Zohreh Hedayati; Abdolaziz Haghnegahdar; Ashkan Bagheri
Abstract
Background and Aim: Age estimation may be needed to plan treatment procedures in pedodontic, and orthodontics. Third molar is the last and most variable tooth to develop and may be used for age estimation in adulthood. The purpose of this study was to investigate relationship between chronological age ...
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Background and Aim: Age estimation may be needed to plan treatment procedures in pedodontic, and orthodontics. Third molar is the last and most variable tooth to develop and may be used for age estimation in adulthood. The purpose of this study was to investigate relationship between chronological age and developmental stages of the mandibular third molar in a population of south Iran.Method: The Demirjian’s classification system was used to evaluate the developmental status of the mandibular third molars on the 500 panoramic radiographs of orthodontic patients. The age range of patients was 12 to 20 years. Mean and Standard deviations of Chronological age for each developmental stages were calculated. One-way ANOVA and post-hoc Tuckey HSD test were used to compare the mean age and developmental stages of molar teeth. The age differences in the developmental stages between the genders was assessed. Correlation between calcification stages of the third molars and age was determined.Results: Crown calcification was completed at the mean age of 13.8 years, and root formation without apex closure was observed at the mean age of 17.5 years. At a mean age of 18.4 years apex closure was occurred. Males were advanced in the most of stages of calcification. A strong correlation between developmental stages of the lower third molars and chronological age was found in both genders.Conclusion: The present investigation could provide reference data for third molar development in our population. Developmental stages of mandibular third molars showed a strong correlation with age. The lower third molars developed earlier in males than females.
Arezoo Jahanbin; Habibollah Esmaily; Yasaman Sardari
Abstract
Aim: A successful orthodontic treatment depends on a variety of Factors such as patient cooperation. Prediction of patient cooperation could be helpful for anticipating problems that might arise during treatment and alleviating them before they can interfere with treatment. Thus the aim of present study ...
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Aim: A successful orthodontic treatment depends on a variety of Factors such as patient cooperation. Prediction of patient cooperation could be helpful for anticipating problems that might arise during treatment and alleviating them before they can interfere with treatment. Thus the aim of present study was to determine the relationship between psychological factors and cooperation of orthodontic patients.Methods and Materials: In this cross-sectional study, 48 Class I female fixed orthodontic patients (13-17 years old) were selected. For all patients Eyesenck questionnaires were completed and personality status of each patient for extroversion, neuroticism, psychoyicism and lie was determined. Patients' cooperation was also assessed through evaluating patients' folders in the first year after treatment using Orthodontic Patient Cooperation Scale. Finally, Spearman correlation test and t- test were used for statistical analysis.Results: The results of present study revealed that there exists a negative relationship between Extraversion (E), Neurosis (N) and Psychosis(P) traits of the Juvenile Eyesenck Personality Test(See Appendix) with patients' cooperation in the girls and a positive relationship between Lying trait(L) of the test and the cooperation. However, the results of Spearman correlation test showed there were no significant differences between patients' cooperation and PEN and L trails of the Juvenile Eyesenck Personality Test (p-value> 0.05).Conclusion: Orthodontic patients' psychological features could not predict their cooperation exactly.
Navid Hosseini; H. Azadikhah; Soghra Yassaie; Mohammad Tayyebi
Abstract
Background and aim: cross bite is an Abnormal relationship between one or more teeth and their corresponding antagonist tooth so that the buccolingual or labiolingual relationship is opposite. Given the high prevalence and impact of these disorders, diagnosis and early treatment of this problem is very ...
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Background and aim: cross bite is an Abnormal relationship between one or more teeth and their corresponding antagonist tooth so that the buccolingual or labiolingual relationship is opposite. Given the high prevalence and impact of these disorders, diagnosis and early treatment of this problem is very important. The aim of this study is to determine the prevalence of anterior and posterior cross bite for girls and boys who were 7-10 years old in Yazd, Iran.Materials and methods: This cross-sectional study on 400 students aged 7-10 was carried out using clinical examination. Examinations were performed by the dentist and the presence or absence of crossbite and occlusal relationship was evaluated in the mixed dentition.Results: The prevalence of anterior cross bite is 11% ,12.9% of girls and 9% of boys and prevalence of posterior cross bite was 3.5%, 4.5% in girls and 2.5% in boys. prevalence of anterior cross-bite at age 9 was 11.9% and posterior cross bite at age 10 was 7.1% which are the highest rates reported .In mouth breathing children 35.7% and 21.4%, had anterior and posterior cross bite respectively. The anterior and posterior cross bite was more in Class II malocclusion than any other malocclusion. Among the cases investigated, mouth breathing and malocclusion have correlation with crossbites.Conclusion: Given the prevalence of anterior and posterior cross bite, mothers should be awared on the prevention and control of these disorders and also periodic examinations of children To prevent complications in future.
