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1.
Daniella Andaluza Dias Matos Marcelo Lucchesi Teixeira Jo?o Henrique Nogueira Pinto José Fernando Scarelli Lopes Gisele da Silva Dalben 《Journal of applied oral science : revista FOB》2006,14(3):157-161
Objective:
to analyze the pattern of disocclusion during excursive mandibular movements and presence or absence of occlusal interferences and occlusal pathologies (gingival recession and abfraction).Method:
examination of 120 individuals divided into two groups, as follows: Group 1-90 patients with complete cleft lip and palate (study group), subdivided into 30 patients with complete left unilateral cleft lip and palate, 30 patients with complete right unilateral cleft lip and palate and 30 patients with complete bilateral cleft lip and palate; Group 2-30 individuals without clefts (control group).Results:
58.8% of patients in Group 1 presented unilateral or bilateral canine guidance, 26.6% presented unilateral or bilateral group function and 54.4% presented lateral movements through the posterior teeth. Regarding protrusive movements, 80% presented anterior guidance and 20% presented posterior guidance. In Group 2, 69.6% of individuals presented unilateral or bilateral canine guidance, 43.2% presented unilateral or bilateral group function and only 13.3% presented lateral movements through the posterior teeth; 3.4% presented protrusion through the posterior teeth.Conclusions:
there was no difference in the pattern of disocclusion between subgroups of patients with clefts. Group 2 presented predominance of bilateral group function, whereas Group 1 presented a higher prevalence of posterior guidance during lateral movements. Protrusion occurred primarily through anterior guidance in Group 2 and through the posterior teeth in Group 1. There was high prevalence of occlusal interferences at the molar area for both groups, yet with no correlation with occlusal pathologies (recession and abfraction). 相似文献2.
PURPOSE
This study investigated the strain of implants using a chewing simulator with strain gauges in mandibular implant-supported fixed prostheses under various dynamic loads.MATERIALS AND METHODS
Three implant-supported 5-unit fixed prostheses were fabricated with three different occlusion types (Group I: Canine protected occlusion, Group II: Unilaterally balanced occlusion, Group III: Bilaterally balanced occlusion). Two strain gauges were attached to each implant abutment. The programmed dynamic loads (0 - 300 N) were applied using a chewing simulator (MTS 858 Mini Bionix II systems, MTS systems corp., Minn, USA) and the strains were monitored. The statistical analyses were performed using the paired t-test and the ANOVA.RESULTS
The mean strain values (MSV) for the working sides were 151.83 µε, 176.23 µε, and 131.07 µε for Group I, Group II, and Group III, respectively. There was a significant difference between Group II and Group III (P < .05). Also, the MSV for non-working side were 58.29 µε, 72.64 µε, and 98.93 µε for Group I, Group II, and Group III, respectively. One was significantly different from the others with a 95% confidence interval (P < .05).CONCLUSION
The MSV for the working side of Groups I and II were significantly different from that for the non-working side (Group I: t = 7.58, Group II: t = 6.25). The MSV for the working side of Group II showed significantly larger than that of Group III (P < .01). Lastly, the MSV for the non-working side of Group III showed significantly larger than those of Group I or Group II (P < .01). 相似文献3.
BACKGROUND
Mandibular displacement is a common complication of condylar fracture. In the mandibular displacement due to condylar fracture, it is difficult to restore both esthetics and function without using orthognathic surgery.CASE DESCRIPTION
This clinical report described a full mouth rehabilitation in the patient with bilateral condylar fractures and displaced mandible using bilateral sagittal split ramus osteotomy (BSSRO) and simultaneous dental implant surgery. Mandibular position was determined by model surgery through the diagnostic wax up and restoration of fractured teeth. The precise amount of the mandibular shift can be obtained from the ideal intercuspation of remaining teeth.CLINICAL IMPLICATION
Mandibular displacement by both condylar fractures can be successfully treated by orthognathic surgery. Determination of occlusal plane and visualization from diagnostic wax up are mandatory for mandibular repositioning of model surgery. Stable occlusion and regular recall check up are needed for long-term outcome. 相似文献4.
