Faculty Bibliography

Fused Filament Fabrication (FFF)-based 3D printing is an efficient technique for developing medical implants, but it is not very useful in developing small yet mechanically robust design-specific fixtures such as dental implants (<15 mm). Specifically, it is challenging to 3D print robust Polyetheretherketone (PEEK) small implants due to PEEK's high melting temperature and melt viscosity. However, in this study, we efficiently utilize high-temperature FFF to develop the first-of-its-kind patient-specific robust PEEK dental implants with high print resolution. Specifically, we explore the effects of critical FFF processing conditions on the mechanical properties of the implants and subsequently determine an optimized set of processing conditions that are essential in developing durable dental implant systems. Our results indicate that the 3D printed dental implants exhibit good fatigue properties and suffice the clinical and industrial requirements for dental implants. Furthermore, we prove that the 3D printed implants exhibit adequate mechanical durability even after simulated (accelerated) aging of 30 years.

Intensive postoperative rehabilitation therapy is associated with positive functional recovery in hand transplants (HTs). Our goal is to share the hand therapy protocol developed for our patient who underwent a combined face and bilateral HT. The patient is a 23-year-old right-hand-dominant male with a history of third-degree burns to 80% of his body following a motor vehicle accident. A multidisciplinary evaluation established his candidacy for a combined face and bilateral HT, and surgery took place in August 2020. Our individualized hand therapy protocol consisted of 4 phases. The pre-surgery phase focused on planning the orthotics and patient/caregivers' education on the rehabilitation process. The intensive care unit (ICU)/acute care phase involved hand allograft protection and positioning via orthotic fabrication, safe limb handling, and edema/wound management. The inpatient rehabilitation phase aimed to prepare the patient for independent living via neuromuscular and sensory re-education, improvement of upper extremities strength/flexibility, training basic activities of daily living, and providing a home exercise program (HEP). Finally, the outpatient phase aimed to maximize our patient's range of motion and independency in performing his routine activities and HEP. The patient's post-transplant functional outcomes showed a significant improvement compared to the pre-operative baseline. We hope this report sheds light on a comprehensive hand therapy program in HT.

OBJECTIVE:The aim of this study was to evaluate the outcomes of orthognathic surgery (OGS) in patients with craniofacial microsomia (CFM) who had previously undergone mandibular distraction osteogenesis (MDO). DESIGN/METHODS:A retrospective cohort study was performed including all patients with CFM who were treated with OGS at a single institution between 1996 and 2019. The clinical records, operative reports, and cone beam computed tomography (CBCT) scans were reviewed. CBCT data before OGS (T1), immediately after OGS (T2), and at long-term follow-up (T3) were analyzed using Dolphin three-dimensional software to measure the occlusal cant and chin point deviation. RESULTS:  =  .808). CONCLUSIONS:Within the limitations of this study, these findings suggest that OGS after MDO in patients with CFM can produce stable results.

BACKGROUND:Despite the increased utilization of nipple-sparing mastectomies (NSM), there is limited data examining long-term cancer recurrence rates in these patients. The objective of this study was to analyze breast cancer recurrence in patients who received therapeutic NSM with a median of 10 years of follow-up. METHODS:All patients undergoing NSM at a single institution were retrospectively reviewed temporally to obtain a median of 10-years of follow up. Patient demographic factors, mastectomy specimen pathology, and oncologic outcomes were analyzed. Univariate analysis was performed to identify independent risk factors for locoregional recurrence. RESULTS:126 therapeutic NSM were performed on 120 patients. The most frequently observed tumor histology included invasive ductal carcinoma (48.4%) and ductal carcinoma in situ (38.1%). Mean tumor size was 1.62 cm. Multifocal or multicentric disease and lymphovascular invasion were present in 31.0% and 10.3% of NSM specimens, respectively. Sentinel lymph node biopsy was performed in 84.9% of NSM and 17.8% were positive. The rate of positive frozen subareolar biopsy was 7.3% (n=82) and permanent subareolar pathology was 9.5% (n=126). The most frequently observed pathologic tumor stages was stage I (44.6%) and stage 0 (33.9%). Incidence of recurrent disease was 3.17% per mastectomy and 3.33% per patient. Upon univariate analysis, no demographic, operative, or tumor-specific variables were independent risk factors for locoregional recurrence. CONCLUSIONS:Overall recurrence rates are low in patients undergoing NSM at a median follow-up of 10-years. Close surveillance should remain a goal for patients and their providers to promptly identify potential recurrence.

