Microradiographic and histological evaluation of the bone-screw and bone-plate interface of orthodontic miniplates in patients

SummaryObjectives: To describe the tissue reactions at the bone-titanium interface of orthodontic miniplates in humans. Materials and methods: Forty-two samples, consisting of tissue fragments attached or not to miniplates or their fixation screws, were collected from 24 orthodontic patients treated with miniplate anchorage, at the time of removal of their miniplates. The samples were embedded in methylmethacrylate and cut into undecalcified sections which were submitted to microradiographic analysis. The sections were also stained and examined under ordinary light. Results: Three types of reactions were observed both on the histological sections and on the microradiographs. 1. The majority of the stable miniplates were easy to remove (34/42). The tissue samples collected consisted mainly in mature lamellar bone with some medullary spaces containing blood vessels, 2. two screws were highly osseointegrated and required the surgeon to remove them by trephining (2/42). They were surrounded by bone tissue which extended to the miniplate. The histological features were similar to the previous group, though the bone-screw contact was higher, and 3. in six samples obtained after unstable miniplate removal during the treatment, we observed either some woven bone trabeculae or loose connective tissue, without any histological sign of inflammation. Limitations and Conclusion: For evident ethical reasons, our data were limited by the size of the tissue fragments and the limited number of patients and variety of clinical presentations. The healing reactions consisted mainly in mature lamellar bone tissue sparsely in contact with the screw or the miniplate, with signs of a moderate remodelling activit

Which factors influence orthodontists in their decision to extract? A questionnaire survey

To evaluate the relative influence of different criteria in the choice between extraction and nonextraction treatment in current orthodontics, and to assess how the percentage of extractions has evolved over time. Pre-treatment records (panoramic radiograph, lateral cephalogram, study casts and photographs) of fourteen cases in permanent dentition (adult or adolescent) with class I molar relationship and moderate anterior crowding were evaluated by 28 orthodontists. For each case, each orthodontist filled out a questionnaire reporting his treatment plan proposal (extraction or nonextraction) and the importance of specific parameters in his decision-making process, using categorical scales. Orthodontists practicing for more than 15 years were also asked to compare this decision with the one they would have taken at the beginning of their professional career. The two most important factors in the decision-making were the soft tissue profile and the amount of crowding. The least important factor was the presence of third molars. In cases of nonextraction treatment, the lack of space was managed mostly by dental expansion and stripping. Twenty percent of the case evaluations revealed extraction(s) decisions. Among the orthodontists practicing for more than 15 years, the current extraction rate reached 24%, whereas the same orthodontists reported they would have extracted in 39% of the cases in the past. The present study suggests that soft tissue profile has a higher impact than traditional criteria such as cephalometric measurements in the extraction decision. This is associated with a decreased extractions rate compared to the past

Root repair after damage due to screw insertion for orthodontic miniplate placement

The aim of this investigation was to describe the healing reactions following root damage caused by placement of a miniplate anchorage system. In 4 beagle dogs, 4 titanium miniplates (2 self-tapping screws per miniplate) were placed in each maxilla, after drilling of pilot-holes. Six fixation screws were unintentionally inserted damaging the root of maxillary canines. Two weeks later, half of the miniplates were loaded with a coil spring. Two dogs were euthanized 7 weeks after placement of the miniplates, while the remaining two after 29 weeks. Histological sections were prepared, microradiographed, observed under U.V. light, then stained and analysed under ordinary light. Four screws caused direct root damage; one was damaged during the drilling process; one caused damage to the periodontal ligament only. Among these 6 screws, 2 were mobile and 4 were stable at sacrifice. Limited root damage showed some repair after 29 weeks, consisting in a thick layer of mineralized cementum including anchoring periodontal fibres. Tissue repair was not related to screw stability or loading status. Limited root damage has shown potential to heal, while extensive root damage has not. Precise position of insertion of the miniplates is thus of utmost importance

Regulation of microglial TMEM119 and P2RY12 immunoreactivity in multiple sclerosis white and grey matter lesions is dependent on their inflammatory environment

Multiple Sclerosis (MS) is the most common cause of acquired neurological disability in young adults, pathologically characterized by leukocyte infiltration of the central nervous system, demyelination of the white and grey matter, and subsequent axonal loss. Microglia are proposed to play a role in MS lesion formation, however previous literature has not been able to distinguish infiltrated macrophages from microglia. Therefore, in this study we utilize the microglia-specific, homeostatic markers TMEM119 and P2RY12 to characterize their immunoreactivity in MS grey matter lesions in comparison to white matter lesions. Furthermore, we assessed the immunological status of the white and grey matter lesions, as well as the responsivity of human white and grey matter derived microglia to inflammatory mediators. We are the first to show that white and grey matter lesions in post-mortem human material differ in their immunoreactivity for the homeostatic microglia-specific markers TMEM119 and P2RY12. In particular, whereas immunoreactivity for TMEM119 and P2RY12 is decreased in the center of WMLs, immunoreactivity for both markers is not altered in GMLs. Based on data from post-mortem human microglia cultures, treated with IL-4 or IFNγ+LPS and on counts of CD3+ or CD20+ lymphocytes in lesions, we show that downregulation of TMEM119 and P2RY12 immunoreactivity in MS lesions corresponds with the presence of lymphocytes and lymphocyte-derived cytokines within the parenchyma but not in the meninges. Furthermore, the presence of TMEM119+ and partly P2RY12+ microglia in pre-active lesions as well as in the rim of active white and grey matter lesions, in addition to TMEM119+ and P2RY12+ rod-like microglia in subpial grey matter lesions suggest that blocking the entrance of lymphocytes into the CNS of MS patients may not interfere with all possible effects of TMEM119+ and P2RY12+ microglia in both white and grey matter MS lesions