Lanza MD Seraidarian PI Jansen WC Lanza MD 《Journal of applied oral science : revista FOB》2011,19(6):655-661
Objectives
In some clinical situations, dentists come across partially edentulous patients, and it might be necessary to connect teeth to implants. The aim of this study was to evaluate a metal-ceramic fixed tooth/implant-supported denture with a straight segment, located in the posterior region of the maxilla, when varying the number of teeth used as abutments.Materials and Methods
A three-element fixed denture composed of one tooth and one implant (Model 1), and a four-element fixed denture composed of two teeth and one implant (Model 2) were modeled. A 100 N load was applied, distributed uniformly on the entire set, simulating functional mastication, for further analysis of the SEQV (Von Mises) principal stresses, which were compared with the flow limit of the materials.Results
In a quantitative analysis, it may be observed that in the denture with one tooth, the maximum SEQV stress was 47.84 MPa, whereas for the denture with two teeth the maximum SEQV stress was 35.82 MPa, both located in the region between the pontic and the tooth.Conclusion
Lower stresses were observed in the denture with an additional tooth. Based on the flow limit of the materials, porcelain showed values below the limit of functional mastication. 相似文献5.
Sara A. Alfadda Hayam A. Al-Fallaj Hajar A. Al-Banyan Ruba M. Al-Kadhi 《Saudi Dental Journal》2015,27(2):93-98
Objective
The purpose of this study was to determine whether there is a correlation between the clinical quality of conventional complete dentures and patient quality of life.Materials and methods
This study included a random sample of 32 completely edentulous patients (15 males and 17 females) who were treated with conventional complete dentures. Using a validated questionnaire, three investigators evaluated the dentures independently on the basis of seven clinical parameters: esthetics (lip support and lower lip line), retention and stability of the maxillary and the mandibular dentures, and occlusion. Patients completed the validated Oral Health Impact Profile-20 (OHIP-20) questionnaire. Correlations were determined by using the point-biserial correlation coefficient.Results
Clinicians rated the overall clinical quality of the dentures satisfactory in 80.3% of patients. The mean (±standard deviation) total OHIP-20 score was 56.3 ± 15.9 out of a possible 120 maximum. A statistically significant negative correlation was found between the stability of the maxillary and mandibular dentures and the total OHIP-20 score (p = 0.009 and 0.0023, respectively). A negative correlation between the total OHIP-20 score and the retention of the mandibular denture approached significance (p = 0.092). Esthetics, retention of the maxillary denture, and occlusion were not correlated with patient quality of life (p > 0.169).Conclusion
Stability of the maxillary and mandibular dentures is the denture quality parameter that can most significantly affect patient quality of life. 相似文献6.
Tiossi R Falcão-Filho HB de Aguiar FA Rodrigues RC de Mattos Mda G Ribeiro RF 《The journal of advanced prosthodontics》2012,4(2):89-92
PURPOSE
Adequate passive-fitting of one-piece cast 3-element implant-supported frameworks is hard to achieve. This short communication aims to present an alternative method for section of one-piece cast frameworks and for casting implant-supported frameworks.MATERIALS AND METHODS
Three-unit implant-supported nickel-chromium (Ni-Cr) frameworks were tested for vertical misfit (n = 6). The frameworks were cast as one-piece (Group A) and later transversally sectioned through a diagonal axis (Group B) and compared to frameworks that were cast diagonally separated (Group C). All separated frameworks were laser welded. Only one side of the frameworks was screwed.RESULTS
The results on the tightened side were significantly lower in Group C (6.43 ± 3.24 µm) when compared to Groups A (16.50 ± 7.55 µm) and B (16.27 ± 1.71 µm) (P<.05). On the opposite side, the diagonal section of the one-piece castings for laser welding showed significant improvement in the levels of misfit of the frameworks (Group A, 58.66±14.30 µm; Group B, 39.48±12.03 µm; Group C, 23.13±8.24 µm) (P<.05).CONCLUSION
Casting diagonally sectioned frameworks lowers the misfit levels. Lower misfit levels for the frameworks can be achieved by diagonally sectioning one-piece frameworks. 相似文献7.
