Cumulative summation analysis of learning curve for endoscopic endonasal transsphenoidal resection of craniopharyngiomas.

Background: To evaluate the cumulative summation (CUSUM) analysis of the learning curve for Endoscopic Endonasal Transsphenoidal resection of craniopharyngioma (EETC). Methods: Retrospectively analyzed the clinical data of 113 patients who underwent EETC by the same neurosurgery team of the first affiliated Hospital of Nanchang University from June 2012 to November 2020. The learning curve was created by the CUSUM method and analyzed, which was divided into two groups: the learning stage and stable stage based on the learning curve trend. The median operation time and minimum surgical case number was calculated and the operation time and postoperative complications were compared between the two groups. Results: The median operation time was 318 min. The best fitting curve equation was y = 227.72 + 49.06x + 0.14x2 - 0.05x3, R2 = 0.949, (p < 0.001). The minimum number of surgical cases was 65. Between the two groups, the operation time decreased from 360.8 ± 106.4 min in the learning group to 281.6 ± 69.9 min in the stable group (p < 0.05). The incidence of postoperative complications (intracranial infection, cerebrospinal fluid rhinorrhea, and diabetes insipidus) was significantly reduced (p < 0.05). Conclusion: The CUSUM learning curve of craniopharyngioma resection via endoscope endonasal transsphenoidal approach could better describe the learning process for a neurosurgeon. The frequency of surgery could be a good factor for strengthening the learning effect and help to shorten the learning time. After 65 cases of EETC, the surgical skills can reach a stable stage, the operation time is obviously shortened, and the postoperative complications are significantly reduced.

A retrospective study of micro-implant anchorage in the upper posterior region to improve gummy smiles / 口腔疾病防治

Objective@#To analyze the ability of micro-implant nails placed in different locations in the posterior region to improve the hard and soft tissues of the labiodental region in patients with gummy smiles to provide a reference for clinicians.@*Methods@#This study was reviewed and approved by the Ethics Committee, and informed consent was obtained from the patients. Thirty young female patients with anterior tooth protrusions and gummy smiles were included in the retrospective study; 18 patients had micro-implant nails implanted between the premolars (group A), and 12 patients had implant nails placed between the roots of the premolar and the molar and an intraoperatively placed rocking-chair archwire (group B). The preoperative and postoperative distances from the incisal end of the upper mesial incisors to the lower point of the upper lip (U1-Stms), the vertical distance from the incisal end of the upper mesial incisors to the palatal plane (U1-PP), the vertical distance from the point of the alveolar ridge to the palatal plane (Spr-PP), the distance from the incisal end of the upper mesial incisors to the point of the alveolar margin (U1-Spr), and the vertical distance from the point of the proximal middle buccal cusp of the maxillary first molar to the palatal plane of the maxillary first molar (U6-PP) were measured in the cephalometric lateral radiographs of the two groups; additionally, the amount of hard and soft tissues of the upper anterior region exposedduring smiling and the maximum amount of gingiva exposed during smiling were assessed from the smile photograph.@*Results@#After correction, the lip-dentition relationship improved significantly in both groups, with an average reduction of 2.6 mm in U1-Stms, 2.4 mm in U1-PP, 1.4 mm in Spr-PP, and 0.9 mm in U1-Spr in Group A. In group B, the U1-Stms was reduced by an average of 2.3 mm, the U1-PPs by an average of 1.6 mm, the Spr-PPs by 1.4 mm, and the U1-Spr by 0.2 mm. The difference between pre- and postoperative U6-PP in both groups was not significant (P>0.05). Group A had greater ∆U1-PP and ∆U1-Spr changes than group B(P<0.05). There was no difference between the two groups in terms of ∆U1-Stms or ∆Spr-PP (P>0.05). The amount of soft and hard tissue exposed and maximum amount of gingiva exposed in the upper anterior region of the smile were reduced in 30 patients postoperatively, with group A having anaverage reduction of 70.19% of the preoperative amount of soft and hard tissue exposed in the upper anterior region and an average reduction of 24.12% of the preoperative maximum amount of gingiva exposed, and group B having an average reduction of 76.12% of the preoperative amount of hard and soft tissue exposed in the upper anterior region and an average reduction of 31.88% of the preoperative maximum gingiva exposed after the operation. The difference in the ratio between the two groups was not statistically significant (P>0.05).@*Conclusion@#For patients with proptosis and gummy smiles, placing micro-implant nails between the roots of maxillary premolars can effectively lead to retraction and intrusion of anterior teeth to improve the lip-dentition relationship and improve gummy smile, and placing micro-implant nails between the roots of the maxillary second premolar and the first molar together with the use of rocking chair arches can also achieve a good therapeutic effect.

