Faculty Bibliography

PURPOSE: To evaluate the reliability of narrow diameter dental implants (NDIs) with similar macrogeometry and 3 implant-abutment connection designs. MATERIALS AND METHODS: Eighty-four NDIs (3.5 x 10 mm) were selected and divided into 4 groups (n = 21/group) according to implant-abutment connection design, as follows:

BACKGROUND:Barbed sutures have become increasingly popular in the field of aesthetic plastic surgery, particularly in body contouring and breast surgeries, in which the use of barbed sutures may offer both time and cost savings. Scar aesthetics is an important outcome for both the surgeons and patients in these procedures; however, there is a paucity of studies assessing the aesthetic outcome of barbed sutures with regards to scarring. METHODS:A systematic review of PubMed, EMBASE, and Cochrane databases was performed from the date of their inception through July 2017 using the search terms barbed suture combined with scar or wound. Studies were included if they were prospective evaluator-blind randomized controlled trials, closed the dermal layer of incisions using barbed sutures, and included an evaluator-blind aesthetic assessment of scarring. RESULTS:Six prospective randomized controlled trials met inclusion criteria. The cosmetic result of scars in 926 patients was evaluated after an average of 8.1 months. Five of the 6 controlled trials found the aesthetic results of wounds closed with barbed sutures to be equivalent to those closed with traditional sutures, and 1 study showed significantly superior aesthetic results with barbed sutures. Use of barbed sutures resulted in shorter operating times in 4 of the 5 studies that timed incision closure. Similar complication rates were observed in all evaluated studies. CONCLUSION/CONCLUSIONS:Based on this systematic review, the majority of studies concluded that there were no differences in scarring aesthetics when dermal layers were closed using barbed sutures compared with traditional suturing techniques.

: The first facial transplantation in 2005 ushered in a new era in reconstructive surgery, offering new possibilities for the repair of severe disfigurements previously limited by conventional techniques. Advances in allograft design, computerized preoperative planning, surgical technique, and postoperative revisions have helped push the boundaries in this new frontier of vascularized composite allotransplantation. Over the past 12 years, 40 of these procedures have been performed across the world, offering the field the opportunity to reflect on current outcomes. Successes achieved in the brief history of facial transplantation have resulted in a new set of obstacles the field must now overcome. In this review, we aim to highlight the achievements, major challenges, and future directions of this rapidly evolving field.

BACKGROUND:Concerns exist that immediate breast reconstruction may delay adjuvant chemotherapy initiation, impacting oncologic outcomes. Here, we determine how post-operative complications impact chemotherapy timing, and identify factors associated with greater risk for delays. METHODS:Retrospective chart review identified patients undergoing immediate breast reconstruction and adjuvant chemotherapy at a single institution from 2010 to 2015. Patients were analyzed based on occurrence of post-operative complications and time to chemotherapy. RESULTS:A total of 182 patients (244 breast reconstructions) were included in the study; 210 (86%) reconstructions did not experience post-operative complications, 34 (13.9%) did. Patients who experienced post-operative complications had a higher mean age (53.6 vs. 48.1 years, p=0.002), and higher rates of diabetes (23.5% vs. 3.8%, p<0.001).The complication group had delays in initiation of chemotherapy (56 vs. 45 days, p=0.017). Only the immediate autologous reconstruction subgroup demonstrated a statistically significant delay in initiation of chemotherapy.Patients who initiated chemotherapy >48.5 days were of higher mean age (55.9 vs. 50.7 years, p=0.074), had increased rates of diabetes (36.8% vs. 6.7%, p=0.053), and immediate autologous reconstruction (31.6% vs. 0%, p=0.027). A predictive model based on these findings determined that patients with at least 1 of these 3 risk factors have a 74% chance of experiencing prolonged times to chemotherapy initiation vs. 18% without risk factors (p=0.003). CONCLUSIONS:Risk factors for delayed chemotherapy in the context of post-operative complications are age >51.7 years, diabetes, and autologous reconstruction. Reconstructive candidates who fit this profile are at highest risk and merit extra consideration and counseling.