Simone Helena Gon?alves de Oliveira Luiz César de Moraes Horácio Faig-Leite Samira Esteves Afonso Camargo Carlos Henrique Ribeiro Camargo 《Journal of applied oral science : revista FOB》2009,17(3):234-239
Objective:
The aim of this study was to verify, in vivo and in vitro, the prevalence of root canal bifurcation in mandibular incisors by digital radiography.Material and Methods:
Four hundred teeth were analyzed for the in vivo study. Digital radiographs were taken in an orthoradial direction from the mandibular incisor and canine regions. The digital radiographs of the canine region allowed visualizing the incisors in a distoradial direction using 20° deviation. All individuals agreed to participate by signing an informed consent form. The in vitro study was conducted on 200 mandibular incisors positioned on a model, simulating the mandibular dental arch. Digital radiographs were taken from the mandibular incisors in both buccolingual and mesiodistal directions.Results:
The digital radiography showed presence of bifurcation in 20% of teeth evaluated in vitro in the mesiodistal direction. In the buccolingual direction, 17.5% of teeth evaluated in vivo and 15% evaluated in vitro presented bifurcation or characteristics indicating bifurcation.Conclusions:
Digital radiography associated with X-ray beam distally allowed detection of a larger number of cases of bifurcated root canals or characteristics of bifurcation. 相似文献8.
Darpan Bhargava Rajkumar Ahirwal Nupur Chakravorty Ashwini Deshpande 《Journal of maxillofacial and oral surgery》2015,14(1):13-16
Purpose
It remains vital for the trauma management team including the anaesthetist and the operating surgeon to assess and evaluate the anticipated difficulty in intubation to secure airway and for administration of anaesthesia. This study assesses the difficulty in intubating patients with vertically unstable mandibular parasymphysis fracture with attached genial tubercles and associated musculature to the fractured segment.Methods
Randomized sampling was done from the cases with maxillofacial trauma planned for a surgical procedure under general anaesthesia. The inclusion criteria was to prospectively identify ten patients each of unilateral unfavourable mandibular parasymphysis fracture with genial tubercle attached to the displaced segment, with bilateral unfavourable mandibular parasymphysis fracture with genial tubercle attached to the displaced segment and with unilateral favourable mandibular parasymphysis fracture with genial tubercle attached to the un-displaced segment. All the patients were intubated by a single anaesthetist, who documented the difficulty in nasoendotracheal intubation using Intubation Difficulty Scale.Results
Nasoendotracheal intubation was found relatively easy in the study group with unilateral favourable mandibular parasymphysis fracture with genial tubercle attached to the un-displaced segment. Clinical difficulty in intubating the patients was maximum in the study group with bilateral unfavourable mandibular parasymphysis fracture with genial tubercle attached to the displaced segment.Conclusion
Displacement of fractured mandible and resultant displacement of the genial musculature should be considered as a vital parameter for assessing difficulty during intubation. 相似文献9.
Ozgur Inan Asli Secilmis Oguz Eraslan 《Journal of applied oral science : revista FOB》2009,17(5):533-538
Objective:
The purpose of this study was to compare the fracture resistance of implant-supported all-ceramic fixed partial dentures, which have three different pontic designs.Material and Methods:
Two implants were placed in a metal model simulating mandibular left second premolar and mandibular left second molar. Thirty standardized 3-unit all-ceramic fixed partial dentures with biconvex, convex or concave pontic designs were fabricated using IPS e.max system (n=10). Afterwards, specimens were centrally loaded on the pontics until failure with a universal testing machine. Results were analyzed by Kruskal-Wallis and Mann-Whitney U tests at 5% significance level.Results:
The fracture resistance values of all-ceramic fixed partial dentures designed with biconvex, convex or concave pontics were 349.71, 438.20 and 300.78 N, respectively. There were no statistically significant differences between the fracture resistances of the groups (p>0.05), except for convex and concave groups (p<0.05 and p=0.009, respectively).Conclusions:
Convex design showed the best mechanical properties as demonstrated by the high values of fracture resistance. 相似文献10.
