Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 111
Filtrar
1.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 55(10): 729-736, 2020 Oct 09.
Artículo en Chino | MEDLINE | ID: mdl-33045783

RESUMEN

Objective: To explore and evaluate a three-dimensional (3D) digital simulated design and implementation technique in esthetic rehabilitation. Methods: Thirty patients with esthetic deficiency, who came to the Department of Prosthodontics, Peking University School and Hospital of Stomatology from December 2017 to July 2019, were recruited and randomly assigned into 2 groups. Four males and 11 females which were (36.0±10.5) years old in the experimental group, 6 males and 9 females which were (32.0±6.7) years old in the control group, were enrolled. In the experimental group, 3D digital simulated design was used to predict the post-treatment effect; and the final restorations were designed duplicating from the pre-treatment digital design confirmed by the patient and milled. In the control group, the final restorations were manufactured by the dental technician according to the design of two-dimensional (2D) digital smile design. The simulation degree of digital design and the similarity between preoperative design and postoperative rehabilitation were scored by the patients with visual analogue scales (VAS) in both groups; and the satisfaction rate to the restorations was evaluated by the patients. The quality of the restorations was accessed by a prosthodontist who did not know the grouping of patients according to the modified criteria of United States Public Health Service (USPHS). Results: Three-dimensional digital simulated design and implementation technique was successfully established. The VAS score on the simulation degree of digital design in the experimental group (8.5±0.5) was higher than that in the control group (7.2±0.7) (P<0.01); the VAS score on the similarity between preoperative design and postoperative rehabilitation in the experimental group (9.6±0.3) was higher than that in the control group (7.0±0.9) (P<0.01). The satisfaction rate of the patients to the restorations was significantly higher in the experimental group than in the control group (P<0.05). There was no significant difference of the quality of the restorations between the two groups on the anatomic form, the marginal adaption and the surface quality (P>0.05). Conclusions: Three-dimensional digital simulated design and implementation technique can help achieving 3D digital simulated design before treatment and duplication to the final restorations, and can improve the patients' satisfaction in esthetic rehabilitation.


Asunto(s)
Estética Dental , Sonrisa , Adulto , Odontólogos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Satisfacción del Paciente , Prostodoncia , Estados Unidos
2.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 55(10): 743-749, 2020 Oct 09.
Artículo en Chino | MEDLINE | ID: mdl-33045785

RESUMEN

Objective: To quantitatively evaluate the change of the long axis angle and the relative displacement of the crown feature points of the posterior teeth under normal bite force utilizing an intraoral scanner, and to provide clinical reference. Methods: From May to December 2019, fifteen graduate volunteers (5 males and 10 females, aged from 22 to 30, with an average age of 25.7 years) from Peking University School and Hospital of Stomatology were recruited to participate in the study. The surface data (U1, L1) of the maxillary and mandibular posterior teeth were scanned by an intraoral scanner i500, and saved as original data. The volunteers were guided to bite in the intercuspal position with normal bite force. The buccal bite data of the posterior teeth were scanned as the basis for registration. The digital casts were imported into Geomagic studio 2013 software and the boundary lines along the gingival margin and mesial and distal contact area of posterior teeth of data (U1, L1) were determined. Long axis of the crown, crown centroid and mesial functional cusp vertex were establishd. The data (U1, L1) were segmented into single tooth. Single tooth was aligned to buccal bite data separately using best-fit alignment command based on the buccal common area of the crown and new casts data (U2, L2) were obtained as the data under bite force. The long axis angle and centroid distance between adjacent teeth (second premolar and first molar, second molar and first molar) were measured and the deviation between data obtained at mouth-open state and that at biting state was calculated. Negative value meant centroid distance became shorter under bite force. The first molar was set as the common area and registrate the U1, L1 to U2, L2. The angle of long axes, and displacement of centroid and of functional cusp vertex between second premolar of two casts were calculated, as well as between second molar of two casts. Wilcoxon signed rank test was used to analyze the differences of teeth displacement between second premolar and second molar, and between maxillary and mandibular jaws with SPSS 26.0 statistical software. Results: The result of second premolar and second molar in the same jaw had no statistical difference (P>0.05). The centroid distance deviation of mandibular second premolar-first molar [-0.022(0.046) mm] was larger than that of maxilla [-0.006 (0.040) mm] (P<0.05). The long axis angle of second premolar itself [0.913°(0.647°)] and centroid distance of second molar itself [0.102 (0.106) mm] on the mandibular jaw were different from that on the maxillary jaw, which were 0.590°(0.550°) and 0.074(0.060) mm respectively (P<0.05). Conclusions: Under bite force, displacement of the second premolar and second molar was present, including the displacement of centroids and deflection of long axes. The mandibular posterior teeth have larger displacement than the maxillary teeth.


