Faculty Bibliography

BACKGROUND:The bulk metallic glass (BMG), Pd79Ag3.5P6Si9.5Ge2, has a high fracture toughness and has been found to accommodate post-yield stress, unlike most other BMG. Moreover, due to its greater noble gas composition it has a intrinsic corrosion resistance, ideal for dental and orthopedic implants. OBJECTIVE:This present study aimed to evaluate the in vivo application of Pd79Ag3.5P6Si9.5Ge2 in a large translational sheep model to assess its efficacy to be utilized as an endosteal device. METHODS:Twelve implants in the form of cylindrical rods (3 mm in diameter) were produced through rapid quenching. Each sheep (n = 12) received one osteotomy in the mandibular region using rotary instrumentation, which was subsequently filled with Pd79Ag3.5P6Si9.5Ge2. After 6- and 24-weeks the animals were euthanized, and samples collected en bloc to conduct histomorphometric analysis. The level/degrees of osseointegration were assessed through bone-to-implant contact (BIC). RESULTS:Favorable BIC was observed with fibrous connective tissue layers at both 6- and 24-weeks. Bone along with interfacial remodeling was observed in proximity with the metallic glass surface at 6 weeks with higher degrees of bone organization being observed at the later healing time, 24 weeks. CONCLUSIONS:The introduced BMG revealed potential to serve as an alternative biomaterial to commonly used Ti alloys given its unique combination of toughness and strength.

INTRODUCTION/BACKGROUND:Simultaneous Le Fort III/I (LF III/I) osteotomies are often performed when a differential advancement of the upper and lower midface is needed. This study aims to evaluate midface position preoperative and 1 week postoperative in patients with severe midface hypoplasia. In addition, this study aims to compare the planned surgical movements to the actual postoperative movements. MATERIALS AND METHODS/METHODS:A retrospective review was conducted using cephalometry for patients treated with a simultaneous LF III/I osteotomy at a single institution. Osteotomies were performed during 1980-2018 on skeletally mature patients with a craniofacial syndrome, with clinical and radiographic follow-up available. RESULTS:Twelve patients met the inclusion criteria with a mean age of 20.2±6.4 years. Treatment resulted in statistically significant anterior movements related to Orbitale, anterior nasal spine, A Point, and the upper incisor tip, and inferior movements related to anterior nasal spine, A Point, upper and lower incisor tips, B point, and pogonion. Stability after 1 year showed only statistically significant changes at ANB. The predictable error for planned movements versus actual movements was greater in the vertical plane than the horizontal plane. CONCLUSIONS:A simultaneous LF III/I osteotomy significantly improved the midface position and occlusal relationship in syndromic patients with midface hypoplasia in a predictable manner. Further multicenter studies with larger sample sizes are needed to validate the conclusions.

BACKGROUND AND OBJECTIVES/OBJECTIVE:The United States is witnessing a rapid increase in kidney transplantation (KTx) among adults aged 65 and over. Despite this demographic shift, older adults' perspectives on KTx remain notably absent from the discourse on transplant policy and practice, and very little research has examined older adults' perceptions and experiences of KTx. RESEARCH DESIGN AND METHODS/METHODS:Employing a phenomenological approach, this study explored the lived experiences of 10 KTx recipients aged 65 and over. Fifteen in-depth interviews were conducted, and analyses followed the processes of phenomenological reduction, imaginative variation, and synthesis. RESULTS:Participants reported experiencing an initial disruption of their sense of embodied identity that ranged from mildly unsettling to deeply distressing. However, they described navigating this 'liminal' period and eventually incorporating the donor kidney into their sense of embodied self. Notably, most participants viewed their older age as protective and reported that their lived experience over time enabled them to cope more effectively with the challenges they faced during the post-transplant recovery and adaptation period. DISCUSSION AND IMPLICATIONS/CONCLUSIONS:Findings from this study can inform more equitable and age-responsive KTx policy, research and clinical practice and may be extended beyond KTx to other forms of solid organ transplantation, vascularized composite allotransplantation and innovative bioengineered organs.