Azita Tehranchi; Hossein Behnia; Sepideh Soheilifar
Abstract
Background and aim: Bilateral mandibular distraction osteogenesis (BMDO) has been suggested as a suitable method for correcting severe mandibular deficiencies. The purpose of this study was to evaluate the cephalometric changes of patients undergoing BMDO.Materials and methods: Seven patients were selected ...
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Background and aim: Bilateral mandibular distraction osteogenesis (BMDO) has been suggested as a suitable method for correcting severe mandibular deficiencies. The purpose of this study was to evaluate the cephalometric changes of patients undergoing BMDO.Materials and methods: Seven patients were selected for BMDO, all suffering from severe mandibular retrognathia as a result of previous trauma. Pre-treatment (T1), post-treatment (T2) and follow up (T3) cephalograms were obtained. The changes in skeletal and soft tissue parameters were assessed by paired t-test within two time intervals (T1-T2 and T2-T3). Results with a P value <0.05 were considered statistically significant. Results: In patients treated by extra-oral distractor, BMDO improved jaw relationships by increasing SNB (12.1˚) and mandibular length (22.5mm) and decreasing ANB (10.3˚) and Wits (17.2mm). Lower facial height increased significantly (4.5mm). Dental relationships were changed by increasing interincisal angle (24.8˚) and decreasing IMPA (23.2˚) and overjet (8.8mm). Reduction in the distance between upper and lower lip to E-line led to changes in the soft tissue profile. Airway space analysis revealed an increase in the nasopharyngeal space (Nph2) (4.7 mm), the oropharyngeal space (Oph2) (5.4mm) and the posterior airway space (PAS) (9mm). The available cases remained stable during the follow up period.
Conclusion: BMDO improved maxillomandibular discrepancy by lengthening mandibular body. Lower anterior facial height was increased significantly. Lip prominency relative to the nose and the chin was decreased and dental relationships were corrected by the treatment. DO procedure significantly improves the pharyngeal spaces.
Hamid reza Fattahi; Hamid reza Pakshir; Rohollah Razmdideh
Abstract
Introduction: This study was designed to compare the tooth size discrepancy as a factor of skeletal mal-occlusion in orthodontic patient population of Shiraz.
Materials and Methods: The study employed the pretreatment models of 200 patients, which were selected through a random available sampling method. ...
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Introduction: This study was designed to compare the tooth size discrepancy as a factor of skeletal mal-occlusion in orthodontic patient population of Shiraz.
Materials and Methods: The study employed the pretreatment models of 200 patients, which were selected through a random available sampling method. The mesiodistal dimensions of teeth were measured by digital electron calipers (accurate to 0.01 mm) and the Bolton indices were determined. The study population was divided into four malocclusion groups according to Angle classification (Class I, Class II Div 1, Class II Div 2 and Class III). The data were analyzed using ANOVA and Duncan tests by SPSS software and the level of significance was p<0.05.
Results: The mean anterior ratio (79.01) of the total malocclusion group had a statistically significant difference with that of Bolton (77.2) but no significant difference was found for the overall ratio. The posterior and overall ratios of Class III malocclusion group were statistically greater than the other malocclusion groups. However, regarding the anterior ratio, the Class Ill group had a greater mean than Class II with no difference with Class I malocclusion group.
Conclusion: Comparing the two types of Class II malocclusion for ratios, no significant differences were observed.
Allahyar Geramy; Ahmad Sodagar; Omid Mortezaee
Abstract
Aim: Anchorage management is a challenging problem while retracting anterior segment in orthodontic treatments. The purpose of this study is to evaluate the effect of anterior teeth labiolingual inclination on the amount of anchorage loss and distance of anterior retraction.Methods and Materials: Six ...