Asunto(s)
Fuerza de la Mordida , Diente Molar , Adulto , Diente Premolar , Oclusión Dental , Femenino , Humanos , Masculino , Maxilar , Diente Molar/diagnóstico por imagen
4.
Beijing Da Xue Xue Bao Yi Xue Ban ; 52(4): 762-770, 2020 Aug 18.
Artículo en Chino | MEDLINE | ID: mdl-32773816

RESUMEN

OBJECTIVE: To compare the clinical efficacy of a kind of complete dentures fabricated using computer aided design/computer aided manufacturing (CAD/CAM) workflow with that of the complete denture fabricated using conventional workflow. METHODS: Twenty edentulous patients were included in this prospective, single-blind, self-controlled clinical trial. Two pairs of complete dentures were fabricated for each participant: one using the functional suitable denture (FSD) system with CAD/CAM, and the other using conventional fabrication workflow. In the final delivery appointment, the conventional dentures worn by the participant for 3 months at first. Then the participant swapped to wear digital denture for another 3 months. The patients' satisfaction and oral health related quality of life (OHRQoL) were measured using the visual analogue scale (VAS) and oral health impact profile (OHIP-20E) at baseline, 2 weeks, 1 month, 2 months, and 3 months following denture delivery. In addition, the masticatory efficiency of each pair of dentures was measured after three months adaptation period for each type of dentures. RESULTS: The VAS scores of the twenty patients in FSD denture group on general satisfaction, ease of cleaning, ability to speak, esthetics, stability and oral health status on these six domains were higher than that of conventional denture group 3 months after delivery. While the VAS cores in FSD denture group on comfort, ability to chew and ability to chew up were the same as those of conventional denture group. But there was no significant difference (P>0.05). The VAS score on each domain in FSD denture group was higher than that of conventional denture group 3 months after delivery, three domains of which reached statistical significance (P < 0.05), involving functional limitation, psychological discomfort and total. The masticatory performance of the FSD denture (1.20±0.54) was slightly higher than that for the conventional denture (1.16±0.53), but the difference did not reach statistical significance (P=0.691). CONCLUSIONS: The clinical efficacy of the FSD complete denture is comparable to that of the conventional complete denture. As for patient satisfaction and oral health related quality of life, FSD dentures received comparable scores as conventional complete dentures did.


Asunto(s)
Dentadura Completa , Calidad de Vida , Humanos , Satisfacción del Paciente , Estudios Prospectivos , Método Simple Ciego , Resultado del Tratamiento
5.
Beijing Da Xue Xue Bao Yi Xue Ban ; 52(2): 368-372, 2020 Apr 18.
Artículo en Chino | MEDLINE | ID: mdl-32306024

RESUMEN

OBJECTIVE: To measure the dimensional data of complete dentures and to design a novel tray for recording maxillomandibular relationship of edentulous patients. METHODS: For the measurement, 100 pairs of complete dentures from the clinic were surveyed for the following parameters: a1, the distance between the middle fossa of the upper left and right first molars; a2, the anterior-posterior distance between the middle fossa of the upper first molars and the incisal edge; a3, the width of the upper denture; a4, the anterior-posterior length of the upper denture; a51, the height from the mesio-lingual cusp of the right upper first molar to the saddle surface; a52, the height from the central fossa of the right lower first molar to the saddle surface; a6, the height from the notch of the upper lip frenulum to the upper central incisor edge; a7, the least thickness of the labial saddle base in the upper central incisor region. Based on the data, the trays with different sizes were designed and fabricated, and the key parameters were: b1, the distance between the foramina of screw posts, b2, the anterior-posterior distance between the foramina of the screw posts and the incisal edge; b3, the width of the tray; b4, the anterior-posterior length of the tray; b51, the height of the posterior platform with the screw nut; b52, the height of the screw post; b6, the height of the anterior tray handle; b7, the thickness of the anterior tray handle. RESULTS: The minimum, average and maximum data for each parameter were (in millimeter): a1: 37.1, 44.5, and 59.6; a2: 22.6, 29.0, and 38.1; a3: 48.5, 58.2, and 76.6; a4: 37.4, 50.8, and 61.0; a51: 5.6, 9.5, and 14.7; a52: 3.8, 9.9, and 18.8; a6: 8.9, 16.6, and 24.7; a7: 1.2, 2.8, and 5.9. Based on the data, the trays in small, medium and large sizes were designed and fabricated. In clinical application, the putty silicone rubber impression material was used to reline the tray, meanwhile the posterior platform and anterior tray handle were set as the occlusal plane, then the screw posts were added and adjusted till the proper vertical dimension, after that, the putty silicone rubber impression material was added around the screw posts to record the horizontal maxillomandibular relationship, finally, the anterior surface of the tray handle was used to record the midline of the face and lower edge of the upper lip at rest and with smile. CONCLUSION: The dimensional data offered reference for the analysis of restoration space in edentulous patients. The tray designed and fabricated in this study may serve as a new tool for recording the maxillomandibular relationship.


