Non-invasive removal of sandblasted and acid-etched titanium palatal implants, a retrospective study

BACKGROUND Short, rough-surfaced palatal implants are an established and reliable anchor for orthodontic treatment. Until recently, removal was only possible surgically using a hollow cylinder trephine. This standard method retrieves the implant combined with a larger bone volume and is therefore considered invasive and has known complications. Lately, an explantation tool which allows a sufficient force application to break the bone-implant-connection and unscrew the palatal implant was developed and, since its introduction, has been used as the method of choice in several orthodontic offices. OBJECTIVES The aim of this study was to assess the complications caused by removing rough-surfaced palatal implants simply by unscrewing them with an explantation tool in contrast to standard protocol by surgical removal with a trephine. MATERIAL AND METHODS The removal of 73 palatal implants using a customized explantation tool has been evaluated retrospectively and was compared to an existing sample of 44 conventional surgical explantations. RESULTS The new clinical procedure resulted in successful removal of 71 (97.3 per cent) palatal implants. In two cases, the new method failed but removal with the established surgical method was still possible with no further complications. The non-invasive palatal implant removal with a customized explantation tool had less medical complications compared to an existing sample of surgical explantations. CONCLUSIONS User's opinion was that the new method is more easily executed, less invasive, and also applicable without local anaesthesia. Therefore, it is considered to be beneficial for patients and the treatment approach of choice. However, further research is needed for verificatio

Epigenetic Silencing of Spermatocyte-Specific and Neuronal Genes by SUMO Modification of the Transcription Factor Sp3

SUMO modification of transcription factors is linked to repression of transcription. The physiological significance of SUMO attachment to a particular transcriptional regulator, however, is largely unknown. We have employed the ubiquitously expressed murine transcription factor Sp3 to analyze the role of SUMOylation in vivo. We generated mice and mouse embryonic fibroblasts (MEFs) carrying a subtle point mutation in the SUMO attachment sequence of Sp3 (IKEE553D mutation). The E553D mutation impedes SUMOylation of Sp3 at K551 in vivo, without affecting Sp3 protein levels. Expression profiling revealed that spermatocyte-specific genes, such as Dmc1 and Dnahc8, and neuronal genes, including Paqr6, Rims3, and Robo3, are de-repressed in non-testicular and extra-neuronal mouse tissues and in mouse embryonic fibroblasts expressing the SUMOylation-deficient Sp3E553D mutant protein. Chromatin immunoprecipitation experiments show that transcriptional de-repression of these genes is accompanied by the loss of repressive heterochromatic marks such as H3K9 and H4K20 tri-methylation and impaired recruitment of repressive chromatin-modifying enzymes. Finally, analysis of the DNA methylation state of the Dmc1, Paqr6, and Rims3 promoters by bisulfite sequencing revealed that these genes are highly methylated in Sp3wt MEFs but are unmethylated in Sp3E553D MEFs linking SUMOylation of Sp3 to tissue-specific CpG methylation. Our results establish SUMO conjugation to Sp3 as a molecular beacon for the assembly of repression machineries to maintain tissue-specific transcriptional gene silencing

Event-Related Potentials Reveal Rapid Verification of Predicted Visual Input

Human information processing depends critically on continuous predictions about upcoming events, but the temporal convergence of expectancy-based top-down and input-driven bottom-up streams is poorly understood. We show that, during reading, event-related potentials differ between exposure to highly predictable and unpredictable words no later than 90 ms after visual input. This result suggests an extremely rapid comparison of expected and incoming visual information and gives an upper temporal bound for theories of top-down and bottom-up interactions in object recognition

Hoxa9 and Meis1 Cooperatively Induce Addiction to Syk Signaling by Suppressing miR-146a in Acute Myeloid Leukemia

