Faculty Bibliography

BACKGROUND:Numerous studies have evaluated the effect of post-mastectomy radiotherapy (PMRT) on autologous breast reconstruction, but the variability of PMRT regimens and inadequate controls have made results difficult to interpret. Therefore, in this study, irradiated free-flaps are compared to non-irradiated internal controls in patients who underwent immediate bilateral reconstruction followed by unilateral PMRT to better delineate the effect of PMRT. The role of regional nodal irradiation (RNI) is also specifically assessed. METHODS:Appropriate patients were identified through retrospective review. Complications such as fat necrosis, fibrosis, infection, delayed healing, and flap loss, as well as revision surgeries, among the irradiated free-flaps were compared to those on the contralateral non-irradiated side. Additional analyses were performed to evaluate the effect of patient demographics and treatment characteristics, such as RNI, on complications involving the irradiated free-flaps. RESULTS:Seventy-three women were included. There was no significant difference between complication rates for the irradiated and non-irradiated free-flaps (39.7% vs. 38.4%, p = .78), although irradiated free-flaps were more likely to have fibrosis (17.0% vs. 0.0%; p < .0001) and multiple complications (9.6% vs. 0.0%; p = .02). Both groups underwent a similar number of revision surgeries (42.5% vs. 41.1%; p = .29). Looking at the irradiated free-flaps, internal mammary node (IMN) irradiation was the only factor predictive of complications (IRR 3.80, CI 1.32-10.97; p = .01). CONCLUSIONS:PMRT may contribute to free-flap fibrosis, but does not appear to affect the overall risk of complications or revision surgeries. However, additional counseling is warranted if IMN irradiation is likely, as it is potentially associated with increased complications.

OBJECTIVE:The effectiveness of GBR procedures for the reconstruction of periodontal defects has been well documented. The objective of this investigation was to evaluate the degradation kinetics and biocompatibility of two resorbable collagen membranes in conjunction with a bovine xenograft material. MATERIALS AND METHODS/METHODS:Lower premolars and first molars were extracted from 18 male Yucatan minipigs. After 4 months of healing, standardized semi-saddle defects were created (12 mm × 8 mm × 8 mm [l˙̇ × W˙ × d]), with 10 mm between adjacent defects. The defects were filled with a bovine xenograft and covered with a either the bilayer collagen membrane (control) or the porcine pericardium-derived collagen membrane (test). Histological analysis was performed after 4, 8, and 12 weeks of healing and the amount of residual membrane evaluated. Non-inferiority was calculated using the Brunner-Langer mixed regression model. RESULTS:Histological analysis indicated the presence of residual membrane in both groups at all time points, with significant degradation noted in both groups at 12 weeks compared to 4 weeks (p = .017). No significant difference in ranked residual membrane scores between the control and test membranes was detected at any time point. CONCLUSIONS:The pericardium-derived membrane was shown to be statistically non-inferior to the control membrane with respect to resorption kinetics and barrier function when utilized for guided bone regeneration in semi-saddle defects in minipigs. Further evaluation is necessary in the clinical setting.