Asunto(s)
Dentadura Completa , Boca Edéntula , Técnica de Impresión Dental , Humanos , Incisivo , Labio , Dimensión Vertical
6.
Beijing Da Xue Xue Bao Yi Xue Ban ; 52(2): 390-394, 2020 Apr 18.
Artículo en Chino | MEDLINE | ID: mdl-32306028

RESUMEN

Fabrication of conventional complete dentures involves a complex restoration method, requiring significant time and typically involving primary impressions, definitive impressions, jaw relation records, clinic try-in, and complete denture placement, which has been used for nearly a century without change. A novel digital system named Functionally Suitable Denture (FSD) was researched and developed so as to reduce clinical steps, operation difficulties and errors of complete denture restoration. It pioneered a unique diagnostic complete denture aided by computer aided design (CAD) & 3D printing, by which, the functional impression, jaw relation, and try-in (3 steps) were simplified to 1 step, thus the number of visits to the dentist was reduced by 2 times. Moreover, for the first time, it put forward a CAD software of template matching based on the expert design, which was an efficient and intelligent design scheme, and the excellent denture experts' experience and skills could be inherited and iterated. The system included the 3D scanner with appropriate accuracy and high efficiency, the CAD software, the special 3D printer and process software, and the innovative clinical operation process. The Patent Cooperation Treaty (PCT) patent international search report showed that all the 15 claims of the technology were of novelty, creativity and industrial utility. All the digital products were independently developed and made by Peking University School and Hospital of Stomatology, China. The design and manufacture process of denture prosthesis was fast, simple and accurate. At the same time, personalized functional and aesthetic matching of the patients after wearing prosthesis was realized. It effectively solved the global problems of "slow, difficult and inaccurate" of the traditional manual technology of complete denture, and brought good news to edentulous patients. Compared with the traditional complete denture treatment, FSD system has a wide range of applications for different types of edentulous patients, including those with severe resorption of the alveolar ridge or a high occlusal force. Furthermore, the low-cost of 3D printers, compared with expensive milling machines, may make the approach more accessible. This review describes that our research is related to the development of the FSD system, including multi-source data acquisition technology, three generations of complete denture design software, 3D printing systems of individual tray and complete denture pattern, the clinical and laboratory operation process of the FSD system.


Asunto(s)
Boca Edéntula , China , Diseño Asistido por Computadora , Creatividad , Dentadura Completa , Humanos
7.
Plant Biol (Stuttg) ; 2020 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-32270571

RESUMEN

Flowers, the reproductive organs of angiosperms, show a high degree of diversity in morphological structure and flowering habit to ensure pollination and fertilization of the plants. Effect of flower movement on pollination and fertilization was investigated in Ipomoea purpurea (Convolvulaceae) in this study. Fluorescence microscopy was used to observe the germination of pollen grains at different temperatures. From 04:00 to 06:00 h, the stigma was taller than the filaments, so that self-pollination could not occur, and cross-pollination was carried out by insects. Pollen grains germinated rapidly after falling on the stigma; the pollen tube reached the ovule to complete fertilization after 2-3 h. From 07:00 to 09:00 h, filaments of two stamens grew rapidly and reached the same height as the stigma, thus allowing self-crossing. But at this time, the ambient temperature was already high and was not conducive to the germination of pollen grains. The corolla closed, forming an inverted bell shape, where the inner microenvironment ensured completion of pollen germination and fertilization. Preferential cross-pollination and delayed self-crossing of I. purpurea provided a doubly guaranteed mechanism for pollination and fertilization, facilitating its adaptation to a high temperature climate.

8.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 55(4): 280-284, 2020 Apr 09.
Artículo en Chino | MEDLINE | ID: mdl-32268631

RESUMEN

With the wide application of digital technology in the field of stomatology, the acquisition of three-dimensional tooth and dentition information through three-dimensional (3D) image data and optical scan data has become an indispensable process in clinical diagnosis and analysis. Cone-beam CT images and optical scanning images have their own characteristics in terms of data acquisition range and the accuracy of data. Single data source is not accurate enough or complete in the delivery of tooth and dental information. At present, two data sources are used to construct a 3D crown root model with high-precision crown and complete root information to meet the requirement of clinical orthodontic functional setup and implant surgical guide design. The integration of tooth crown and root is one of the focused topics of clinical research. This review will summarize the research progress of 3D crown root model construction method, introduce the application of various algorithms, and analyze the characteristics of these approaches, in order to provide reference for clinical application and scientific research.