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Aim: Anchorage management is a challenging problem while retracting anterior segment in orthodontic treatments. The purpose of this study is to evaluate the effect of anterior teeth labiolingual inclination on the amount of anchorage loss and distance of anterior retraction.Methods and Materials: Six 3D computer models of an upper anterior segment were designed in SolidWorks 2006 (SolidWorks, Concord, Massachusetts, USA).The models contained supporting structure, upper central and lateral incisors, their PDLs, the brackets and an anterior retraction arch wire with two vertical open loops. The models were the same except for the torque of anterior teeth which were 0, 5, 10, 15, 22, and 35 degrees consequently. ANSYS Workbench Version 12.1 (ANSYS Inc., Southpointe, Canonsburg, PA, USA) was selected for the analysis. At each analysis, the end points of the arch wire were displaced distally simulating the anterior retraction arch wire activation. The displacement produced in the labio-mesio-incisal point angle and the mesializing force applied to the terminal molar was assessed.Results: Torque degree of 0 to 22 exerting almost equal force on anchorage unit during retraction while 35 degrees of torque causing more reciprocal force. Ten degrees of anterior torque resulted in maximum displacement of anterior segment.Conclusions: To have maximum anchorage and faster anterior teeth movement during retraction degree of torque suggested to be about average and neither too protruded nor uprighted.
Ahmad Sodagar; Tahura Etezadi; K. Manshaie
Abstract
Background and aim: The aim of present study was to predict post treatment space available of mandibular arch and compare this method of measurement with the previous methods. Materials and methods: Pretreatment lower dental arch models of 33 patients attending to the department of orthodontics ...
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Background and aim: The aim of present study was to predict post treatment space available of mandibular arch and compare this method of measurement with the previous methods. Materials and methods: Pretreatment lower dental arch models of 33 patients attending to the department of orthodontics of Tehran University of medical sciences were randomly selected. Two conventional methods of brass wire and sectional way were done for estimating space available in traditional method. In predictive method two mathematical arch forms, β-function and the sixth degree polynomial function were selected as the based arches. Post treatment arch perimeter predicted according to these arch forms separately and finally the results were compared with traditional method of brass wire.Results: According to this study, two traditional methods are so closed to each other and also two predictive methods, but differences between traditional method and predictive methods measurements were considerable. Conclusions: Using of post treatment arch parameters would be useful to predict post treatment space available in arches, and also detecting arch form, the position of the teeth, the retention requirements and so on.
Vahid Molabashi; Zohreh Hedayati; Amirfarhang Miresmaeili; Farhad Kashi; Maryam Dinparvar
Abstract
Background and aim: Accurate identification of dental and skeletal characteristics of different kinds of malocclusions is necessary for educational purposes, proper treatment planning and to reach successful results. The aim of this study was to assess skeletal and dental differences of class II division ...
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Background and aim: Accurate identification of dental and skeletal characteristics of different kinds of malocclusions is necessary for educational purposes, proper treatment planning and to reach successful results. The aim of this study was to assess skeletal and dental differences of class II division I patients in Shiraz and Hamadan Dental Schools.
Method: In this retrospective study lateral cephalograms of 98 patients from Hamadan (53 girls and 45 boys) and 96 Patients from Shiraz (48 girls and 48 boys) with class II division I malocclusion and age range of 9-14 years old were evaluated. Cephalograms with ANB angle higher than 5 degree were traced with Dolphin program. Statistical analysis was performed using SPSS software. Student t- test was used for between group comparisons. Chi- Square tests used for dichotomous variables.Results: Comparison of mean values of variables between the two groups showed significant differences between SNB, MP-SN, U1-NA0,Y-Axis, Inter incisal angle and PFH/AFH. High percent of patients in both groups had mandibular retrusion, vertical facial growth pattern, protrusion of upper and lower anterior teeth. These characteristics were not statistically significant between boys and girls.Conclusion: This study revealed that there was more mandibular retrusion, vertical facial growth and maxillary protruded incisors in class II division I patients of Hamadan in comparison to Shiraz.
Valiullah Arash; Reza Nosrati; Mahmoud Hajiahmadi
Abstract
Objective: The use of lateral cephalometric radiography for evaluating cervical vertebral bone age is a method that can substitute for the hand-wrist radiography method. The aim of this study was to determine the correlation between the cervical vertebral bone age, chronological age and hand-wrist bone ...
