Elucidation of a lingual detection mechanism for high-viscosity solutions in humans.

While perception of high-viscosity solutions (η > 1000 cP) is speculated to be linked to filiform papillae deformation, this has not been demonstrated psychophysically. Presently, just-noticeable-viscosity-difference thresholds were determined using the forced-choice staircase method and high-viscosity solutions (η = 4798-12260 cP) with the hypotheses that the tongue would be chiefly responsible for viscosity perception in the oral cavity, and that individuals with more, longer, narrower filiform papillae would show a greater acuity for viscosity perception. Subjects (n = 59) evaluated solutions in a normal, "unblocked" condition as well as in a "palate blocked" condition which isolated the tongue so that only perceptual mechanisms on the lingual tissue were engaged. Optical profiling was used to characterize papillary length, diameter, and density in tongue biopsies of a subset (n = 45) of participants. Finally, psychophysical and anatomical data were used to generate a novel model of the tongue surface as porous media to predict papillary deformation as a strain-detector for viscosity perception. Results suggest that viscosity thresholds are governed by filiform papillae features. Indeed, anatomical characterization of filiform papillae suggests sensitivity to high-viscosity solutions is associated with filiform papillae length and density (r = 0.68, p < 0.00001), but not with diameter. Modelling indicated this is likely due to a reciprocal interaction between papillae diameter and fluid shear stress. Papillae with larger diameters would result in higher viscous shear stress due to a narrower gap and stronger fluid-structure interaction, but a larger-diameter papilla would also deform less easily.

Medical Emergency Management in the Dental Office (MEMDO): A Pilot Study Assessing a Simulation-Based Training Curriculum for Dentists.

In the event of a medical emergency in the dental office, the dentist must be able to identify a patient in distress, assess the situation, and institute proper management. This study assessed the impact of a simulation-based medical emergency preparedness curriculum on a resident's ability to manage medical emergencies. This interventional and pre-post educational pilot study included 8 participants who completed a standard curriculum and 8 who completed a modified curriculum (N = 16). The intervention consisted of a comprehensive medical emergency preparedness curriculum that replaced lecture sessions in a standard curriculum. Participants completed performance assessments using scenario-based objective structured clinical examinations (OSCEs) that were recorded and evaluated by calibrated faculty reviewers using a customized scoring grid. The intervention group performed significantly better than the control group on their summative OSCEs, averaging 90.9 versus 61.2 points out of 128 (p = .0009). All participants from the intervention group passed their summative OSCE with scores >60%, while none from the control group received passing scores. Completion of a simulation-based medical emergency preparedness curriculum significantly improved resident performance during simulated medical emergencies.

Medical emergencies in the dental school setting.

PURPOSE/OBJECTIVES: An aging population with an increasing chronic disease burden may make management of medical emergencies in dental practice more common. Previous research has differed significantly in the reported frequency of medical emergencies in a dental setting, often relying on survey-based protocols. This study examines the incidence and type of emergencies encountered in a dental school setting. Additional examination of contributing medical co-morbidities is provided. METHODS: A retrospective study was designed to review 121 incident reports at the Ohio State University College of Dentistry (OSU CoD) from July 1, 2013 to January 24, 2019. Sixty-five of the recorded events were classified as medical emergencies and were further analyzed. RESULTS: The most common emergency encountered was syncope, followed by cardiac events, seizures, and diabetic complications. Emergencies most commonly occurred in the pre-doctoral general dentistry clinics. Many of the affected patients had no significant medical history. CONCLUSION: Identifying emergencies most encountered by dentists is critical for process improvement, awareness, and targeted educational initiatives. This may reduce the frequency of medical emergencies in dental practices and allow for more efficient management should they occur.

Effects of orthognathic surgery on quality of life compared with nonsurgical controls in an American population.