Disc repositioning surgery combined with orthodontic treatment of patients with temporomandibular disorders and facial asymmetry: a case report and literature review / 口腔疾病防治

Objective@#To investigate the clinical efficacy of disc repositioning surgery combined with orthodontic treatment in patients with temporomandibular disorder and facial asymmetry.@*Methods@#One patient who underwent disc repositioning surgery combined with orthodontic treatment for temporomandibular joint disorder and facial asymmetry was reported. Preoperatively, the patient had a skewed shape of the opening, mild pressure pain in the right preauricular region with left mandibular deviation, and a mismatch between the width of the upper and lower dental arches. In the arthrosurgery department, bilateral temporomandibular disc replacement and anchorage were performed through a transauricular incision, and an auxiliary splint was worn to stabilize the jaw position for 6 months. In the orthopedic department, maxillary skeletal expansion was used in combination with the multiloop edgewise archwire technique to reconstruct the occlusion after 16 months of orthodontic treatment.@*Results@#The deviation was corrected by wearing an occlusal splint for six months after joint repositioning and anchoring; moreover, the pain symptoms disappeared, and the cone beam CT examination showed that the bilateral temporomandibular joint space was uniformly enlarged, the lower alveolar ridge midline deviated to the right, the posterior regions of the teeth were bilaterally inverted, and the anterior region and the posterior region of the left side were open. The orthodontic treatment matched the width of the upper and lower dental arches and established the cuspal molar neutrality relationship and the normal overjet coverage of the anterior teeth; additionally, the mandibular position was not obviously skewed. A review of the results of the related literature shows that abnormal occlusal relationships, such as mismatched arch width and skewed occlusal plane, can cause adaptive mandibular deviation, which can lead to the occurrence of TMD. Temporomandibular joint disc anchorage with splint treatment can effectively improve maxillofacial deformity in young TMD patients. After the establishment of a stable, physiologically functional disc-condylar relationship, orthodontic treatment is required to remove the interfering factors to rebuild the occlusion, and long-term postoperative review and follow-up are needed.@*Conclusion@#In patients with TMD and mandibular accommodative deviation due to occlusal anomalies, establishing a normal disc-condylar relationship and eliminating occlusal interference through disc repositioning surgery combined with orthodontic treatment can effectively improve facial shape and establish a stable jaw position.

Palladium-Catalyzed Thiocarbonylation of Aryl Iodides with S-Aryl Thioformates via Thioester Transfer.

Herein we reported a novel approach to synthesize thioesters with S-aryl thioformates as thioester sources. The reaction proceeded at ambient temperature using widely available starting ingredients, wherein the thioester moiety was smoothly transferred to aryl iodides from S-aryl thioformates. A variety of substrates with various electronic natures were all tolerated under the reaction conditions to furnish desirable thioesters in ranges from moderate to excellent yields. The gram-scale reaction was also conducted, and there was virtually little change in chemical yield, indicating that large-scale synthesis of thioesters may be viable using this method.

Palladium-Catalyzed Highly Chemo- and Stereoselective Bisthiolation of Terminal Alkynes with Allyl Phenyl Sulfides via C-S Bond Cleavage.

A facile and general method for palladium-catalyzed stereoselective bisthiolation of terminal alkynes with allyl phenyl sulfides has been developed. The scope and versatility of the reaction have been demonstrated, and a broad range of substrates bearing electron-donating and -withdrawing groups on the aromatic rings were all compatible with this reaction, providing the desired (Z)-1,2-dithio-1-alkenes in moderate to good yields. Preliminary mechanistic studies demonstrated that the sulfur source of the desired products may be successively incorporated into alkynes via C-S bond cleavage of two molecules of allyl phenyl sulfides and ruled out the possibility of vinyl sulfides, alkynyl sulfides, and disulfide intermediates being involved in this reaction.

