Pub Date : 2017-06-15DOI: 10.22037/JDS.V35I2.24629
V. Zand, M. Oshagh, N. I. Nasrabadi, P. Kharazi, Fatemeh Bahramnia
Objectives Different theories have been suggested to define factors involved in skeletal and craniofacial morphology. Many of these theories explain that the bone morphology is the result of the bone tissue capability to adapt in response to biomechanical forces exerted during growth. Also, it seems logical to hypothesize that there is a relationship between biomechanical connections of muscles to bones with the morphology of musculodentoskeletofacial complex. A few studies have evaluated muscle orientation in different skeletal occlusions (class I, II and III). The aim of this study was to evaluate correlations between masticatory muscle orientation and craniodentofacial morphology in different skeletal malocclusions. Materials and Methods A total of 160 lateral cephalograms of patients between 10–17 years in a dental clinic were evaluated for the orientation of masticatory muscles and craniofacial morphology. All cephalograms were traced and confirmed by an orthodontist. Thirty- seven parameters (skeletal, dental, muscular) were measured. For statistical analysis, canonical correlation, variation and linear regression analysis were performed. Results Increase of the masseter muscle angulation was accompanied by a more superior position of the muscle in female subjects with Class II malocclusion. Increase of temporalis muscle angulation was seen in long face males. Increase of the masseter muscle angulation and its higher position were seen in short face males. Conclusion Increase of the masseter muscle angulation was accompanied by a more superior position of the muscle in female patients with class II properties. Increase of temporalis muscle angulation was seen in male patients with long face characteristics. Increase of the masseter muscle angulation and its higher position were seen in male patients with short face properties.
{"title":"Evaluation of Canonical Correlations between Masticatory Muscle Orientation and Craniodentofacial Morphology in 10-17 Year_Olds","authors":"V. Zand, M. Oshagh, N. I. Nasrabadi, P. Kharazi, Fatemeh Bahramnia","doi":"10.22037/JDS.V35I2.24629","DOIUrl":"https://doi.org/10.22037/JDS.V35I2.24629","url":null,"abstract":"Objectives Different theories have been suggested to define factors involved in skeletal and craniofacial morphology. Many of these theories explain that the bone morphology is the result of the bone tissue capability to adapt in response to biomechanical forces exerted during growth. Also, it seems logical to hypothesize that there is a relationship between biomechanical connections of muscles to bones with the morphology of musculodentoskeletofacial complex. A few studies have evaluated muscle orientation in different skeletal occlusions (class I, II and III). The aim of this study was to evaluate correlations between masticatory muscle orientation and craniodentofacial morphology in different skeletal malocclusions. Materials and Methods A total of 160 lateral cephalograms of patients between 10–17 years in a dental clinic were evaluated for the orientation of masticatory muscles and craniofacial morphology. All cephalograms were traced and confirmed by an orthodontist. Thirty- seven parameters (skeletal, dental, muscular) were measured. For statistical analysis, canonical correlation, variation and linear regression analysis were performed. Results Increase of the masseter muscle angulation was accompanied by a more superior position of the muscle in female subjects with Class II malocclusion. Increase of temporalis muscle angulation was seen in long face males. Increase of the masseter muscle angulation and its higher position were seen in short face males. Conclusion Increase of the masseter muscle angulation was accompanied by a more superior position of the muscle in female patients with class II properties. Increase of temporalis muscle angulation was seen in male patients with long face characteristics. Increase of the masseter muscle angulation and its higher position were seen in male patients with short face properties.","PeriodicalId":21563,"journal":{"name":"Shahid Beheshti University Dental Journal","volume":"34 1","pages":"123-132"},"PeriodicalIF":0.0,"publicationDate":"2017-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78294087","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-12-15DOI: 10.22037/JDS.V34I4.24635
Niloofar Kianvash Rad, B. Javid, N. Panahandeh, A. Ghasemi, Ali Kamali, Gholamhasan Mohammadi
Objectives : Microleakage is the main concern in composite restorations. This study aimed to compare the microleakage of two bulk-fill and one conventional composite at two different time points. Methods : Class II cavities were prepared in 60 premolar teeth and divided into six groups of 20. Groups 1 and 4 were incrementally filled with Grandio composite. Groups 2 and 5 were filled with X-tra fil bulk-fill composite. Groups 3 and 6 were filled with Tetric-N-Ceram bulk-fill composite in one layer. The samples were thermocycled for 5000 cycles between 25-55°C. In groups 1-3, the samples were incubated for 24 hours and then immersed in 1% methylene blue dye. Groups 4-6 were incubated for three months and then immersed in dye. All samples were mesiodistally sectioned and degree of microleakage was scored under a light microscope. The data were analyzed using Mann Whitney and Kruskal-Wallis tests. Results : The results showed no significant difference among groups 1-5 and 6 in terms of microleakage ( P >0.05) but a significant difference was noted between groups 1 and 4 in this regard ( P =0.01). The microleakage in groups 4-6 was higher than that in groups 1-3 ( P =0.02). Also, microleakage in gingival margins was greater than that in occlusal margins ( P =0.02). Conclusion : The microleakage of bulk-fill composites is comparable to that of conventional composites both at 24 hours and three months after restoration.