INTRODUCTION: To determine the psychosocial effects of a facial skeletal mal-relationship with its subsequent surgical correction in a group of patients treated using surgical orthodontics compared with a matched group of nontreated controls. METHODS: This study was approved by The Ohio State University Institutional Review Board. Subjects were patients presenting with facial skeletal mal-relationships whose proposed treatment plans included orthognathic surgery. This study used valid and reliable questionnaires: Orthognathic Quality of Life Questionnaire (OQLQ), Beck Depression Inventory II (Children's Depression Inventory - 2), Satisfaction with Life Scale, and State Trait Anxiety Inventory (State Trait Anxiety Inventory for Children), administered at 3 different stages of treatment (time 1 = initial pretreatment, time 2 = before oral surgery, and time 3 = at completion of treatment). Matched controls recruited at each time point completed the same questionnaires. RESULTS: A total of 267 subjects were recruited to participate in this study. There were no significant differences between treatment and control groups in age, sex, education level, or employment status at any of the 3 time points. The randomization test was used to compare values for all outcome variables between groups at the 3 stages of treatment. For the pretreatment period, T1, there were significant differences between patients and controls in domains 1 (P = 0.0126), 2 (P = 0.0000), and 3 (P = 0.0000) of the OQLQ (social aspects, facial esthetics, and oral function, respectively) as well as total OQLQ (P = 0.0000). For the presurgery period, T2, there were significant differences between patients and controls in domains 2 (P = 0.0136) and 3 (P = 0.0001) of the OQLQ (facial esthetics and oral function) as well as total OQLQ (P = 0.0291). Finally, for the posttreatment period, T3, there was a significant difference between patients and controls only in domain 3 (P = 0.0196) of the OQLQ (oral function). CONCLUSIONS: The psychosocial profile of patients with a facial skeletal mal-relationship does not differ from the general population in depression, anxiety, and overall satisfaction with life. However, these patients do report a reduced quality of life based on condition-specific measures in social aspects, facial esthetics, and oral function. Concerns about oral function remain even up to 2 years after treatment is completed.

Managing the Posterior Maxilla with Implants Using Bone Grafting to Enhance Implant Sites.

The edentulous posterior maxilla poses challenges to reconstruction. Posterior forces are great, yet bone quality and quantity are diminished. There is frequent loss of bone resulting from ridge resorption as well as sinus pneumatization. There are also advantages of placing implants in the posterior maxilla compared with the anterior maxilla, such as improved hygiene, esthetics and phonetics, and biomechanical load distribution. This article will present strategies and techniques for improving implant support in the posterior maxilla through various grafting techniques.

Malignant Hyperthermia: A Case Study in the Dental Ambulatory Surgery Setting.

Historically, patients who developed malignant hyperthermia had an extremely high rate of mortality. Today, if treated appropriately, patients who experience an episode of malignant hyperthermia will most likely survive. This dramatic decrease in mortality associated with malignant hyperthermia is due to several factors, including an increased understanding of the disease, improved diagnostic and monitoring equipment, and the development of lifesaving pharmacologic agents. This article presents the very likely case of acute malignant hyperthermia in a 24-year-old man with special needs, who presented for restorative dentistry under general anesthesia in the outpatient clinic of The Ohio State University's College of Dentistry.

Reconstructing jaw defects with MSCs and PLGA-encapsulated growth factors.

Cell and growth factor-based tissue engineering has shown great potentials for skeletal regeneration. This study tested its feasibility in reconstructing large mandibular defects and compared the efficacy of varied construction materials and sealing methods. Bilateral mandibular critical-size (5-cm(3)) defects were created on six 4-month-old domestic pigs, and grafted with ß-tricalcium phosphate (ßTCP) only (Group-A), ßTCP with autologous bone marrow-derived mesenchymal stem cells (BM-MSCs) (Group-B), and ßTCP with BM-MSCs and biodegradable poly(lactic-co-glycolic acid) (PLGA) microspheres containing bone morphogenetic protein-2 (BMP-2) and vascular endothelial growth factor (VEGF) (Group-C). The buccal sides of Groups-B/-C were either sealed by fibrin sealant or by a biodegradable PLGA barrier membrane before soft-tissue closure. Computed tomography (CT), microCT and histology analyses were performed 12 weeks postoperatively. In vitro data demonstrated that BM-MSCs, with MSC properties confirmed, remained vital after integration with ßTCP; and PLGA microspheres exhibited an initial burst followed by slow and continuous release of growth factors over a period of 28 days. In vivo data demonstrated that Group-B/-C sites had significantly greater gap obliteration, higher tissue mineral densities and more residual ßTCP granules (p<0.05, Kruskal-Wallis tests). Qualitatively, Group-B/-C defect sites had started remodeling while Group-A sites were mainly forming new bone to bridge the gaps. Furthermore, ßTCP degradation was not mediated by macrophages or osteoclasts, and was significantly slowed down by sealing the defects with barrier membrane. Combined, these data present a promising formulation composed of ßTCP granules, autologous MSCs, controlled-release growth factors and biodegradable PLGA barrier membrane for the reconstruction of critical-size mandibular defects.

You Do What You Got To Do: African-American Women's Perspectives of Managing Breast Cancer.

