addition, the authors explore the ethical implications of approaching vascularized composite allotransplantation as a "last resort" or as a "high-risk, improved-outcome" procedure, focusing on whether nontransplant options eventually preclude vascularized composite allotransplantation, or whether vascularized composite allotransplantation limits future nontransplant reconstruction.

Radiation therapy is an effective treatment strategy for many types of cancer but is limited by its side effects on normal tissues, particularly the skin, where persistent and progressive fibrotic changes occur and can impair wound healing. In this study, we attempted to mitigate the effects of irradiation on skin using a novel transcutaneous topical delivery system to locally inhibit p53 upregulated modulator of apoptosis (PUMA) gene expression with small interfering RNA (siRNA). In an isolated skin irradiation model, the dorsal skin of C57 wild-type mice was irradiated. Prior to irradiation, PUMA and nonsense siRNA were applied via a novel hydrogel formulation to dorsal skin and reapplied weekly. Skin was harvested at multiple time points to evaluate dermal siRNA penetration, mRNA expression, protein expression, dermal thickness, subcutaneous fat, stiffness, vascular hypertrophy, SCAR index, and reactive oxygen species (ROS) generation. Murine skin treated with topical PUMA siRNA via optimized hydrogel formulation demonstrated effective PUMA inhibition in irradiated tissue at 3-4 days. Tissue stiffness, dermal thickness, vascular hypertrophy, SCAR index, ROS levels, and mRNA levels of MnSOD and TGF-β were all significantly reduced with siPUMA treatment compared to nonsense controls. Subcutaneous fat area was significantly increased, and levels of SMAD3 and Phospho-SMAD3 expression were unchanged. These results show that PUMA expression can be effectively silenced in vivo using a novel hydrogel lipoplex topical delivery system. Moreover, cutaneous PUMA inhibition mitigates radiation induced changes in tissue character, restoring a near-normal phenotype independent of SMAD3 signaling.

PURPOSE/OBJECTIVE:Limited cross-institutional studies compare strip craniectomy versus cranial vault remodeling (CVR) for craniosynostosis management. Given competing surgical preferences, the authors conducted a large-scale analysis of socioeconomic differences, costs, and complications between treatment options. METHODS:Nonsyndromic craniosynostosis patients receiving strip craniectomies or CVR were identified in the Kids' Inpatient Database for years 2000 to 2009. Demographics, socioeconomic background, hospital characteristics, charge, and outcomes were tabulated. Univariate and multivariate analyses were performed for comparison. RESULTS:Two hundred fifty-one strip craniectomies and 1811 CVR patients were captured. Significantly more strip craniectomy patients were White while more CVR patients were Hispanic or Black (P < 0.0001). Strip craniectomy patients more often had private insurance and CVR patients had Medicaid (P < 0.0001). Over time, CVR trended toward treating a higher proportion of Hispanic and Medicaid patients (P = 0.036). Peri-operative charges associated with CVR were $27,962 more than strip craniectomies, and $11,001 after controlling for patient payer, income, bedsize, and length of stay (P < 0.0001). Strip craniectomies were performed more frequently in the West and Midwest, while CVR were more common in the South (P = 0.001). Length of stay was not significant. Postsurgical complications were largely equivocal; CVR was associated with increased accidental puncture (P = 0.025) and serum transfusion (P = 0.002). CONCLUSION/CONCLUSIONS:Our national longitudinal comparison demonstrates widening socioeconomic disparities between strip craniectomy and CVR patients. Cranial vault remodeling is more commonly performed in underrepresented minorities and patients with Medicaid, while strip craniectomy is common in the White population and patients with private insurance. While hospital charges and complications were higher among CVR, differences were smaller than expected.

Background/UNASSIGNED:In Crouzon's syndrome, cranial base deformities begin sequentially in the anterior cranial fossa initially, and later to the posterior cranial base. Facial characteristics are likely related to cranial base development. The temporal correlation between cranial base development and facial features is in need of clarification in Crouzon's patients, to clarify initial sites of deformity, which may impact surgical decision making. Methods/UNASSIGNED:Thirty-six computed tomography scans of unoperated Crouzon's syndrome patients and 54 controls were included and divided into 5 age-subgroups. All the planes used for analysis were set as perpendicular to a defined "midplane" to offset the confounding factor caused by potential asymmetry. Results/UNASSIGNED:= 0.007) with a peak timeframe from 2 to 18 years. Facial lateral curvature related measurements indicate the whole face is inclined posteriorly and inferiorly direction in relation to the anterior cranial base. Conclusion/UNASSIGNED:Crouzon's facial malformation development is synchronous and positionally correlational with cranial base deformity. It transmitted from orbit to mandible, with the most evident morphologic changes are in the orbit and midface.