Asunto(s)
Imagenología Tridimensional , Corona del Diente , Diente , Tomografía Computarizada de Haz Cónico , Humanos , Corona del Diente/diagnóstico por imagen , Raíz del Diente
9.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 55(3): 201-205, 2020 Mar 09.
Artículo en Chino | MEDLINE | ID: mdl-32193920

RESUMEN

Intraoral three-dimensional scanning technology has been adopted in stomatology field and developed rapidly with improved accuracy. At present, the scanning accuracy of the intraoral three-dimensional scanners used in restoration of single crown, three unit fixed partial bridge and single implant crown satisfies the clinical requirements. While for restoration of multi-unit fixed, the scanning accuracy is not enough. There are still technical bottlenecks for scanning functional motion boundary of soft tissue, especially for direct acquisition of edentulous functional impressions. Through literature review and analysis, we summarize the intraoral scanning accuracy of oral hard and soft tissues, and analyze the clinical applicability and limitations of intraoral scanning technology, providing reference for clinical application.


Asunto(s)
Técnica de Impresión Dental , Imagenología Tridimensional , Boca Edéntula , Modelos Dentales , Humanos
10.
Beijing Da Xue Xue Bao Yi Xue Ban ; 52(1): 107-112, 2020 Feb 18.
Artículo en Chino | MEDLINE | ID: mdl-32071472

RESUMEN

OBJECTIVE: To study the visual sensitivity threshold of physician's naked eye to the difference of nasolabial angle in edentulous jaw patients, and to provide a reference value for the study of aesthetic evaluation of soft tissue profile for the difference of nasolabial angle that can be recognized by human eyes. METHODS: Three-dimensional facial images of three edentulous patients with different diagnostic dentures introoral were obtained. Lateral screenshots of each patient's three-dimensional facial image with the same scale were obtained by using reverse engineering software (Geomagic studio 2014).The screenshot of the patient's three-dimensional facial image with suitable lip support (The suitable lip support was confirmed by both patients and prosthodontists who had clinical experience for more than 20 years) was taken as the reference picture, and the remaining pictures were grouped with it respectively. All the pictures were observed in random order by the subjects. Fifteen dentists were asked to judge the difference of nasolabial angle between the two pictures of each group on the computer screen. The difference of nasolabial angle between the two pictures in each group was measured and calculated. The ROC curve was drawn, and the best cut-off value was calculated as the visual sensitivity threshold. RESULTS: The data of the 15 subjects were used to draw ROC curves separately. The maximum and minimum best cut-off values were 5.55 degrees and 3.12 degrees respectively. The ROC curve of the whole 15 subjects was drawn after data aggregation, and the best cut-off value was 5.36 degrees (AUC=0.84>0.5, P=0.000<0.05). When the difference of nasolabial angle was above 5.36 degrees, the subjects could recognize it effectively. CONCLUSION: There is a visual limit in the observation of the nasolabial angle with the naked eye. In this study, a visual sensitivity threshold of 5.36 degrees for the difference of the nasolabial angle was obtained. The difference of nasolabial angle below this value can be regarded as no clinical significance. This result provides a reference value for human eyes to recognize the difference of nasolabial angle in soft tissue profile aesthetic evaluation. It can be applied to the aesthetic evaluation of soft tissue profile and can be used as the error level of related research with nasolabial angle as an index for accuracy evaluation.


Asunto(s)
Arcada Edéntula , Nariz , Estética , Cara , Humanos , Labio , Agudeza Visual
11.
Beijing Da Xue Xue Bao Yi Xue Ban ; 52(1): 129-137, 2020 Feb 18.
Artículo en Chino | MEDLINE | ID: mdl-32071476