The purpose of this study is to build a grounded theory of the process of diagnosis, treatment, and coping in African-American women diagnosed with stage 1-3 breast cancer, and identifying factors that may lead to resiliency in these women. Factors promoting resiliency identified by the participants included having a voice, self-attunement, spirituality, pragmatism, and keeping positive. Based on the findings, the researchers suggest health care providers work to create patient-centered healthcare,facilities for cancer treatment, validate patient self-agency, encourage communion, and hire staff that have been previously diagnosed with breast cancer to act as mentors.

Establishing a critical-size mandibular defect model in growing pigs: characterization of spontaneous healing.

PURPOSE: A large animal model is desired for preclinical studies aimed at reconstructing severe mandibular skeletal defects using tissue engineering techniques. To identify the size and location requirements for a mandibular critical-size bone defect in growing pigs, the present study investigated the spontaneous healing of surgically created mandibular defects. MATERIALS AND METHODS: Six 4-month-old domestic pigs were used. In pigs 1 and 2, a 3-, 5-, or 7-cm(3) subperiosteal mandibular defect was created. In pigs 3 to 6, 3- to 5-cm(3) bilateral defects were randomly created at the anterior (apical to the molars) and posterior (mandibular angle) mandibular regions. Spontaneous healing of these defects was assessed by serial computed tomography scans (postoperative week 1, 6, and 12) and histologic analyses. RESULTS: In pigs 1 and 2, regardless of defect size, the anterior, but not posterior, defects had largely healed. Systematic analyses of pigs 3 to 6 revealed, first, the extent of defect regeneration from spontaneous healing was significantly less in the posterior than in the anterior defects, with about two thirds and one third of the original defect volume remaining, respectively. Second, histologically, the posterior defects had considerably less regeneration and more evident tapering of the new bone than did the anterior defects. Finally, the buccal periosteum had completely regenerated in the anterior defects, but had only partially done so in the posterior defects. Also, the buccal surface contour was moderately concave in the anterior defects, but it was severely concave in the posterior defects. CONCLUSIONS: Despite robust spontaneous healing of mandibular defects in growing pigs, 5-cm(3) defects in the mandibular angle region without buccal periosteum would be a reasonable critical-size defect model relevant to mandibular defects in adolescent humans.

Topical application of a mucoadhesive freeze-dried black raspberry gel induces clinical and histologic regression and reduces loss of heterozygosity events in premalignant oral intraepithelial lesions: results from a multicentered, placebo-controlled clinical trial.

PURPOSE: Approximately 30% higher grade premalignant oral intraepithelial neoplasia (OIN) lesions will progress to oral cancer. Although surgery is the OIN treatment mainstay, many OIN lesions recur, which is highly problematic for both surgeons and patients. This clinical trial assessed the chemopreventive efficacy of a natural product-based bioadhesive gel on OIN lesions. EXPERIMENTAL DESIGN: This placebo-controlled multicenter study investigated the effects of topical application of bioadhesive gels that contained either 10% w/w freeze-dried black raspberries (BRB) or an identical formulation devoid of BRB placebo to biopsy-confirmed OIN lesions (0.5 g × q.i.d., 12 weeks). Baseline evaluative parameters (size, histologic grade, LOH events) were comparable in the randomly assigned BRB (n = 22) and placebo (n = 18) gel cohorts. Evaluative parameters were: histologic grade, clinical size, and LOH. RESULTS: Topical application of the BRB gel to OIN lesions resulted in statistically significant reductions in lesional sizes, histologic grades, and LOH events. In contrast, placebo gel lesions demonstrated a significant increase in lesional size and no significant effects on histologic grade or LOH events. Collectively, these data strongly support BRB's chemopreventive impact. A cohort of very BRB-responsive patients, as demonstrated by high therapeutic efficacy, was identified. Corresponding protein profiling studies, which demonstrated higher pretreatment levels of BRB metabolic and keratinocyte differentiation enzymes in BRB-responsive lesions, reinforce the importance of local metabolism and differentiation competency. CONCLUSIONS: Results from this trial substantiate the LOH reductions identified in the pilot BRB gel study and extend therapeutic effects to significant improvements in histologic grade and lesional size.

Scaffold-based delivery of autologous mesenchymal stem cells for mandibular distraction osteogenesis: preliminary studies in a porcine model.

