Unilateral otitis media with effusion caused by retained surgical gauze as an unintended iatrogenic complication of orthognathic surgery: case report

Inadvertent retention of surgical gauze during an operation can have disastrous consequences for both the patient and the surgeon. Several cases have been reported, particularly after abdominal surgery. However, it has never to our knowledge been reported as a leading cause of dysfunction of the Eustachian tube after orthognathic surgery. We recently encountered a patient in whom it presented with unilateral otitis media with an effusion after orthognathic surgery. All surgeons involved with orthognathic surgery should be aware that remnants of surgical gauze after orthognathic surgery can compromise the Eustachian tube and cause otitis media with an effusion.     

Effect of Mineral Trioxide Aggregate Surface Treatments on Morphology and Bond Strength to Composite Resin

Introduction

The aim of this study was to evaluate the micromorphologic changes that accompany different surface treatments on mineral trioxide aggregate (MTA) and their effect on the bond strength to the composite resin with 4 adhesive systems.

Methods

Three types of MTA cement, ProRoot MTA (WMTA) (Dentsply, Tulsa, OK), MTA Angelus (AMTA) (Angelus, Londrina, PR, Brazil), and Endocem MTA (EMTA) (Maruchi, Wonju, Korea), were prepared and stored for a week to encourage setting. Surface treatment was performed using phosphoric acid or self-etch primer, and an untreated MTA surface was prepared as a control. The surface changes were observed using scanning electron microscopy. MTA surfaces were bonded with 4 adhesive systems, including Scotchbond Multipurpose (3M ESPE, St Paul, MN), Single Bond 2 (3M ESPE), Clearfil SE BOND (Kuraray, Osaka, Japan), and AdheSE One F (Ivoclar Vivadent, Schaan, Liechtenstein), to evaluate the adhesive effectiveness of MTA followed by composite resin restoration. The shear bond strength of the polymerized specimens was tested.

Results

For WMTA and AMTA, untreated surfaces showed an irregular crystalline plate with clusters of globular aggregate particles. For EMTA, the untreated surface presented a reticular matrix with acicular crystals. After surface treatment, superficial crystalline structures were eroded regardless of the MTA cement and adhesive system used. WMTA bonded significantly more strongly than AMTA and EMTA, regardless of the adhesive system used. In the WMTA and AMTA groups, AdheSE One F showed the highest bond strength to the composite. For EMTA, no significant differences were found across adhesive systems.

Conclusions

Acidic treatment of the MTA surface affected the micromorphology and the bond strength to the composite. Within the limitations of this study, using a 1-step self-etch adhesive system might result in a strong bond to WMTA when the composite resin restoration is required over MTA cement.     

Oral health behaviors and metabolic syndrome: the 2008–2010 Korean National Health and Nutrition Examination Survey

Objectives

This study examined whether oral health behaviors are associated with metabolic syndrome (MetS) in Korean adults involved in the 2008–2010 Korea National Health and Nutrition Examination Survey (KNHANES).

Materials and methods

A total of 18,742 subjects (8,034 men and 10,708 women) were included. MetS was defined according to the criteria of the American Heart Association/National Heart, Lung, and Blood Institute Scientific Statement for Asians. Oral health behavior was assessed using a questionnaire included in the KNHANES.

Results

Subjects with MetS brushed their teeth less frequently and used fewer secondary oral products than subjects without MetS (p?<?0.01). As frequency of toothbrushing and number of secondary oral products increased, body mass index, waist circumference, diastolic blood pressure, fasting plasma glucose, triglyceride, and white blood cell count decreased, but high-density lipoprotein–cholesterol increased (all p for trend <0.01). In the multivariable logistic regression models, as frequency of toothbrushing increased, the odds ratios (ORs) for MetS, abdominal obesity, and hyperglycemia are more than one after adjusting for age, gender, education, income, alcohol and tobacco use, physical activity, and the components of MetS. The ORs for MetS, abdominal obesity, and high blood pressure were more than one in subjects who do not use dental floss after adjusting for all covariates.

Conclusion

MetS is associated with infrequent daily toothbrushing and disuse of dental floss in South Korean.

Clinical relevance

Dentists may recommend evaluation for MetS in the patients with infrequent daily toothbrushing and disuse of dental floss.     

Three dimensional finite element analysis of the stress distribution around the mandibular posterior implant during non-working movement according to the amount of cantilever

PURPOSE

In case of large horizontal discrepancy of alveolar ridge due to severe resorption, cantilevered crown is usually an unavoidable treatment modality. The purpose of this study was to evaluate the clinical criteria for the placement of the aforementioned implant crown.