Ant?nio Francisco GRANDO Carlos Eduardo Edwards REZENDE Edson Ant?nio Capello SOUSA José Henrique RUBO 《Journal of applied oral science : revista FOB》2014,22(3):209-217
Knowing how stresses are dissipated on the fixed implant-supported complex allows
adequate treatment planning and better choice of the materials used for prosthesis
fabrication.
Objectives
The aim of this study was to evaluate the deformation suffered by cantilevered implant-supported fixed prostheses frameworks cast in silver-palladium alloy and coated with two occlusal veneering materials: acrylic resin or porcelain.Material and Methods
Two strain gauges were bonded to the inferior surface of the silver-palladium framework and two other were bonded to the occlusal surface of the prosthesis framework covered with ceramic and acrylic resin on each of its two halves. The framework was fixed to a metallic master model and a 35.2 N compression force was applied to the cantilever at 10, 15 and 20 mm from the most distal implant. The measurements of deformation by compression and tension were obtained. The statistical 2-way ANOVA test was used for individual analysis of the experiment variables and the Tukey test was used for the interrelation between all the variables (material and distance of force application).Results
The results showed that both variables had influence on the studied factors (deformation by compression and tension).Conclusion
The ceramic coating provided greater rigidity to the assembly and therefore less distortion compared with the uncoated framework and with the resin-coated framework. The cantilever arm length also influenced the prosthesis rigidity, causing higher deformation the farther the load was applied from the last implant. 相似文献11.
PURPOSE
To study the distribution of various occlusal schemes as well as associated static occlusal relationship among Thais.MATERIALS AND METHODS
The subjects'' occlusal schemes on the left and right sides were classified as canine protected occlusion, group function, or unclassified according to the definition from Glossary of Prosthodontic Terms (8th edition). In addition, the presence of occlusal interferences during mandibular excursions were recorded. The measurement of the horizontal overlap and vertical overlap was also performed. Chi-square, One-way ANAVA and Mann-Whitney U statistical tests were used with level of significance set at P=.05.RESULTS
Total of 104 subjects were included in this study. The ratio for male to female was 1.8 to 1. Average age of the population was 25.01±6.87 years old. The mean vertical overlap and horizontal overlap were 1.94±1.20 and 2.41±1.32 mm respectively. The majority of the populations (68.3%) possessed group function occlusal scheme. For the remaining, 17.3% possess canine protected occlusion and 12.5% possess combination of both occlusal schemes. We also found that occlusal interference was presented in 20.2% of the population. The most common was protrusive interference (57.14%), the second was balancing interference (38.1%) and the third was working interference (4.1%).CONCLUSION
Among Thais, the most common occlusal scheme was group function, however there were no significant occlusal factors related to any particular occlusal scheme. 相似文献12.
Shah FK Gebreel A Elshokouki AH Habib AA Porwal A 《The journal of advanced prosthodontics》2012,4(2):61-71
PURPOSE
To compare the changes in the occlusal vertical dimension, activity of masseter muscles and biting force after insertion of immediate denture constructed with conventional, tooth-supported and Implant-supported immediate mandibular complete denture.MATERIALS AND METHODS
Patients were selected and treatment was carried out with all the three different concepts i.e, immediate denture constructed with conventional (Group A), tooth-supported (Group B) and Implant-supported (Group C) immediate mandibular complete dentures. Parameters of evaluation and comparison were occlusal vertical dimension measured by radiograph (at three different time intervals), Masseter muscle electromyographic (EMG) measurement by EMG analysis (at three different positions of jaws) and bite force measured by force transducer (at two different time intervals). The obtained data were statistically analyzed by using ANOVA-F test at 5% level of significance. If the F test was significant, Least Significant Difference test was performed to test further significant differences between variables.RESULTS
Comparison between mean differences in occlusal vertical dimension for tested groups showed that it was only statistically significant at 1 year after immediate dentures insertion. Comparison between mean differences in wavelet packet coefficients of the electromyographic signals of masseter muscles for tested groups was not significant at rest position, but significant at initial contact position and maximum voluntary clench position. Comparison between mean differences in maximum biting force for tested groups was not statistically significant at 5% level of significance.CONCLUSION
Immediate complete overdentures whether tooth or implant supported prosthesis is recommended than totally mucosal supported prosthesis. 相似文献13.