RESUMEN

OBJECTIVE: To provide a reference for using intraoral scanners for making clinical diagnostic dentures of edentulous jaws by comparing the accuracy of three intraoral scanners for primary impression and jaw relation record of edentulous jaws. METHODS: This study contained 6 primary impressions of the edentulous patients. Each of the impressions consisted of the maxillary primary impression, the mandibular primary impression and the jaw relation record. For each of them, a dental cast scanner (Dentscan Y500) was used to obtain stereolithography (STL) data as reference scan, and then three intraoral scanners including i500, Trios 3 and CEREC Primescan were used for three times to obtain STL data as experiment groups. In Geomagic Studio 2013 software, trueness was obtained by comparing experiment groups with the reference scan, and the precision was obtained from intragroup comparisons. Registered maxillary data of the intraoral scan with reference scan, the morphological error of jaw relation record was obtained by comparing jaw relation record of the intraoral scan with the reference scan. Registered mandibular data with jaw relation record of intraoral scan and the displacement of the jaw position were evaluated. Independent samples t test and Mann-Whitney U test in the SPSS 20.0 statistical software were used to statistically analyze the trueness, precision and morphological error of jaw relation record of three intraoral scanners. The Bland-Altman diagram was used to evaluate the consistency of the jaw relationship measured by the three intraoral scanners. RESULTS: The trueness of i500, Trios 3 and CEREC Primescan scanners was (182.34±101.21) µm, (145.21±71.73) µm, and (78.34±34.79) µm for maxilla; (106.42±21.63) µm, and 95.08 (63.08) µm, (78.45±42.77) µm for mandible. There was no significant difference in trueness of the three scanners when scanning the maxilla and mandible(P>0.05). The precision of the three scanners was 147.65 (156.30) µm, (147.54±83.33) µm, and 40.30 (32.80) µm for maxilla; (90.96±30.77) µm, (53.73±23.56) µm, and 37.60 (93.93) µm for mandible. The precision of CEREC Primescan scanner was significantly better than that of the other two scanners for maxilla (P<0.05). Trios 3 and CEREC Primescan scanners were significantly better than i500 scanner for mandible (P<0.05). The precision of the i500 and Trios 3 scanners for mandible was superior to maxilla (P<0.05). The upper limit of 95% confidence intervals of trueness and precision of three scanners for both maxilla and mandible were within ±300 µm which was clinically accepted. The morphological error of jaw relation record of the three scanners was (337.68±128.54) µm, (342.89±195.41) µm, and (168.62±88.35) µm. The 95% confidence intervals of i500 and Trios 3 scanners were over 300 µm. CEREC Primescan scanner was significantly superior to i500 scanner(P<0.05).The displacement of the jaw position of the three scanners was (0.83±0.56) mm, (0.80±0.45) mm, and (0.91±0.75) mm for vertical dimension; (0.79±0.58) mm, (0.62±0.18) mm, and (0.53±0.53) mm for anterior and posterior directions; (0.95±0.59) mm, (0.69±0.45) mm, and (0.60±0.22) mm for left and right directions. The displacement of the jaw position of the three scanners in vertical dimension, anterior and posterior directions and the left and right directions were within the 95% consistency limit. CONCLUSION: Three intraoral scanners showed good trueness and precision. The i500 and Trios 3 scanners had more errors in jaw relation record, but they were used as primary jaw relation record. It is suggested that three intraoral scanners can be used for obtaining digital data to make diagnostic dentures and individual trays, reducing possible deforming or crack when sending impressions from clinic to laboratory.


Asunto(s)
Técnica de Impresión Dental , Arcada Edéntula , Diseño Asistido por Computadora , Modelos Dentales , Humanos , Imagenología Tridimensional
12.
Beijing Da Xue Xue Bao Yi Xue Ban ; 52(1): 138-143, 2020 Feb 18.
Artículo en Chino | MEDLINE | ID: mdl-32071477

RESUMEN

OBJECTIVE: To evaluate the three-dimensional (3D) reconstruction accuracy of the intercuspal occlusion (ICO) of the dental casts, by the dental articulator position method, and provide a reference for clinical application. METHODS: The standard dental casts in ICO were mounted on average values articulator, and five pairs of milling resin cylinders were respectively attached to the base of both the casts. 100 µm articulating paper and occlusal record silicone rubber were used to detect the occlusal contact number between the posterior teeth of casts mounted on articulator in ICO. The occlusal contact numbers NA detected by the two methods were calculated simultaneously, as the reference. After the upper and lower casts were scanned separately, and the buccal data of casts in ICO were scanned with the aid of the dental articulator position, registration was carried out utilizing the registration software. Then the digital casts mounted in ICO as well as the buccal occlusal data were saved in standard tessellation language (STL) format. Geomagic Studio 2013 software was used to analyze the contact number NS between digital upper and lower casts by the "deviation analysis" function. The differences were compared between NS and NA, to evaluate the sensitivity and positive predict value (PPV) of the model scanner to reproduce the occlusal contact with the aid of dental articulator position. The distance DR between the centers of the circles at the top surface of the upper and lower corresponding cylinders was obtained by the three-coordinate measuring system Faro Edge, as the reference value. The Geomagic Studio 2013 software was used to construct the cylinders of digital casts and the distance DM between the centers of the circles at the top surface of the corresponding cylinders were measured, as the test value. The one-sample T test was used to analyze the variable differences between DM and DR. RESULTS: The PPV of reproducing the occlusal contact point was 0.76 and sensitivity was 0.81. The distance error of the opposite cylinder was (0.232±0.089) mm. There was no statistical difference between the feature points 5-5', while there were statistical differences between the other feature points. CONCLUSION: By the dental articulator position method, the model scanner reproduces the occlusal contact point with high sensitivity and PPV, and that meets clinical needs. Meanwhile, the distance between the feature points is greater than the reference value, which will lead to occlusal disturbance, and require clinical grinding.