{"title":"Microleakage of Bulk-Fill Composites at Two Different Time Points","authors":"Niloofar Kianvash Rad, B. Javid, N. Panahandeh, A. Ghasemi, Ali Kamali, Gholamhasan Mohammadi","doi":"10.22037/JDS.V34I4.24635","DOIUrl":"https://doi.org/10.22037/JDS.V34I4.24635","url":null,"abstract":"Objectives : Microleakage is the main concern in composite restorations. This study aimed to compare the microleakage of two bulk-fill and one conventional composite at two different time points. Methods : Class II cavities were prepared in 60 premolar teeth and divided into six groups of 20. Groups 1 and 4 were incrementally filled with Grandio composite. Groups 2 and 5 were filled with X-tra fil bulk-fill composite. Groups 3 and 6 were filled with Tetric-N-Ceram bulk-fill composite in one layer. The samples were thermocycled for 5000 cycles between 25-55°C. In groups 1-3, the samples were incubated for 24 hours and then immersed in 1% methylene blue dye. Groups 4-6 were incubated for three months and then immersed in dye. All samples were mesiodistally sectioned and degree of microleakage was scored under a light microscope. The data were analyzed using Mann Whitney and Kruskal-Wallis tests. Results : The results showed no significant difference among groups 1-5 and 6 in terms of microleakage ( P >0.05) but a significant difference was noted between groups 1 and 4 in this regard ( P =0.01). The microleakage in groups 4-6 was higher than that in groups 1-3 ( P =0.02). Also, microleakage in gingival margins was greater than that in occlusal margins ( P =0.02). Conclusion : The microleakage of bulk-fill composites is comparable to that of conventional composites both at 24 hours and three months after restoration.","PeriodicalId":21563,"journal":{"name":"Shahid Beheshti University Dental Journal","volume":"48 1","pages":"225-234"},"PeriodicalIF":0.0,"publicationDate":"2016-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80768352","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-06-15DOI: 10.22037/JDS.V34I2.24683
M. Moshfeghi, M. Amintavakoli, Dara Ghaznavi, A. Ghaznavi
Objective: Cone beam computed tomography (CBCT) is applied for the imaging of the maxillofacial and dental structures, particularly for surgical treatments and dental implants. The aim of this study was to assess the effect of slice thickness on the accuracy of CBCT linear measurements. Methods: In this diagnostic accuracy study, forty-two titanium pins with the same dimensions were inserted into seven dry sheep mandibles. The length of the pins before the insertion was carefully measured by a digital caliper, (0.01mm accuracy). Imaging of the mandible performed using CBCT New Tom VGi. After image reconstruction by NNT Viewer, linear measurements were made on cross-sectional slices (thicknesses of 0.125, 0.5, 1 and 2mm) by three radiologists. The accuracy of measurements assessed using descriptive indices and compared between different slice thicknesses by repeated measures ANOVA.Results: Repeated measures ANOVA showed a significant difference between different slice thicknesses (P=0.024). According to the least significant difference (LSD) test, the difference in absolute errors was significant in all thicknesses (P=0.024). Measurements at 0.125 mm thickness were significantly different from others, with a higher error rate (mean absolute error=0.17). Measurements at 0.5mm thickness showed a significant difference with those at 0.125 and 2mm (mean absolute error=0.15). Measurements at 2mm thickness were significantly different from those at 0.125 mm thickness (mean absolute error=0.13).The average error rate was lower in 2mm thickness and the measurements were more accurate.Conclusion: A statistically significant difference was seam between CBCT measurements and actual sizes in different slice thicknesses. The differences were below 1mm, and clinically acceptable.