OBJECTIVES/OBJECTIVE:To evaluate peri-implant bone formation of titanium implants using an in vivo rat model with and without uncontrolled diabetes mellitus (DM) to evaluate osseointegration of hydrophobic (Neoporos®) and hydrophilic (Acqua®) surfaces. MATERIALS AND METHODS/METHODS:54 rats were divided into two groups: DM group (DMG) (streptozotocin-induced diabetes) and a control group (CG). Implants with hydrophobic (Neoporos®) and hydrophilic surfaces (Acqua) were placed in the left or right tibia of animals. Animals were further divided into three groups (n = 9) euthanized after 7, 14, or 28 days. Bone-to-implant contact (BIC) and bone area fraction occupancy (BAFO) were assessed in total, cortical, and medullary areas. RESULTS:The DMG group, after a 7-day healing period, yielded with the Acqua implants presented significantly higher total BIC (+37.9%; p=0.03) and trabecular BIC (%) (+46.3%; p=0.02) values in comparison to the Neoporos implants. After 28 days of healing, the CG yielded that the cortical BAFO of Acqua implants to be significantly, 14%, higher (p=0.04) than Neoporos implants. CONCLUSION/CONCLUSIONS:The positive effects of the Acqua surface were able to counteract the adverse impact of uncontrolled DM at early osseointegration periods. After 28 days in vivo, the metabolic systemic impairment caused by DM overcame the surface treatment effect, leading to impaired osseointegration in both hydrophilic and hydrophobic implants. CLINICAL RELEVANCE/CONCLUSIONS:The adverse effects of diabetes mellitus with respect to bone healing may be minimized by deploying implants with strategically modified surfaces. This study evaluated the effects of implants with Acqua® and Neoporos® surfaces in both diabetic and healthy animals. During the initial healing period in diabetic animals, the hydrophilic surface was demonstrated to have beneficial effect on osseointegration in comparison to the hydrophobic surface. The results provide an insight into early healing, but the authors suggest that a future short-term and long-term clinical study is needed to assess the possible benefit of the Acqua® implant as well as in increasing the predictability of implant osseointegration.

OBJECTIVE:To describe the outcomes of single-stage and staged repairs in properly selected patients with phalloplasty anastomotic strictures. METHODS:A bi-institutional retrospective review was performed of all patients who underwent anastomotic stricture repairs between 7/2014-8/2020. Those who had prior augmented urethroplasties or poorly vascularized tissue underwent two-stage repairs (Group-2), all others underwent single-stage repair with a double-face (dorsal inlay and ventral onlay) buccal mucosal graft urethroplasty (Group-1). Postoperatively, urethral patency and patient reported outcome measures (PROMs) were assessed. RESULTS:Twenty-three patients with anastomotic strictures were identified. Fourteen patients met inclusion criteria and had 1-year follow-up (9 in Group-1; 5 in Group-2). Nine patients (64%) had prior failed interventions (56% Group-1; 80% Group-2). At a mean follow-up of 33.9 (Group-1) and 35.2 months (Group-2) there were two stricture recurrences in Group-1 (22%) and none in Group-2. PROMs were completed by 12 patients. All patients reported the ability to void standing. Post-void dribbling was present in the majority of patients (7/7 Group-1; 2/4 in Group-2). Mean IPSS was 3.9 (0-14) for Group-1 and 1 (0-3) for Group-2. All reported at least a moderate improvement in their condition on GRA (Group-1 +3 71%, +2 29%; Group-2 +3 100%). CONCLUSION/CONCLUSIONS:Single-stage repairs are feasible for patients with anastomotic strictures who have well vascularized tissue and no prior single-stage buccal mucosa augmented urethroplasty failures. Staged repairs are feasible for patients with poor tissue quality. Proper patient selection is important for successful reconstruction.

PURPOSE:To evaluate the effect of two surface modifications on early osseointegration parameters of conical implants in a translational pre-clinical model. MATERIALS AND METHODS:), surface energy and contact angle. Subsequently, implants were installed in the ilium crest of nine female sheep (weighing ~65 kg). Torque out, histological and histomorphometric analyses were conducted after 3 and 6 weeks in-vivo. The percentage of bone to implant contact (%BIC) and bone area fraction occupancy within implant threads (%BAFO) were quantified, and the results were analyzed using a general linear mixed model analysis as function of surface treatment and time in-vivo. RESULTS:. Torque-out testing yielded significantly higher values for IMP Sur + AE in comparison to the IMP Sur at 3- (62.78 ± 15 and 33.49 ± 15 N.cm, respectively) and 6-weeks (60.74 ± 15 and 39.80 ± 15 N.cm, respectively). Histological analyses depicted similar osseointegration features for both surfaces, where an intramembranous-type healing pattern was observed. At histomorphometric analyses, IMP Sur + AE implants yielded higher values of BIC in comparison to IMP Sur at 3- (40.48 ± 38 and 27.98 ± 38%, respectively) and 6-weeks (45.86 ± 38 and 34.46 ± 38%, respectively). Both groups exhibited a significant increase in %BAFO from 3 (~35%) to 6 weeks (~44%), with no significant differences between surface treatments. CONCLUSION:Supplemental acid-etching and its interplay with implant thread design, positively influenced the BIC and torque-out resistance at early stages of osseointegration.

