Faculty Bibliography

STATEMENT OF PROBLEM/BACKGROUND:The bonding of implant-supported prostheses is determined by abutment material, convergence angle, height, surface treatment, and luting agents. However, studies evaluating the bonding of luting agents to titanium base abutments with different heights under fatigue conditions are scarce. PURPOSE/OBJECTIVE:The purpose of this in vitro study was to evaluate the retention of zirconia crowns bonded with different luting agents to titanium base abutments of different heights before and after fatigue testing. MATERIAL AND METHODS/METHODS:cycles; 100 N; and 15 Hz), followed by pull-out testing of fatigued specimens. Collected data were statistically evaluated by using a linear mixed model after post hoc comparisons by the least significant difference test (α=.05). RESULTS:Luting agents, abutment heights, and fatigue influenced the bonding retention of zirconia crowns to titanium base abutments. SU/RU agents promoted higher pull-out compared with MP/GC for both abutment heights before and after fatigue. Higher abutment height increased pull-out regarding lower abutment height for SU/RU materials before and after fatigue testing. Although fatigue had no significant effect on the pull-out of MP/GC, lower bond retention was observed for SU/RU after fatigue, regardless of abutment height. CONCLUSIONS:Luting agent composition and the interaction with abutment height and fatigue influenced the retention of zirconia crowns to titanium base abutments.

BACKGROUND:Condylar adaptations following orthognathic surgery remain an area of interest. Prior studies do not use 3-dimensional imaging modalities and lack standardization in the choice of osteotomy and movement when assessing condylar changes. PURPOSE:The purpose of this study was to use 3-dimensional cephalometry to measure the association between osteotomy type (sagittal split osteotomy [SSO] vs vertical ramus osteotomy [VRO]) and changes in condylar volume and position. STUDY DESIGN, SETTING, AND SAMPLE:This is a retrospective cohort study from January 2021 through December 2022 of patients at Bellevue Hospital in New York City, New York who were treated with either SSO or VRO for the correction of Class III skeletal malocclusion. PREDICTOR/EXPOSURE/INDEPENDENT VARIABLE:The primary predictor was the type of mandibular osteotomy, sagittal split osteotomy, and vertical ramus osteotomy. MAIN OUTCOME VARIABLES:) and relative position (anterior-posterior change utilizing the Pullinger and Hollinder method). COVARIATES:Covariates included patient age, sex, setback magnitude, temporomandibular joint symptoms, and fixation method for SSO patients. ANALYSES:tests. If there were multiple significant univariate predictors, multiple regression models were created to predict volume and position changes. A P < .05 value was considered statistically significant. RESULTS:; P = .03) and positional change (68.2 vs 12.5%; P < .01). Self-reported measures of postoperative pain, internal derangement, and myofascial symptoms were not significantly associated with either volume or positional changes. CONCLUSIONS AND RELEVANCE:The SSO resulted in greater postoperative condylar volume loss and positional changes. These volume and positional changes were not correlated with self-reported temporomandibular disorder symptoms.