{"title":"Effect of Slice Thickness on the Accuracy of Linear Measurements Made on Cone Beam Computed Tomography Images (InVitro)","authors":"M. Moshfeghi, M. Amintavakoli, Dara Ghaznavi, A. Ghaznavi","doi":"10.22037/JDS.V34I2.24683","DOIUrl":"https://doi.org/10.22037/JDS.V34I2.24683","url":null,"abstract":"Objective: Cone beam computed tomography (CBCT) is applied for the imaging of the maxillofacial and dental structures, particularly for surgical treatments and dental implants. The aim of this study was to assess the effect of slice thickness on the accuracy of CBCT linear measurements. Methods: In this diagnostic accuracy study, forty-two titanium pins with the same dimensions were inserted into seven dry sheep mandibles. The length of the pins before the insertion was carefully measured by a digital caliper, (0.01mm accuracy). Imaging of the mandible performed using CBCT New Tom VGi. After image reconstruction by NNT Viewer, linear measurements were made on cross-sectional slices (thicknesses of 0.125, 0.5, 1 and 2mm) by three radiologists. The accuracy of measurements assessed using descriptive indices and compared between different slice thicknesses by repeated measures ANOVA.Results: Repeated measures ANOVA showed a significant difference between different slice thicknesses (P=0.024). According to the least significant difference (LSD) test, the difference in absolute errors was significant in all thicknesses (P=0.024). Measurements at 0.125 mm thickness were significantly different from others, with a higher error rate (mean absolute error=0.17). Measurements at 0.5mm thickness showed a significant difference with those at 0.125 and 2mm (mean absolute error=0.15). Measurements at 2mm thickness were significantly different from those at 0.125 mm thickness (mean absolute error=0.13).The average error rate was lower in 2mm thickness and the measurements were more accurate.Conclusion: A statistically significant difference was seam between CBCT measurements and actual sizes in different slice thicknesses. The differences were below 1mm, and clinically acceptable.","PeriodicalId":21563,"journal":{"name":"Shahid Beheshti University Dental Journal","volume":"68 1","pages":"100-108"},"PeriodicalIF":0.0,"publicationDate":"2016-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83780922","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-03-15DOI: 10.3329/BJMS.V15I2.21474
S. Saghafi, Reza Zare Mahmoodabadi, N. Ghazi, Abdollah Javan, Mohammad Zargari, Hamed, Mortazavi
Objective : The purpose of this study was to retrospectively analyze the demographic characteristics of patients with central giant cell granulomas (CGCGs) and peripheral giant cell granulomas (PGCGs) in Iranian population. Methods : The data were obtained from records of 1019 patients with CGCG and PGCG of the jaws referred to our department between 1972 and 2010. This 38-year retrospective study was based on existing data. Information regarding age distribution, gender, location of the lesion and clinical signs and symptoms was documented. Results : A total of 1019 patients were affected GCGLs including 435 CGCGs and 584 PGCGs during the study. The mean age was 28.91 ± 18.16. PGCGs and CGCGs had a peak of occurrence in the first and second decade of life respectively. A female predominance was shown in CGCG cases (57.70%), whereas PGCGs were more frequent in males (50.85%). Five hundred and ninety-eight cases of all giant cell lesions (58.7 %) occurred in the mandible. Posterior mandible was the most frequent site for both CGCG and PGCG cases. The second most common site for PGCG was posterior maxilla (21%), whereas anterior mandible was involved in CGCG (19.45%). The majority of patients were asymptomatic. Conclusions : In contrast to most of previous studies PGCGs occur more common in the first decade and also more frequently in male patients. Although the CGCGs share some histopathologic similarities with PGCGs, differences in demographic features may be observed in different populations which may help in the diagnosis and management of these lesions. Bangladesh Journal of Medical Science Vol.15(2) 2016 p.220-223
{"title":"A 38- year demographic study of central and peripheral giant cell granulomas of the jaws","authors":"S. Saghafi, Reza Zare Mahmoodabadi, N. Ghazi, Abdollah Javan, Mohammad Zargari, Hamed, Mortazavi","doi":"10.3329/BJMS.V15I2.21474","DOIUrl":"https://doi.org/10.3329/BJMS.V15I2.21474","url":null,"abstract":"Objective : The purpose of this study was to retrospectively analyze the demographic characteristics of patients with central giant cell granulomas (CGCGs) and peripheral giant cell granulomas (PGCGs) in Iranian population. Methods : The data were obtained from records of 1019 patients with CGCG and PGCG of the jaws referred to our department between 1972 and 2010. This 38-year retrospective study was based on existing data. Information regarding age distribution, gender, location of the lesion and clinical signs and symptoms was documented. Results : A total of 1019 patients were affected GCGLs including 435 CGCGs and 584 PGCGs during the study. The mean age was 28.91 ± 18.16. PGCGs and CGCGs had a peak of occurrence in the first and second decade of life respectively. A female predominance was shown in CGCG cases (57.70%), whereas PGCGs were more frequent in males (50.85%). Five hundred and ninety-eight cases of all giant cell lesions (58.7 %) occurred in the mandible. Posterior mandible was the most frequent site for both CGCG and PGCG