Kazem S. Khiabani Shahrokh Raisian Meghdad Khanian Mehmandoost 《Journal of maxillofacial and oral surgery》2015,14(2):363-369
Purpose
The endoscopic-assisted technique for the treatment of subcondylar fractures has been used successfully and its acceptance develops as more surgeons gain experience. We present the short term results of this technique in a randomized prospective clinical trial.Methods and Materials
A total of 40 patients with mandibular subcondylar fracture were included in our study in two groups randomly. Patients of first group were treated by closed treatment technique and patients of second group by transoral endoscopic-assisted open reduction. All patients were followed for minimum of 12 weeks and occlusion, Mandibular Anterior Opening (MAO), mandibular deviation, and posterior ramal height were assessed.Results
In the endoscopic group the MAO was significantly greater and mandibular deviation was lesser at 2nd and 4th week of follow up. Posterior ramal height showed significant increase in the endoscopic group rather than closed treatment group.Conclusion
The transoral endoscopic-assisted technique is a reliable and successful technique to address subcondylar fractures. The patients who were treated by this technique showed better results in the fields of mandibular function and patient satisfaction and comfort, although it is time consuming and needs expensive instruments. 相似文献14.
Janson G Quaglio CL Pinzan A Franco EJ de Freitas MR 《Journal of applied oral science : revista FOB》2011,19(2):118-124
Objective
The objective of this study was to compare the skeletal, dental and soft tissue characteristics of Caucasian and Afro-Caucasian Brazilian subjects with normal occlusion and to evaluate sexual dimorphism within the groups.Material and Methods
The sample comprised lateral cephalograms of untreated normal occlusion subjects, divided into 2 groups. Group 1 included 40 Caucasian subjects (20 of each sex), with a mean age of 13.02 years; group 2 included 40 Afro-Caucasian subjects (20 of each sex), with a mean age of 13.02 years. Groups 1 and 2 and males and females within each group were compared with t tests.Results
Afro-Caucasian subjects presented greater maxillary protrusion, smaller upper anterior face height and lower posterior face height, larger upper posterior face height, greater maxillary and mandibular dentoalveolar protrusion as well as soft tissue protrusion than Caucasian subjects. The Afro-Caucasian female subjects had less mandibular protrusion and smaller total posterior facial height and upper posterior facial height than males.Conclusions
Brazilian Afro-Caucasian subjects have greater dentoalveolar and soft tissue protrusion than Brazilian Caucasian subjects, with slight sexual dimorphism in some variables. 相似文献15.
PURPOSE
The purpose of this study was to compare stress distributions of implant-supported crown placed in fibula bone model with those in intact mandible model using three-dimensional finite element analysis.MATERIALS AND METHODS
Two three-dimensional finite element models were created to analyze biomechanical behaviors of implant-supported crowns placed in intact mandible and fibula model. The finite element models were generated from patient''s computed tomography data. The model for grafted fibula was composed of fibula block, dental implant system, and implant-supported crown. In the mandible model, same components with identical geometries with the fibula model were used except that the mandible replaced the fibula. Vertical and oblique loadings were applied on the crowns. The highest von Mises stresses were investigated and stress distributions of the two models were analyzed.RESULTS
Overall stress distributions in the two models were similar. The highest von Mises stress values were higher in the mandible model than in the fibula model. In the individual prosthodontic components there was no prominent difference between models. The stress concentrations occurred in cortical bones in both models and the effect of bicortical anchorage could be found in the fibula model.CONCLUSION
Using finite element analysis it was shown that the implant-supported crown placed in free fibula graft might function successfully in terms of biomechanical behavior. 相似文献16.
