Localized juvenile spongiotic gingival hyperplasia possibly originates from the junctional gingival epithelium-an immunohistochemical study.

AIMS: To immunohistochemically evaluate the cytokeratin (CK) pattern of expression in localized juvenile spongiotic gingival hyperplasia (LJSGH) as compared with the gingival epithelium (GE). METHODS AND RESULTS: Ten cases of LJSGH were semiquantitatively evaluated for the immunohistochemical pattern of CK1/10, CK4, CK8/18, and CK19. GE controls were taken from 10 cases of reactive gingival fibroepithelial hyperplasia. GEs showed mean positivity rates of 80% for both CK1/10 and CK4, and 5% for both CK8/18 and CK19. LJSGHs showed mean positivity rates of 65% for CK19, 60% for CK8/18, 30% for CK4, and 5% for CK1/10. The differences between LJSGHs and GEs were statistically significant (P < 0.01). CONCLUSIONS: The LJSGH pattern of CK expression is reminiscent of the profile described in the literature for the junctional epithelium (JE). Possibly, JE exteriorized from the gingival sulcus would be more prone to irritation from a variety of sources, resulting in inflammation and hyperplasia, with the subsequent development of LJSGH.

Flapless cortical bone damage has no effect on medullary bone mesial to teeth being moved.

INTRODUCTION: In this study, we evaluated the effects of bone awl-induced damage to bone surrounding a tooth that was moved. METHODS: A randomized split-mouth design with 7 foxhounds was performed to evaluate protraction of the mandibular third premolars for 56 days with 200 g of orthodontic force. Before initiating tooth movements, a bone awl was used on the experimental side to create 60 buccal and lingual microfracture injuries to the cortical bone without a periosteal flap. Tooth movements were performed on the control and experimental sides. Microcomputed tomography and histology were used to assess bone morphology and modeling. Radiographic and caliper measures were used to assess tooth movements. RESULTS: The awl-induced injuries produced significant damage and microfractures (95 mm(3)). Buccal and lingual cortical bone volume fractions and densities were significantly less and cortical modeling was significantly greater on the experimental sides than on the control sides. Bone volume fractions and densities mesial to the third premolars were the same on the experimental and control sides. Experimental side tooth movements (1.40 ± 0.25 mm) were statistically the same as the control side tooth movements (1.57 ± 0.45 mm). CONCLUSIONS: The effects of flapless, bone awl-induced damage were limited to the cortical bone. Because there was no effect on the medullary bone mesial to the tooth being moved, no differences in tooth movements were produced.

Bony adaptation after expansion with light-to-moderate continuous forces.

INTRODUCTION: The purpose of this study was to evaluate the biologic response of dentoalveolar bone to archwire expansion with light-to-moderate continuous forces. METHODS: With a split-mouth experimental design, the maxillary right second premolars of 7 adult male dogs were expanded for 9 weeks using passive self-ligating brackets (Damon Q; Ormco, Orange, Calif) and 2 sequential archwires (0.016 × 0.022-in copper-nickel-titanium alloy, followed by 0.019 × 0.025-in copper-nickel-titanium alloy). Intraoral and radiographic measurements were made to evaluate tooth movements and tipping associated with expansion; archwire forces were measured using a force gauge. Microcomputed tomography was used to compare buccal bone height, total tooth height, total root height, and buccal bone thickness. Bone formation was evaluated histologically using tetracycline and calcein fluorescent labels and hematoxylin and eosin stains. RESULTS: Buccal expansion was produced by forces between 73 and 178 g. Compared with the control side, which showed no tooth movement, the experimental second premolars were expanded by 3.5 ± 0.9 mm and tipped by 15.8°. Buccal bone thickness was significantly thinner (about 0.2 mm) in the coronal aspects and significantly thicker (about 0.9 mm) in the apical aspects over the mesial roots. The tipping and expansion significantly (P <0.05) reduced buccal bone height (ie, caused dehiscences) at the mesial (about 2.9 mm) and distal (about 1.2 mm) roots. Bony apposition occurred on the trailing edges of tooth movement and on the leading edges of the second premolar apices. The axial microcomputed tomography slices indicated, and the bone histomorphometry and histology demonstrated, newly laid-down bone on the periosteal side of the buccal cortical surfaces. Ordered osteoblast aggregation was also evident on the periosteal surfaces of buccal bone, just cervical to the apparent center of rotation of the tooth. Tooth and root heights showed no significant differences between the experimental and control second premolars. CONCLUSIONS: Buccal expansion with light-to-moderate continuous forces produced 3.5 mm of tooth movement, uncontrolled tipping, and bone dehiscence, but no root resorption. Bone formation on the periosteal surfaces of cortical bone indicates that apposition is possible on the leading edge of tooth movements.