OBJECTIVES/OBJECTIVE:To investigate how muscle and fasciocutaneous flaps influence the progression of bone healing in acute Gustilo IIIB tibia fractures. DESIGN/METHODS:Retrospective Chart Review. SETTING/METHODS:Urban Academic Level I Trauma Center. PATIENTS/PARTICIPANTS/METHODS:Between 2006 and 2016, 39 patients from a database of operatively treated long bone fractures met the inclusion criteria, which consisted of adults with acute Gustilo IIIB tibia shaft fracture requiring flap coverage and having at least 6 months of radiographic follow-up. INTERVENTION/METHODS:Soft tissue coverage for patients with Gustilo IIIB open tibia fractures was performed with either a muscle flap or fasciocutaneous flap. MAIN OUTCOME MEASUREMENTS/METHODS:A radiographic union score for tibia (RUST) fractures, used to evaluate fracture healing, was assigned to patients' radiographs postoperatively, at 3, 6, and 12 months from the initial fracture date. Mean RUST scores at these time points were compared between those of patients with muscle flaps and fasciocutaneous flaps. Union was defined as a RUST score of 10 or higher. RESULTS:There was a significant difference (P = 0.026) in the mean RUST score at 6 months between the muscle group (8.54 ± 1.81) and the fasciocutaneous group (6.92 ± 2.46). There was no significant difference in the mean RUST score at 3 months (P = 0.056) and at 12 months (P = 0.947) between the 2 groups. There was also significance in the number of fractures reaching union, favoring muscle flaps, at 6 months (P = 0.020). CONCLUSIONS:Patients with acute Gustilo IIIB tibia fractures who received muscle flaps have significantly faster radiographic progression of bone healing in the first 6 months than do patients who received fasciocutaneous flaps. Furthermore, according to radiographic evaluation, more Gustilo IIIB tibia fractures receiving muscle flaps reach union by 6 months than those flapped with fasciocutaneous tissue. LEVEL OF EVIDENCE/METHODS:Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

BACKGROUND:Initially performed only in prophylactic cases, indications for nipple-sparing mastectomy have expanded. Trends and surgical outcomes stratified by nipple-sparing mastectomy indication have not yet been fully examined. METHODS:Demographics and outcomes for all nipple-sparing mastectomies performed from 2006 to 2017 were compared by mastectomy indication. RESULTS:A total of 1212 nipple-sparing mastectomies were performed: 496 (40.9 percent) for therapeutic and 716 (59.1 percent) for prophylactic indications. Follow-up time was similar between both the therapeutic and prophylactic nipple-sparing mastectomy groups (47.35 versus 46.83 months, respectively; p = 0.7942). Therapeutic nipple-sparing mastectomies experienced significantly greater rates of major (p = 0.0165) and minor (p = 0.0421) infection, implant loss (p = 0.0098), reconstructive failure (p = 0.0058), and seroma (p = 0.0043). Rates of major (p = 0.4461) and minor (p = 0.2673) mastectomy flap necrosis and complete (p = 0.3445) and partial (p = 0.7120) nipple necrosis were equivalent. The overall rate of locoregional recurrence/occurrence per nipple-sparing mastectomy was 0.9 percent: 2.0 percent in therapeutic nipple-sparing mastectomies and 0.1 percent in prophylactic nipple-sparing mastectomies (p < 0.0001). CONCLUSIONS:Approximately 40 percent of nipple-sparing mastectomies are currently performed for therapeutic indications. Therapeutic nipple-sparing mastectomies had higher rates of infectious complications and reconstructive failure. Rates of locoregional cancer recurrence/occurrence are low, but occur significantly more often after therapeutic nipple-sparing mastectomy. CLINICAL QUESTION/LEVEL OF EVIDENCE/METHODS:Therapeutic, III.