cases. The second most common site for PGCG was posterior maxilla (21%), whereas anterior mandible was involved in CGCG (19.45%). The majority of patients were asymptomatic. Conclusions : In contrast to most of previous studies PGCGs occur more common in the first decade and also more frequently in male patients. Although the CGCGs share some histopathologic similarities with PGCGs, differences in demographic features may be observed in different populations which may help in the diagnosis and management of these lesions. Bangladesh Journal of Medical Science Vol.15(2) 2016 p.220-223","PeriodicalId":21563,"journal":{"name":"Shahid Beheshti University Dental Journal","volume":"48 2","pages":"51-57"},"PeriodicalIF":0.0,"publicationDate":"2016-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91507226","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-09-15DOI: 10.22037/JDS.V33I3.24701
M. Akbari, M. Moghaddas, Sh. Gilshan, A. B. Niat
Objective: Fiber-reinforced composite (FRC) posts have recently become more popular for restoring endodontically treated teeth because of providing esthetics, better stress distribution and lower risk of root fracture. Resistance against tensile forces dislodging the post from the root canal is a prerequisite for these posts. This study aimed to evaluate the tensile retention (strength) of intracanal glass fiber posts produced by three manufacturers.Methods: In this interventional study, the crowns of 30 sound human maxillary central incisors were cut at the cementoenamel junction and the roots were endodontically treated. Post space was prepared to a length of 10mm and the specimens were divided into three groups of 10. HtCo, Anthogyr and Svenskposts were used in groups 1, 2 and 3, respectively. The posts were cemented with Panavia F2 resin cement according to the manufacturer’s instructions. Specimens were then immersed in water at 37°C for 30 days and were then subjected to 7500 thermal cycles between 5- 55°C. Intracanal tensile retention (strength) was measured at a crosshead speed of 0.5 mm/min. Data were analyzed using one-way ANOVA at p<0.05 level of significance.Results: The mean retention was 188.53 (15.43), 183.81 (16.37) and 192.19 (17.50) N in Htco, Anthogyr and Svensk posts, respectively. Statistical analyses showed no significant difference in this regard among groups (p=0.111).Conclusion: Within the limitations of this study, retention of HtCo glass fiber posts in the root canals was similar to that of two other posts.
{"title":"Intracanal Retention of Glass Fiber Posts","authors":"M. Akbari, M. Moghaddas, Sh. Gilshan, A. B. Niat","doi":"10.22037/JDS.V33I3.24701","DOIUrl":"https://doi.org/10.22037/JDS.V33I3.24701","url":null,"abstract":"Objective: Fiber-reinforced composite (FRC) posts have recently become more popular for restoring endodontically treated teeth because of providing esthetics, better stress distribution and lower risk of root fracture. Resistance against tensile forces dislodging the post from the root canal is a prerequisite for these posts. This study aimed to evaluate the tensile retention (strength) of intracanal glass fiber posts produced by three manufacturers.Methods: In this interventional study, the crowns of 30 sound human maxillary central incisors were cut at the cementoenamel junction and the roots were endodontically treated. Post space was prepared to a length of 10mm and the specimens were divided into three groups of 10. HtCo, Anthogyr and Svenskposts were used in groups 1, 2 and 3, respectively. The posts were cemented with Panavia F2 resin cement according to the manufacturer’s instructions. Specimens were then immersed in water at 37°C for 30 days and were then subjected to 7500 thermal cycles between 5- 55°C. Intracanal tensile retention (strength) was measured at a crosshead speed of 0.5 mm/min. Data were analyzed using one-way ANOVA at p<0.05 level of significance.Results: The mean retention was 188.53 (15.43), 183.81 (16.37) and 192.19 (17.50) N in Htco, Anthogyr and Svensk posts, respectively. Statistical analyses showed no significant difference in this regard among groups (p=0.111).Conclusion: Within the limitations of this study, retention of HtCo glass fiber posts in the root canals was similar to that of two other posts.","PeriodicalId":21563,"journal":{"name":"Shahid Beheshti University Dental Journal","volume":"41 1","pages":"189-195"},"PeriodicalIF":0.0,"publicationDate":"2015-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90110197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-11-15DOI: 10.22037/JDS.V32I4.24775
F. Eslamipour, Imaneh Asgari, A. Tabesh
Objective: Oral health status particularly maxillofacial disorders in adolescents can affect different aspects of the quality of life. This study aimed to assess the age-related quality of life of students in two age groups of 11-14 years and 14-18 years to evaluate its correlation with orthodontic treatment need in adolescents in Isfahan. Methods: This cross-sectional study was conducted on 11-18 year-old middle school and high- school students. Subjects were selected via two-stage stratified random sampling from 30 schools in different areas of Isfahan city. After examination by two calibrated clinicians, Dental Health Component of Index of Orthodontic Treatment Need (DHC-IOTN) was recorded for all subjects. The Oral Health Related Quality of Life (OHRQoL) was assessed using self-reported Child Perception Questionnaire (CPQ) in 11-14 year-olds and Child Oral Health Impact Profile (COHIP) in 14-18 year-olds. After descriptive analyses, the correlation between the DHC-IOTN and the quality of life score of subjects was assessed using the Spearman’s correlation test and the Mann Whitney U test. Results: A total of 1,227 students were evaluated. The mean and standard deviation (SD) was found to be 18.3 (13.7) for CPQ score in 11-14 year olds. For COHIP score it was found to be 103.6 (18) in 14-18 year olds. A total of 22% from the 604 students examined in the first group, and 17% of 570 students in the second group definitely needed orthodontic treatment. Significant differences existed in the mean quality of life score among the three groups requiring orthodontic treatment in the two age groups ( p <0.05). The correlation between the malocclusion severity and quality of life subscales was weak. Conclusion: Based on the results, malocclusion significantly affects the dental function and social and emotional domains of quality of life. However, considering the role of confounders, studies with condition-specific formats of the questionnaire are required to assess the correlation of malocclusions with the quality of life after controlling for other factors.
{"title":"Orthodontic Treatment Need and Oral Health Related Quality of Life in Students in Isfahan","authors":"F. Eslamipour, Imaneh Asgari, A. Tabesh","doi":"10.22037/JDS.V32I4.24775","DOIUrl":"https://doi.org/10.22037/JDS.V32I4.24775","url":null,"abstract":"Objective: Oral health status particularly maxillofacial disorders in adolescents can affect different aspects of the quality of life. This study aimed to assess the age-related quality of life of students in two age groups of 11-14 years and 14-18 years to evaluate its correlation with orthodontic treatment need in adolescents in Isfahan. Methods: This cross-sectional study was conducted on 11-18 year-old middle school and high- school students. Subjects were selected via two-stage stratified random sampling from 30 schools in different areas of Isfahan city. After examination by two calibrated clinicians, Dental Health Component of Index of Orthodontic Treatment Need (DHC-IOTN) was recorded for all subjects. The Oral Health Related Quality of Life (OHRQoL) was assessed using self-reported Child Perception Questionnaire (CPQ) in 11-14 year-olds and Child Oral Health Impact Profile (COHIP) in 14-18 year-olds. After descriptive analyses, the correlation between the DHC-IOTN and the quality of life score of subjects was assessed using the Spearman’s correlation test and the Mann Whitney U test. Results: A total of 1,227 students were evaluated. The mean and standard deviation (SD) was found to be 18.3 (13.7) for CPQ score in 11-14 year olds. For COHIP score it was found to be 103.6 (18) in 14-18 year olds. A total of 22% from the 604 students examined in the first group, and 17% of 570 students in the second group definitely needed orthodontic treatment. Significant differences existed in the mean quality of life score among the three groups requiring orthodontic treatment in the two age groups ( p <0.05). The correlation between the malocclusion severity and quality of life subscales was weak. Conclusion: Based on the results, malocclusion significantly affects the dental function and social and emotional domains of quality of life. However, considering the role of confounders, studies with condition-specific formats of the questionnaire are required to assess the correlation of malocclusions with the quality of life after controlling for other factors.","PeriodicalId":21563,"journal":{"name":"Shahid Beheshti University Dental Journal","volume":"23 1","pages":"187-196"},"PeriodicalIF":0.0,"publicationDate":"2014-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85488496","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Objective: Since orthodontic and orthognathic treatment planning in each ethnic group must be done according to the soft tissue facial characteristics regarded as beauty, they thus vary from country to country. The main purpose of this articlewas to determine the mean range of the middle third of soft tissue facial profile and anteroposterior lip positioning using 3angular and 2 linear measurements in adult male and female Iranians to compare with European standards.Methods: After clinical examination of 180 dental students, 70 Iranian adults who had normal occlusion aged between 21 to 29 years (mean:24.5 years) were selected(35 males and 35females). After obtaining consent form, lateral cephalograms were taken in natural head position (NHP) (as seen in a mirror) and analyzed according to the Rickets(E-Line),Tweed-Merrifield(Z-angle) and Holdaway (H-angle).For comparison of data with standards, the One-Sample-t-test and for comparison of measurements between groups, Independent Sample-t-test was used.Results: Radiographic evaluation revealed that all Iranian samples had significant differences with European standards with no differences between males and females. In the Rickets (E-Line) analysis, both upper (p<0.001)and lower(p<0.01) lips were behind the E-line. In the Tweed- Merrifield (Z-angle) analysis this angle in the Iranian sample was smaller (p<0.001) and in the Holdaway (H-angle) analysis our sample had smaller H-angle as well (p<0.001).Conclusion: Iranian adults have retruded upper and lower lip position in both sexes and more convex profile than European standards; thismay be due to a more retruded position of the chin and lips or more prominence of the nose in Iranian samples.
