Pediatric Orbital Fractures: Outcomes in Relation to Time of Surgery.

INTRODUCTION: Orbital trapdoor fractures in children and adolescents can cause persistent problems with vision and appearance. Early surgery is recommended, although, because of the rarity of these fractures, there is a lack of evidence regarding the optimal timing of surgery.The objective of this study was to examine the effect of the time from trauma to surgery on the recovery time and severity of diplopia in children and adolescents with orbital trapdoor fractures. MATERIALS AND METHODS: A retrospective cohort study was performed of all orbital fractures in children and adolescents aged 0 to 20 years, treated at a tertiary referral center in 2005-2017. Data relating to demographics, cause of injury, surgery, time of follow-up, and final outcomes were extracted. The cases of trapdoor fracture were specifically examined with regard to the time from trauma to surgery and diplopia at last follow-up, which was the primary outcome. RESULTS: One hundred thirty-five patients, aged 2.4 to 20 years (mean 17.0), were treated for orbital fractures during the period; 37 (27%) had an isolated orbital floor fracture and 12 (9%) had a trapdoor fracture. All patients with trapdoor fractures underwent surgery; the mean time to surgery was 11.9 days in 2007-2011 and 1.1 days in 2012-2017. Although statistical significance cannot be proven in this small and retrospective study, a shorter time from trauma to surgery seems to lead to fewer problems with diplopia and 2 patient cases that highlight this are presented. CONCLUSIONS: Delayed surgical intervention in pediatric orbital trapdoor fractures increases the risk of delayed recovery and persistent diplopia. Other factors, such as the degree of muscle incarceration and necrosis and the surgeon's experience and skill, may, however, also influence the outcomes.

Smoking cessation and the role of the dental practitioner.

As dentists we are uniquely positioned to influence the rate of tobacco smoking and could contribute to a decrease in the associated mortality and morbidity. The detrimental effects of smoking on oral health are well established; thus, a structured approach to initiate smoking cessation, help to manage the initial phase of withdrawal symptoms, and provide long-term support is an important role for our profession. It has been shown that smoking cessation advice for even a few minutes increases long-term smoking abstinence rates by 5%, which can be increased by 50-70% with the use of adjunctive pharmacotherapy, e.g., nicotine replacement therapy, for withdrawal symptoms. This article aims to give a brief overview of smoking in relation to oral health, review the management of tobacco smoking dependence, and discuss how we as dentists can help our patients to quit smoking.

CD244 is expressed on dendritic cells and regulates their functions.

Signaling lymphocytic activation molecule (SLAM) receptors have an important role in the development of immune responses because of their roles, for exampe, in NK cell cytotoxicity and cytokine production by NK, T cells and myeloid cells. The SLAM receptor CD244 (2B4, SLAMf4) is expressed on a variety of immune cell types but most of its functions have been examined on NK and T cells. In the present study, we investigated expression and function of CD244 in murine subsets of dendritic cells (DCs). We report that all subsets of murine DCs examined expressed CD244, although the expression levels of CD244 varied between subsets. Splenic and resident mesenteric lymph node (MLN) DCs from CD244(-/-) mice expressed lower levels of CD86 and MHC class II compared with wild-type mice. Upon Toll-like receptor (TLR) stimulation, no differences in surface expression of these molecules were observed between DCs from CD244(-/-) and wild-type mice. However, splenic DCs from CD244(-/-) mice upon stimulation with TLR binding ligands lipopolysaccharide (LPS) and CpG produced significantly higher levels of pro-inflammatory cytokines. In addition, DCs from CD244(-/-) mice elicited increased NK cell activation in vitro. These data add CD244 to a growing list of immuno-modulatory receptors found on DCs.

Bisphosphonate therapy and ankylosis of the temporomandibular joint: is there a relationship? A case report.

Bisphosphonates are an effective class of drugs used for various pathologies of bone tissues such as osteoporosis and solid malignant metastatic disease. Although reports on adverse events such as bisphosphonate-induced osteonecrosis of the jaw are common, ankylosis of the temporomandibular joint in an older patient that is possibly associated with bisphosphonate treatment has not, to our knowledge, been previously reported. The patient, a 70-year-old woman with none of the usual causes for ankylosis, presented with bilateral ankylosis to the temporomandibular joints on a background of bisphosphonate treatment. No obvious etiologic factor for the bilateral ankylosis was found; thus, this might represent another complication of bisphosphonate therapy that dentists and physicians need to be aware of. The approach to management of the ankylosis is described.

Surgical treatment of recurring ameloblastoma, are there options?

Our aim was to evaluate the treatment given to patients with intraosseus ameloblastomas with special emphasis on recurrence and the outcomes of primary and secondary resection. Forty-eight patients who were treated for intraosseous ameloblastoma at 8 centres across Sweden met the inclusion criteria. They showed typical distribution of age, sex, site of lesion, and characteristic presenting features. Eleven of the 48 were initially treated with radical resection and none recurred. Twenty-two of the remaining 37 who were initially treated by conservative resection presented with recurrences. Sixteen of the 22 then had conservative secondary resections, which resulted in further recurrence in 6 patients. Initial radical resection is therefore superior to conservative management as far as recurrences are concerned. We argue, however, that a conservative surgical approach is adequate for many intraosseous ameloblastomas with limited extension, because relapse can be followed by radical resection if clinically indicated in selected cases.

Human herpesvirus 6A partially suppresses functional properties of DC without viral replication.

Human herpesvirus 6A (HHV-6A) is a common virus with a worldwide distribution that has been associated with multiple sclerosis. Whether HHV-6A can replicate in dendritic cells (DC) and how the infection might modulate the functional properties of the cell are currently not well known and need further investigations. Here, we show that a non-productive infection of HHV-6A in DC leads to the up-regulation of HLA-ABC, via autocrine IFN-α signaling, as well as the up-regulation of HLA-DR and CD86. However, HHV-6A exposure reduces IL-8 secretion by DC and their capacity to stimulate allogenic T cell proliferation. The ability to suppress DC functions important for activation of innate and adaptive immune responses might be one successful strategy by which HHV-6A avoids the induction of appropriate host defense mechanisms, and thus facilitating persistent infection.

Selenite induces posttranscriptional blockade of HLA-E expression and sensitizes tumor cells to CD94/NKG2A-positive NK cells.

CD94/NKG2A is an inhibitory receptor that controls the activity of a large proportion of human NK cells following interactions with the nonclassical HLA class Ib molecule HLA-E expressed on target cells. In this study, we show that selenite (SeO(3)(2-)), an inorganic selenium compound, induces an almost complete loss of cell surface expression of HLA-E on tumor cells of various origins. Selenite abrogated the HLA-E expression at a posttranscriptional level, since selenite exposure led to a dose-dependent decrease in cellular HLA-E protein expression whereas the mRNA levels remained intact. The loss of HLA-E expression following selenite treatment was associated with decreased levels of intracellular free thiols in the tumor cells, suggesting that the reduced HLA-E protein synthesis was caused by oxidative stress. Indeed, HLA-E expression and the level of free thiols remained intact following treatment with selenomethionine, a selenium compound that does not generate oxidative stress. Loss of HLA-E expression, but not of total HLA class I expression, on tumor cells resulted in increased susceptibility to CD94/NK group 2A-positive NK cells. Our results suggest that selenite may be used to potentiate the anti-tumor cytotoxicity in settings of NK cell-based immunotherapies.

Gelsolin-independent podosome formation in dendritic cells.

Podosomes, important structures for adhesion and extracellular matrix degradation, are claimed to be involved in cell migration. In addition, podosomes are also reported to be of importance in tissue remodelling, e.g., in osteoclast-mediated bone resorption. Podosomes are highly dynamic actin-filament scaffolds onto which proteins important for their function, such as matrix metallo-proteases and integrins, attach. The dynamics of the podosomes require the action of many proteins regulating actin assembly and disassembly. One such protein, gelsolin, which associates to podosomes, has been reported to be important for podosome formation and function in osteoclasts. However, podosome-like structures have been reported in gelsolin-deficient dendritic cells, but the identity of these structures was not confirmed, and their dynamics and function was not investigated. Like many other cells, dendritic cells of the immune system also form matrix degrading podosomes. In the present study, we show that dendritic cells form podosomes independently of gelsolin, that there are no major alterations in their dynamics of formation and disassembly, and that they exhibit matrix-degrading function. Furthermore, we found that gelsolin is not required for TLR4-induced podosome disassembly. Thus, the actin cytoskeleton of podosomes involved in dendritic cell extracellular matrix degradation appears to be regulated differently than the cytoskeleton in podosomes of osteoclasts mediating bone resorption.

Dendritic cell function at low physiological temperature.

Compared with the stable core temperature, the skin temperature is lower and varies depending on ambient temperature and convection conditions. The function of DCs, which are plentiful in the skin at lower physiological temperatures, has not been reported. We show that DC performed some functions normally at 28°C, including phagocytosis and macropinocytosis. TLR-4 signaling via MAPK pathways was delayed at 28°C but reached normal levels, which may explain the observed slower kinetics of stimulated macropinocytosis and TNF production. TLR-4-induced NO production was compromised severely at 28°C. Collagen degradation and migration through matrigel-coated transwell inserts were decreased, but no effect on podosome number or DC migration through noncoated transwell filters was seen. Lowering the temperature differentially regulated functions associated with the role of DCs in adaptive immunity. LPS-induced up-regulation of CD86 was normal; however, CD40 up-regulation was suppressed after TLR-4 stimulation at 28°C. Nonactivated DC processed and presented antigen on MHC class II equally well at 28°C and 37°C. However, DCs that were loaded with antigens and stimulated with TLR ligand at 28°C were poor at activating T cells at 37°C compared with DCs that were activated and loaded with antigen at 37°C.

Dendritic Cell Regulation by Cannabinoid-Based Drugs.

Cannabinoid pharmacology has made important advances in recent years after the cannabinoid system was discovered. Studies in experimental models and in humans have produced promising results using cannabinoid-based drugs for the treatment of obesity and cancer, as well as neuroinflammatory and chronic inflammatory diseases. Moreover, as we discuss here, additional studies also indicates that these drugs have immunosuppressive and anti-inflammatory properties including modulation of immune cell function. Thus, manipulation of the endocannabinoid system in vivo may provide novel therapeutic strategies against inflammatory disorders. At least two types of cannabinoid receptors, cannabinoid 1 and cannabinoid 2 receptors are expressed on immune cells such as dendritic cells (DC). Dendritic cells are recognized for their critical role in initiating and maintaining immune responses. Therefore, DC are potential targets for cannabinoid-mediated modulation. Here, we review the effects of cannabinoids on DC and provide some perspective concerning the therapeutic potential of cannabinoids for the treatment of human diseases involving aberrant inflammatory processes.