MATERIALS AND METHODS

The mandible model with 2 mm thick cortical bone and cancellous bone was fabricated from CT cross-section image. An external connection type implant was installed and cantilevered crowns with increasing offset of 3, 4, 5, 6, and 7 mm were connected. Vertical load and 30° oblique load of 300 N was applied and stress around bone and implant component was analyzed. A total of 14 cases were modeled and finite element analysis was performed using COSMOS Works (Solid works Inc, USA).

RESULTS

As for the location of the vertical load, the maximum stress generated on the lingual side of the implant became larger according to the increase of offset distance. When the oblique load was applied at 30°, the maximum stress was generated on the buccal side and its magnitude gradually decreased as the distance of the offset load increased to 5 mm. After that point, the magnitude of implant component''s stress increased gradually.

CONCLUSION

The results of this study suggest that for the patient with atrophied alveolar ridge following the loss of molar teeth, von-Mises stress on implant components was the lowest under the 30° oblique load at the 5 mm offset point. Further studies for the various crown height and numbers of occusal points are needed to generalize the conclusion of present study.     

Synthetic control of mammalian-cell motility by engineering chemotaxis to an orthogonal bioinert chemical signal

Directed migration of diverse cell types plays a critical role in biological processes ranging from development and morphogenesis to immune response, wound healing, and regeneration. However, techniques to direct, manipulate, and study cell migration in vitro and in vivo in a specific and facile manner are currently limited. We conceived of a strategy to achieve direct control over cell migration to arbitrary user-defined locations, independent of native chemotaxis receptors. Here, we show that genetic modification of cells with an engineered G protein-coupled receptor allows us to redirect their migration to a bioinert drug-like small molecule, clozapine-N-oxide (CNO). The engineered receptor and small-molecule ligand form an orthogonal pair: The receptor does not respond to native ligands, and the inert drug does not bind to native cells. CNO-responsive migration can be engineered into a variety of cell types, including neutrophils, T lymphocytes, keratinocytes, and endothelial cells. The engineered cells migrate up a gradient of the drug CNO and transmigrate through endothelial monolayers. Finally, we demonstrate that T lymphocytes modified with the engineered receptor can specifically migrate in vivo to CNO-releasing beads implanted in a live mouse. This technology provides a generalizable genetic tool to systematically perturb and control cell migration both in vitro and in vivo. In the future, this type of migration control could be a valuable module for engineering therapeutic cellular devices.The ability of many cell types to migrate long distances within the body and specifically localize to target sites of action is critical for their proper function. For example, immune cells rapidly home to sites of infection, concentrating their powerful cytotoxic and proinflammatory activities for maximum efficacy while limiting damage to healthy tissue. In morphogenesis, cells undergo a complex stereotyped process involving migration as well as proliferation, differentiation, and programmed cell death to produce fully developed multicellular structures. In wound healing and regenerative processes, stem and progenitor cells home to injured tissues from nearby sites—as well as from distant locations including the bone marrow—to provide a stream of new cells to replenish and provide trophic support to old and damaged cells.Cell migration is also an important factor to consider in the use of cells as therapeutic agents. The use of cells for the treatment of a growing array of diseases including cancer, autoimmunity, and chronic wounds is currently being explored (1–6). The appropriate and efficient localization of therapeutic cells to sites of disease has been identified as an important factor for successful cell-based therapy (7–17). However, preclinical studies and clinical trials to date have shown that the homing to sites of disease of many cell types commonly used as therapeutics is frequently impaired or limited, especially after ex vivo expansion of cells in culture (7, 12, 18, 19).The ability to redirect the migration of cells to any user-specified location in the body would be a powerful enabling technology for basic research as well as for future applications, but there are currently few easily generalizable strategies to accomplish this goal. We conceived of an approach to direct cellular homing to small molecules by expressing, in motile cells, engineered G protein-coupled receptors (GPCRs) called receptors activated solely by a synthetic ligand (RASSLs) (20, 21).RASSLs are engineered to be unresponsive to endogenous ligands but can be activated by pharmacologically inert orthogonal small molecules (Fig. 1A). Versions of these receptors exist for the three major GPCR signaling pathways (Gαs-, Gαi-, and Gαq-coupled receptors), and the design of a new arrestin-biased variant has recently been reported (21, 22). Because GPCRs control many important physiological functions, including cell migration, we hypothesized that, by expressing these engineered receptors in motile cells, we could develop a general strategy for establishing user control over cell homing (Fig. 1B). Here, we use a family of second-generation RASSLs, known as designer receptors exclusively activated by a designer drug (DREADDs), that are activated only by the small molecule clozapine-N-oxide (CNO), an inert metabolite of the FDA-approved antipsychotic drug clozapine (Fig. S1) (20). CNO is highly bioavailable in rodents and humans, lacks affinity for any known receptors, channels, and transporters, and does not cause any appreciable physiological effects when systemically administered in normal mice (20, 23, 24).Open in a separate windowFig. 1.Engineered Gαi-coupled GPCRs Di3 and Di mediate cytoskeletal changes and chemotaxis of HL-60 neutrophils in response to CNO. (A) RASSLs are engineered GPCRs that interact orthogonally with a bioinert small-molecule drug. Natural ligands do not interact with the engineered receptors, and the bioinert drug that activates the engineered receptors does not interact with native receptors. (B) We tested whether certain second-generation RASSLs known as DREADDs could mediate cell motility. (C) Changes in electrical impedance that result from cell spreading in response to drug or ligand are detected by an electrode array. HL-60 neutrophils transiently transfected to express engineered GPCRs were plated on fibronectin-coated impedance assay plates and stimulated with vehicle control, 100 nM fMLP (positive control chemoattractant) or 100 nM CNO. All cells responded to fMLP whereas only Di3- or Di-expressing cells responded to CNO. Mean ± SEM for n = 3 replicates is shown. (D) Cell migration of HL-60 neutrophils transiently transfected with engineered GPCRs was quantitated in a porous transwell Boyden-chamber assay. All cells migrated in response to fMLP whereas only Di3- or Di-expressing cells migrated in response to CNO. Drug concentrations used: 100 nM CNO, 100 nM fMLP. Mean ± SEM for n = 3 replicates is shown. (E) Polarization and cell migration in neutrophils involves Rac and PI3K activation. Di-expressing HL-60 neutrophils were treated with 100 nM fMLP or 100 nM CNO before immunoblotting for phosphorylated Akt and phosphorylated PAK as readouts for PI3K and Rac activity, respectively. Peak levels of phospho-Akt and phospho-PAK are shown for each condition. Both were increased by CNO stimulation in Di cells but not in control cells (P < 0.01 by Student t test). Stimulation with fMLP increased phospho-Akt and phospho-PAK levels in both Di and control cells (P < 0.01 by Student t test), but Di cells showed higher peak levels of phospho-Akt than did control cells (P < 0.01 by Student t test). Three (for CNO) or four (for fMLP) independent experiments were performed and mean ± SEM are shown.     

Total Hip Arthroplasty Using Large-Diameter Metal-On-Metal Articulation in Patients With Neuromuscular Weakness

The purpose of this prospective study was to evaluate the clinical and functional outcomes of THA using large-diameter metal-on-metal articulation in patients with neuromuscular weakness. Nineteen consecutive patients (19 hips) with neuromuscular weakness and displaced femoral neck fractures were enrolled. Functional improvement and recovery, radiological evaluation of THA and surgical morbidity were assessed. Mean Harris hip and WOMAC scores at final follow-up were 81.0 and 42.9, respectively. At final follow-up, no dislocation, metal hypersensitivity, or osteolysis was observed and no patient required revision of THA. The findings of this study indicate that the functional results of THA using large-diameter metal-on-metal articulation in patients with neuromuscular weakness can produce satisfactory outcomes with early functional recovery and a low dislocation rate.     

Familial interactions and physical,lifestyle, and dietary factors to affect bone mineral density of children in the KNHANES 2009–2010

We examined familial bone mineral density (BMD) interactions between parents and children and lifestyle factors affecting BMD in the Korean general population of children under 20 and parents under 50 years of age. This cross-sectional study included 2,453 participants (667 daughters, 705 sons, 719 mothers, and 362 fathers) in the 2009–2010 Korean National Health and Nutrition Examination Survey. We calculated prevalence ratios and 95 % confidence intervals for BMD values of whole femur, femur neck, lumbar spine, and whole body excluding the head being in the low tertile in adolescents according to parental BMD tertile after adjusting for physical, lifestyle, and dietary factors. For daughters and sons, there were significant differences in BMD at the four bone sites according to age group, body fat percentage, regular walking and exercise, and milk consumption compared to the reference value for each classification category. Surprisingly, there were no differences in BMD according to serum 25-OH-D levels. Birth order affected BMD of only whole body except head, but its impact was less than that of lifestyle factors. The mean differences in BMD between daughters and sons in the first and third parental BMD tertiles were statistically significant. Notably, the prevalence ratio of whole body without head BMD being in the low tertile increased eight and ten-folds in adolescent daughters and sons, respectively, when parents were in the low BMD tertile. In specific bone regions, parental BMD had a greater effect on total femur in daughters but in the lumbar spine in sons. In conclusion, parental BMD positively influences BMD in daughters and sons after adjustment for environmental parameters. This suggests that the children from parents with low BMD need to make an extra effort to increase BMD through dietary and lifestyle changes.