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Objective: The use of lateral cephalometric radiography for evaluating cervical vertebral bone age is a method that can substitute for the hand-wrist radiography method. The aim of this study was to determine the correlation between the cervical vertebral bone age, chronological age and hand-wrist bone age.Methods: Lateral cephalometric and hand-wrist radiographs of 125 girls (8-13 wars) who needed orthodontic treatments were chosen. The dimensions of the 3rd and 4th cervical vertebral bodies were measured by a digital micrometer caliper with 0.02-mm accuracy and determined a regression formula to obtain cervical vertebral bone age. The data were collected and analyzed by a stepwise multiple regression analysis, and the results were compared with those obtained using the hand-wrist radiography method.Results: Our investigation shows that the correlation coefficient between cervical vertebral bone age and hand-wrist bone age (0.734) is significantly (p<0.01) higher than that obtained for the relationship between cervical vertebral bone age and chronological age (0.367). The correlation between hand-wrist bone age and chronological age was 0.701. In addition, we show that the average difference (absolute value) between cervical vertebral bone age and hand-wrist bone age (0.71±0.59 years) is significantly (p<0.05) lower than that between cervical vertebral bone age and chronological age (1.27± 0.92 years).
Conclusions: By using lateral cephalometric radiography, it is possible to carry out a proper evaluation of skeletal maturity without any need for exposing the patient to extra radiation.
Nasrin Farhadian; Zahra Shahrokhi
Abstract
Background and aim: Cleft lip and palate is a common craniofacial congenital malformation. Treatment of this deformity has always been a matter of great concern for physicians and specialists. Data on the incidence and prevalence rate of this condition can help medical authorities plan for the healthcare ...
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Background and aim: Cleft lip and palate is a common craniofacial congenital malformation. Treatment of this deformity has always been a matter of great concern for physicians and specialists. Data on the incidence and prevalence rate of this condition can help medical authorities plan for the healthcare of these patients. Present study aimed to determine the incidence rate and related risk factors of cleft lip and palate in Hamadan province in 2007.
Materials and methods: In this study, 29,822 newborns were evaluated in Hamadan Province hospitals, Iran. Variables such as neonatal gender, parents’ occupations, place of residence, family background, parental consanguinity, and neonatal co-occurring disorders, as well as maternal factors such as age at pregnancy, diseases during pregnancy, medications, drug abuse, smoking, alcohol consumption, radiography, and radiotherapy during pregnancy were recorded. Finally, the data were analyzed using SPSS version 13. Results: 25 neonates (14 male and 11 female subjects) were born with various forms of cleft lip and cleft palate. The incidence rate was 0.83 per 1000 live births. Cleft lip and palate (bi or unilateral) and isolated cleft palate were the most and least frequently reported cases, respectively. In total, 28% of the newborns presented with other co-occurring disorders. Consanguineous marriage was reported in approximately 28% of the neonates’ parents and 12% of the mothers used medications such as phenytoin, imipramine, and trifluoperazine during pregnancy. Conclusion: The incidence rate of cleft lip and palate was close to the average global rate and reports in European and East Asian countries. The incidence rate of clefts was higher in males, compared to females. According to the results, parental consanguinity and mother’s medication, especially at the beginning of pregnancy, are regarded as risk factors for cleft lip and palate.
Ahmad Sodagar; E. Sanaeie; Tahereh HosseinZadehNik; sedigheh SheikhZadeh
Abstract
Background and aim: With the hypothesis that there is an interrelation between the cephalometric characteristics and difference in the arch widths, the aim of this study was to evaluate the relationship between the dental and skeletal features.Materials and methods: Lateral cephalograms and dental casts ...
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Background and aim: With the hypothesis that there is an interrelation between the cephalometric characteristics and difference in the arch widths, the aim of this study was to evaluate the relationship between the dental and skeletal features.Materials and methods: Lateral cephalograms and dental casts of 42 untreated cl II div 1 patients with excessive vertical growth were evaluated for arch widths and cephalometric parameters. Student t -test was used to evaluate the difference of variables with normal distributions and Mann-Whitney as the nonparametric equivalent of t-test.Results: Maxillary arch width in class II div1 subjects is narrower than normal groups in both genders and mandibular arch width is the same as normal group in females and smaller in males. In females, a moderate to high relationship was seen between cephalometric parameters and arch widths.Conclusion: The existence of relationship between craniofacial dimensions and arch widths should be mentioned in treatment planning to prevent unwanted side effects and relapse.
Mojgan Kachoie; Baharak Divband; Masoumeh khatamian; Azin Nourian
Abstract
Introduction: NiTi wires which are considered the ideal alloys used during the alignment and leveling stage of comprehensive orthodontic treatment exhibit very high frictional resistance. Therefore, overcoming such resistance to sliding results in a rapid tooth movement and proper anchorage control. ...