BACKGROUND:There is a paucity of data on the impact of cytomegalovirus (CMV) serostatus and CMV infection on outcomes in facial vascularized composite allotransplantation. METHODS:This international, multicenter, retrospective cohort study presents data on CMV and basic transplant-related demographics, including pretransplant viral D/R serostatus, and duration of antiviral prophylaxis. CMV-related complications (viremia, disease), allograft-related complications (rejection episodes, loss), and mortality were analyzed. RESULTS:We included 19 patients, 4 of whom received CMV high-risk transplants (D+/R-). CMV viremia was noted in 6 patients (all 4 D+/R- patients and 2 D-/R+), mostly within the first-year posttransplant, shortly after discontinuation of antiviral prophylaxis (median 2 mo). CMV disease occurred in 2 D+/R- patients. The high-risk group experienced relatively more rejection episodes per month follow-up. None of D+/R- patients suffered allograft loss due to rejection (longest follow-up: 121 mo). CONCLUSIONS:D+/R- patients were at increased risk of CMV-related complications. Although a higher number of rejections was noted in this group, none of the D+/R- patients lost their allograft or died because of CMV or rejection. Thus, CMV D+/R- face transplantation can likely be safely performed with prophylaxis, active surveillance, and prompt treatment.

OBJECTIVE:This study aims to develop guidelines for the transfer of patients with isolated craniomaxillofacial (CMF) trauma. METHODS:A national, multidisciplinary, expert panel was assembled from leadership in national organizations and contributors to published literature on facial reconstruction. The final panel consisted of five plastic surgeons, four otolaryngologist-head and neck surgeons, and four oral and maxillofacial surgeons. The expert panelist's opinions on transfer guidelines were collected using the modified Delphi process. Consensus was pre-defined as ≥ 90% agreement per statement. RESULTS:After 4 Delphi consensus building rounds, 13 transfer guidelines were established, including statements on fractures of the frontal sinus, orbit, midface and mandible, as well as soft tissue injuries. Twelve guidelines reached consensus. CONCLUSIONS:The decision to transfer a patient with CMF trauma to another facility is complex and multifactorial. While a percentage of overtriage is acceptable to promote safe disposition of trauma patients, unnecessarily high rates of secondary overtriage divert emergency medical services, increase costs, delay care, overload tertiary trauma centers, and result in tertiary hospital staff providing primary emergency coverage for referring hospitals. These CMF transfer guidelines were designed to serve as a tool to improve, and safely streamline, the care of facial trauma patients. Such efforts may decrease the additional healthcare expenditures associated with secondary overtriage while decompressing emergency medical systems and tertiary emergency departments.

Bone defects are associated with trauma, congenital disorders, non-unions, or infections following surgical procedures. Defects which are unable to heal spontaneously are categorized as "critical sized" and are commonly treated using bone grafts in an effort to facilitate bone regeneration and stabilization. Grafting materials can be either natural or synthetic, each having their respective advantages and disadvantages. Synthetic bone grafts are favored due to their ability to be tailored to exhibit desired properties and geometric configurations. β-tricalcium phosphate (β-TCP) is a synthetic grafting material that has been widely utilized for regenerative purposes due to its favorable osteoconductive properties. In combination with 3D printing, grafting materials can be further customized with respect to their macro and micro features. One way to customize devices is by using 3D printing and varying the surface area, by varying the internal component measurements. The objective of this study was to compare the effect of porosity and surface area of 3D printed β-TCP scaffolds with different strut diameters and the effect on cell proliferation in vitro. ß-TCP scaffolds were printed using a custom-built 3D direct-write micro printer with syringes equipped with different extrusion tip diameters (fdiameter: 200 µm, 250 µm and 330 µm). After sintering and post processing, scaffolds were subjected to micro-computed tomography (µCT) and a Scanning Electron Microscope (SEM) to evaluate surface area and porosity, respectively. Compressive strength was assessed using a universal testing machine. Cell proliferation was assessed through cellular viability, using human osteoprogenitor cells. The surface area of the scaffolds was found to increase with smaller strut diameters. Statistically significant differences (p<0.05) were detected for cellular proliferation, between the smallest extrusion diameter, 200 μm, and the largest diameter, 330 μm, after 48-, 72-, and 168-hours. No statistical significances were detected (p>0.05) with regards to the mechanical properties between groups. This study demonstrated that a smaller diameter rod yielded a higher surface area resulting in increased levels of cellular proliferation. Therefore, tailoring rod dimensions has the capacity to enhance cellular adhesion and ultimately, proliferation.