Application of a novel intraorally customized transport distraction device in the reconstruction of segmental mandibular defect.

PURPOSE: The purpose of this study was to evaluate the clinical result of segmental mandible reconstruction by using a novel intraorally customized trifocal curvilinear distractor. METHODS: A customized curvilinear distractor with self-locking system and bidirection transport assembly was designed on the basis of the mandibular contour of a patient diagnosed with ameloblastoma. Two transport disks, each containing the first molar, were designed for trifocal distraction osteogenesis after partial mandibulectomy intraorally. The latency period is 7 days and distraction rhythm is 1 mm/d. After 6 months of consolidation, the second operation was performed to remove the device. RESULTS: A new bone bridged the mandibular defects through transport distraction successfully. Partial bony nonunion between the transport disks was noted when removing the distractor; rigid internal fixation using a titanium plate and bone graft was carried out to ensure the continuity. Bilateral sagittal split ramus osteotomy was performed to advance the mandible when anterior-posterior jaw bone discrepancy occurred before final denture restoration. CONCLUSIONS: Customized trifocal curvilinear transport distraction osteogenesis can successfully reconstruct segmental mandible defect intraorally, but special consideration should be paid on the dock site bone healing and overcorrection of curvilinear reconstruction in the future.

Fully Automated Localization and Measurement of Levator Hiatus Dimensions Using 3-D Pelvic Floor Ultrasound.

OBJECTIVE: To develop an algorithm for the automated localization and measurement of levator hiatus (LH) dimensions (AI-LH) using 3-D pelvic floor ultrasound. METHODS: The AI-LH included a 3-D plane regression model and a 2-D segmentation model, which first achieved automated localization of the minimal LH dimension plane (C-plane) and measurement of the hiatal area (HA) on maximum Valsalva on the rendered LH images, but not on the C-plane. The dataset included 600 volumetric data. We compared AI-LH with sonographer difference (ASD) as well as the inter-sonographer differences (IESD) in the testing dataset (n = 240). The assessment encompassed the mean absolute error (MAE) for the angle and center point distance of the C-plane, along with the Dice coefficient, MAE, and intra-class correlation coefficient (ICC) for HA, and included the time consumption. RESULTS: The MAE of the C-plane of ASD was 4.81 ± 2.47° with 1.92 ± 1.54 mm. AI-LH achieved a mean Dice coefficient of 0.93 for LH segmentation. The MAE on HA of ASD (1.44 ± 1.12 mm²) was lower than that of IESD (1.63 ± 1.58 mm²). The ICC on HA of ASD (0.964) was higher than that of IESD (0.949). The average time costs of AI-LH and manual measurement were 2.00 ± 0.22 s and 59.60 ± 2.63 s (t = 18.87, p < 0.01), respectively. CONCLUSION: AI-LH is accurate, reliable, and robust in the localization and measurement of LH dimensions, which can shorten the time cost, simplify the operation process, and have good value in clinical applications.

Two- and three-dimensional models for the visualization of jaw tumors based on CT-MRI image fusion.

PURPOSE: The objective of this study was to demonstrate the feasibility of two- and three-dimensional (2D and 3D) models based on computed tomography-magnetic resonance imaging (CT-MRI) image fusion for the visualization of jaw tumors. METHODS: Seven patients with proved jaw tumors were involved in this study. Both preoperative CT and MRI image data were acquired in DICOM format and imported into Surgicase CMF software, respectively. Then, the structures of interest, including tumor, muscle, and vascular, and so on, were segmented based on different thresholds and reconstructed in 3D texture. Finally, CT-MRI image fusion was semiautomatically performed to obtain the fused 2D images and 3D models for the visualization of jaw tumors. The qualities of the fused 2D images and 3D models together with their potential applications in surgical management of jaw tumors were qualitatively assessed. Besides, the importance of this imaging technique in terms of training junior surgeons was also discussed in detail. RESULTS: Computed tomography-MRI image fusion clearly showed the relationship between tumors and adjacent structures. The qualitative assessment of fused images was satisfied. CONCLUSIONS: Although there are some limitations, the 2D images and 3D models based on CT-MRI image fusion can provide a powerful tool for the visualization of jaw tumors. It may offer surgeons an assisted tool for the subject-specific preoperative planning, surgical simulation, and intraoperative guidance for jaw tumors. Furthermore, it also may offer valuable 2D and 3D models for training junior surgeons or provide a useful tool for surgeons to communicate well with patients.

Spatial Effect of Ecological Environmental Factors on Mumps in China during 2014-2018.

(1) Background: although mumps vaccines have been introduced in most countries around the world in recent years, mumps outbreaks have occurred in countries with high vaccination rates. At present, China remains the focus of the global fight against mumps. This study aims to observe the epidemic characteristics and spatial clustering patterns of mumps and to investigate the potential factors affecting the disease incidence, which could provide novel ideas and avenues for future research as well as the prevention and control of mumps. (2) Methods: we used ArcGIS software to visualize the spatial distribution and variation of mumps. Spatial autocorrelation analysis was applied to detect the spatial dependence and clustering patterns of the incidence. We applied the Spatial Durbin Panel Model (SDPM) to explore the spatial associations of ecological environmental factors with mumps. (3) Results: overall, the incidence rate showed a significant upward trend from 2014 to 2018, with the highest number of cases in the 10-15-year age group and from May to June. Geographically, the high incidence clusters were concentrated in southern regions, including Hunan, Hubei, Chongqing, Guizhou, Guangdong, and Guangxi. This study also found that mumps has a positive spatial spillover effect in the study area. The average temperature and GDP of the local and adjacent areas have a significant impact on mumps. The increase in PM2.5 contributes to the rise in the incidence of mumps in this region. (4) Conclusions: these results can offer some novel ideas for policymakers and researchers. Local meteorological conditions and economic levels can extend to surrounding areas to affect the occurrence of mumps, so regional cooperation becomes particularly important. We recommend investment of public health funds in areas with a high incidence of mumps and developing economies to reduce and control the incidence of mumps.

Spatial analysis and influencing factors of pulmonary tuberculosis among students in Nanning, during 2012-2018.

BACKGROUND: Economically underdeveloped areas in western China are hotspots of tuberculosis, especially among students. However, the related spatial and temporal patterns and influencing factors are still unclear and there are few studies to analyze the causes of pulmonary tuberculosis in students from the perspective of space. METHODS: We collected data regarding the reported incidence of pulmonary tuberculosis (PTB) among students at township level in Nanning, from 2012 to 2018. The reported incidence of pulmonary tuberculosis among students in Nanning was analyzed using spatial autocorrelation and spatial scan statistical analysis to depict hotspots of PTB incidence and spatial and temporal clustering. Spatial panel data of the reported incidence rates and influencing factors at district and county levels in Nanning were collected from 2015 to 2018. Then, we analyzed the spatial effects of incidence and influencing factors using the spatial Durbin model to explore the mechanism of each influencing factor in areas with high disease prevalence under spatial effects. RESULTS: From 2012 to 2018, 1609 cases of PTB were reported among students in Nanning, with an average annual reported incidence rate of 14.84/100,000. Through the Joinpoint regression model, We observed a steady trend in the percentage of cases reported each year (P>0.05). There was spatial autocorrelation between the annual reported incidence and the seven-years average reported incidence from 2012 to 2018. The high-incidence area was distributed in the junction of six urban areas and spread to the periphery, with the junction at the center. The population of college students, per capita financial expenditure on health, per capita gross domestic product, and the number of health technicians per 1,000 population were all influencing factors in the reported incidence of PTB among students. CONCLUSION: We identified spatial clustering of the reported incidence of PTB among students in Nanning, mainly located in the urban center and its surrounding areas. The clustering gradually decreased from the urban center to the surrounding areas. Spatial effects influenced the reported incidence of PTB. The population density of college students, per capita health financial expenditure, gross domestic product (GDP) per capita, and the number of health technicians per 1,000 were all influencing factors in the reported incidence of PTB among students.

Sequential maxillary bifocal transport distraction osteogenesis after radiotherapy.

Maxillary defects secondary to ablative surgery are common, and functional maxillary reconstruction is challenging. Adjuvant radiotherapy further complicates reconstructive surgical planning. In this article, successful functional reconstruction of a partial maxillary defect was achieved using segmental osteotomy, sequential bifocal distraction osteogenesis, and prosthodontic treatment. The current evidence is reviewed, and the surgical planning and technique are described in detail.

Effects of small-dose remifentanil combined with index of consciousness monitoring on gastroscopic polypectomy: a prospective, randomized, single-blinded trial.