Asunto(s)
Articuladores Dentales , Modelos Dentales , Oclusión Dental , Imagenología Tridimensional , Registro de la Relación Maxilomandibular , Programas Informáticos
13.
Beijing Da Xue Xue Bao Yi Xue Ban ; 52(1): 144-151, 2020 Feb 18.
Artículo en Chino | MEDLINE | ID: mdl-32071478

RESUMEN

OBJECTIVE: To analyze the distribution and area of occlusal contacts of clinical dental model using three kinds of digital analysis methods, to compare the results of these methods and traditional occlusal analysis method, and to further analyze the characteristics of each digital analysis method. METHODS: A set of plaster models of normal subjects was selected. The models were scanned by lab scanner 3shape E4 and the files were exported in a stereolithography file format. In 3D analysis software Geomagic Studio 2013 and Geomagic Qualify 2013, the corresponding results of 3D occlusal contact distribution and occlusal contact area were obtained through three digital analysis methods: "3D color difference map method", "point cloud analysis method", and "virtual articulating paper method". The occlusal contact distribution and occlusal contact area were also obtained by two traditional occlusal analysis methods: "silicone interocclusal recording material method" and "scanned articulating paper mark method". A threshold of 100 µm was used to analyze the occlusal contacts and 100 µm was also the thickness of articulating paper used in this study. The results of these five different occlusal analysis methods were evaluated qualitatively and quantitatively. RESULTS: The results of 3D occlusal contact distribution obtained by the above five methods were basically consistent. The total occlusal contact area obtained by 3D color difference map method, point cloud analysis method, virtual articulating paper method, silicone interocclusal recording material method and scanned articulating paper mark method were 133.10 mm², 142.08 mm², 128.95 mm², 163.31 mm², and 100.55 mm² respectively. There was little difference between the results of three digital analysis methods. The results of occlusal contact area obtained by the digital methods and the traditional methods were different. CONCLUSION: The three digital analysis methods can provide reliable and accurate analysis results of occlusal contact distribution and occlusal contact area of dental model. The results obtained by these methods can serve as references for the digital occlusal surface design of dental prosthesis and clinical occlusal analysis.


Asunto(s)
Modelos Dentales , Programas Informáticos , Imagenología Tridimensional
14.
Animal ; 14(7): 1392-1401, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31870464

RESUMEN

In the livestock husbandry compensatory growth may be explored as a means to improve nutrient utilization, to reduce gut health problems due to excess protein intake, to simplify feeding strategies and thus to improve production efficiencies. This study investigated the effects of early protein restriction (EPR) and early antibiotic intervention (EAI) on growth performance, intestinal morphology, colonic bacteria, metabolites and mucosal gene expressions during the restriction phase and re-alimentation phase. A total of 64 piglets (10.04 ± 0.73 kg) were randomly divided into four treatment groups according to a 2 × 2 factorial arrangement with two levels of proteins (14% v. 20%) and two levels of antibiotics (0 v. 50 mg/kg kitasamycin and 20 mg/kg colistin sulphate). After a 30-day restriction phase with four kinds of diets, all groups were fed the same diets for another 74 days. The results showed that EPR decreased BW, average daily gain (ADG), average daily feed intake in the restriction phase (P < 0.01) and increased ADG on days 66 to 104 of the late re-alimentation phase. Early protein restriction could decrease the villus height in the jejunum (P < 0.05), while shifting to the same diets restored the villus height. Meanwhile, during the re-alimentation phase, pigs in the protein restriction groups had increased concentrations of total short chain fatty acids (P < 0.05), and modified the abundances of Firmicutes and Bacteroidetes in the colon. Furthermore, the lower microbial diversity caused by EPR was improved, and gene expression analysis indicated a better barrier function in the colon. During the whole trial, EAI had no interaction with EPR and played a dispensable role in compensatory growth. Collectively, the retardation of growth caused by EPR can be compensated for in the later stages of pig raising, and accompanied by altered intestinal morphology, microbial composition.


Asunto(s)
Alimentación Animal , Proteínas en la Dieta , Microbioma Gastrointestinal , Alimentación Animal/análisis , Animales , Antibacterianos , Dieta/veterinaria , Mucosa Intestinal , Porcinos/crecimiento & desarrollo
16.
Beijing Da Xue Xue Bao Yi Xue Ban ; 51(3): 430-438, 2019 Jun 18.
Artículo en Chino | MEDLINE | ID: mdl-31209413