BACKGROUND: Stacked and conjoined (SC) flaps are a useful means of increasing flap volume in autologous breast reconstruction. The majority of studies, however, have been limited to smaller, single-center series. METHODS: A systematic literature review was performed to identify outcomes-based studies on microvascular SC-flap breast reconstruction. Pooled rates of flap and operative characteristics were analyzed. Meta-analytic effect size estimates were calculated for reconstructive complication rates and outcomes of studies comparing SC flaps to non-SC flaps. Meta-regression analysis identified risk factors for flap complications. RESULTS: = 0.00%), though rates of any flap and donor-site complication were similar. Age, body mass index, flap weight, and flap donor site and recipient vessels were not associated with increased risk of any flap complication. CONCLUSION/CONCLUSIONS: A global appraisal of the current evidence demonstrated the safety of SC-flap breast reconstruction with low complication rates, regardless of donor site, and lower rates of fat necrosis compared with non-SC flaps.

BACKGROUND:Patients undergoing breast reduction mammoplasty for symptomatic macromastia have a significantly improved quality of life postoperatively. However, there are no data that examine the effect of reduction mammoplasty on quality of life as a function of the weight of tissue removed. Because the process by which insurance providers consider patients' candidacy for this breast reduction mammoplasty is most often based on the proposed weight of tissue to be removed, this gap in our understanding is particularly glaring. We therefore designed a prospective trial with the intent of investigating the correlation between breast reduction specimen weight and postoperative pain and quality of life. METHODS:After obtaining institutional review board (IRB) approval, patients presenting for breast reduction mammoplasty at a single academic medical center between January 2016 and September 2019 were prospectively enrolled in the study. Study participants completed the Numerical Pain Rating Scale (NPRS), the short-form McGill Pain Questionnaire (SF-MPQ), and the BREAST-Q at set time points (preoperatively, 1 week/1 month/3 months/6 months postoperatively). Patients were divided into three cohorts based on breast reduction specimen weights: small (<500 g reduction), intermediate (500-1000 g reduction), and large (>1000 g reduction). The surveys were then analyzed while controlling for demographic factors and complications. RESULTS:A total of 85 women were enrolled in the study and completed pre- and postoperative surveys (small reduction n = 21 (25%), intermediate n = 45 (53%), and large n = 19 (22%)). Regardless of reduction specimen weight, patients reported decreased overall pain and increased satisfaction with their breasts, as well as improved psychosocial, sexual, and physical well-being at each postoperative visit. Preoperative SF-MPQ pain scores were significantly lower in the small specimen weight group compared with either the intermediate or the large group (p = 0.001). Postoperatively, both the intermediate and large groups reported significant improvement in pain at each time point. The small specimen weight group did not report significant pain improvement until 3 months postoperatively. CONCLUSIONS:Patients undergoing breast reduction mammoplasty experience decreased pain and improved quality of life regardless of reduction specimen weight. Improvement in these parameters manifests as early as 1 week postoperatively and maintained at 3 months postoperatively. These data suggest that many patients who are denied coverage for reduction mammoplasty on the basis of low projected reduction specimen weight would derive significant benefit from the procedure.

