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PURPOSE@#The maximum width between the mesial and distal labial transitional line angles, described as “esthetic width” herein, could significantly influence the visual perception of the teeth and smile. This study aimed to conduct biometric research on esthetic width and to explore whether regular distribution exists in the esthetic width of human teeth. @*MATERIALS AND METHODS@#A total of 4,264 maxillary and mandibular anterior teeth were measured using the Geomagic studio software program. The proportions of maxillary to mandibular homonymous teeth and proportions between the adjacent teeth were calculated. Bilateral symmetry and the correlation between the esthetic and mesiodistal widths were both accounted for during the measurement procedures. @*RESULTS@#The mean esthetic widths were 6.773 ± 0.518 mm and 4.329 ± 0.331 mm for maxillary and mandibular central incisors, respectively, 5.451 ± 0.487 mm and 5.008 ± 0.351 mm for maxillary and mandibular lateral incisors, respectively, and 3.340 ± 0.353 mm and 5.958 ± 0.415 mm for maxillary and mandibular canines, respectively. Except for the mandibular canines, no significant difference in esthetic width was found among homonymous teeth from the same jaw. A high linear correlation was found between the esthetic and mesiodistal widths of the same tooth, except for the maxillary canines. Esthetic width proportions among different tooth categories showed some regular patterns, which were similar to those of the mesiodistal width. @*CONCLUSION@#Esthetic width is regularly distributed among the teeth in the Chinese population. This could provide an important reference for anterior dental restorations and dimension recovery in esthetic reconstruction of anterior teeth.
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Objective:To investigate the clinical application of cervix-uterine internal target volume (ITV) in volume-modulated arc therapy (VMAT) for cervical cancer under different bladder filling conditions, aiming to obtain more accurate planning target volume (PTV).Methods:Sixty-two patients with cervical cancer receiving radiotherapy rather than surgery were selected and randomly divided into the study ( n=31) and control groups ( n=31). In the study group, individualized ITV, PTV and PTV margin were obtained under three bladder filling status by localization CT scan to compare the VMAT. The target area and organs at risk (OARs) within the target area were statistically compared between two groups. The target missing rate in CBCT, adverse events and short-term efficacy of radiotherapy were analyzed in two groups. Results:There was no significant difference in the volume of target area and OARs in the target area between two groups (both P>0.05). In the study group, the target missing rate and target missing volume were significantly lower compared with those in the control group (both P<0.05). There was no significant difference in the incidence of acute radiation-induced adverse events between two groups ( P>0.05). The 1-, 2-year overall survival and progress-free survival did not significantly differ between two groups (all P>0.05). One patient in the study group had uterine recurrence and 2 cases in the control group. Conclusion:Application of individualized cervix-uterine ITV and PTV in definitive VMAT under different bladder filling conditions can improve the accuracy of target area contouring and improve the local control rate in cervical cancer patients.
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Objective To investigate the impact of bladder filling status on the movement of uterine and on the volume of organs at risk(OAR), so as to provide theoretical basis for individualized internal target volume ( ITV) and planning target volume ( PTV) . Methods Simulation CT images for a total of 27 patients with locally advanced cervical cancer were acquired with empty bladder, 1. 0 h after bladder filling, 1. 5 h after bladder filling, respectively. The volumes of uterine corpus, cervix, OARs, CTV and PTV 1. 0 h after bladder filling were delineated. The impact of bladder filling status on the displacements of cervix and corpus, volumetric changes of rectum, small intestine, and the volumes of small intestine, bladder and rectum within PTV were analyzed. The correlation between bladder filling status and uterine displacement and volume of OAR was also investigated, as well as the volume of cervix and corpus in the PTV with empty bladder and 1. 5 h after bladder filling. Results Bladder filling status is different for individual cases. The maximum movement range of cervix and uterine body with bladder filling state was 0-3.04 cm and 0-4.31 cm respectively. The anterior displacements of corpus (F=7. 818, P<0. 05) , the volumetric changes of blander, as well the volume of bladder and small intestine in the PTV ( F=46. 197, 44. 609, 29. 546, P<0. 05 ) were significantly different between different bladder filling status. The bladder filling status was correlated with the displacements of the anterior of corpus, volumetric changes of small intestine, and the volumes of bladder and small intestine within the PTV ( r=-0. 232,-0. 298, 0. 915, -0. 336, P<0. 05) . The volumes of cervix and corpus out of the PTV were significantly different between the empty bladder and 1. 5 h after bladder filling ( t=-1. 326, -1. 559, P<0. 05 ) . Conclusions Bladder filling status was different for individual patients. The displacements of the anterior of the corpus were significantly affected by the bladder filling status. Increasing the anterior margin of PTV was recommended. The consistency of bladder filling status was critical for the precise cervical cancer IMRT.