The US FDA in response to concerns that patients undergoing breast implant surgery were not adequately informed about the risks of receiving an implanted medical device mandated a patient decision checklist (PDC) in October 2021. Breast implant manufactures communicated with plastic surgeons in 2022 regarding the use of the PDC as a condition for the sale of breast implants. Plastic surgeons voiced concerns over the accuracy of content in the PDC and its confusing statements about risk of adverse events associated with breast surgery. In April 2022, the Aesthetic Society developed a survey that was sent to its members regarding their experiences with the PDC. This was a 5-question survey and one additional place for comments. The purpose for this survey was to develop data on the six-month experience of plastic surgeons using the PDC. A total of 206 Aesthetic Society members (9%) participated in the survey (1849 total active members in the United States). Patients deserve appropriate information prior to breast implant surgery to make an informed decision after reviewing the potential risks and benefits. The authors believe that there is still more work to be done on an ideal PDC will make it fair and balanced and that it scientifically describes risk incidence in a way that patients understand and can be updated.

Lambdoid craniosynostosis (CS) is a congenital anomaly resulting from premature fusion of the cranial suture between the parietal and occipital bones. Predominantly sporadic, it is the rarest form of CS and its genetic etiology is largely unexplored. Exome sequencing of 25 kindreds, including 18 parent-offspring trios with sporadic lambdoid CS, revealed a marked excess of damaging (predominantly missense) de novo mutations that account for ~ 40% of sporadic cases. These mutations clustered in the BMP signaling cascade (P = 1.6 × 10^-7), including mutations in genes encoding BMP receptors (ACVRL1 and ACVR2A), transcription factors (SOX11, FOXO1) and a transcriptional co-repressor (IFRD1), none of which have been implicated in other forms of CS. These missense mutations are at residues critical for substrate or target sequence recognition and many are inferred to cause genetic gain-of-function. Additionally, mutations in transcription factor NFIX were implicated in syndromic craniosynostosis affecting diverse sutures. Single cell RNA sequencing analysis of the mouse lambdoid suture identified enrichment of mutations in osteoblast precursors (P = 1.6 × 10^-6), implicating perturbations in the balance between proliferation and differentiation of osteoprogenitor cells in lambdoid CS. The results contribute to the growing knowledge of the genetics of CS, have implications for genetic counseling, and further elucidate the molecular etiology of premature suture fusion.

Although generally regarded as degradatory enzymes, certain proteases are also signaling molecules that specifically control cellular functions by cleaving protease-activated receptors (PARs). The four known PARs are members of the large family of G protein-coupled receptors. These transmembrane receptors control most physiological and pathological processes and are the target of a large proportion of therapeutic drugs. Signaling proteases include enzymes from the circulation, from immune, inflammatory epithelial and cancer cells, as well as from commensal and pathogenic bacteria. Advances in our understanding of the structure and function of PARs provide insights into how diverse proteases activate these receptors to regulate physiological and pathological processes in most tissues and organ systems. The realization that proteases and PARs are key mediators of disease, coupled with advances in understanding the atomic level structure of PARs and their mechanisms of signaling in subcellular microdomains, has spurred the development of antagonists, some of which have advanced to the clinic. Herein we review the discovery, structure and function of this receptor system, highlight the contribution of PARs to homeostatic control, and discuss the potential of PAR antagonists for the treatment of major diseases.

Head and neck squamous cell carcinoma (HNSCC) causes more severe pain and psychological stress than other types of cancer. Despite clinical evidence linking pain, stress, and cancer progression, the underlying relationship between pain and sympathetic neurotransmission in oral cancer is unknown. We found that human HNSCC tumors and mouse tumor tissue are innervated by peripheral sympathetic and sensory nerves. Moreover, [beta]-adrenergic 1 and 2 receptors ([beta]-AR) are overexpressed in human oral cancer cell lines, and norepinephrine treatment increased [beta]-AR2 protein expression as well as cancer cell proliferation in vitro. We have recently demonstrated that inhibition of tumor necrosis factor alpha (TNF[alpha]) signaling reduces oral cancer-induced nociceptive behavior. Norepinephrine-treated cancer cell lines secrete more TNF[alpha] which, when applied to tongue-innervating trigeminal neurons, evoked a larger Ca2+ transient; TNF-TNFR inhibitor blocked the increase in the evoked Ca2+ transient. Using an orthotopic xenograft oral cancer model, we found that mice demonstrated significantly less orofacial cancer-induced nociceptive behavior during systemic [beta]-adrenergic inhibitory treatment with propranolol. Furthermore, chemical sympathectomy via guanethidine led to a significant reduction in tumor size and nociceptive behavior. We infer from these results that sympathetic signaling modulates oral cancer pain via TNF[alpha] secretion and tumorigenesis. Further investigation of the role of neuro-cancer communication in cancer progression and pain is warranted.

