Faculty Bibliography

OBJECTIVE:(ZTA Zpex) compared to a translucent zirconia (Zpex) and Alumina. METHODS:Disc-shaped specimens were obtained by uniaxial and isostatic pressing the synthesized powders (n = 70/material). After sintering and polishing, half of the specimens underwent aging (20 h, 134 °C, 2.2 bar). Crystalline content and microstructure were evaluated using X-ray diffraction and scanning electron microscopy, respectively. Specimens underwent biaxial flexural strength testing to determine the characteristic stress, Weibull modulus, and reliability. Translucency parameter (TP) and Contrast ratio (CR) were calculated to characterize optical properties. RESULTS:ZTA Zpex demonstrated a compact surface with a uniform dispersion of zirconia particles within the alumina matrix, and typical alumina and zirconia crystalline content. ZTA Zpex and alumina exhibited higher CR and lower TP than Zpex. ZTA Zpex and Zpex showed significantly higher characteristic stress relative to alumina. While aging did not affect optical and mechanical properties of ZTA Zpex and alumina, Zpex demonstrated a significant increase in translucency, as well as a in characteristic stress. Alumina reliability was significantly lower than others at 300 MPa, ZTA Zpex and Zpex reliability decreased at 800 MPa, except for aged Zpex. SIGNIFICANCE/CONCLUSIONS:While aging did not affect the mechanical nor the optical properties of ZTA Zpex and alumina, it did alter both properties of Zpex. The results encourage further investigations to engineer ZTA as a framework material for long span fixed dental prostheses specially where darkened substrates, such as titanium implant abutments or endodontically treated teeth, demand masking.

WE43 Mg alloy proved to be an ideal candidate for production of resorbable implants in both clinical and trial settings. In previous studies we tested biocompatibility and degradation properties of WE43 (as-cast) and artificially aged (WE43-T5) Mg alloys in a sheep model. Both alloys showed excellent biocompatibility with the as-cast, WE43, form showing increased degradability compared to the artificially aged, WE43-T5. In the present study, our group assessed the biological behavior and degradation pattern of the same alloys when implanted as endosteal implants in a sheep model. Twelve screws (3x15 mm) were evaluated, one screw per each composition was placed bi-cortically in the mandible of each animal with a titanium (2x12 mm) screw serving as an internal positive control. At 6 and 24 weeks histomorphological analysis was performed, at 6 weeks as cast, WE43, yielded a higher degradation rate, increased bone remodeling and osteolysis compared to the WE43-T5 alloy; however, at 24 weeks WE43-T5 showed higher degradation rate and increased bone remodeling than as-cast. In vitro assay of cell growth, adhesion and differentiation was also conducted to investigate possible mechanisms underlying the behavior expressed from the alloys in vivo. In conclusion WE43-T5 indicated bone/implant interaction properties that makes it more suitable for fabrication of endosteal bone screws.

BACKGROUND:Virtual surgical planning has contributed to technical advancements in free fibula flap mandible reconstruction. The authors present the largest comparative study on the latest modification of this technology: the use of patient-specific, preoperatively customized reconstruction plates for fixation. METHODS:A retrospective chart review was performed on all patients undergoing mandibular reconstruction with virtually planned free fibula flaps at a single institution between 2008 and 2018. Patient demographics, perioperative characteristics, and postoperative outcomes were reviewed. Reconstructions using traditional fixation methods were compared to those using prefabricated, patient-specific reconstruction plates. RESULTS:A total of 126 patients (mean age, 48.5 ± 20.3 years; 61.1 percent male) underwent mandibular reconstruction with a free fibula flap. Mean follow-up time was 23.5 months. A customized plate was used in 43.7 percent of cases. Reconstructions with patient-specific plates had significantly shorter total operative times compared with noncustomized fixation methods (643.0 minutes versus 741.7 minutes; p = 0.001). Hardware complications occurred in 11.1 percent of patients, with a trend toward a lower rate in the customized plate group (5.5 percent versus 15.5 percent; p = 0.091). Multivariate regression showed that the use of customized plates was a significant independent predictor of fewer overall complications (p = 0.03), shorter operative time (p = 0.014), and shorter length of stay (p = 0.001). CONCLUSIONS:Compared to traditional fixation methods, patient-specific plates are associated with fewer complications, shorter operative times, and reduced length of stay. The use of customized reconstruction plates increases efficiency and represents the latest technological innovation in mandibular reconstruction. CLINICAL QUESTION/LEVEL OF EVIDENCE:Therapeutic, III.

BACKGROUND:Since the 1990s, the field of vascularized composite allotransplantation has gained momentum, offering unprecedented solutions for patients with defects not amenable to autologous reconstruction. As with solid organ donation, the vascularized composite allotransplant donor pool remains limited. This systematic review identifies past successes and failures in organ donation campaigns to guide future strategies for expanding vascularized composite allotransplant donation. METHODS:A systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Three databases (PubMed/MEDLINE, PsycINFO, and Embase) were searched through July 31, 2019. The study compiled solid organ and vascularized composite allotransplant campaigns that aimed to increase donor registration. Articles depicting the current state of vascularized composite allotransplant donation were also assessed. RESULTS:Of an initial 3318 articles identified, 40 were included. Six articles described direct mail or print interventions, 10 depicted Web-based interventions, 13 dealt with interpersonal interventions, and seven used multimodal interventions. Four articles described the current state of vascularized composite allotransplant donation. A qualitative synthesis was conducted. The authors found that social media campaigns can have a robust but fleeting effect on registration trends and that interpersonal interventions are effective at increasing registration rates. In addition, the opportunity for participants to immediately register as organ donors, by means of either return mail, in-person, or online, is vital to campaign success. CONCLUSIONS:Public organ donation campaigns have had success in increasing organ donor registration rates, particularly through the use of social media and interpersonal interventions that allow for immediate registration. Synthesizing this information, we propose a multimodal campaign to expand the vascularized composite allotransplant donor pool.

Anesthetic considerations are integral to the success of facial transplantation (FT), yet limited evidence exists to guide quality improvement. This study presents an institutional anesthesia protocol, defines reported anesthetic considerations, and provides a comprehensive update to inform future directions of the field.