Promising aesthetic and functional outcomes in facial transplantation have fueled the interest of patients and providers alike. However, there are currently only 11 active face transplant centers in the United States, and only five have accumulated operative experience to date, resulting in an extremely unbalanced geographical distribution of providers. Since face transplant recipients must receive life-long follow-up, this presents unique challenges for face transplant candidates and provider teams, as long-distance travel may add considerable difficulty to pre- and post-transplant care. Furthermore, by compromising follow-up, this burden of travel may impact the ability of experienced face transplant centers to collect data, share knowledge as these patients are followed, and continue to advance the field. This article highlights the unique logistical and ethical implications of the highly probable long-distance nature of face transplant care in the United States, a challenging aspect of management that has not been previously discussed in the literature. Furthermore, we review current strategies in the long-distance management of solid organ transplantation (SOT) recipients, and propose several possibilities to help address these challenges in facial transplantation based on SOT experience.

GENERAL PURPOSE/UNASSIGNED:To provide information about the pathophysiology, diagnosis, and treatment options for systemic sclerosis. TARGET AUDIENCE/BACKGROUND:This continuing education activity is intended for physicians, physician assistants, nurse practitioners, and nurses with an interest in skin and wound care. LEARNING OBJECTIVES/OUTCOMES/UNASSIGNED:After participating in this educational activity, the participant should be better able to:1. Describe the pathophysiology, signs, symptoms, and diagnosis of systemic sclerosis.2. Outline the evidence-based medical and surgical management of systemic sclerosis. ABSTRACT/UNASSIGNED:OBJECTIVE:: To perform a targeted review of systemic sclerosis, including epidemiology, pathophysiology, diagnosis, signs and symptoms, and medical and surgical management of upper extremity manifestations. DATA SOURCES AND STUDY SELECTION/METHODS:An electronic literature review was conducted using PubMed for all publication dates through October 2017. Searches were performed using combinations of terms including "systemic sclerosis," "scleroderma," "management," "upper extremity," "hypercalcinosis," "Raynaud's phenomenon," "sympathectomy," and "digital ulcers." Only full-length articles written in English that discussed the management of upper extremity scleroderma were used. DATA EXTRACTION AND SYNTHESIS/METHODS:The epidemiology, pathophysiology, diagnosis, upper extremity manifestations, and medical and surgical management of systemic sclerosis were reviewed. The case described in this article reports the utility of microsurgical interventions in the treatment of medically refractory upper extremity systemic sclerosis. CONCLUSIONS:Systemic sclerosis is a rare rheumatologic disease that greatly impacts quality of life. Medical management is the mainstay of treatment, propelling an improvement in the dismal 10-year cumulative survival rate from 54% in the 1970s to 66% in the 1990s. However, the pathophysiology of this disease is still poorly understood, and when medical management fails and the disease inevitably progresses, surgical approaches are critical.

PURPOSE/OBJECTIVE:To evaluate Ti-Base abutment height and cement type on the retentiveness of zirconia-based restorations. MATERIAL AND METHODS/METHODS:Four millimeter (tall) and 2.5-mm-height (short) abutments along with temporary (provisional), glass ionomer (Meron), self-adhesive (U200), and conventional resin cement (Ultimate) were evaluated using pull-out testing (n = 10 crowns/group). RESULTS:Tall and short abutments demonstrated similar retention for all within cement comparisons, except U200 (P = 0.032). Resin cements exhibited superior retentiveness than others (P < 0.01). Although no significant difference was evidenced between resin cements for short abutments, Ultimate evidenced higher retention than U200 for tall abutments (P = 0.043). CONCLUSIONS:Although Ti-Base abutment height has not influenced zirconia superstructures' retentiveness, resin-based cements significantly evidenced higher retention than glass ionomer and temporary cements.