{"title":"Soft tissue facial profile and anteroposterior lip positioning in Iranians","authors":"Fataneh Ghorbanyjavadpour, Mashaallah Khanemasjedi","doi":"10.22037/JDS.V32I2.24802","DOIUrl":"https://doi.org/10.22037/JDS.V32I2.24802","url":null,"abstract":"Objective: Since orthodontic and orthognathic treatment planning in each ethnic group must be done according to the soft tissue facial characteristics regarded as beauty, they thus vary from country to country. The main purpose of this articlewas to determine the mean range of the middle third of soft tissue facial profile and anteroposterior lip positioning using 3angular and 2 linear measurements in adult male and female Iranians to compare with European standards.Methods: After clinical examination of 180 dental students, 70 Iranian adults who had normal occlusion aged between 21 to 29 years (mean:24.5 years) were selected(35 males and 35females). After obtaining consent form, lateral cephalograms were taken in natural head position (NHP) (as seen in a mirror) and analyzed according to the Rickets(E-Line),Tweed-Merrifield(Z-angle) and Holdaway (H-angle).For comparison of data with standards, the One-Sample-t-test and for comparison of measurements between groups, Independent Sample-t-test was used.Results: Radiographic evaluation revealed that all Iranian samples had significant differences with European standards with no differences between males and females. In the Rickets (E-Line) analysis, both upper (p<0.001)and lower(p<0.01) lips were behind the E-line. In the Tweed- Merrifield (Z-angle) analysis this angle in the Iranian sample was smaller (p<0.001) and in the Holdaway (H-angle) analysis our sample had smaller H-angle as well (p<0.001).Conclusion: Iranian adults have retruded upper and lower lip position in both sexes and more convex profile than European standards; thismay be due to a more retruded position of the chin and lips or more prominence of the nose in Iranian samples.","PeriodicalId":21563,"journal":{"name":"Shahid Beheshti University Dental Journal","volume":"41 1","pages":"90-95"},"PeriodicalIF":0.0,"publicationDate":"2014-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73933535","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-07-15DOI: 10.22037/JDS.V31I2.29092
S. A. Moghadam, M. Pourmahdi, M. Gholamian, H. Pedram, F. A. Moghadam
Objective: E-cadherin is a classic cadherin that plays a key role in epithelial cell adhesion. This protein is being referred to as the suppressor of proliferation and invasion. Limited studies have investigated E-cadherin expression in salivary gland neoplasms. This study sought to assess the expression of E-cadherin and its possible role in progression and invasion of salivary gland neoplasms. Methods: In this retrospective cross-sectional study, 15 samples of pleomorphic adenoma (PA) and 9 samples of mucoepidermoid carcinoma (MEC) were immunohistochemically stained for evaluation of E-cadherin expression. Degree of staining was calculated as the percentage of positively stained cell membranes out of a minimum of 1000 neoplastic cells. Results: In normal salivary gland specimens, intense membrane staining was observed around the acinar mucous and serous cells as well as the ductal cells. Myoepithelial cells were negative. In PA, intense staining was noted along the membrane of attached cells forming the ducts, islands, cellular cords and cellular sheets but the stromal myoepithelial cells were negative. In MEC, epidermoid and intermediate cells showed intense membrane staining. Mucous cells also showed membrane staining. After statistical analysis, the percentage of positive cells was found to be 82.56±11.66 and 67.4±7.24 in MEC and PA, respectively. This difference was not statistically significant (P>0.05). Conclusion: E-cadherin expression was not a suitable marker for differentiation of PA from MEC. It was only correlated with cell phenotype.