Three-dimensional assessment of maxillary changes associated with bone anchored maxillary protraction

Bone-anchored maxillary protraction has been shown to be an effective treatment modality for the correction of Class III malocclusions. The purpose of this study was to evaluate 3-dimensional changes in the maxilla, the surrounding hard and soft tissues, and the circummaxillary sutures after bone-anchored maxillary protraction treatment

Modified Miniplates for Temporary Skeletal Anchorage in Orthodontics: Placement and Removal Surgeries

Skeletal anchorage systems are increasingly used in orthodontics. This article describes the techniques of placement and removal of modified surgical miniplates used for temporary orthodontic anchorage and reports surgeons’ perceptions of their use

Prolonged QTc Interval and Risk of Sudden Cardiac Death in a Population of Older Adults

ObjectivesThis study sought to investigate whether prolongation of the heart rate-corrected QT (QTc) interval is a risk factor for sudden cardiac death in the general population.BackgroundIn developed countries, sudden cardiac death is a major cause of cardiovascular mortality. Prolongation of the QTc interval has been associated with ventricular arrhythmias, but in most population-based studies no consistent association was found between QTc prolongation and total or cardiovascular mortality. Only very few of these studies specifically addressed sudden cardiac death.MethodsThis study was conducted as part of the Rotterdam Study, a prospective population-based cohort study that comprises 3,105 men and 4,878 women aged 55 years and older. The QTc interval on the electrocardiogram was determined during the baseline visit (1990 to 1993) and the first follow-up examination (1993 to 1995). The association between a prolonged QTc interval and sudden cardiac death was estimated using Cox proportional hazards analysis.ResultsDuring an average follow-up period of 6.7 years (standard deviation, 2.3 years) 125 patients died of sudden cardiac death. An abnormally prolonged QTc interval (>450 ms in men, >470 ms in women) was associated with a three-fold increased risk of sudden cardiac death (hazard ratio, 2.5; 95% confidence interval, 1.3 to 4.7), after adjustment for age, gender, body mass index, hypertension, cholesterol/high-density lipoprotein ratio, diabetes mellitus, myocardial infarction, heart failure, and heart rate. In patients with an age below the median of 68 years, the corresponding relative risk was 8.0 (95% confidence interval 2.1 to 31.3).ConclusionsAbnormal QTc prolongation on the electrocardiogram should be viewed as an independent risk factor for sudden cardiac death

Patients' and clinicians' preferences in adjuvant treatment for high-risk endometrial cancer:Implications for shared decision making

Background. Decision making regarding adjuvant therapy for high-risk endometrial cancer is complex. The aim of this study was to determine patients' and clinicians' minimally desired survival benefit to choose chemoradiotherapy over radiotherapy alone. Moreover, influencing factors and importance of positive and negative treatment effects (i.e. attribute) were investigated. Methods. Patients with high-risk endometrial cancer treated with adjuvant pelvic radiotherapy with or without chemotherapy and multidisciplinary gynaecologic oncology clinicians completed a trade-off questionnaire based on PORTEC-3 trial data. Results. In total, 171 patients and 63 clinicians completed the questionnaire. Median minimally desired benefit to make chemoradiotherapy worthwhile was significantly higher for patients versus clinicians (10% vs 5%, p = 0.02). Both patients and clinicians rated survival benefit most important during decision making, followed by long-term symptoms. Older patients (OR 0.92 [95%CI 0.87 & ndash;0.97]; p = 0.003) with comorbidity (OR 0.34 [95% CI 0.12 & ndash;0.89]; p = 0.035) had lower preference for chemoradiotherapy, while patients with better numeracy skills (OR 1.2 [95%CI 1.05 & ndash;1.36], p = 0.011) and chemoradiotherapy history (OR 25.0 [95%CI 8.8 & ndash;91.7]; p < 0.001) had higher preference for chemoradiotherapy. & nbsp;Conclusions. There is a considerable difference in minimally desired survival benefit of chemoradiotherapy in high-risk endometrial cancer among and between patients and clinicians. Overall, endometrial cancer patients needed higher benefits than clinicians before preferring chemoradiotherapy. (c) 2021 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/)

Low preoperative skeletal muscle density is predictive for negative postoperative outcomes in older women with ovarian cancer

Objective. To determine the predictive value of lumbar skeletal muscle mass and density for postoperative outcomes in older women with advanced stage ovarian cancer.Methods. A multicenter, retrospective cohort study was performed in women >= 70 years old receiving surgery for primary, advanced stage ovarian cancer. Skeletal muscle mass and density were assessed in axial CT slices on level L3. Low skeletal muscle mass was defined as skeletal muscle index = 2).Conclusion. Low skeletal muscle density, as a proxy of muscle quality, is associated with poor postoperative outcomes in older patients with advanced stage ovarian cancer. These findings can contribute to postoperative risk assessment and clinical decision making. (C) 2021 The Author(s). Published by Elsevier Inc.Cervix cance