Robin sequence (RS) is diagnosed in infants born with micrognathia, glossoptosis and varying degrees of upper airway obstruction (UAO). Due to the variable levels of hypoxia, severe breathing and feeding problems can occur. Treatment is determined by clinical severity, ranging from conservative interventions for mild cases to surgical interventions for severe cases. Mandibular distraction osteogenesis (MDO) is a surgical technique that gradually lengthens the mandible after an osteotomy by using an internal or external distraction device, directly correcting the micrognathia. This review will focus on advantages and disadvantages of mandibular distraction in infants with RS.

Oral squamous cell carcinoma (SCC) pain is more prevalent and severe than pain generated by any other form of cancer. We previously showed that protease-activated receptor-2 (PAR₂) contributes to oral SCC pain. Cathepsin S is a lysosomal cysteine protease released during injury and disease that can activate PAR₂. We report here a role for cathepsin S in PAR₂-dependent cancer pain. We report that cathepsin S was more active in human oral SCC than matched normal tissue, and in an orthotopic xenograft tongue cancer model than normal tongue. The multiplex immunolocalization of cathepsin S in human oral cancers suggests that carcinoma and macrophages generate cathepsin S in the oral cancer microenvironment. After cheek or paw injection, cathepsin S evoked nociception in wild-type mice but not in mice lacking PAR₂ in Na_v1.8-positive neurons (Par₂Na_v1.8), nor in mice treated with LY3000328 or an endogenous cathepsin S inhibitor (cystatin C). The human oral SCC cell line (HSC-3) with homozygous deletion of the gene for cathepsin S (CTSS) with CRISPR/Cas9 provoked significantly less mechanical allodynia and thermal hyperalgesia, as did those treated with LY3000328, compared to the control cancer mice. Our results indicate that cathepsin S is activated in oral SCC, and that cathepsin S contributes to cancer pain through PAR₂ on neurons.

OBJECTIVE:Evaluate the effect of aging using two different methods on the three-dimensional fit of zirconia abutments at the implant-abutment connection and estimate the probability of survival of anterior crowns supported by straight and 17-degree angled abutments. MATERIALS AND METHODS/METHODS:Two different zirconia abutment designs, straight and 17-degree angled abutments (n = 63/group), were evaluated in the current study. The abutments were randomly allocated into three experimental groups according to laboratory aging condition (134°C, 2.2 bar, 20 h): (i) control, (ii) autoclave aging, and (iii) hydrothermal reactor aging. Crystalline content was determined by X-Ray diffraction (XRD) and Raman spectroscopy, and microstructure was analyzed using field-emission gun scanning electron microscope (FEG-SEM). Implant-abutment volume misfit was determined in the straight abutments by micro-computed tomography using the silicone replica technique. For fatigue testing, abutments were torqued to the implants and connected to standardized maxillary incisor zirconia crowns. The assemblies were subjected to step-stress accelerated life testing (SSALT) in water until fracture or suspension. The use level probability Weibull curves and probability of survival for a mission of 50,000 cycles at 50, 100, 150 and 200 N were calculated and plotted. Fractured samples were analyzed using a stereomicroscope and scanning electron microscope. RESULTS:). The beta (β) values indicated that failures were predominantly controlled by material strength rather than fatigue damage accumulation for all groups, except for straight control abutments. Irrespective of aging, the probability of survival of straight and angled zirconia abutments was up to 95% (95-100%) at 50 and 100 N. A 50N-increase in the load resulted in wider range of survival estimate, with straight autoclave abutments percentage significantly lower probability of survival (77%) than angled hydrothermal reactor abutments (99%). At 200N, angled hydrothermal reactor (97%) or autoclave (82%) aged abutments demonstrated the highest probability of survival, angled control (71%) and straight hydrothermal reactor (69%) abutments intermediate values, and straight autoclave (23%) and control (7%) abutments the lowest estimate. The failure mode predominantly involved abutment and/or abutment screw fracture for both straight and angled abutments. CONCLUSIONS:Hydrothermal aging significantly influenced volume misfit, as well as the probability of survival of zirconia abutments at higher loads for both angled and straight abutments.