The transcription factor Meis1 drives myeloid leukemogenesis in the context of Hox gene overexpression but is currently considered undruggable. We therefore investigated whether myeloid progenitor cells transformed by Hoxa9 and Meis1 become addicted to targetable signaling pathways. A comprehensive (phospho)proteomic analysis revealed that Meis1 increased Syk protein expression and activity. Syk upregulation occurs through a Meis1-dependent feedback loop. By dissecting this loop, we show that Syk is a direct target of miR-146a, whose expression is indirectly regulated by Meis1 through the transcription factor PU.1. In the context of Hoxa9 overexpression, Syk signaling induces Meis1, recapitulating several leukemogenic features of Hoxa9/Meis1-driven leukemia. Finally, Syk inhibition disrupts the identified regulatory loop, prolonging survival of mice with Hoxa9/Meis1-driven leukemia..O. and T. Berg (BE 4198/1-1 and BE 4198/2-1) are supported by the Deutsche Forschungsgemeinschaft (DFG). K.S. is supported by a Leukemia and Lymphoma Society Scholar Award and by the National Cancer Institute (R01 CA140292). F.C. is supported by an EMBO long-term fellowship (1305-2015 and Marie Curie ActionsLTFCOFUND2013/GA-2013-609409). F.K. was supported by grants from Deutsche Krebshilfe (grant 109420; Max-Eder program), fellowship 2010/04 by the European Hematology Association, and by the DFG (SFB 1074, project A5). A.R. was supported by the DFG (SFB 1074, project A5) and the gender equality program by the DFG (SFB 1074, project Z2), a fellowship from the Canadian Institutes of Health Research, and the Baustein Startförderung Program of the Medical Faculty, Ulm University. Work in the Department of Haematology in Cambridge is supported by Bloodwise (grant ref. 13003), the Wellcome Trust (grant ref. 104710/Z/14/Z), the Medical Research Council (MC_PC_12009), the Kay Kendall Leukemia Fund (KKL952), the Cambridge NIHR Biomedical Research Center (NF-BR-0412-10321), the Cambridge Experimental Cancer Medicine Centre itself receives funding from NIHR (NF-EC-0412-10442), the Leukemia and Lymphoma Society of America (grant ref. 07037), and core support grants from the Wellcome Trust (100140/Z/12/Z and 097922/Z/11/Z) and MRC (MC_PC_12009)

Apical root resorption due to mandibular first molar mesialization: A split-mouth study

INTRODUCTION: Our aim was to evaluate the risk of external apical root resorption (EARR) in mesialized mandibular molars due to space closure in patients with unilateral second premolar agenesis. The contralateral side served as the control. METHODS: After application of eligibility criteria, 25 retrospectively selected subjects (median age, 14.9 years; range, 12.0-31.9 years) were analyzed. Space closure (approximately 10 mm) was performed using skeletal anchorage. EARR was measured at the mandibular permanent canines, first premolars, and first molars in the pretreatment and posttreatment orthopantomograms. Measurements were performed by 2 examiners independently and were corrected for distortion and magnification of radiographs, which were assessed in a pilot study. Multivariate analysis of covariance and pairwise comparisons were performed. RESULTS: The mean enlargement factor of the panoramic machine was 29% ± 0.3%. Distortion exceeded 5% only in cases of large positioning errors (>20°). Intraclass correlation coefficients showed strong to almost perfect agreement (mean, 0.80 mm; 95% CI, 0.75-0.85) of the two examiners. Multivariate analysis of covariance resulted in no difference in EARR between the canines and premolars of the space closure and control sides. On the contrary, there was a statistically significant difference between mesialized and nonmezialized molars (0.73 mm; 95% confidence interval, 0.19-1.27). The mean total EARR in each tooth type did not exceed 1 mm. CONCLUSIONS: Space closure through extensive tooth movement in the mandible was identified as a risk factor for EARR. However, the amount of EARR attributed to space closure and the total EARR were not considered clinically significant

Non-invasive removal of sandblasted and acid-etched titanium palatal implants, a retrospective study

BACKGROUND Short, rough-surfaced palatal implants are an established and reliable anchor for orthodontic treatment. Until recently, removal was only possible surgically using a hollow cylinder trephine. This standard method retrieves the implant combined with a larger bone volume and is therefore considered invasive and has known complications. Lately, an explantation tool which allows a sufficient force application to break the bone-implant-connection and unscrew the palatal implant was developed and, since its introduction, has been used as the method of choice in several orthodontic offices. OBJECTIVES The aim of this study was to assess the complications caused by removing rough-surfaced palatal implants simply by unscrewing them with an explantation tool in contrast to standard protocol by surgical removal with a trephine. MATERIAL AND METHODS The removal of 73 palatal implants using a customized explantation tool has been evaluated retrospectively and was compared to an existing sample of 44 conventional surgical explantations. RESULTS The new clinical procedure resulted in successful removal of 71 (97.3 per cent) palatal implants. In two cases, the new method failed but removal with the established surgical method was still possible with no further complications. The non-invasive palatal implant removal with a customized explantation tool had less medical complications compared to an existing sample of surgical explantations. CONCLUSIONS User's opinion was that the new method is more easily executed, less invasive, and also applicable without local anaesthesia. Therefore, it is considered to be beneficial for patients and the treatment approach of choice. However, further research is needed for verification