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Objective@#To investigate the impact of bladder filling status on the movement of uterine and on the volume of organs at risk(OAR), so as to provide theoretical basis for individualized internal target volume (ITV) and planning target volume (PTV).@*Methods@#Simulation CT images for a total of 27 patients with locally advanced cervical cancer were acquired with empty bladder, 1.0 h after bladder filling, 1.5 h after bladder filling, respectively. The volumes of uterine corpus, cervix, OARs, CTV and PTV 1.0 h after bladder filling were delineated. The impact of bladder filling status on the displacements of cervix and corpus, volumetric changes of rectum, small intestine, and the volumes of small intestine, bladder and rectum within PTV were analyzed. The correlation between bladder filling status and uterine displacement and volume of OAR was also investigated, as well as the volume of cervix and corpus in the PTV with empty bladder and 1.5 h after bladder filling.@*Results@#Bladder filling status is different for individual cases. The maximum movement range of cervix and uterine body with bladder filling state was 0-3.04 cm and 0-4.31 cm respectively. The anterior displacements of corpus (F=7.818, P<0.05), the volumetric changes of blander, as well the volume of bladder and small intestine in the PTV (F=46.197, 44.609, 29.546, P<0.05) were significantly different between different bladder filling status. The bladder filling status was correlated with the displacements of the anterior of corpus, volumetric changes of small intestine, and the volumes of bladder and small intestine within the PTV (r=-0.232, -0.298, 0.915, -0.336, P<0.05). The volumes of cervix and corpus out of the PTV were significantly different between the empty bladder and 1.5 h after bladder filling (t=-1.326, -1.559, P<0.05).@*Conclusions@#Bladder filling status was different for individual patients. The displacements of the anterior of the corpus were significantly affected by the bladder filling status. Increasing the anterior margin of PTV was recommended. The consistency of bladder filling status was critical for the precise cervical cancer IMRT.
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Objective:To explore a new method of whole-process digital esthetic prosthodontic rehabilitation combined with periodontic surgery for complicated anterior teeth esthetic defects accompanied by soft tissue morphology,to provide an alternative choice for solving this problem under the guidance of three-dimensional (3 D) printing digital dental model and surgical guide,thus completing periodontic surgery and digital esthetic rehabilitation of anterior teeth.Methods:In this study,12 patients with complicated esthetic problems accompanied by soft tissue morphology in their anterior teeth were included.The dentition and facial images were obtained by intra-oral scanning and three-dimensional (3D) facial scanning and then calibrated.Two esthetic designs and prosthodontic outcome predictions were created by computer aided design/computer aided manufacturing (CAD/CAM) software combined with digital photography,including consideration of white esthetics and comprehensive consideration of pink-white esthetics.The predictive design of prostheses and the facial appearances of the two designs were evaluated by the patients.If the patients chose the design of comprehensive consideration of pink-white esthetics,they would choose whether they would receive periodontic surgery before esthetic rehabilitation.The dentition design cast of those who chose periodontic surgery would be 3D printed for the guide of periodontic surgery accordingly.Results:In light of the two digital designs based on intra-oral scanning,facing scanning and digital photography,the satisfaction rate of the patients was significantly higher for the comprehensive consideration of pink-white esthetic design (P ＜ 0.05) and more patients tended to choose priodontic surgery before esthetic rehabilitation.The 3 D printed digital dental model and surgical guide provided significant instructions for periodontic surgery,and achieved success transfer from digital design to clinical application.The prostheses were fabricated by CAD/CAM,thus realizing the whole-process digital esthetic rehabilitation.Conclusion:The new method for esthetic rehabilitation of complicated anterior teeth esthetic defects accompanied by soft tissue morphology,including patient-involved digital esthetic analysis,design,esthetic outcome prediction,3D printing surgical guide for periodontic surgery and digital fabrication is a practical technology.This method is useful for improvement of clinical communication efficiency between doctor-patient,doctor-technician and doctors from different departments,and is conducive to multidisciplinary treatment of this complicated anterior teeth esthetic problem.
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Objective:To explore a method of constructing universal 3-dimensional (3D)colorized digital dental model which can be displayed and edited in common 3 D software (such as Geomagic se-ries),in order to improve the visual effect of digital dental model in 3D software.Methods:The mor-phological data of teeth and gingivae were obtained by intra-oral scanning system (3Shape TRIOS),con-structing 3D digital dental models.The 3D digital dental models were exported as STL files.Meanwhile, referring to the accredited photography guide of American Academy of Cosmetic Dentistry (AACD),five selected digital photographs of patients’teeth and gingivae were taken by digital single lens reflex camera (DSLR) with the same exposure parameters (except occlusal views ) to capture the color data.In Geomagic Studio 201 3,after STL file of 3D digital dental model being imported,digital photographs were projected on 3D digital dental model with corresponding position and angle.The junctions of different photos were carefully trimmed to get continuous and natural color transitions.Then the 3 D colorized digital dental model was constructed,which was exported as OBJ file or WRP file which was a special file for software of Geomagic series.For the purpose of evaluating the visual effect of the 3 D colorized digital model,a rating scale on color simulation effect in views of patients’evaluation was used.Sixteen patients were recruited and their scores on colored and non-colored digital dental models were recorded.The data were analyzed using McNemar-Bowker test in SPSS 20.Results:Universal 3D colorized digital dental model with better color simulation was constructed based on intra-oral scanning and digital photography. For clinical application,the 3D colorized digital dental models,combined with 3D face images,were in-troduced into 3D smile design of aesthetic rehabilitation,which could improve the patients’cognition for the esthetic digital design and virtual prosthetic effect.Conclusion:Universal 3 D colorized digital dental model with better color simulation can be constructed assisted by 3 D dental scanning system and digital photography.In clinical practice,the communication between dentist and patients could be improved as-sisted by the better visual perception since the colorized 3 D digital dental models with better color simula-tion effect.