Searched for: school:SOM
Department/Unit:Plastic Surgery
The Effect of Three-Dimensional Stabilization Thread Design on Biomechanical Fixation and Osseointegration in Type IV Bone
Iglesias, Nicholas J; Nayak, Vasudev Vivekanand; Castellano, Arthur; Witek, Lukasz; Souza, Bruno Martins de; Bergamo, Edmara T P; Almada, Ricky; Slavin, Blaire V; Bonfante, Estevam A; Coelho, Paulo G
Achieving the appropriate primary stability for immediate or early loading in areas with low-density bone, such as the posterior maxilla, is challenging. A three-dimensional (3D) stabilization implant design featuring a tapered body with continuous cutting flutes along the length of the external thread form, with a combination of curved and linear geometric surfaces on the thread's crest, has the capacity to enhance early biomechanical and osseointegration outcomes compared to implants with traditional buttressed thread profiles. Commercially available implants with a buttress thread design (TP), and an experimental implant that incorporated the 3D stabilization trimmed-thread design (TP 3DS) were used in this study. Six osteotomies were surgically created in the ilium of adult sheep (N = 14). Osteotomy sites were randomized to receive either the TP or TP 3DS implant to reduce site bias. Subjects were allowed to heal for either 3 or 12 weeks (N = 7 sheep/time point), after which samples were collected en bloc (including the implants and surrounding bone) and implants were either subjected to bench-top biomechanical testing (e.g., lateral loading), histological/histomorphometric analysis, or nanoindentation testing. Both implant designs yielded high insertion torque (ITV ≥ 30 N⋅cm) and implant stability quotient (ISQ ≥ 70) values, indicative of high primary stability. Qualitative histomorphological analysis revealed that the TP 3DS group exhibited a continuous bone-implant interface along the threaded region, in contrast to the TP group at the early, 3-week, healing time point. Furthermore, TP 3DS's cutting flutes along the entire length of the implant permitted the distribution of autologous bone chips within the healing chambers. Histological evaluation at 12 weeks revealed an increase in woven bone containing a greater presence of lacunae within the healing chambers in both groups, consistent with an intramembranous-like healing pattern and absence of bone dieback. The TP 3DS macrogeometry yielded a ~66% increase in average lateral load during pushout testing at baseline (T = 0 weeks, p = 0.036) and significantly higher bone-to-implant contact (BIC) values at 3 weeks post-implantation (p = 0.006), relative to the traditional TP implant. In a low-density (Type IV) bone model, the TP 3DS implant demonstrated improved performance compared to the conventional TP, as evidenced by an increase in baseline lateral loading capacity and increased BIC during the early stages of osseointegration. These findings indicate that the modified implant configuration of the TP 3DS facilitates more favorable biomechanical integration and may promote more rapid and stable bone anchorage under compromised bone quality conditions. Therefore, such improvements could have important clinical implications for the success and longevity of dental implants placed in regions with low bone density.
PMCID:12190597
PMID: 40558364
ISSN: 2313-7673
CID: 5874542
Effect of bulk material on the reliability and failure mode of narrow implants
Benalcázar-Jalkh, Ernesto B; Lopes, Adolfo C O; Bergamo, Edmara T P; de Carvalho, Laura F; Witek, Lukasz; Coelho, Paulo G; Zahoui, Abbas; Bonfante, Estevam A
The aim of the study was to assess the effect of bulk material on the reliability and failure modes of narrow-diameter implants. Narrow implants (Ø3.5 × 10 mm - 11° internal conical connection) were manufactured from three different bulk materials: commercially pure titanium grade-IV (CP4), cold-worked titanium (CW), and 4Titude (4Ti), and were evaluated under fatigue testing. Eighteen samples per group were tested under step-stress accelerated life testing through 30° off-axis load application in mild, moderate, and aggressive loading profiles. The number of cycles and load at failure were used to calculate use-level probability curves and reliability for missions of 100,000 cycles up to 200 N, followed by fractographic analyses. Beta values suggested that damage accumulation dictated failures. Reliability analyses at 80, 120, and 150 N evidenced high reliability for narrow implants independent of bulk material. At 200 N, a decrease in reliability was observed for all groups (∼46%). Failure mode analysis depicted similar failures for all groups and comprised implant fracture, abutment fracture, and implant + abutment fractures. Narrow implants presented high reliability for physiologic masticatory forces in the anterior region. Characteristic strength, reliability, and failure modes were similar regardless of bulk material, suggesting that fatigue damage accumulation at thin wall implants dictated failure over bulk material strength.