Effects of pilot holes on longitudinal miniscrew stability and bony adaptation.

INTRODUCTION: The purposes of this study were to longitudinally evaluate the effects of pilot holes on miniscrew implant (MSI) stability and to determine whether the effects can be attributed to the quality or the quantity of bone surrounding the MSI. METHODS: Using a randomized split-mouth design in 6 skeletally mature female foxhound-mix dogs, 17 MSIs (1.6 mm outer diameter) placed with pilot holes (1.1 mm) were compared with 17 identical MSIs placed without pilot holes. Implant stability quotient measurements of MSI stability were taken weekly for 7 weeks. Using microcomputed tomography with an isotropic resolution of 6 µm, bone volume fractions were measured for 3 layers of bone (6-24, 24-42, and 42-60 µm) surrounding the MSIs. RESULTS: At placement, the MSIs with pilot holes showed significantly (P <0.05) higher implant stability quotient values than did the MSIs placed without pilot holes (48.3 vs 47.5). Over time, the implant stability quotient values decreased significantly more for the MSIs placed with pilot holes than for those placed without pilot holes. After 7 weeks, the most coronal aspect of the 6- to 24-µm layer of cortical bone and the most coronal aspects of all 3 layers of trabecular bone showed significantly larger bone volume fractions for the MSIs placed without pilot holes than for those placed with pilot holes. CONCLUSIONS: MSIs placed with pilot holes show greater primary stability, but greater decreases in stability over time, due primarily to having less trabecular bone surrounding them.

In-Person, Remote, or Hybrid Instruction? A Quality Improvement Assessment of a Six Week Interprofessional Education Pathway Program for Undergraduate Pre-Health Students.

There is an emphasis on increasing the diversity of healthcare providers with the goal of reducing health disparities among racial/ethnic minorities. To support this initiative, pathway programs were designed to provide educational and career support to students belonging to racial/ethnic minorities or those who have challenges applying to or entering health professions. As a consequence of the COVID-19 pandemic, pathway programs have assumed various instructional delivery formats (e.g., face to face, virtual, hybrid) with little knowledge on the satisfaction of such methods. The current preliminary study examines whether in person, virtual, or hybrid learning is most effective for underrepresented pre-health undergraduate students who are engaged in a six-week interprofessional health pathway program. Quantitative and qualitative data was collected at one time point towards the end of the program when it was offered in person, virtually, and in hybrid format. Results revealed that the pre-health pathway program received highest satisfaction when presented in a hybrid format and least satisfaction when presented in virtual instruction. Qualitative data suggests that virtual instruction increases feelings of isolation and complicates educational information due to the limitations of virtual streaming. Implications for pathway design are discussed.

Alterations in Local Peri-Infarct Blood Gases in Stroke Patients Undergoing Thrombectomy.