{"title":"Immunohistochemical Analysis of E-Cadherin Expression in Pleomorphic Adenoma and Mucoepidermoid Carcinoma of Salivary Glands","authors":"S. A. Moghadam, M. Pourmahdi, M. Gholamian, H. Pedram, F. A. Moghadam","doi":"10.22037/JDS.V31I2.29092","DOIUrl":"https://doi.org/10.22037/JDS.V31I2.29092","url":null,"abstract":"Objective: E-cadherin is a classic cadherin that plays a key role in epithelial cell adhesion. This protein is being referred to as the suppressor of proliferation and invasion. Limited studies have investigated E-cadherin expression in salivary gland neoplasms. This study sought to assess the expression of E-cadherin and its possible role in progression and invasion of salivary gland neoplasms. Methods: In this retrospective cross-sectional study, 15 samples of pleomorphic adenoma (PA) and 9 samples of mucoepidermoid carcinoma (MEC) were immunohistochemically stained for evaluation of E-cadherin expression. Degree of staining was calculated as the percentage of positively stained cell membranes out of a minimum of 1000 neoplastic cells. Results: In normal salivary gland specimens, intense membrane staining was observed around the acinar mucous and serous cells as well as the ductal cells. Myoepithelial cells were negative. In PA, intense staining was noted along the membrane of attached cells forming the ducts, islands, cellular cords and cellular sheets but the stromal myoepithelial cells were negative. In MEC, epidermoid and intermediate cells showed intense membrane staining. Mucous cells also showed membrane staining. After statistical analysis, the percentage of positive cells was found to be 82.56±11.66 and 67.4±7.24 in MEC and PA, respectively. This difference was not statistically significant (P>0.05). Conclusion: E-cadherin expression was not a suitable marker for differentiation of PA from MEC. It was only correlated with cell phenotype.","PeriodicalId":21563,"journal":{"name":"Shahid Beheshti University Dental Journal","volume":"30 1","pages":"104-109"},"PeriodicalIF":0.0,"publicationDate":"2013-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90105272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-03-15DOI: 10.22037/JDS.V31I1.28641
H. Nojehdehyan, M. Moezzyzadeh, H. Haghi
Objective: Zirconium oxide has gained the spotlight during the recent years as a high strength ceramic material. However, despite its mechanical superiorities, it forms a weak bond with different synthetic substrates and tissues due to its neutral nature and resistance against chemical agents. Therefore, it is important to improve the bonding technique in order to prevent microleakage and increase retention and fracture resistance of the restoration. Literature Review: Since the discovery of zirconium oxide, several surface treatment methods have been evaluated to increase its bond strength to resin cement such as surface grinding with micro- abrasion, burs or abrasive papers, tribochemical silica coating, silicoating, glass micropearls, glaze- on technique, selective infiltration etching, hot etching and use of phosphate ester monomers. The mentioned techniques and related articles are reviewed and discussed in the present study. Conclusion: Despite extensive studies, no consensus has been reached about a specific treatment as the standard protocol for improving the bond strength of zirconia restorations.