Chromosomal Characterization of Tripidium arundinaceum Revealed by Oligo-FISH.

Sugarcane is of important economic value for producing sugar and bioethanol. Tripidium arundinaceum (old name: Erianthus arundinaceum) is an intergeneric wild species of sugarcane that has desirable resistance traits for improving sugarcane varieties. However, the scarcity of chromosome markers has hindered the cytogenetic study of T. arundinaceum. Here we applied maize chromosome painting probes (MCPs) to identify chromosomes in sorghum and T. arundinaceum using a repeated fluorescence in situ hybridization (FISH) system. Sequential FISH revealed that these MCPs can be used as reliable chromosome markers for T. arundinaceum, even though T. arundinaceum has diverged from maize over 18 MYs (million years). Using these MCPs, we identified T. arundinaceum chromosomes based on their sequence similarity compared to sorghum and labeled them 1 through 10. Then, the karyotype of T. arundinaceum was established by multiple oligo-FISH. Furthermore, FISH results revealed that 5S rDNA and 35S rDNA are localized on chromosomes 5 and 6, respectively, in T. arundinaceum. Altogether, these results represent an essential step for further cytogenetic research of T. arundinaceum in sugarcane breeding.

Examining motor evoked potential amplitude and short-interval intracortical inhibition on the up-going and down-going phases of a transcranial alternating current stimulation (tacs) imposed alpha oscillation.

Many brain regions exhibit rhythmical activity thought to reflect the summed behaviour of large populations of neurons. The endogenous alpha rhythm has been associated with phase-dependent modulation of corticospinal excitability. However, whether exogenous alpha rhythm, induced using transcranial alternating current stimulation (tACS) also has a phase-dependent effect on corticospinal excitability remains unknown. Here, we triggered transcranial magnetic stimuli (TMS) on the up- or down-going phase of a tACS-imposed alpha oscillation and measured motor evoked potential (MEP) amplitude and short-interval intracortical inhibition (SICI). There was no significant difference in MEP amplitude or SICI when TMS was triggered on the up- or down-going phase of the tACS-imposed alpha oscillation. The current study provides no evidence of differences in corticospinal excitability or GABAergic inhibition when targeting the up-going (peak) and down-going (trough) phase of the tACS-imposed oscillation.

Combined transcranial alternating current stimulation and continuous theta burst stimulation: a novel approach for neuroplasticity induction.

Non-invasive brain stimulation can induce functionally relevant plasticity in the human cortex, making it potentially useful as a therapeutic tool. However, the induced changes are highly variable between individuals, potentially limiting research and clinical utility. One factor that might contribute to this variability is the level of cortical inhibition at the time of stimulation. The alpha rhythm (~ 8-13 Hz) recorded with electroencephalography (EEG) is thought to reflect pulsatile cortical inhibition; therefore, targeting non-invasive brain stimulation to particular phases of the alpha rhythm may provide an approach to enhance plasticity induction. Transcranial alternating current stimulation (tACS) has been shown to entrain cortical oscillations in a frequency-specific manner. We investigated whether the neuroplastic response to continuous theta burst stimulation (cTBS) was enhanced by timing bursts of stimuli to the peak or the trough of a tACS-imposed alpha rhythm. While motor evoked potentials (MEPs) were unaffected when cTBS was applied in-phase with the peak of the tACS-imposed oscillation, MEP depression was enhanced when cTBS was applied in-phase with the trough. This enhanced MEP depression was dependent on the individual peak frequency of the endogenous alpha rhythm recorded with EEG prior to stimulation, and was strongest in those participants classified as non-responders to standard cTBS. These findings suggest that tACS may be used in combination with cTBS to enhance the plasticity response. Furthermore, the peak frequency of endogenous alpha, as measured with EEG, may be used as a simple marker to pre-select those individuals likely to benefit from this approach.