BACKGROUND: Ischemic stroke is a prevalent, devastating disease with high morbidity and mortality. Despite extensive research using animal models, significant gaps remain in understanding the pathological processes in human stroke. We previously developed a tissue bank to analyze the blood immediately proximal and distal to an intracranial thrombus in patients undergoing mechanical thrombectomy (ClinicalTrials.gov identifier, NCT03153683). Our goal for the present project was to evaluate the blood gas changes and acid/base balance during stroke and determine how vascular collateralization affects these changes. METHODS: We analyzed the blood samples and computed tomography angiography collateral scores from the first 62 patients in the BACTRAC (Blood and Clot Thrombectomy Registry and Collaboration) registry. The bicarbonate, partial pressure of oxygen, and partial pressure of carbon dioxide (pCO2) values of the intracranial (distal) and systemic (proximal) arterial blood relative to the occlusive thrombus were analyzed. Analysis of the group differences in systemic and intracranial blood gas values was also performed. RESULTS: The partial pressure of oxygen, pCO2, and bicarbonate levels were all significantly higher in the systemic blood than in the intracranial blood (P < 0.001 for all) at thrombectomy. Collateralization did not significantly affect the distal blood gas values. Compared with the female patients, the male patients had had higher systemic pCO2 values (39.8 vs. 36.6 mm Hg; P = 0.0065) and lower systemic and intracranial pH values (7.351 vs. 7.392; P = 0.0047). CONCLUSIONS: The arterial blood gases differed immediately proximal and distal to thrombi in large vessel occlusive stroke. Although vascular collateralization did not appear to affect the blood gas changes, some blood gas values differed between men and women. The changes in bicarbonate and pCO2 suggested a compensatory acid-base process occurring at the time of infarction.

Effects of iodine in microbial control of dental treatment water.

OBJECTIVE: To determine the effects of low levels of iodine constantly present in the dental unit water system on microbial control of dental treatment water and biofilm control. MATERIALS AND METHODS: This study used a dental unit water system simulator with eight dental unit waterline systems built to scale and function, each controlled via computer. Each of the eight units was operated independently, four units supplied with self-contained water reservoirs and four units supplied with municipal water. Four units were precleaned to remove biofilm buildup. The study had a well-balanced design with equal representation (variables) of presence/absence of biofilms, selfcontained reservoirs for introduction of treatment water, source water directly connected to municipal water source and iodinated cartridges within the self-contained reservoirs and between municipal water and dental unit. Point-of-use iodinated resin cartridges (IRC) were retrofitted proximal to handpiece and air/ water syringe tip lines in four units, and iodinated resin water cartridges (IRSWC) were fitted to the other four units at the source water output. Heterotrophic plate counts were performed at baseline and twice weekly for a period of 6 weeks. One representative waterline sample was taken from each group at baseline and end-of-study to analyze changes in biofilm status using scanning electron microscopy. RESULTS: Waterlines not previously contaminated with biofilms did not show organization of biofilm matrix in units equipped with IRSWC. Constantly present low levels of iodine, demonstrated some disruption of biofilms in waterlines already contaminated with mature biofilms. All groups showed contamination levels < 500 cfu/ml (colony forming units per milliliter) consistent with the CDC and ADA guidelines. CONCLUSION: In this 6 weeks study, IRSWC equipped waterlines showed disruption of established biofilms, controlled formation of new biofilms in clean lines and rendered the dental treatment water < 500 cfu/ml. Point-of-use iodinated resin cartridges were also effective in controlling contamination in the dental treatment water. CLINICAL SIGNIFICANCE: Dental unit water systems that are in use get contaminated with microbes and biofilms in weeks of being put into use. These biofilms contaminate the treatment water thereby putting patients and staff at risk of infection by predominantly gram-negative microbes. Biofilms in the water systems must be cleaned periodically with a strong decontaminant and the dental treatment source water needs to be modified with a low-grade antimicrobial that can preserve the water quality yet safe to humans. In this translational research study, we evaluate the effects of elemental iodine dissolved in water flowing through an iodine containing cartridge in controlling biofilm and dental treatment water contamination using a dental unit water system simulator, prior to clinical utilization.

Effect of phosphate treatment of Acid-etched implants on mineral apposition rates near implants in a dog model.

PURPOSE: This study evaluated the effects of phosphate coating of acid-etched titanium on the mineral apposition rate (MAR) and new bone-to-implant contact (BIC) in a canine model. MATERIALS AND METHODS: Titanium implants (2.2 3 4 mm) with acid-etched surfaces that were electrolytically phosphated or not were placed in 48 mandibular sites in six foxhounds. Tetracycline and calcein dyes were administered 1 week after implant placement and 1 week before sacrifice. At 12 weeks after implant placement, the animals were sacrificed. MAR and BIC were evaluated using fluorescence microscopy. Light microscopic and histologic evaluations were performed on undecalcified sections. RESULTS: Microscopic evaluation showed the presence of healthy osteoblasts lining bone surfaces near implants. Similar BIC was observed in phosphated and nonphosphated titanium implant sites. MAR was significantly higher around the nonphosphated titanium implant surfaces than around the phosphated titanium samples. No significant differences were found between dogs or implant sites. CONCLUSION: Acid-etched implants showed significantly higher MARs compared to acid-etched, phosphate-coated implants. Int J Maxillofac Implants 2010;25:278-286.

Republished: A lumbar arteriovenous fistula presenting with intraventricular hemorrhage and hydrocephalus.

Pediatric spinal vascular malformations are rare entities that typically present with symptoms from their effect on surrounding structures. Here we report a unique case of lumbar spinal dural/perimedullary arteriovenous fistula (AVF) that presented with intraventricular hemorrhage and hydrocephalus. The previously healthy child presented with lethargy and headache, and initial imaging revealed only ventriculomegaly with trace intraventricular blood. His mental status improved with CSF diversion via an external ventricular drain. Further workup revealed a spinal AVF that was treated via endovascular embolization. His course was complicated by vasospasm requiring endovascular treatment and he eventually required ventriculoperitoneal shunt placement. He made a full recovery and has returned to his normal activities. This is a unique case of spinal AVF presentation and highlights the importance of considering imaging of the entire neuroaxis during workup for hydrocephalus.

A lumbar arteriovenous fistula presenting with intraventricular hemorrhage and hydrocephalus.

Pediatric spinal vascular malformations are rare entities that typically present with symptoms from their effect on surrounding structures. Here we report a unique case of lumbar spinal dural/perimedullary arteriovenous fistula (AVF) that presented with intraventricular hemorrhage and hydrocephalus. The previously healthy child presented with lethargy and headache, and initial imaging revealed only ventriculomegaly with trace intraventricular blood. His mental status improved with CSF diversion via an external ventricular drain. Further workup revealed a spinal AVF that was treated via endovascular embolization. His course was complicated by vasospasm requiring endovascular treatment and he eventually required ventriculoperitoneal shunt placement. He made a full recovery and has returned to his normal activities. This is a unique case of spinal AVF presentation and highlights the importance of considering imaging of the entire neuroaxis during workup for hydrocephalus.

Effects of intentional damage of the roots and surrounding structures with miniscrew implants.

INTRODUCTION: The purposes of the study were to evaluate the immediate damage to roots and periodontal structures after initial miniscrew implant (MSI) placement and the short- and long-term damage after MSIs were left in situ. METHODS: The roots of the maxillary second, third, and fourth premolars of 7 mature beagle dogs were randomly assigned to undergo immediate, short-term (left for 6 weeks), or long-term (left for 12 weeks) damage. Intentional damage was inflicted with self-tapping screws (1.8 x 8 mm) placed with a stent. Alternating tetracycline and calcein labels were administered at 6-week intervals. Undecalcified sections were stained and evaluated histologically to determine the extent of damage; healing was evaluated by using fluorescence labels. RESULTS: Histology showed damage to 73.8% of the teeth, ranging from displacement of bone into the periodontal ligament to invasion of the pulp chamber. Displacement of bone into the periodontal ligament and direct damage to the periodontal ligament occurred in 3 (7.2%) instances. Damage was isolated to the cementum of 8 (19.0%) teeth, whereas damage occurred in the dentin of 11 (26.2%) teeth. Loss of bone in the furcation was evident in 3 (7.2%) teeth, and severe damage into the pulp occurred in 6 (14.2%) teeth. No differences in the amounts of damage were evident between the immediate, short-, and long-term groups. Healing often occurred with cementum around the unloaded MSIs. CONCLUSIONS: Extensive damage can be caused by MSIs, with little to no differences evident over time. Unloaded MSIs that remain in contact with roots of teeth can show varying degrees of healing.