Once activated at the surface of cells, G protein-coupled receptors (GPCRs) redistribute to endosomes, where they can continue to signal. Whether GPCRs in endosomes generate signals that contribute to human disease is unknown. We evaluated endosomal signaling of protease-activated receptor-2 (PAR₂), which has been proposed to mediate pain in patients with irritable bowel syndrome (IBS). Trypsin, elastase, and cathepsin S, which are activated in the colonic mucosa of patients with IBS and in experimental animals with colitis, caused persistent PAR₂-dependent hyperexcitability of nociceptors, sensitization of colonic afferent neurons to mechanical stimuli, and somatic mechanical allodynia. Inhibitors of clathrin- and dynamin-dependent endocytosis and of mitogen-activated protein kinase kinase-1 prevented trypsin-induced hyperexcitability, sensitization, and allodynia. However, they did not affect elastase- or cathepsin S-induced hyperexcitability, sensitization, or allodynia. Trypsin stimulated endocytosis of PAR₂, which signaled from endosomes to activate extracellular signal-regulated kinase. Elastase and cathepsin S did not stimulate endocytosis of PAR₂, which signaled from the plasma membrane to activate adenylyl cyclase. Biopsies of colonic mucosa from IBS patients released proteases that induced persistent PAR₂-dependent hyperexcitability of nociceptors, and PAR₂ association with β-arrestins, which mediate endocytosis. Conjugation to cholestanol promoted delivery and retention of antagonists in endosomes containing PAR₂ A cholestanol-conjugated PAR₂ antagonist prevented persistent trypsin- and IBS protease-induced hyperexcitability of nociceptors. The results reveal that PAR₂ signaling from endosomes underlies the persistent hyperexcitability of nociceptors that mediates chronic pain of IBS. Endosomally targeted PAR₂ antagonists are potential therapies for IBS pain. GPCRs in endosomes transmit signals that contribute to human diseases.

Abnormal pigmentation is commonly seen in the wound scar. Despite advancements in the research of wound healing, little is known about the repopulation of melanocytes in the healed skin. Previous studies have demonstrated the capacity of melanocyte stem cells (McSCs) in the hair follicle to contribute skin epidermal melanocytes following injury in mice and humans. Here, we focused on the Wnt pathway, known to be a vital regulator of McSCs in efforts to better understand the regulation of follicle-derived epidermal melanocytes during wound healing. We showed that transgenic expression of Wnt inhibitor, Dkk1 in melanocytes reduced epidermal melanocytes in the wound scar. Conversely, forced activation of Wnt signaling by genetically stabilizing β-catenin in melanocytes increases epidermal melanocytes. Furthermore, we reveal that deletion of Wntless, a gene required for Wnt ligand secretion, within epithelial cells, results in failure in activating Wnt signaling in adjacent epidermal melanocytes. These results reveal the essential function of extrinsic Wnt ligands to initiate Wnt signaling in follicle-derived epidermal melanocytes during wound healing. Collectively, our results suggest the potential for Wnt signal regulation to promote melanocyte regeneration and provide a potential molecular window to promote proper melanocyte regeneration following wounding as well as in conditions such as vitiligo.

Ionizing radiation is a known carcinogen. Its damaging effects can be deterministic or stochastic. Deterministic effects occur only after radiation exposure thresholds are reached, but stochastic effects are random, and there is no known threshold below which harmful effects will not occur. Therefore, the use of ionizing radiation in orthodontic treatment should bring a benefit to the patient that outweighs the risks. No legally binding statutes, rules, or regulations provide explicit radiographic prescription protocols for orthodontic practice. The objective of this article was to discuss guidelines and risk management strategies for appropriate and defensible use of ionizing radiation in orthodontics. Guidelines are discussed for radiographic acquisition at different points along the orthodontic treatment timeline. In addition, risk management strategies and best practices are presented regarding adequate and defensible radiographic interpretation. These guidelines are not rigid and do not establish standards of care; they should be modified as necessary for each patient and each clinical encounter.