To evaluate the cellular response of both an intact fish skin membrane and a porcine-derived collagen membrane and investigate the bone healing response of these membranes using a translational, preclinical, guided-bone regeneration (GBR) canine model. Two different naturally sourced membranes were evaluated in this study: (i) an intact fish skin membrane (Kerecis Oral®, Kerecis) and (ii) a porcine derived collagen (Mucograft®, Geistlich) membrane, positive control. For the in vitro experiments, human osteoprogenitor (hOP) cells were used to assess the cellular viability and proliferation at 24, 48, 72, and 168 h. ALPL, COL1A1, BMP2, and RUNX2 expression levels were analyzed by real-time PCR at 7 and 14 days. The preclinical component was designed to mimic a GBR model in canines (n = 12). The first step was the extraction of premolars (P1-P4) and the 1st molars bilaterally, thereby creating four three-wall box type defects per mandible (two per side). Each defect site was filled with bone grafting material, which was then covered with one of the two membranes (Kerecis Oral® or Mucograft®). The groups were nested within the mandibles of each subject and membranes randomly allocated among the defects to minimize potential site bias. Samples were harvested at 30-, 60-, and 90-days and subjected to computerized microtomography (μCT) for three-dimensional reconstruction to quantify bone formation and graft degradation, in addition to histological processing to qualitatively analyze bone regeneration. Neither the intact fish skin membrane nor porcine-based collagen membrane presented cytotoxic effects. An increase in cell proliferation rate was observed for both membranes, with the Kerecis Oral® outperforming the Mucograft® at the 48- and 168-hour time points. Kerecis Oral® yielded higher ALPL expression relative to Mucograft® at both 7- and 14-day points. Additionally, higher COL1A1 expression was observed for the Kerecis Oral® membrane after 7 days but no differences were detected at 14 days. The membranes yielded similar BMP2 and RUNX2 expression at 7 and 14 days. Volumetric reconstructions and histologic micrographs indicated gradual bone ingrowth along with the presence of particulate bone grafts bridging the defect walls for both Kerecis Oral® and Mucograft® membranes, which allowed for the reestablishment of the mandible shape after 90 days. New bone formation significantly increased from 30 to 60 days, and from 60 to 90 days in vivo, without significant differences between membranes. The amount of bovine grafting material (%) within the defects significantly decreased from 30 to 90 days. Collagen membranes led to an upregulation of cellular proliferation and adhesion along with increased expression of genes associated with bone healing, particularly the intact fish skin membrane. Despite an increase in the bone formation rate in the defect over time, there was no significant difference between the membranes.

BACKGROUND/UNASSIGNED:In properly selected patients, combined face and whole eye transplantation (FWET) may offer a more optimal aesthetic and potentially functional outcome while avoiding the complications and stigma of enucleation and prosthetics. This study presents the most comprehensive cadaveric assessment for FWET to date, including rehearsal allograft procurement on a brain-dead donor. METHODS/UNASSIGNED:Over a 2-year period, 15 rehearsal dissections were performed on 21 cadavers and one brain-dead donor. After identification of a potential recipient, rehearsals assessed clinical feasibility and enabled operative planning, technical practice, refinement of personalized equipment, and improved communication among team members. Operative techniques are described. RESULTS/UNASSIGNED:Facial allograft procurement closely followed previously described face transplant techniques. Ophthalmic to superficial temporal (O-ST) vessel anastomosis for globe survival was assessed. Craniectomy allowed for maximal optic nerve and ophthalmic vessel pedicle length. Appropriate pedicle length and vessel caliber for O-ST anastomosis was seen. Research procurement demonstrated collateral blood flow to the orbit and surrounding structures from the external carotid system as well as confirmed the feasibility of timely O-ST anastomosis. Personalized cutting guides enabled highly accurate bony inset. CONCLUSIONS/UNASSIGNED:This study formalizes an approach to FWET, which is feasible for clinical translation in judiciously selected patients. O-ST anastomosis seems to minimize retinal ischemia time and allow perfusion of the combined allograft on a single external carotid pedicle. Although restoration of vision likely remains out of reach, globe survival is possible.

OBJECTIVE:To define "high osteotomy" and determine the feasibility of performing this procedure. DESIGN/METHODS:Single institution, retrospective review. SETTING/METHODS:Academic tertiary referral hospital. PATIENTS, PARTICIPANTS/METHODS:34 skeletally mature, nonsyndromic patients with unilateral CLP who underwent Le Fort I osteotomy between 2013 and 2020. Patients with cone-beam computed tomography (CBCT) scans completed both pre- (T1) and post-operatively (T2) were included. Patients with bilateral clefts and rhinoplasty prior to post-operative imaging were excluded. INTERVENTIONS/METHODS:Single jaw one-piece Le Fort I advancement surgery. MAIN OUTCOME MEASURES/METHODS:Measurements of the superior ala and inferior turbinates were taken from the post-operative CBCT. RESULTS:The sample included 26 males and 8 females, 12 right- and 22 left-sided clefts. The inferior turbinates are above the superior alar crease at a rate of 73.53% and 76.48% on the cleft and non-cleft sides, respectively. One (2.9%) osteotomy cut was above the level of the cleft superior alar crease, and no cuts were above the level of the non-cleft superior ala. On average, the superior ala was 2.63 mm below the inferior turbinates. The average vertical distances from the superior alar crease and the inferior turbinates to the base of the non-cleft side pyriform aperture were 12.17 mm (95% CI 4.00-20.34) and 14.80 mm (95% CI 4.61-24.98), respectively. To complete a "high osteotomy," with 95% confidence, the cut should be 20.36 mm from the base of the pyriform aperture. CONCLUSIONS:A "high" osteotomy is not consistently possible due to the relationship between the superior alar crease and the inferior turbinate.