PURPOSE: Bone regeneration through distraction osteogenesis (DO) is promising but remarkably slow. To accelerate it, autologous mesenchymal stem cells have been directly injected to the distraction site in a few recent studies. Compared to direct injection, a scaffold-based method can provide earlier cell delivery with potentially better controlled cell distribution and retention. This pilot project investigated a scaffold-based cell-delivery approach in a porcine mandibular DO model. MATERIALS AND METHODS: Eleven adolescent domestic pigs were used for two major sets of studies. The in-vitro set established methodologies to: aspirate bone marrow from the tibia; isolate, characterize and expand bone marrow-derived mesenchymal stem cells (BM-MSCs); enhance BM-MSC osteogenic differentiation using FGF-2; and confirm cell integration with a gelatin-based Gelfoam scaffold. The in-vivo set transplanted autologous stem cells into the mandibular distraction sites using Gelfoam scaffolds; completed a standard DO-course and assessed bone regeneration by macroscopic, radiographic and histological methods. Repeated-measure ANOVAs and t-tests were used for statistical analyses. RESULTS: From aspirated bone marrow, multi-potent, heterogeneous BM-MSCs purified from hematopoietic stem cell contamination were obtained. FGF-2 significantly enhanced pig BM-MSC osteogenic differentiation and proliferation, with 5 ng/ml determined as the optimal dosage. Pig BM-MSCs integrated readily with Gelfoam and maintained viability and proliferative ability. After integration with Gelfoam scaffolds, 2.4-5.8×10(7) autologous BM-MSCs (undifferentiated or differentiated) were transplanted to each experimental DO site. Among 8 evaluable DO sites included in the final analyses, the experimental DO sites demonstrated less interfragmentary mobility, more advanced gap obliteration, higher mineral content and faster mineral apposition than the control sites, and all transplanted scaffolds were completely degraded. CONCLUSION: It is technically feasible and biologically sound to deliver autologous BM-MSCs to the distraction site immediately after osteotomy using a Gelfoam scaffold to enhance mandibular DO.

Bone ingrowth and initial stability of titanium and porous tantalum dental implants: a pilot canine study.

PURPOSE: To investigate if a dental implant system with a midsection covered by 3-dimensionally porous tantalum material would exhibit stability comparable with a traditional threaded titanium alloy implant system and whether bone would grow into the porous section. METHODS: Three experimental and 3 control implants were placed in the individual mandibles of 8 dogs. Resonance frequency analysis assessed implant stability at 0, 2, 4, 8, and 12 weeks of healing. Histomorphometric and backscattered scanning electron microscopic analyses examined the presence of bone ingrowth into the experimental implant's porous section and bone-to-implant contact along the titanium surfaces of both implants. RESULTS: Implant stability did not significantly differ during 0 to 12 weeks of healing. Progressive tissue mineralization developed inside porous sections from weeks 2 to 12. Porous implants exhibited a combination of progressive osseointegration along their titanium surfaces and bone ingrowth inside their porous tantalum sections. CONCLUSIONS: Cortical and apical implant threads, combined with the porous section, were able to stabilize the experimental implant to the same degree as the fully threaded control implant.

A prospective clinical study to evaluate early success of short implants.

PURPOSE: Short implants are an alternative to bone augmentation procedures for patients with reduced bone height. This study evaluated the success of short implants in posterior locations prior to loading. MATERIALS AND METHODS: Eighteen patients received at least four Astra Tech implants in symmetric posterior locations. Implants (n = 82) ranged from 6 to 11 mm with 70 implants ≤ 9 mm and 38 implants = 6 mm. Placement was planned virtually using software and cone beam computed tomography (CBCT) scans. Computer-generated guides were ordered for all patients; however, lack of interarch distance precluded their use for five patients. In these situations, guides were used to communicate pilot drill position only. Osteotomies were prepared using the guides and accompanying drill sequence following a two-stage surgical approach. Degree of bone mineralization (DBM) parameters for implant osteotomy sites were measured using three-dimensional CBCT images taken before and after implant placement. A paired t test was performed to compare the DBM parameters between failed and successful implantation sites. RESULTS: Early failure occurred for 7 out of 82 implants or 8.5%. All of the failed implants were 6 mm in length and placed using computer-aided design/computer-assisted manufacture (CAD/CAM) surgical guides. Three failures occurred in one patient. Bone grafting was done for failed implant sites, and after healing, new implants were placed using conventional surgical guides. No further failures occurred. The most frequent value (peak) for DBM was significantly higher for failed implant sites than for successful ones (paired t test, P = .043). CONCLUSION: Current failures suggest that CAD/CAM guides used with external irrigation may pose a greater risk for the success of 6-mm implants placed in posterior areas with advanced bone loss. This may be due to the bone density in these highly resorbed areas combined with limited irrigation reaching the osteotomy sites.