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Introduction: NiTi wires which are considered the ideal alloys used during the alignment and leveling stage of comprehensive orthodontic treatment exhibit very high frictional resistance. Therefore, overcoming such resistance to sliding results in a rapid tooth movement and proper anchorage control. Recently, coating the wires with nanoparticles has been introduced to decrease resistance to sliding. The aim of this invitro study was to evaluate effect of ZnO nanoparticles on resistance to sliding of nickel titanium orthodontic wires. Materials and methods: 40 straight pieces of 0.016-inch NiTi wires were evaluated in two groups with and without spherical ZnO nanoparticle coating, along with 40 standard system 0.018 stainless steel brackets. ZnO nanoparticles were deposited on NiTi wires and analyzed by SEM. A universal testing machine was used to determine friction between the wires and brackets at an angle of 5°. Student’s t-test were used for data analysis. Results: The SEM results confirmed the homogeneous deposition of ZnO nanoparticles on NiTi wires. At 5º angle between the wires and brackets the means of frictional forces were 1.2475±0.13 and 1.5075±0.12 N with and without ZnO nanoparticle deposits on the wires, respectively, revealing a significant decrease of 17.24% in frictional forces in coated wires (P<0.001).Conclusion: Based on the results of this study, ZnO nanoparticle coating reduces the resistance to sliding of nickel titanium orthodontic wires.
Ghasem Mighani
Abstract
Introduction: Mesiodens is the most common supernumerary tooth occurring in 0.15% to 1.9% of The population. A racial variation is believed in the prevalence of supernumeraries. The purpose of This crosssectional study was to determine the prevalence of mesiodens.
Materials and Methods: 2687 Iranian ...
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Introduction: Mesiodens is the most common supernumerary tooth occurring in 0.15% to 1.9% of The population. A racial variation is believed in the prevalence of supernumeraries. The purpose of This crosssectional study was to determine the prevalence of mesiodens.
Materials and Methods: 2687 Iranian children 6-9 years old were selected and peripcal radiographs were taken.
Results: The general prevalence of mesiodens was found to be 1.6% (1.11 , 2.08). Males showed a higher prevalence of mesiodens than that of females; 5:10.
Conclusion: A maxillary occlusal radiograph is highly recommended to make clear The presence or absence of supernumerary teeth.
Abdolreza Jamilian; Hadi Parhiz; Hossein Rastegariyan; Saeedeh Nobakht
Abstract
Background and Purpose: Dental impressions often carry microorganisms that may cause cross infection from patients to dental staff. The purpose of this study was to evaluate the disinfecting efficacy of three commercially available disinfectants on Staphylococcus aureus. Methods and subjects: Impressions ...
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Background and Purpose: Dental impressions often carry microorganisms that may cause cross infection from patients to dental staff. The purpose of this study was to evaluate the disinfecting efficacy of three commercially available disinfectants on Staphylococcus aureus. Methods and subjects: Impressions were made of a sterile metal model of the maxillary arch that had been contaminated with Staphylococcus aureus. The Impressions were cultured before and after immersion in one of the following disinfectants: 15 minutes in Micro 10⁺ (5%), 5 minutes in Deconex (2%) and 10 minutes Glutaraldehyde (2%).
Results: Kruskal-Wallis test was used to evaluate the colony forming units (CFUs) of Staphylococcus Aureus.in each of the three groups. The same test showed that the colony forming units (CFUs) were reduced to Zero by all disinfectants.
Conclusion: This study showed that all disinfectants were fully successful in complete removal of Staphylococcus Aureus.
Maryam Omidkhoda; Zoha Sahebnasagh; Maryam Poosti; M. Yaghoobi; A. Izadpanahi
Abstract
Introduction: Since orthodontic therapy may have detrimental effects to the tooth structures or periodontium, practitioners recommend their patients to use different mouth washes. These chemical agents may be potentially damaging to metal components of orthodontic appliances. The aim of the present study ...
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Introduction: Since orthodontic therapy may have detrimental effects to the tooth structures or periodontium, practitioners recommend their patients to use different mouth washes. These chemical agents may be potentially damaging to metal components of orthodontic appliances. The aim of the present study was to evaluate the effect of three common mouthwashes on mechanical properties of NiTi orthodontic wires.
Materials and Methods: 27 pieces of 0.016inch Niti wires were randomly assigned into 9 groups including 3 control and 6 experimental groups. After the first month of immersion in artificial saliva, the wires in 3 groups were immersed in Chlorhexidine, Persica and Hydrogene Peroxide for 30min, 1.5h and 1.5h respectively. The control groups included as received wires, wires immersed only in artificial saliva and Saliva + tooth brush. