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@#Abnormal implant placement is a common challenge in clinical work, including root direction, occlusion direction, mesial direction, distal direction, buccal (lip) direction, tongue (palate) direction, a total of 6 directions. Clinicians should pay great attention to the risk of many complications due to improper placement of implants. Understanding the etiology is the premise to effectively prevent the complications of implant restoration, and this article will discuss the causes, the classification of complications and related treatment principles and treatment plans from 6 different directions of abnormal implant positions.
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Objective:To evaluate the effects of the changes in respiratory status on gated stereotactic radiotherapy under free breathing guided by real-time position management (RPM).Methods:This study simulated the baseline shift, change in respiratory rate, end-expiratory delay, end-inspiratory delay, and irregular breathing using an in-house developed motion phantom. Moreover, this study analyzed the correlation between the changes in the above states of three plans, three-dimensional conformal radiotherapy(3D-CRT), intensity modulated radiotherapy(IMRT), and volumetric modulated arc therapy(VMAT) and the position of the ball at the center of the motion phantom (L) and the exposed dose of the phantom in the ionization chamber (the dose).Results:The in-house developed phantom presented high setup repeatability and measurement stability. There was a positive correlation between L and the baseline shift ( r = 0.99, P < 0.01). The change in the dose was less than 4% when the baseline shift was less than the setup error, while the dose declined rapidly and was negatively correlated with the baseline shift otherwise ( r= -0.95, P < 0.01). Moreover, there was statistically significant difference in dose when the baseline shift exceeded the setup error or not ( Z = -3.06, P < 0.01). There was no significant difference in the rate of the dose affected by baseline shift in the three plans ( P > 0.05). The changes in respiratory rate had little effect on L and the dose. Both end-inspiratory delay and end-expiratory delay reduced the planned dose of the three plans, with a maximum decrease of up to -1.74%. Furthermore, the end-inspiratory delay has greater effects on the planned dose than the end-expiratory delay( Z = -2.67, P< 0.01). However, there was no significant correlation between the dose and the delay duration ( P > 0.05), and no significant difference in the rate of the planned dose of the three plans affected by respiratory waveform change ( P > 0.05). Irregular breathing had greater effects on the dose. Specifically, the dose from six repeated measurements of 3D-CR, IMRT, VMAT was (709.68±180.00), (751.40±127.16), and (750.00±185.60) cGy, respectively, all less than the prescribed dose with a poor consistency. Conclusions:The changes in the patients′ respiratory status will reduce the dose, especially when the baseline shift exceeds the setup error threshold or large respiratory waveform variation corresponding to irregular breathing occurs. Moreover, there is no correlation between the decrease in the dose and the radiotherapy technology.
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Objective To present a medical image transmission scheme based on fast healthcare interoperability resources(FHIR) proxy gateway which can enable medical personnel to access the hospital's medical imaging system via the Internet using mobile terminals,and then raise the medical staffs' working efficiency.Methods RESTful WebServices as the interoperability mechanism of image data was used in combination with FHIR image resource model and construct an intermediate gateway to three-tier network architecture,in order to solve the problem of transmitting image data to mobile terminals through gateway via the hospital's network.Results During its half-year trial run,the Internet mobile terminal reading system based on this method ran stably and was in good condition,in the actual hospital environment.Conclusion The gateway method is simple,flexible,and can fully support the mobile terminals' access to the background image data center.
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Objective:To analyze the stress distribution in the fixed denture of edentulous maxilla supported by 6 implants at different implant position.Methods:The skull of a volunteer with total anodontia and moderate alveolar bone absorption was scanned by CBCT.Computer software,Abaqus 6.9,Geomagic Studio 12,and Mimics10.01,were applied for data processing and reconstruction of a 3D finite element model of implant-supported fixed denture with 6 implants in different location;and then,the stress distribution was analisized.Results:3D finite element model of edentulous maxillary implant-supported fixed bridge with good geometric similarity was established.The implant neck bone interface stress value of the distal of the implant fixed bridge at the molar area,the stress concentration area,was the maximum.The main stresses were compressive in the cortical bone adjacent to the mesial or the distal implants.The shift of the denture decreased from anterior to posterior.In model Ⅰ (implants at 13,15,17,23,25 and 27) distal cantilever was not used and the stress distribution was the evenest.Conclusion:The implant position at 13,15,17,23,25 and 27 of edentulous maxillary 6-implants-supported fixed bridge was the best for the stress distribution among the 8 models.
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<p><b>UNLABELLED</b>OBJECTIVE To evaluate the aesthetic effect of restorations with custom pressable metal ceramic abutments for defective soft and hard tissue in the maxillary anterior zone.</p><p><b>METHODS</b>Fifty-two patients with missing anterior teeth in the maxillar were selected, who had problems such as exposure of abutment metal, excessively large angle deviation, excessively long ceramic crown and missing gingival papilla, affecting the aesthetic effect of implant denture. Custom pressable metal ceramic abutments were made on the conventional castable metal abutment surface and restored with all-ceramic crowns to overcome the blackness at the implant neck.</p><p><b>RESULTS</b>Clinical evaluation for aesthetic effects 3 and 6 months after the restorations were placed. In 63 restorations of 52 patients, the blackness at the implant neck were eliminated and the aesthetic effect were ideal. The gingival was in healthy condition, showing no further gingival retreat or inflammation around the implant denture.</p><p><b>CONCLUSION</b>Custom pressable metal ceramic abutments can effectively improve the aesthetic appearance of the implant denture in maxillary anterior zone.</p>