RESUMEN

OBJECTIVE: To quantify the relationship between cerebral blood flow velocity and peripheral blood pressure during hypotension period, aiming to predict the brain hypotension before symptomatic occurrence. METHODS: Twenty vasovagal syncope (VVS) patients who had a previous clinical history were selected in groups and 20 pair-matched control subjects underwent 70° tilt-up test. The subjects remained supine for 30 minutes before recordings when Doppler probes, electrodes and Finapres device were prepared. After continuous baseline recordings for 10 min, the subjects underwent head up tilt (HUT) test (70°), and were standing upright for 30 minutes or until syncope was imminent. For ethical reasons, the subjects were turned back to supine position immediately after SBP dropped to ≥20 mmHg, when their consciousness persisted. The point of syncope was synchronized for all the subjects by the point SBP reached the minima. Their beat-to-beat blood pressures (BP) were recorded continuously and bilateral middle cerebral artery (MCA) flow velocities were obtained with two 2 MHz Doppler probes from a transcranial Doppler ultrasonography (TCD) system. A nonlinear dynamic method--multimodal pressure flow (MMPF) analysis was introduced to access cerebral autoregulation during different time intervals. We introduced a new indicator--syncope index (SI), which was extracted from blood flow velocity (BFV) signal to evaluate the variation of cerebral vascular tension, and could reflect the deepness of dicrotic notch in BFV signal. RESULTS: Compared with the syncope index of the baseline value at the beginning of the tilt test, SI in VVS group showed significantly lower when the VVS occurred (0.16±0.10 vs.0.27±0.10,P<0.01),while there was no significant difference in syncope index between the control group at the end of the tilt test and the baseline value at the beginning of the tilt test. For those VVS patients, pulse index and resistance index had no significant change. Syncope index decreased significantly 3 minutes before the point of syncope (0.23±0.07 vs.0.29±0.07,P<0.01). CONCLUSION: Dynamic regulation is exhausted when vasovagal syncope occurred. Tension decrease of small vessels could have some relationship with loss of the cerebral autoregulation capability. The proposed syncope index could be a useful parameter in predicting syncope of VVS patients since it decreased significantly up to 3 minutes earlier from the point of syncope.


Asunto(s)
Síncope Vasovagal , Presión Sanguínea , Frecuencia Cardíaca , Humanos , Dinámicas no Lineales , Síncope , Pruebas de Mesa Inclinada
17.
Zhonghua Fu Chan Ke Za Zhi ; 54(5): 293-300, 2019 May 25.
Artículo en Chino | MEDLINE | ID: mdl-31154709

RESUMEN

Objective: To investigate the prevalence of high-risk HPV subtypes in different pathological types of cervical cancer, and analyze the attribution of carcinogenic HPV subtypes in different pathological types. Methods: A total of 1 541 patients with cervical cancer were treated between February 2009 and October 2016 in Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College. The median age at diagnosis was 49 years (ranged 20-82 years old). The numbers of patients with cervical cancer from North China, Northeast China, East China, Central China and other regions (including Northwest, Southwest and South China) were 961, 244, 175, 87 and 74 cases, respectively. Pathological types: 1 337 cases of squamous cell carcinoma (SCC), 87 usual adenocarcinoma (ADC), 23 adenosquamous carcinoma (ASC), 20 mucinous carcinoma (MC), 19 clear cell carcinoma (CCC), 12 endometrioid carcinoma (EC), 25 neuroendocrine carcinoma (NEC), 9 serous carcinoma (SC), 5 villous adenocarcinoma (VADC) and 4 minimal deviation adenocarcinoma (MDAC). The prevalence of high-risk HPV in different regions, age groups at diagnosis and pathological types in cervical cancer were analyzed. The attribution of 13 high-risk HPV subtypes in different pathological types of cervical cancer based on proportional attribution method, and the attribution of high-risk HPV subtypes prevented by 9-valent HPV vaccine in SCC and ADC were calculated. Results: (1) The prevalence of high-risk HPV in 1 541 patients with cervical cancer was 86.6% (1 335/1 541). The multiple high-risk HPV infection rate in patients with SCC ≥60 years old (23.0%, 37/161) was significantly higher than those in patients aged 45-59 years old and ≤44 years old [11.4% (85/747) vs 11.7% (50/429), P<0.01], and the high-risk HPV infection rates of patients with cervical cancer in North China, Northeast China, East China, Central China and other regions were respectively 86.8% (834/961), 87.7% (214/244), 83.4% (146/175), 83.9% (73/87) and 91.9% (68/74). SCC (86.8%, 1 337/1 541) and ADC (5.6%, 87/1 541) were the most common pathological types in cervical cancer. The high-risk HPV prevalence of SCC, ADC, ASC, MC, NEC and VADC were 90.1% (1 205/1 337), 74.7% (65/87), 87.0% (20/23), 65.0% (13/20), 72.0% (18/25) and 5/5 respectively. The high-risk HPV infection rates of SC, EC, CCC and MDAC were 4/9, 3/12, 2/19 and 0/4 respectively. (2) According to proportional attribution, HPV 16 (69.5%), HPV 18 (5.6%), HPV 58 (2.2%), HPV 31 (1.9%), HPV 52 (1.4%) and HPV 33 (1.3%) were the six common high-risk HPV subtypes in SCC. While, HPV 18 (44.1%), HPV 16 (20.5%), HPV 52 (2.3%), HPV 58 (1.2%) and HPV 51 (1.2%) were the main carcinogenic subtypes in ADC. The main carcinogenic high-risk HPV subtypes of ASC, NEC and MC were HPV 18 and HPV 16. The total attribution of HPV 16, 18, 31, 33, 45, 52 and 58 prevented by 9-valent HPV vaccine in SCC and ADC were 82.6% and 68.1% respectively; the attribution of HPV 45 in SCC and ADC were only 0.8% and 0. Conclusions: SCC and ADC are the main pathological types in cervical cancer. SCC, ADC, ASC, MC, NEC and VADC are closely related to high-risk HPV infection. HPV 16 is the main carcinogenic genotypes of SCC. HPV 18 maybe play an important role in the pathogenesis of ADC.