17.
Objective
Some factors such as gender, age, craniofacial morphology, body structure, occlusal contact patterns may affect the maximum bite force. Thus, the purposes of this study were to determine the mean maximum bite force in individuals with normal occlusion, and to examine the effect of gender, facial dimensions, body mass index (BMI), type of functional occlusion (canine guidance and group function occlusion) and balancing side interferences on it.Material and Methods
Thirty-four individuals aged 19-20 years-old were selected for this study. Maximum bite force was measured with strain-gauge transducers at first molar region. Facial dimensions were defined by standardized frontal photographs as follows: anterior total facial height (ATFH), bizygomathic facial width (BFW) and intergonial width (IGW). BMI was calculated using the equation weight/height2. The type of functional occlusion and the balancing side interferences of the subjects were identified by clinical examination.Results
Bite force was found to be significantly higher in men than women (p<0.05). While there was a negative correlation between the bite force and ATFH/BFW, ATFH/IGW ratios in men (p<0.05), women did not show any statistically significant correlation (p>0.05). BMI and bite force correlation was not statistically significant (p>0.05). The average bite force did not differ in subjects with canine guidance or group function occlusion and in the presence of balancing side interferences (p>0.05).Conclusions
Data suggest that bite force is affected by gender. However, BMI, type of functional occlusion and the presence of balancing side interferences did not exert a meaningful influence on bite force. In addition, transverse facial dimensions showed correlation with bite force in only men. 相似文献18.
Mesiodistal root angulation of permanent teeth in children with mixed dentition and normal occlusion
Jesuino FA Costa LR Valladares-Neto J 《Journal of applied oral science : revista FOB》2010,18(6):625-629
Objective
There is little information regarding the mesiodistal angulation of permanent teeth in mixed dentition. The aim of this study was to evaluate mesiodistal root angulation of permanent incisors, canines and first molars of 100 Brazilian children, using a new horizontal reference plane based on the midpoint of the intercuspation of primary canines and permanent first molars in panoramic radiographs during the mixed-dentition phase.Material and methods
Children were equally divided between the genders with a mean age of 8.9 years (SD=0.76), normal occlusion and no eruptive disturbances.Results
The angulation of the permanent maxillary first molars was close to the vertical, whereas the mandibular molars presented approximately 25 degrees of distal root angulation. The maxillary canines were the most distally angulated teeth, whereas the permanent mandibular canines were vertically positioned. The evaluation of the anterior maxillary area showed vertical position of permanent lateral, and central incisors with a slight distal angulation, whereas the permanent mandibular incisors tended to a mesial radicular convergence.Conclusions
The proposed reference line could be useful in mixed dentition root angulation evaluation; there was a slight asymmetry in the mesiodistal angulation among homologous teeth, and also a small variation between the male and the female groups, but no difference between 8-and 10-year-old children. 相似文献19.
Mohamed I. El-Anwar Salah A. Yousief Tarek A. Soliman Mahmoud M. Saleh Wael S. Omar 《Saudi Dental Journal》2015,27(4):201-207
Objective
This study aimed to evaluate stress patterns generated within implant-supported mandibular overdentures retained by two different attachment types: ball and socket and locator attachments.Materials and methods
Commercial CAD/CAM and finite element analysis software packages were utilized to construct two 3D finite element models for the two attachment types. Unilateral masticatory compressive loads of 50, 100, and 150 N were applied vertically to the overdentures, parallel to the longitudinal axes of the implants. Loads were directed toward the central fossa in the molar region of each overdenture, that linear static analysis was carried out to find the generated stresses and deformation on each part of the studied model.Results
According to FEA results the ball attachment neck is highly stressed in comparison to the locator one. On the other hand mucosa and cortical bone received less stresses under ball and socket attachment.Conclusions
Locator and ball and socket attachments induce equivalent stresses on bone surrounding implants. Locator attachment performance was superior to that of the ball and socket attachment in the implants, nylon caps, and overdenture. Locator attachments are highly recommended and can increase the interval between successive maintenance sessions. 相似文献20.