{"title":"The Effect of Physicochemical Surface Treatment Methods on Bond Strength of Zirconia to Resin Cement: A Review of the Literature","authors":"H. Nojehdehyan, M. Moezzyzadeh, H. Haghi","doi":"10.22037/JDS.V31I1.28641","DOIUrl":"https://doi.org/10.22037/JDS.V31I1.28641","url":null,"abstract":"Objective: Zirconium oxide has gained the spotlight during the recent years as a high strength ceramic material. However, despite its mechanical superiorities, it forms a weak bond with different synthetic substrates and tissues due to its neutral nature and resistance against chemical agents. Therefore, it is important to improve the bonding technique in order to prevent microleakage and increase retention and fracture resistance of the restoration. Literature Review: Since the discovery of zirconium oxide, several surface treatment methods have been evaluated to increase its bond strength to resin cement such as surface grinding with micro- abrasion, burs or abrasive papers, tribochemical silica coating, silicoating, glass micropearls, glaze- on technique, selective infiltration etching, hot etching and use of phosphate ester monomers. The mentioned techniques and related articles are reviewed and discussed in the present study. Conclusion: Despite extensive studies, no consensus has been reached about a specific treatment as the standard protocol for improving the bond strength of zirconia restorations.","PeriodicalId":21563,"journal":{"name":"Shahid Beheshti University Dental Journal","volume":"8 1","pages":"23-32"},"PeriodicalIF":0.0,"publicationDate":"2013-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90640471","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-03-15DOI: 10.22037/JDS.V31I1.28639
Mandana Nasseri, Mozhgan Momayyez, Z. Ahangari
Objective: Knowledge about the internal anatomy of the root canal and apical foramen is a critical prerequisite for root canal therapy and is necessary for the success of endodontic treatment. This study aimed to determine the distance of apical foramen from the anatomical apex and apical constriction, evaluate the deviation of apical foramen from the anatomical apex and specify the most common canal types in maxillary premolar teeth using stereomicroscope. Methods: In this laboratory experimental study, 100 extracted first and second maxillary premolars of patients presenting to dental clinics in Tehran were selected. After the disinfection of roots and access cavity preparation, apical foramen deviation and its distance from the anatomical apex were determined by introducing a #10 hand file into the canal and observation under stereomicroscope; 2% methylene blue was then injected into the canals and demineralization and clearing process were carried out to measure the distance of apical foramen from the apical constriction and evaluate the canal type. Results: The mean distance of apical foramen from the anatomical apex and apical constriction was 0.4-0.5 and 0.5-0.7 mm, respectively in maxillary first premolars and 0.3-0.7 and 0.6-1 mm, respectively in maxillary second premolars. In less than 17% of first premolars and 37% of second premolars, the canal followed a straight path to the anatomical apex without any deviation towards the mesiodistal or buccolingual directions. The most common canal type according to Vertucci’s classification was type IV in the first and type I in the second premolars. In general, 94% (n=47) of the first premolars and 46% (n=23) of the second premolars had 2 canals while the remaining teeth had a single canal. Conclusion: This study showed that the apical foramen in premolar teeth is located at a 0.3-0.7 mm distance from the anatomical apex and 0.5-1 mm distance from the apical constriction. In more than 83% of first premolars and 63% of second premolars the apical foramen did not correspond to the anatomical apex. First and second premolars had 2 canals in 94% and 46% of cases, respectively.
{"title":"Topographic Evaluation of Apex and Root Canal of Maxillary Premolars in an Iranian Population","authors":"Mandana Nasseri, Mozhgan Momayyez, Z. Ahangari","doi":"10.22037/JDS.V31I1.28639","DOIUrl":"https://doi.org/10.22037/JDS.V31I1.28639","url":null,"abstract":"Objective: Knowledge about the internal anatomy of the root canal and apical foramen is a critical prerequisite for root canal therapy and is necessary for the success of endodontic treatment. This study aimed to determine the distance of apical foramen from the anatomical apex and apical constriction, evaluate the deviation of apical foramen from the anatomical apex and specify the most common canal types in maxillary premolar teeth using stereomicroscope. Methods: In this laboratory experimental study, 100 extracted first and second maxillary premolars of patients presenting to dental clinics in Tehran were selected. After the disinfection of roots and access cavity preparation, apical foramen deviation and its distance from the anatomical apex were determined by introducing a #10 hand file into the canal and observation under stereomicroscope; 2% methylene blue was then injected into the canals and demineralization and clearing process were carried out to measure the distance of apical foramen from the apical constriction and evaluate the canal type. Results: The mean distance of apical foramen from the anatomical apex and apical constriction was 0.4-0.5 and 0.5-0.7 mm, respectively in maxillary first premolars and 0.3-0.7 and 0.6-1 mm, respectively in maxillary second premolars. In less than 17% of first premolars and 37% of second premolars, the canal followed a straight path to the anatomical apex without any deviation towards the mesiodistal or buccolingual directions. The most common canal type according to Vertucci’s classification was type IV in the first and type I in the second premolars. In general, 94% (n=47) of the first premolars and 46% (n=23) of the second premolars had 2 canals while the remaining teeth had a single canal. Conclusion: This study showed that the apical foramen in premolar teeth is located at a 0.3-0.7 mm distance from the anatomical apex and 0.5-1 mm distance from the apical constriction. In more than 83% of first premolars and 63% of second premolars the apical foramen did not correspond to the anatomical apex. First and second premolars had 2 canals in 94% and 46% of cases, respectively.","PeriodicalId":21563,"journal":{"name":"Shahid Beheshti University Dental Journal","volume":"13 1","pages":"8-14"},"PeriodicalIF":0.0,"publicationDate":"2013-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78024572","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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