PMID: 40500134
ISSN: 1600-0722
CID: 5869432
Pretreatments of Ex Vivo Vascularized Composite Allografts: A Scoping Review
Baker, Caroline E; Stead, Thor S; Pullmann, Dominika; Shah, Alay R; Chinta, Sachin; Tran, David L; Brydges, Hilliard T; Laspro, Matteo; Gelb, Bruce E; Rodriguez, Eduardo D; Rabbani, Piul S
PURPOSE/OBJECTIVE:The various physiological profiles comprising vascularized composite allografts (VCAs) pose unique challenges to preservation. Minimizing ischemia, reperfusion injury, and rejection remains a primary focus of graft pretreatments (PTs). Currently, the gold standard PT consists of flushing the graft and placing it in static cold storage in the University of Wisconsin solution. With this method, graft viability is limited to 4 to 6 hours. Prolonging this time limit will increase donor allocation radius, access to care, and positive patient outcomes. We aimed to evaluate novel PTs that could potentially enhance and lengthen VCA viability. METHODS:Following PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) guidelines, we conducted a comprehensive literature search of EMBASE, Cochrane, and PubMed. Studies had to be published prior to June 15, 2022. PTs had to target cell physiology, rather than immunogenicity. We extracted data including study design, PT details, evaluation metrics, and outcomes. RESULTS:We identified 13 studies, categorized into 3 groups: solution-based alterations to the gold standard, ex vivo perfusion, and other novel techniques. The incorporation of hydrogen sulfide and Perfadex as solutions in the gold standard protocol demonstrated a 6-day delay in rejection and limited reperfusion injury markers, respectively. In an ex vivo perfusion study, after 24 hours of PT and 12 hours posttransplant, VCA muscle contractility remained close to normal. The gold standard PT did not demonstrate the same success. However, graft weight gain, up to 50% of baseline among the reviewed articles, is a prominent adverse effect of perfusion. Another technique, cryopreservation, displayed 90% graft failure by venous thrombosis, despite high free graft viability following 2 weeks of storage. CONCLUSIONS:This study of PT modalities found a variety of encouraging preservation techniques for grafts with high levels of tissue diversity. Ex vivo perfusion dominated PT innovation with promising results in preserving the viability and functionality of muscle, which is central to the restoration of movement. Future studies are necessary to evaluate long-term graft outcomes and to optimize PT protocols for extended preservation times to ensure clinical relevance.
PMID: 40532232
ISSN: 1536-3708
CID: 5871082
Bridging the evidence gap in gender-affirming care: urgent research needs
Dolendo, Isabella; Zhao, Lee; Bluebond-Langner, Rachel; Anger, Jennifer T
Gender-affirming care has emerged as a critical component of healthcare, addressing the specific medical and psychosocial needs of transgender and non-binary individuals. In this review article, we address what we see as the most pressing evidence gaps in the gender health literature: long-term effects of pubertal blockers and gender-affirming hormone therapy and the lack of standardised outcome measures of gender-affirming care. Substantial uncertainties persist regarding long-term effects of hormone therapy and the implications of gender-affirming therapy on cancer risk. Though there is some uncertainty about the long-term effects of gender-affirming medical therapy, providers must also consider the potential negative consequences of prolonging a dysphoric experience. Additionally, there is a dearth of validated measures for patient-reported outcomes and a lack of standardisation in the reporting of data that is detrimental to the progress of understanding the impacts of gender-affirming care.
PMID: 40457589
ISSN: 1464-410x
CID: 5862202
Discussion: Mastectomy for Individuals with Gender Dysphoria Younger Than 26 Years: A Systematic Review and Meta-Analysis
Schechter, Loren; Berli, Jens Urs; Bluebond-Langner, Rachel
PMID: 40434656
ISSN: 1529-4242
CID: 5855362
Three-Dimensional Assessment of Internal and Marginal Fit of Provisional Crowns Fabricated Using 3D-Printing Technology
Willers, Amanda Endres; Giannini, Marcelo; Hirata, Ronaldo; Bergamo, Edmara T P; de Cássia Romano, Beatriz; André, Carolina Bosso; Atria, Pablo J; Witek, Lukasz
To evaluate the effect of silanized filler particles and blue light-sensitive photoinitiator system on the internal and marginal fit of 3D printed resin crowns as well as the volume of provisional cement space. This study evaluated three commercially available 3D-printing resins (Smart Print Temp/SP, Resilab 3D Temp/RL, and Cosmos Temp/CT). The experimental groups consisted of the addition of 30% by weight (30 wt%) of silanized filler particles and a blue light-sensitive Ternary Photoinitiator System (TPS). Samples were printed for each group (n = 10) and evaluated for internal and marginal fit and volume of cement space using a micro-computed tomography (μCT). The obtained data were analyzed by Generalized Linear Models (α = 0.05). The incorporation of TPS and filler particles to the 3D printing resins altered the internal fit and the marginal fit, increasing the cement space at the occlusal face and decreasing the cement space of the axial walls for all tested materials. The volume was significantly affected too, especially for RL and CT. Internal misfit was significantly higher with the addition of TPS, and marginal misfit with the addition of filler particles. In general, the incorporation of TPS and 30 wt% of filler particles promoted an increase in the volume of cement space, as well as an increase in occlusal space and marginal space and a decrease in the axial walls' spaces.
PMID: 40387426
ISSN: 1552-4981
CID: 5852502
Is a Seroma the "Kiss of Death" in Prepectoral Tissue Expander Reconstruction?
