Faculty Bibliography

Aged skin heals wounds poorly, increasing susceptibility to infections. Restoring homeostasis after wounding requires the coordinated actions of epidermal and immune cells. Here we find that both intrinsic defects and communication with immune cells are impaired in aged keratinocytes, diminishing their efficiency in restoring the skin barrier after wounding. At the wound-edge, aged keratinocytes display reduced proliferation and migration. They also exhibit a dampened ability to transcriptionally activate epithelial-immune crosstalk regulators, including a failure to properly activate/maintain dendritic epithelial T cells (DETCs), which promote re-epithelialization following injury. Probing mechanism, we find that aged keratinocytes near the wound edge don't efficiently upregulate Skints or activate STAT3. Notably, when epidermal Stat3, Skints, or DETCs are silenced in young skin, re-epithelialization following wounding is perturbed. These findings underscore epithelial-immune crosstalk perturbations in general, and Skints in particular, as critical mediators in the age-related decline in wound-repair.

The gain of eccrine sweat glands in hairy body skin has empowered humans to run marathons and tolerate temperature extremes. Epithelial-mesenchymal cross-talk is integral to the diverse patterning of skin appendages, but the molecular events underlying their specification remain largely unknown. Using genome-wide analyses and functional studies, we show that sweat glands are specified by mesenchymal-derived bone morphogenetic proteins (BMPs) and fibroblast growth factors that signal to epithelial buds and suppress epithelial-derived sonic hedgehog (SHH) production. Conversely, hair follicles are specified when mesenchymal BMP signaling is blocked, permitting SHH production. Fate determination is confined to a critical developmental window and is regionally specified in mice. In contrast, a shift from hair to gland fates is achieved in humans when a spike in BMP silences SHH during the final embryonic wave(s) of bud morphogenesis.

Radiation therapy (RT) is and essential treatment for many oral cavity and oropharynx tumors. However, radiation may cause significant long-term morbidity for survivors. A serious jaw complication from radiation includes osteoradionecrosis (ORN) requiring mandibulectomy and reconstruction, which has significant medical, economic, and quality of life implications for affected patients. Reconstructing ORN defects is challenging due to late effects of radiotherapy on bone and soft tissue tissues resulting in severe fibrosis and possibly infected wound environments. Microvascular free flaps (MVFF) are commonly used for mandibular reconstruction in ORN. When MVFF reconstructions are contraindicated, regional pedicle flaps combined with rigid fixation and autologous bone grafts are commonly reported options that can provide satisfactory functional and aesthetic outcomes. In the present case report we describe an osteomyocutaneous rotational flap using a rib to reconstruct a continuity defect due to ORN. The patient is a 64-year-old female with a history of successful simple surgical treatment for ORN of the left body of the mandible that included hyperbaric oxygen (HBO) therapy who developed ORN and pathologic fracture of the right body of the mandible. Another long-term concern was the prognosis for the clinically healed left mandible. Treatment options were presented to the patient including a microvascular osteocutaneous fibula free flap. However, the patient's ambulation and recovery time was a major concern and she preferred an osteomyocutaneous pectoralis major rib graft. The risks and benefits of both options were discussed. Three months postoperatively she developed an extraoral soft tissue dehiscence with exposure of the plate without infection. Computed tomography seven months postoperatively demonstrated a bone union of the rib at both the proximal and distal resection margins. She subsequently underwent examination of the graft which was found to be healed. The reconstruction plate was removed and the cutaneous defect was repaired using a full thickness skin graft to the right mandible. Reports on vascularized osteocutaneous rib grafts to reconstruct the mandible for ORN have been brief.1 Reconstruction of the mandible using rib has been reported primarily as a free bone graft.2,3 Additional considerations for our patient with a history of ORN of the left mandible include: the 25% failure rate associated with simple surgical treatment (i.e., sequestrectomy),4 the controversial efficacy of perioperative HBO therapy 5,6 and the increased risk of ORN over time.7An osteomyocutaneous pectoralis major rib graft was able to restore continuity of the right mandible and maintain the option for a microvascular fibula graft in the event of recurrent ORN in either or both sides of the mandible. The limitations for this option are the size of the defect and inability to place dental implants. The conclusion from this case report is that a rotational osteomyocutaneous rib graft may be an option for some patients with ORN

The fibula microvascular free flap is widely used for mandible reconstruction including patients with medication- related osteonecrosis of the jaw(MRONJ) who are refractory to conservative management.1 In comparison with other free flaps used in mandible reconstruction, the fibula provides the greatest bone length and provides soft tissue replacement. While the fibula has little effect on bearing weight, it is an essential insertion for the biceps femoris muscle, one of the hamstrings, which assists in flexion of the knee as well as rotation of the leg. In addition, it is an attachment of the fibular collateral ligament, a structural component of the knee joint.2 There is a paucity of literature related to the feasibility of mandible reconstruction utilizing a microvascular free fibula flap in a patient with previous knee replacement surgery. Our patient is a 60-year-old female diagnosed with medication-related osteonecrosis of the jaw (MRONJ). She was refractory to multiple courses of antibiotic therapy and oral rinses. Upon physical examination, intraorally she has draining fistula at the right body of the mandible. Computed tomography of the mandible was significant for osteolytic bone destruction from at the body of the right mandible and nearing the inferior border. Her concerning surgical history included bilateral knee replacements which was taken into consideration during surgical planning. Due to the size of the planned defect, reconstruction with a fibula microvascular free flap was planned using virtual surgical planning (Medical Modeling Inc., Golden CO) and a prefabricated reconstruction plate (Stryker, Kalamazoo, MI). The surgical procedure included a tracheostomy, segmental resection of the right body of the mandible, rigid fixation, extraction of all teeth and microvascular fibular free flap reconstruction. The patient continued physical therapy and occupational therapy and became full weight bearing 12-days postoperatively. The patient was back to her preoperative ambulatory status one month after surgery. An English language search of three databases (PubMed, Science Direct, OvidMD) was performed to determine if a microvascular free fibula flap had been attempted in a patient with a history of knee replacement. The dearth of literature related to this concern lead to an interdisciplinary meeting between the Oral and Maxillofacial Surgery, Plastic Surgery, and Orthopaedic Surgery services to review the feasibility and risks for the proposed reconstruction in our patient. It was determined that as long as 10 cm of superior bone was to remain in place, the stability of the patient's knee should not be compromised. We conclude that microvascular fibular graft reconstruction of the mandible remains an option for patients with bilateral knee replacement

Neurologic diseases can have a major impact on functional capacity. Patients with neurologic disease require individualized management considerations depending on the extent of impairment and impact on functional capacity. This article reviews 4 of the more common and significant neurologic diseases (Alzheimer disease, cerebrovascular accident/stroke, multiple sclerosis, and Parkinson disease) that are likely to present to a dental office and provides suggestions on the dental management of patients with these conditions.

PURPOSE: To compile the current evidence on biomechanical, biologic, and clinical outcomes of undersized surgical preparation protocols in dental implant surgery. MATERIALS AND METHODS: An electronic search using three different databases (PubMed, Web of Science, and Cochrane Library) and a manual hand search were performed including in vitro, animal, and clinical studies published prior to October 2015. Studies in which an undersized drilling protocol was compared with a nonundersized drilling protocol were included. RESULTS: From an initial selection of 1,655 titles, 29 studies met the inclusion criteria, including 14 biomechanical, 7 biologic, 6 biologic and biomechanical, and 2 clinical. Due to methodologic variation, meta-analysis was not performed. Several studies showed that implants inserted with an undersized drilling approach reached a significantly higher insertion torque value than conventional drilling in low-density substrates, while this effect is less evident if a thick cortical layer is present. Similar results in terms of boneto-implant contact (BIC) were achieved in the longer term between implants inserted with undersized and nonundersized protocols. Results in the short term were inconclusive. Clinical studies did not show negative outcomes for undersized drilling, although clinical evidence was sparse. No data are available on marginal bone loss. CONCLUSION: From the biomechanical standpoint, an undersized drilling protocol is effective in increasing insertion torque in low-density bone. Biologic response in long-term healing after undersized implant placement is comparable to that in the nonundersized surgical drilling protocol. Clinical studies indicate that performing an undersized drilling protocol on low-density bone is a safe procedure; however, more extensive studies are needed to confirm these data.

Lymphedema is a debilitating disease that is commonly caused by cancer and it is treatments in the developed world. Surgery is an option for refractory disease. Lymphovenous bypass and vascularized lymph node transfer are newer modalities that show great promise. Further work is necessary to determine proper patient selection and ensure minimum donor site morbidity. Liposuction and direct excision still have a role, especially in advanced cases. Further investigations into prevention of iatrogenic lymphedema are underway. J. Surg. Oncol. 2016;113:932-939. (c) 2016 Wiley Periodicals, Inc.

Background The time to detection of vascular compromise is a significant predictor of free flap salvage outcomes as early reexploration improves salvage rates. Continuous transcutaneous near-infrared tissue oximetry is an objective, quantitative method of detecting flap vascular compromise and has been shown to allow earlier reexploration and higher salvage rates than clinical assessment alone. We designed a novel text messaging system to improve communication using tissue oximetry monitoring. Methods A retrospective review was performed of a prospectively collected database of all microsurgical breast reconstructions from 2008 to 2015. A novel text messaging system was introduced in 2013 and programmed to send text messages alert when the tissue oximetry readings suggested potential flap compromise based on established thresholds. Patient demographics and complications, including rate of reexploration and flap loss were assessed. Results There were 900 autologous microsurgical breast free flaps during the study period: 614 were monitored with standard clinical monitoring and tissue oximetry compared with 286 flaps with the additional text messaging system. There were 27 unplanned returns to the operating room in the tissue oximetry group and 5 in the text messaging group with 1 complete flap loss in each group. Reexploration occurred sooner as a result of these text message alerts (17.5 vs. 26.6 hours postoperatively), however, it did not achieve statistical significance. Conclusions We were able to demonstrate the use of a novel text messaging system for tissue oximetry. This alert system shows promise in identifying impending flap loss with rapid notification of the surgical team.