Non-resorbable dental barrier membranes entail the risk of dehiscence due to their smooth and functionally inert surfaces. Non-thermal plasma (NTP) treatment has been shown to increase the hydrophilicity of a biomaterials and could thereby enhance cellular adhesion. This study aimed to elucidate the role of allyl alcohol NTP treatment of poly(tetrafluoroethylene) in its cellular adhesion. The materials (non-treated PTFE membranes (NTMem) and NTP-treated PTFE membranes (PTMem)) were subjected to characterization using scanning electron microscopy (SEM), contact angle measurements, X-ray photoelectron spectroscopy (XPS), and electron spectroscopy for chemical analysis (ESCA). Cells were seeded upon the different membranes, and cellular adhesion was analyzed qualitatively and quantitatively using fluorescence labeling and a hemocytometer, respectively. PTMem exhibited higher surface energies and the incorporation of reactive functional groups. NTP altered the surface topography and chemistry of PTFE membranes, as seen through SEM, XPS and ESCA, with partial defluorination and polymer chain breakage. Fluorescence labeling indicated significantly higher cell populations on PTMem relative to its untreated counterparts (NTMem). The results of this study support the potential applicability of allyl alcohol NTP treatment for polymeric biomaterials such as PTFE-to increase cellular adhesion for use as dental barrier membranes.

CASE/METHODS:Given the rare incidence of sternal nonunion after traumatic injury, literature describing the management of posttraumatic sternal reconstruction is limited. We present a case of a 54-year-old man with a history of traumatic chest wall injury with multiple unsuccessful attempts at sternal repair who presented with chronic sternal nonunion and persistent bone defect. Sternal reconstruction using a vascularized double-barrel free fibula flap with rigid fixation in multiple planes was performed, with confirmed bony union at 6 months. CONCLUSION/CONCLUSIONS:This novel approach to sternal nonunion management allowed effective bridging of posttraumatic sternal bone defects while facilitating osseous integration and long-term stabilization.

BACKGROUND:The incidence of transgender adolescents seeking gender affirming surgery (GAS) in increasing. Surgical care of the adolescent transgender patient is associated with several unique technical, legal, and ethical factors. The authors present a review of the current literature on gender affirming surgery for individuals under the age of legal majority and propose directions for future research. METHODS:A scoping review of recent literature was performed to assess evidence on gender affirming surgery in individuals under the age of legal majority. Papers were included that examined either ethical or technical factors unique to pediatric GAS. Study characteristics and conclusions were analyzed in conjunction with expert opinion. RESULTS:Twelve papers were identified meeting inclusion criteria. Ten of these papers discussed ethical challenges in adolescent GAS, seven papers discussed legal challenges, and five papers discussed technical challenges. Ethical discussions focused on the principles of beneficence, nonmaleficence, and autonomy. Legal discussions centered on informed consent and insurance coverage. Technical discussions focused on the impact of puberty blockade on natal tissue. CONCLUSIONS:Surgical care of the adolescent transgender patient involves important ethical, legal, and technical considerations that must be addressed by the clinical team. As the population of individuals seeking GAS after puberty blockade increases, future research is needed describing functional and psychosocial outcomes in these individuals.