Healing of the roots and surrounding structures after intentional damage with miniscrew implants.

INTRODUCTION: In this study, we evaluated the healing potential of the roots and surrounding periodontium (cementum, periodontal ligament [PDL], and bone) after intentional damage during miniscrew implant (MSI) placement. METHODS: A randomized split-mouth design was used to evaluate healing 6 and 12 weeks after intentional root damage. Seven skeletally mature male beagle dogs had MSIs placed into the roots of 8 mandibular teeth (6 premolars, 2 first molars). After root contact had been verified by using insertion torques and radiographs, the MSIs were immediately removed, and the sites were allowed to heal for 6 or 12 weeks. Sequential point labeling was performed at 6-week intervals with tetracycline and calcein. Demineralized and undemineralized sections were stained, and healing was histologically evaluated. RESULTS: The placement torque was twice as high with root contact than without contact (23.8 vs 50.7 Ncm). Damage to the roots and periodontium ranged from cementum interruption to pulp invasion. New bone, PDL, and cementum were observed in 64.3% of the teeth, with significant (P <0.05) increases in the percentages of cementum over time. Sequential labeling confirmed healing at both 6 and 12 weeks. Abnormal healing was found in 35.7% of teeth; it included lack of PDL and bone regeneration, bone degeneration in the furcation area, ankylosis, and no healing associated with inflammatory infiltrate or pulpal invasion. CONCLUSIONS: Under favorable conditions (no inflammatory infiltrate or pulpal invasion), healing can occur when root damage caused by MSIs is limited to the cementum or the dentin. Increased resistance should be used as an indicator of possible root contact during MSI placement.

Creation of a Collaborative Disaster Preparedness Video for Daycare Providers: Use of the Delphi Model for the Creation of a Comprehensive Disaster Preparedness Video for Daycare Providers.

OBJECTIVE: Eight million American children under the age of 5 attend daycare and more than another 50 million American children are in school or daycare settings. Emergency planning requirements for daycare licensing vary by state. Expert opinions were used to create a disaster preparedness video designed for daycare providers to cover a broad spectrum of scenarios. METHODS: Various stakeholders (17) devised the outline for an educational pre-disaster video for child daycare providers using the Delphi technique. Fleiss κ values were obtained for consensus data. A 20-minute video was created, addressing the physical, psychological, and legal needs of children during and after a disaster. Viewers completed an anonymous survey to evaluate topic comprehension. RESULTS: A consensus was attempted on all topics, ranging from elements for inclusion to presentation format. The Fleiss κ value of 0.07 was obtained. Fifty-seven of the total 168 video viewers completed the 10-question survey, with comprehension scores ranging from 72% to 100%. CONCLUSION: Evaluation of caregivers that viewed our video supports understanding of video contents. Ultimately, the technique used to create and disseminate the resources may serve as a template for others providing pre-disaster planning education. (Disaster Med Public Health Preparedness. 2019;13:123-127).

Integrating Diverse Disciplines to Enhance Interprofessional Competency in Healthcare Delivery.

Interprofessional education (IPE) typically involves clinical simulation exercises with students from medical and nursing schools. Yet, healthcare requires patient-centered teams that include diverse disciplines. Students from public health and informatics are rarely incorporated into IPE, signaling a gap in current educational practices. In this study, we integrated students from administrative and non-clinical disciplines into traditional clinical simulations and measured the effect on communication and teamwork. From July 2017-July 2018, 408 students from five schools (medicine, nursing, dentistry, public health, and informatics) participated in one of eight three-hour IPE clinical simulations with Standardized Patients and electronic health record technologies. Data were gathered using a pre-test-post-test interventional Interprofessional Collaborative Competency Attainment Survey (ICCAS) and through qualitative evaluations from Standardized Patients. Of the total 408 students, 386 (94.6%) had matched pre- and post-test results from the surveys. There was a 15.9% improvement in collaboration overall between the pre- and post-tests. ICCAS competencies showed improvements in teamwork, communication, collaboration, and conflict management, with an average change from 5.26 to 6.10 (t = 35.16; p < 0.001). We found by creating new clinical simulations with additional roles for non-clinical professionals, student learners were able to observe and learn interprofessional teamwork from each other and from faculty role models.

Evaluation and Gap Analysis of Pediatric Disaster Preparedness Resources.

The goal of this research was to identify, summarize, and evaluate pediatric disaster preparedness resources in the United States and to identify areas that need improvement or further development. Using standard literature, gray literature and website reviews, relevant resources were identified and the 50 most relevant resources were studied in depth. Each resource was given a grade of A, B, or C based on content, format, quality, and thoroughness. These resources were divided into 3 categories: (1) hospital resources, (2) school resources, and (3) training/education resources. Half of the 50 resources (25) were given a grade of A, indicating the highest level of quality and thoroughness, with pertinent information presented in a clear format. Sixteen of the resources were given a rating of B, while 9 of the resources were given a rating of C. Over 60% of the resources did not contain culturally sensitive information and more than 60% of the resources did not contain preparedness information for children with disabilities. Resources specific to hospitals and schools were limited in number and quality available, while training/education resources were widely available. In addition, 60% of resources were not specific to schools, children's hospitals, or to certain occupations (ie, nurses, doctors, teachers, principals). Based on these results, gaps in cultural sensitivity were identified and limitations in resources for children with disabilities and for schools and hospitals currently exist. All these areas require further development in the field of pediatric disaster preparedness (Disaster Med Public Health Preparedness. 2019;13:330-337).

The efficacy of IntraFlow intraosseous injection as a primary anesthesia technique.

The purpose of this study was to compare the efficacy of intraosseous injection and inferior alveolar (IA) nerve block in anesthetizing mandibular posterior teeth with irreversible pulpitis. Thirty human subjects were randomly assigned to receive either intraosseous injection using the IntraFlow system (Pro-Dex Inc, Santa Ana, CA) or IA block as the primary anesthesia method. Pulpal anesthesia was evaluated via electric pulp testing at 4-minute intervals for 20 minutes. Two consecutive 80/80 readings were considered successful pulpal anesthesia. Anesthesia success or failure was recorded and groups compared. Intraosseous injection provided successful anesthesia in 13 of 15 subjects (87%). The IA block provided successful anesthesia in 9 of 15 subjects (60%). Although this difference was not statistically significant (p = 0.2148), the results of this preliminary study indicate that the IntraFlow system can be used as the primary anesthesia method in teeth with irreversible pulpitis to achieve predictable pulpal anesthesia.

Capsaicin sensitive neurons role in the inflamed TMJ acute nociceptive response of female and male rats.

Computerized meal pattern analysis, and more specifically meal duration, has recently been used as a non-invasive biological marker of nociception in the temporomandibular joint (TMJ). Cells responsible for the nociceptive response in the inflamed TMJ may include capsaicin (CAP) sensitive neurons. To test the role of CAP sensitive neurons in acute nociceptive responses first, male and female rats were treated neonatally with vehicle or CAP, an agent known to destroy a majority of C fibers. Second, after 56 days the rats were divided into four groups: neonatal vehicle-injected and treated with and without complete Freund's adjuvant (CFA). Treatment groups included neonatal non-CAP vehicle treated and TMJ not-injected (CON); vehicle treated and TMJ CFA injected (CFA); CAP-treated and not-injected (CAP); and CAP-treated and CFA injected (CAP+CFA). Meal patterns were analyzed for two days after injection. CFA-injection in non-CAP-treated rats lengthened meal duration on the first and second day after treatment in the males, but only on the first day in the females. CAP treatment in male and female rats prevented significant lengthening of meal duration induced by CFA. CAP treatment attenuated the CFA-induced increase in calcitonin gene-related peptide expression in the trigeminal ganglia similarly in males and females. The data suggests CAP-sensitive neurons are responsible, in part, for transmission of acute nociceptive responses associated with CFA administration and suggest gender can affect nociception in the inflamed TMJ region.