Asunto(s)
Papillomaviridae/aislamiento & purificación , Infecciones por Papillomavirus/epidemiología , Neoplasias del Cuello Uterino/epidemiología , Adulto , Anciano , Anciano de 80 o más Años , China/epidemiología , Femenino , Humanos , Persona de Mediana Edad , Papillomaviridae/clasificación , Papillomaviridae/genética , Infecciones por Papillomavirus/virología , Prevalencia , Neoplasias del Cuello Uterino/virología , Adulto Joven
19.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 54(4): 278-281, 2019 Apr 09.
Artículo en Chino | MEDLINE | ID: mdl-30955303

RESUMEN

Food impaction with tight proximal contacts, also known as kinetic food impaction and food impaction without anatomical structure destruction, is mainly caused by a transient separation in contacts area during mastication. It's an intractable food impaction with high morbidity and low cure rate. There are two kinds of pathogenesis accepted: the shifting of anterior teeth incongruous with adjacent teeth or lack of anterior shifting; lack of food escape grooves. The preferred treatment is occlusal adjustment, but it's difficult to determine the area and extent of selective grinding, to quantify the occlusal adjustment, or to predict the prognosis. This review summarized the pathogenesis and treatment modality for kinetic food impaction in order to provide evidence for future researches and clinical application.


Asunto(s)
Alimentos , Masticación , Ajuste Oclusal , Humanos , Diente
20.
Beijing Da Xue Xue Bao Yi Xue Ban ; 51(2): 335-339, 2019 Apr 18.
Artículo en Chino | MEDLINE | ID: mdl-30996378

RESUMEN

OBJECTIVE: To explore a novel method for fabricating removable partial dentures (RPDs) using polyetheretherketone (PEEK) by computer-aided design and computer-aided manufacturing (CAD/CAM) technologies and to evaluate their fits for different assemblies in vitro. METHODS: A standard stone cast of mandibular partial edentulous jaw was scanned using a lab scanner. Based on the digital cast, thirteen complete RPDs were designed combing dental CAD software and reverse engineering software, and then fabricated using PEEK by milling machine. Fits of assemblies were evaluated quantitatively by measuring the spaces between RPDs and casts. The gaps between RPDs and stone casts in different assemblies were duplicated using light-body silicone impression material and then measured using three-dimensional (3D) digital analysis methods in virtue of a dedicated software. Statistically, one-way analysis of variance (ANOVA) was used to compare the difference of gaps among assemblies in different shapes such as occlusal rest, denture base, and major connector. Paired-samples t test was used to compare the gaps difference for the similar shape assemblies in different areas. RESULTS: One-piece PEEK RPDs were successfully designed and fabricated by CAD/CAM, and all the RPDs were well-seated on stone casts. The gaps between occlusal rests and casts [(84.3±23.6) µm] were significantly larger than those of denture bases [(32.5±27.8) µm] and major connectors [(49.9±47.0) µm], which meant that the fits of denture bases and major connectors were better than that of occlusal rests. However, the fits of all assemblies could be accepted clinically. For the similar shape assemblies in different areas, there were no significantly differences for gaps between distal extension denture bases [(25.1±55.3) µm] and non-extensive denture bases [(41.5±17.7) µm]. The gaps of occlusal rests adjacent and nonadjacent to the edentulous space were (86.1±29.8) µm and (80.8±42.1) µm respectively and there were no significantly difference between them either. These results implied that different locations had no apparent effect on the fits of assemblies. CONCLUSION: With the computer-aided design and computer-aided manufacturing technology, PEEK can be used to fabricate one-piece removable partial dentures. And all assemblies of the one-piece PEEK RPDs showed satisfying fits in vitro, indicating a promising clinical application in the future.


Asunto(s)
Dentadura Parcial Removible , Diseño Asistido por Computadora , Cetonas , Polietilenglicoles
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA