Faculty Bibliography

G protein-coupled receptors (GPCRs) regulate many pathophysiological processes and are major therapeutic targets. The impact of disease on the subcellular distribution and function of GPCRs is poorly understood. We investigated trafficking and signaling of protease-activated receptor 2 (PAR₂) in colitis. To localize PAR₂ and assess redistribution during disease, we generated knockin mice expressing PAR₂ fused to monomeric ultrastable green fluorescent protein (muGFP). PAR₂-muGFP signaled and trafficked normally. PAR₂ messenger RNA was detected at similar levels in Par₂-mugfp and wild-type mice. Immunostaining with a GFP antibody and RNAScope in situ hybridization using F2rl1 (PAR₂) and Gfp probes revealed that PAR₂-muGFP was expressed in epithelial cells of the small and large intestine and in subsets of enteric and dorsal root ganglia neurons. In healthy mice, PAR₂-muGFP was prominently localized to the basolateral membrane of colonocytes. In mice with colitis, PAR₂-muGFP was depleted from the plasma membrane of colonocytes and redistributed to early endosomes, consistent with generation of proinflammatory proteases that activate PAR₂ PAR₂ agonists stimulated endocytosis of PAR₂ and recruitment of Gα_q, Gα_i, and β-arrestin to early endosomes of T84 colon carcinoma cells. PAR₂ agonists increased paracellular permeability of colonic epithelial cells, induced colonic inflammation and hyperalgesia in mice, and stimulated proinflammatory cytokine release from segments of human colon. Knockdown of dynamin-2 (Dnm2), the major colonocyte isoform, and Dnm inhibition attenuated PAR₂ endocytosis, signaling complex assembly and colonic inflammation and hyperalgesia. Thus, PAR₂ endocytosis sustains protease-evoked inflammation and nociception and PAR₂ in endosomes is a potential therapeutic target for colitis.

Efficacy of monoclonal antibodies against calcitonin gene-related peptide (CGRP) or its receptor (calcitonin receptor-like receptor/receptor activity modifying protein-1, CLR/RAMP1) implicates peripherally-released CGRP in migraine pain. However, the site and mechanism of CGRP-evoked peripheral pain remain unclear. By cell-selective RAMP1 gene deletion, we reveal that CGRP released from mouse cutaneous trigeminal fibers targets CLR/RAMP1 on surrounding Schwann cells to evoke periorbital mechanical allodynia. CLR/RAMP1 activation in human and mouse Schwann cells generates long-lasting signals from endosomes that evoke cAMP-dependent formation of NO. NO, by gating Schwann cell transient receptor potential ankyrin 1 (TRPA1), releases ROS, which in a feed-forward manner sustain allodynia via nociceptor TRPA1. When encapsulated into nanoparticles that release cargo in acidified endosomes, a CLR/RAMP1 antagonist provides superior inhibition of CGRP signaling and allodynia in mice. Our data suggest that the CGRP-mediated neuronal/Schwann cell pathway mediates allodynia associated with neurogenic inflammation, contributing to the algesic action of CGRP in mice.

BACKGROUND:Patients with head and neck cancer (HNC) treated with radiation therapy (RT) are at risk for jaw osteoradionecrosis (ORN), which is largely characterized by the presence of exposed necrotic bone. This report describes the incidence and clinical course of and risk factors for exposed intraoral bone in the multicenter Observational Study of Dental Outcomes in Head and Neck Cancer Patients (OraRad) cohort. METHODS:Participants were evaluated before RT and at 6, 12, 18, and 24 months after RT. Exposed bone was characterized by location, sequestrum formation, and other associated features. The radiation dose to the affected area was determined, and the history of treatment for exposed bone was recorded. RESULTS:The study enrolled 572 participants; 35 (6.1%) were diagnosed with incident exposed bone at 6 (47% of reports), 12 (24%), 18 (20%), and 24 months (8%), with 60% being sequestrum and with 7 cases (20%) persisting for >6 months. The average maximum RT dose to the affected area of exposed bone was 5456 cGy (SD, 1768 cGy); the most frequent associated primary RT sites were the oropharynx (42.9%) and oral cavity (31.4%), and 76% of episodes occurred in the mandible. The diagnosis of ORN was confirmed in 18 participants for an incidence rate of 3.1% (18 of 572). Risk factors included pre-RT extractions (P = .008), a higher RT dose (P = .039), and tobacco use (P = .048). CONCLUSIONS:The 2-year incidence of exposed bone in the OraRad cohort was 6.1%; the incidence of confirmed ORN was 3.1%. Exposed bone after RT for HNC is relatively uncommon and, in most cases, is a short-term complication, not a recurring or persistent one.

Social interactions powerfully impact the brain and the body, but high-resolution descriptions of these important physical interactions and their neural correlates are lacking. Currently, most studies rely on labor-intensive methods such as manual annotation. Scalable and objective tracking methods are required to understand the neural circuits underlying social behavior. Here we describe a hardware/software system and analysis pipeline that combines 3D videography, deep learning, physical modeling, and GPU-accelerated robust optimization, with automatic analysis of neuronal receptive fields recorded in interacting mice. Our system ("3DDD Social Mouse Tracker") is capable of fully automatic multi-animal tracking with minimal errors (including in complete darkness) during complex, spontaneous social encounters, together with simultaneous electrophysiological recordings. We capture posture dynamics of multiple unmarked mice with high spatiotemporal precision (~2 mm, 60 frames/s). A statistical model that relates 3D behavior and neural activity reveals multiplexed 'social receptive fields' of neurons in barrel cortex. Our approach could be broadly useful for neurobehavioral studies of multiple animals interacting in complex low-light environments.

BACKGROUND:Transoral robotic surgery has been successfully used by head and neck surgeons for a variety of procedures but is limited by rigid instrumentation and line-of-sight visualization. Non-linear systems specifically designed for the aerodigestive tract are needed. Ease of use of these new systems in both training and clinical environments is critical in its widespread adoption. METHODS:Residents, fellows, and junior faculty performed four tasks on an anatomical airway mannequin using the Medrobotics FLEX™ Robotic System: expose and incise the tonsil, grasp the epiglottis, palpate the vocal processes, and grasp the interarytenoid space. These tasks were performed once a day for four days; after a 4-month time gap, subjects were asked to perform these same tasks for three more days. Time to task completion and total distance driven were tracked. In addition, a retrospective analysis was performed analyzing one attending physician's experience with clinical usage of the robot. RESULTS:13 subjects completed the initial round of the mannequin simulation and 8 subjects completed the additional testing 4 months later. Subjects rapidly improved their speed and efficiency at task completion. Junior residents were slower in most tasks initially compared to senior trainees but quickly reached similar levels of efficiency. Following the break there was minimal degradation in skills and continued improvement in efficiency was observed with additional trials. There was significant heterogeneity in the analyzed clinical cases, but when analyzing cases of similar complexity and pathology, clear decreases in overall operative times were demonstrable. CONCLUSION:Novice users quickly gained proficiency with the FLEX™ Robotic System in a training environment, and these skills are retained after several months. This learning could translate to the clinical setting if a proper training regimen is developed. The Medrobotics FLEX™ Robotic System shows promise as a surgical tool in head and neck surgery in this study.

STATEMENT OF PROBLEM/BACKGROUND:Understanding how maxillofacial prosthodontists are perceiving changes in head and neck care and the impact of advanced digital technologies on maxillofacial prosthodontics is important. However, no studies could be identified that specifically addressed these subjects. PURPOSE/OBJECTIVE:The purpose of this review of selected literature was to identify issues that guided the development of maxillofacial prosthodontics and the concerns that persist. The review also considered contemporary influences that will affect the future of maxillofacial prosthodontics. The conclusions of the review were used to interpret the results of the exploratory survey reported in Part II. MATERIAL AND METHODS/METHODS:The review of selected literature was related to the development of maxillofacial prosthodontics in North America between 1950 and 2018. Literature that was considered relevant to the purpose of the review was included. RESULTS:The review yielded 37 references of interest: 34 peer-reviewed publications, 1 guideline, 1 historical publication, and 1 website. Periods in the development of maxillofacial prosthodontics in North America were identified as formation, consolidation, and innovation. CONCLUSIONS:It was concluded that concerns in subspecialty programs and clinical practice had origins in the formation and consolidation periods. These persisting concerns extended into the innovation period. Contemporary influences in head and neck surgery will continue to affect the future of maxillofacial prosthodontics. Advanced digital technologies appeared to be central to driving change. Understanding the evolution of maxillofacial prosthodontics was an important first step in providing context when interpreting the results of a survey of maxillofacial prosthodontists reported as Part II of this work.

STATEMENT OF PROBLEM/BACKGROUND:Head and neck care has been transformed by the introduction of advanced digital technologies that will continue to be important change drivers for maxillofacial prosthodontics. Insight into these changes is important in answering the question of whether maxillofacial prosthodontics is appropriately prepared to contribute effectively to future multidisciplinary care of the head and neck. PURPOSE/OBJECTIVE:The purpose of this survey was to gain insight into the perception of changes experienced by maxillofacial prosthodontists in relation to clinical practice. The findings of this survey may assist the future development of the subspecialty. MATERIAL AND METHODS/METHODS:An exploratory cross-sectional survey was conducted by using a convenience sample of members of the American Academy of Maxillofacial Prosthetics. The survey considered 10 domains and 31 questions. Fully completed surveys (164) provided a 59% response. Descriptive statistics used percentage responses to reduce and characterize perceptions across respondents. RESULTS:Eighty-four percent of the respondents were from the United States. Results should be interpreted based on this cohort. Respondents reported a change in care delivered over the past 10 years (72%), with the most important causes of change attributed to surgery (60%) and advanced digital technologies (56%). Respondents perceived advanced digital technologies as being central to the future of maxillofacial prosthodontics (89%) and important in attracting younger colleagues (88%). Sixty-three percent believed training programs were not providing adequate education and training in the use of advanced digital technology. CONCLUSIONS:The perception of maxillofacial prosthodontists regarding changes taking place in care delivery was that the most important changes in the past 10 years were attributed to surgery and advanced digital technologies, that persisting pressures related to few institutional positions, that the subspecialty was poorly visible, that remuneration for care was inadequate and referring disciplines did not understand the subspecialty, that advanced digital technologies were considered central to the future of maxillofacial prosthodontics and important to attract younger colleagues to the subspecialty, that barriers to advanced digital technology use included funding for equipment acquisition, institutional funding support, and remuneration for their use in care delivery, and that maxillofacial prosthodontic programs were not providing adequate education and training in advanced digital technologies.

Gaining, improving, and maintaining nasal tip projection is one of the most essential elements of successful endonasal rhinoplasty. For years the hallmark of inadequate nasal tip projection following rhinoplasty has been the Polly beak deformity. Early rhinoplasty technique consisted of intracartilaginous excision of the cephalic margin of the lower lateral cartilages, cartilage and bony hump reduction, and osteotomies. Some of these simple rhinoplasties still look good decades later, however, many are conspicuous in their lack of nasal tip projection. The reason for this inconsistency in rhinoplasty results was the surgeon's inattention to the structural integrity and anatomical position of the LLC. The senior author uses a combination of suture, strut, and cartilage grafting techniques to achieve ideal projection in a manor tailored to each patient's unique anatomic needs.

Laryngeal inhalation injury carries a significant increase in mortality rate and often indicates immediate airway evaluation. This may be difficult in the setting of clinical deterioration necessitating immediate intubation, which itself can synergistically cause mucosal damage. Prior studies do not encompass predictive factors or long-term outcomes for the laryngotracheal complex. This systemic review of PubMed, Embase, and Cochrane identified studies investigating inhalational injuries of the upper airway. Demographic data as well as presentation, physical findings, and delayed sequelae were documented. Laryngotracheal burn patients were divided into two cohorts based on timing of laryngeal injury diagnosis (before- versus after-airway intervention). 1051 papers met initial search criteria and 43 studies were ultimately included. Airway stenosis was more common in patients that were intubated immediately (50.0%, n = 18 versus 5.2%, n = 13; p = 0.57). Posterior glottic involvement was only identified in patients intubated prior to airway evaluation (71.4%, n = 15). All studies reported a closed space setting for those patients in whom airway intervention preceded laryngeal evaluation. Laryngeal inhalational injuries are a distinct subset that can have a variety of minor to severe laryngotracheal delayed sequelae, particularly for thermal injuries occurring within enclosed spaces. Given these findings, early otolaryngology referral may mitigate or treat these effects.

OBJECTIVES/OBJECTIVE:Pain localized to the thyrohyoid region may be due to neuralgia of the superior laryngeal nerve (SLN), inflammation of the thyrohyoid complex, or a voice disorder. We present outcomes of treatment of paralaryngeal pain and odynophonia with SLN block. STUDY DESIGN/METHODS:Retrospective Review. METHODS:A retrospective chart review of patients undergoing in-office SLN block for paralaryngeal pain between 2015 and 2018 at two tertiary care centers was conducted. Patient demographics, indications, and response to treatment were analyzed. RESULTS:Thirty-eight patients underwent blockade of the internal branch of the SLN for paralaryngeal pain, with 10 excluded for incomplete medical records. Eighty-two percent (23/28) reported an improvement in their symptoms. Patients underwent an average of 2.5 blocks (SD = 1.88, range 1-8), with 10 patients (36%) undergoing a single procedure. Of the 18 patients who underwent multiple blocks, nine had eventual cessation of symptoms (50%) compared to resolution in 6/10 undergoing a single injection. Eleven patients (39%) noted odynophonia related to vocal effort, and all of these patients had improvement in or resolution of their symptoms and were more likely to improve compared to those without odynophonia (P = .006). Of the four patients who had a vocal process granuloma (VPG) at presentation, three had complete resolution of the lesion at follow-up. CONCLUSION/CONCLUSIONS:In-office SLN block is effective in the treatment of paralaryngeal pain. It may be used as an adjunct in the treatment of vocal process granulomas, as well as voice disorders where odynophonia is a prominent symptom. LEVEL OF EVIDENCE/METHODS:4 Laryngoscope, 2021.