Hemal, Kshipra; Boyd, Carter; Perez Otero, Sofia; Kabir, Raeesa; Sorenson, Thomas J; Thanik, Vishal; Levine, Jamie; Cohen, Oriana; Choi, Mihye; Karp, Nolan S
BACKGROUND/UNASSIGNED:A seroma following prepectoral tissue expander (TE) reconstruction often begets other complications, which may compromise the reconstruction. This study investigated the association between seroma and subsequent complications. METHODS/UNASSIGNED:All consecutive prepectoral TE reconstructions performed between March 2017 and December 2022 at a single center were reviewed. Demographics, operative characteristics, and complications data were extracted for all patients and analyzed. RESULTS/UNASSIGNED:< 0.01). CONCLUSIONS/UNASSIGNED:Although causality cannot be determined, our data suggests that seroma may be the "kiss of death" in prepectoral TE reconstruction because half of all breasts with a seroma went on to develop other complications.
PMCID:12144650
PMID: 40487834
ISSN: 2169-7574
CID: 5868962
Ventral hernia repair with T-line hernia mesh: A multi-institutional experience
Emovon, Emmanuel O; Oyola, Anna Malysz; Arias-Espinosa, Luis; Naga, Hani I; Volk, Angela S; Hope, William; Malcher, Flavio; Levine, Jamie P; Harris, Hobart W; Yoo, Jin; Patel, Ash
INTRODUCTION/UNASSIGNED:Ventral hernia repair (VHR) is a common procedure complicated by high hernia recurrence rates exceeding 30 % over ten years. The T-Line® Hernia Mesh is a synthetic, polypropylene mesh featuring mesh extensions designed to prevent anchor point failure by evenly distributing tension to reduce ventral hernia recurrences. This study evaluates the outcomes of the T-Line® mesh in VHR with 1-3 year follow-up. METHODS/UNASSIGNED:This study is a multi-institutional retrospective cohort study on patients who underwent VHR with T-Line® mesh between October 2020 and December 2022. Patient demographics, surgical details, and postoperative outcomes were collected. Patient-reported outcomes were assessed using HerQLes and ACHQC surveys. RESULTS/UNASSIGNED:= 7, 12.3 %). Of the five patients that reported feeling a slight bulge at their previous hernia site, upon clinical evaluation two patients had a recurrence (one recurrence was caused by the suture tearing through the underlying laparotomy repair while the mesh remained anchored intact above the repair, and the second recurrence was caused by inadequate mesh fixation at the caudal border of the mesh), while no patients reported using pain medication for abdominal wall discomfort. CONCLUSIONS/UNASSIGNED:The T-Line® Hernia Mesh demonstrated safety and effectiveness in ventral hernia repair, with low recurrences and postoperative complications rates over a 1-3-year period, suggesting it is a valuable tool for complex hernia repairs.
PMCID:12152597
PMID: 40503355
ISSN: 2666-2620
CID: 5869462
Computer-based Simulation of Facial Flap and Cleft Lip Reconstruction Using Multiresolution Physics
Wang, Qisi; Cutting, Court B; Sifakis, Eftychios
Computer-based simulation of complex local flap reconstructions of the face requires very high-density finite elements to render accurately due to the intricate incision designs frequently used. This is particularly true in detailed cleft lip/nose repairs. If the entire anatomic model is embedded in a high-resolution solid lattice, the element count becomes so high that simulator performance is very slow, even on a high-performance workstation. This article introduces a simulator in which the model is initially presented at a low, but acceptable physical resolution. As the surgeon operates on the model, only the areas impacted are recut at very high resolution. This surgical subvolume is then merged back into the rest of the model. The dramatic reduction in finite element count results in a surgical simulation program that is quite fast, even on a modest personal computer. This article presents examples of this simulator used in a variety of facial flap and cleft lip reconstructions. Future uses in plastic surgery for patient-specific simulation, education, and illustration are discussed. The simulator is available as free, open-source software.
PMCID:12133145
PMID: 40469555
ISSN: 2169-7574
CID: 5862632
Patient reliability and surgical decision-making biases amongst hand surgeons
Rocks, Madeline C; Brown, Riana; Noh, Karen J; Glickel, Steven Z; Yang, S Steven; Hacquebord, Jacques H
The perception of patient reliability may create surgical decision-making biases amongst hand surgeons. In this study, anonymous surveys were distributed to hand surgeons to understand how patient 'reliability' is defined and how it alters treatment decisions. Participants rated the importance of patient factors in assessing reliability, then completed fictional clinical vignettes detailing histories of patients undergoing elective surgery. Suspected substance usage and history of mental illness were rated as important factors in determining reliability, while gender and race were rated as not important. Physicians were significantly less likely to recommend surgery and exhibited less confidence in their recommendations when presented with a patient with a history of mental illness (p < 0.001) or suspected substance usage (p = 0.003). These findings suggest that while race and gender may not explicitly impact surgical decision-making, biases related to mental illness and substance use do affect treatment decisions and confidence levels. Recognizing these biases is critical for ensuring equitable care, and future efforts should explore strategies to mitigate their impact on surgical recommendations. Level of evidence: IV.
PMID: 40439076
ISSN: 2043-6289
CID: 5854712