The field of additive manufacturing, 3D printing (3DP), has experienced an exponential growth over the past four decades, in part due to increased accessibility. Developments including computer-aided design and manufacturing, incorporation of more versatile materials, and improved printing techniques/equipment have stimulated growth of 3DP technologies within various industries, but most specifically the medical field. Alternatives to metals including ceramics and polymers have been garnering popularity due to their resorbable properties and physiologic similarity to extracellular matrix. 3DP has the capacity to utilize an assortment of materials and printing techniques for a multitude of indications, each with their own associated benefits. Within the field of medicine, advances in medical imaging have facilitated the integration of 3DP. In particular, the field of orthopedics has been one of the earliest medical specialties to implement 3DP. Current indications include education for patients, providers, and trainees, in addition to surgical planning. Moreover, further possibilities within orthopedic surgery continue to be explored, including the development of patient-specific implants. This review aims to highlight the use of current 3DP technology and materials by the orthopedic community, and includes comments on current trends and future direction(s) within the field.

PURPOSE/OBJECTIVE:Basal joint osteoarthritis (OA) is a highly prevalent and debilitating condition. Recent clinical evidence suggests that autologous fat transfer (AFT) may be a promising, minimally invasive treatment for this condition. However, the mechanism of action is not fully understood. It is theorized that AFT reduces inflammation in the joint, functions to regenerate cartilage, or acts as a mechanical buffer. The purpose of this study was to better understand the underlying mechanism of AFT using an in vitro model. We hypothesize that the addition of stromal vascular fraction (SVF) cells will cause a reduction in markers of inflammation. METHODS:Articular chondrocytes were expanded in culture. Liposuction samples were collected from human subjects and processed similarly to AFT protocols to isolate SVF rich in adipose-derived stem cells. A control group was treated with standard growth media, and a positive control group (OA group) was treated with inflammatory cytokines. To mimic AFT, experimental groups received inflammatory cytokines and either a low or high dose of SVF. Expression of relevant genes was measured, including interleukin (IL)-1ß, IL-1 receptor antagonist, and matrix metalloproteinases (MMP). RESULTS:Compared to the OA group, significant decreases in IL-1ß, MMP3, and MMP13 expression on treatment day 3 were found in the high-dose SVF group, while MMP13 expression was also significantly decreased in the low-dose SVF group on day 3. CONCLUSIONS:In this study, we found that SVF treatment reduced expression of IL-1ß, MMP3, and MMP13 in an in vitro model of OA. These results suggest that an anti-inflammatory mechanism may be responsible for the clinical effects seen with AFT in the treatment of basal joint OA. CLINICAL RELEVANCE/CONCLUSIONS:An anti-inflammatory mechanism may be responsible for the clinical benefits seen with AFT for basal joint arthritis.

BACKGROUND/PURPOSE/OBJECTIVE:This paper describes the changes in maxillary arch morphology in infants with bilateral cleft lip and palate (BCLP) following nasoalveolar molding (NAM) and with follow up to assess the need for secondary alveolar bone grafting (ABG) and premaxillary repositioning surgery at preadolescence. METHODS/DESCRIPTION/UNASSIGNED:Treatment records of infants with BCLP treated with NAM between 2003 and 2013 were reviewed. Patients with complete BCLP who underwent NAM and had complete sets of maxillary casts at T 0 pre-NAM (mean = 27 days), T 1 post-NAM (mean = 6 months and 5 days), and T 2 before palate surgery (mean = 11 months and 15 days) were included. The sample comprised 23 infants (18 male, 5 female). Casts were digitized and analyzed using three dimensional software. The need for secondary ABG and premaxillary repositioning surgery was assessed at preadolescent follow-up (mean = 8.3 years). RESULTS:Cleft width was reduced on average by 4.73 mm (SD ± 3.15 mm) and 6.56 mm (SD ± 4.65) on the right and left sides, respectively. At T 1, 13 (56.52%) patients underwent bilateral gingivoperiosteoplasty (GPP), 8 (34.78%) patients unilateral GPP, and 2 patients (8.7%) did not undergo GPP. 34/46 clefts sites (73.91%) underwent GPP while 12 (26.08%) did not. At preadolescent follow-up of 19 patients, 7 patients (36.84%) did not need ABG on either side, 8 (42.10%) needed ABG on 1 side, and 4 (21.05%) needed ABG on both sides. None of the patients needed premaxillary repositioning surgery. CONCLUSIONS:Nasoalveolar molding treatment significantly improves the position of the premaxilla before primary repair, and there is a significant reduction in the need for secondary ABG and premaxillary repositioning surgery at preadolescence.