BACKGROUND: With the development of painless diagnosis and treatment, remifentanil, a synthetic opioid agonist, is increasingly used in gastroscopy for its rapid, short-term, and potent analgesic effect. However, the dosage of remifentanil used in endoscopy is unclear. Index of consciousness (IOC) is a new anesthesia depth-monitoring indicator that can be divided into index of consciousness 1 (IOC1) and index of consciousness 2 (IOC2); IOC1 is used for estimating a patient's sedation state, whereas IOC2 reflects analgesic depth. We hypothesized that combining with IOC1 and IOC2 monitoring may be helpful to identify an optimal remifentanil dosage in gastroscopic polypectomy. METHODS: One hundred twenty patients scheduled for gastroscopic polypectomy were enrolled and were randomly assigned to remifentanil 2 ng/mL (group R2), 4 ng/mL (group R4), or 6 ng/mL (group R6), and 40 cases were in each group. During the anesthesia period, remifentanil was kept at the initial given concentration but propofol was adjusted according to IOC1. The primary outcomes were the dosage of propofol and remifentanil. The secondary outcomes were the variety of IOC1 and IOC2, patients' awakening time, and peri-operative adverse reactions such as hypotension, hypertension, bradycardia, tachycardia, body movements, hypoxemia, therapy interruption, nausea, vomiting, aspiration, and intra-operative awareness. RESULTS: With the increasing dosage of remifentanil, the propofol dosage and patients' awakening time decreased significantly, the morbidity of hypertension and body movements also declined, but the incidence of hypotension, bradycardia, and hypoxemia rose. In group R2, the value of IOC2 remained above 50 during the treatment. However, IOC2 dropped to below 30 at the beginning of the gastroscopy in group R6, and there was statistical difference in hypoxemia between groups R2 and R6 (P <0.05). CONCLUSIONS: With the help of IOC monitoring, we found that a target concentration of remifentanil 4 ng/mL is comparatively ideal in patients under gastroscopic polypectomy. TRIAL REGISTRATION: Chinese Clinical Trial Register: ChiCTR-OOD-16009489 , on October 19, 2016.

Synthesis and antibacterial activities of antibacterial peptides with a spiropyran fluorescence probe.

In this report, antibacterial peptides 1-3 were prepared with a spiropyran fluorescence probe. The probe exhibits a change in fluorescence when isomerized from a colorless spiro-form (spiropyran, Sp) to a colored open-form (merocyanine, Mc) under different chemical environments, which can be used to study the mechanism of antimicrobial activity. Peptides 1-3 exhibit a marked decrease in antimicrobial activity with increasing alkyl chain length. This is likely due to the Sp-Mc isomers in different polar environments forming different aggregate sizes in TBS, as demonstrated by time-dependent dynamic light scattering (DLS). Moreover, peptides 1-3 exhibited low cytotoxicity and hemolytic activity. These probe-modified peptides may provide a novel approach to study the effect of structural changes on antibacterial activity, thus facilitating the design of new antimicrobial agents to combat bacterial infection.

Magainin II modified polydiacetylene micelles for cancer therapy.

Polydiacetylene (PDA) micelles have been widely used to deliver anticancer drugs in the treatment of a variety of tumours and for imaging living cells. In this study, we developed an effective strategy to directly conjugate magainin II (MGN-II) to the surface of PDA micelles using a fluorescent dye. These stable and well-defined PDA micelles had high cytotoxicity in cancer cell lines, and were able to reduce the tumour size in mice. The modified PDA micelles improved the anticancer effects of MGN-II in the A549 cell line only at a concentration of 16.0 µg mL(-1) (IC50). In addition, following irradiation with UV light at 254 nm, the PDA micelles gave rise to an energy transfer from the fluorescent dye to the backbone of PDA micelles to enhance the imaging of living cells. Our results demonstrate that modified PDA micelles can not only be used in the treatment of tumors in vitro and in vivo in a simple and directed way, but also offer a new platform for designing functional liposomes to act as anticancer agents.

A novel device for preoperative registration and automatic tracking in cranio-maxillofacial image guided surgery.

OBJECTIVE: Two key issues in image guided surgery are accurate patient-to-image registration and ongoing tracking of the patient's motion. To address these concerns, a novel device for preoperative registration and automatic tracking was designed, and the accuracy attainable with the device was evaluated in experiments with a skull and in a clinical study. METHODS: The device consists of a system of four titanium screws and four fluorescent spheres fixed to carbon bars which can be easily mounted on the maxillary dentition splint. Before surgery, CT image data of a skull with the device in place was acquired and registered in a navigation system. The rigidity and reproducibility of positioning of the device were measured in 15 repeated CT acquisitions of the skull with the device in place. The registration accuracy was compared to that obtained using micro-screw markers fixed to the maxillary alveolus. To determine the potential of the device in aiding image guided cranio-maxillofacial surgery, registration accuracy and surgical outcome were assessed. RESULTS: Fifteen tests were performed for CT scanning with no loosening of the splint and device. The arithmetic mean of the standard deviation (SD) ranged from 0.47 mm to 0.70 mm. When the device was used for registration, the mean deviations for the eight anatomical structures investigated ranged from 0.56 mm at the left infra-orbital foramen to 0.96 mm at the right temple. Compared with the method in which titanium screws are fixed to the maxillary alveolus, the target registration error (TRE) obtained using the new device was much less. Using this device, clinical reduction of a zygomatic-orbital-maxillary complex fracture was successfully completed with a registration discrepancy of less than 0.5 mm. CONCLUSIONS: By successfully addressing the two key issues of image guided surgery, the device could be considered accurate and potentially useful for assisting in cranio-maxillofacial surgery.

[Color distribution of the anterior teeth in 137 elder people].

PURPOSE: To study the color distribution of the anterior teeth in elder people. METHODS: 612 anterior teeth from 137 people aging from 60 to 81 years and 200 anterior teeth from 100 young people aging from 20 to 40 years were collected. A digital colorimeter was used to measure the value of L*,a*,b* of the teeth, and the chromatism (deltaE) was calculated according to the formula deltaE=(deltaL*(2)+deltaa*(2)+deltab*(2))1/2. All data were analyzed with SAS 6.12 software package for Student's t test. RESULTS: Totally, there were 612 vital anterior teeth from elder people, including 201 central incisors,199 lateral incisors and 212 canines, were collected. No difference was found between the teeth on the right side and the left side in terms of L*,a*,b*value(P>0.05). The mean value of L*,a*,b* of the central incisors was 71.2+/-6.22,0.97+/-1.12,15.9+/-5.04, respectively and that of the lateral incisors and the canines were 69.6+/-5.52,0.6+/-1.18,13.9+/-4.15 and 68.4+/-5.99,0.15+/-1.02,19.6+/-4.87, respectively.The mean value of L*,a*,b* of the central incisors and the canines from the youngster was 75.82,-0.11,12.68 and 72.07,1.22,17.92, respectively.There were significant differences between the central incisors and the lateral incisors as well as the canines (P<0.05) in terms of L* value. Meanwhile difference was also found among the incisors and the canines in terms of a* and b* value(P<0.05). The deltaE between the central incisors and the lateral incisors was 2.945NBS, and the value between the canines and the central incisors as well as the lateral incisors was 4.629NBS and 5.832NBS, respectively, indicating that the color difference could be perceived visually. Compared to the youngster, the teeth of the elder people demonstrated a lower L* and a* value, but a higher b* value (P<0.05). CONCLUSIONS: Among elder people, the central incisors look much brighter than the lateral incisors and canines, while the canines have more redness and yellowness than the incisors, and the color of the lateral incisors exhibits lighter than the central incisors and the canines. Compared to the teeth from younger people, the teeth from elder people look much darker and yellower but less red. Supported by Shanghai Leading Academic Discipline Project (Grant No.T0202).

[The influence of the try-in pastes on the colour of all-ceramic veneers].

PURPOSE: To study the influence of the try-in pastes on the color of all-ceramic veneers made by Ips-empress II system. METHODS: 50 discolored teeth were collected and restored with all-ceramic veneers. Five try-in pastes including A1, A3, transleucent(Trt), white opaque(WOT) and B0.5 opaque(B0.5),which were different in shade, were respectively used to try in before cementing. The color was measured by the ShadeEye, a digital colorimeter, and expressed in terms of 3 coordinate values (L*,a*,b*) of the CIEL*a*b* system. Then the color differences(deltaEa*b*) of all-ceramic veneers[deltaEa*b*=(deltaL*(2)+deltaa*(2)+deltab*(2))(1/2)] as well as the value of L*deltaC(ab)[C(ab)=(a*(2)+b*(2))(1/2)] and H(ab)[H(ab)=arctan(b*/a*)]were calculated. Meanwhile,the thickness of the measurement point was measured and recorded. One-way ANOVA was used to analyze deltaEa*b* as well as L*,C(ab) and Hab. RESULTS: The average thickness of the ceramic was 1.088mm, and the colour of the veneers after try in with WOT paste and B0.5 paste performed a higher L* value than the other pastes (P<0.05).And the veneers also showed a higher C(ab) value after try in with WOT,B0.5 and A3 paste than the A1 and Trt paste (P<0.05). No significant differences were found in Hab value after these 50 veneers tried in with these five kinds of pastes. CONCLUSIONS: It's more advisable to choose the WOT or the B0.5 luting agent to cement the veneer when the abutment tooth is severely discolored, while the Trt or the A1 shade and A3 shade luting resin may be more appropriate if the abutment tooth doesn't discolor or a little compared with the adjacent tooth.

[A preliminary study on the relationship between the wearing time of full denture and EMG in edentulous patients].

PURPOSE: This study was aimed to analyze the relationship between the periods of wearing time of full denture and function of mastication in edentulous patients. METHODS: Electromyogram (EMG) was done at an initial time of wearing full denture for 30 patients (Group A) and at an interval of wearing full denture for more than 3 months for 32 patients (Group B). EMG activities were recorded for 2 pairs of muscles (anterior temporalis, masseter) by means of Medelec Synergy Electromyography. Student's t test was used for statistical analysis. RESULTS: EMG amplitude of Group A was significantly lower than that of Group B (left anterior temporalis P < 0.05, bilateral masseter P < 0.05). Group A has larger area than Group B (P < 0.05); No significant difference was found in asymmetry index between Group A and Group B (P > 0.05). CONCLUSION: The function of mastication in patients who wore full denture for short time has not been achieved as expected.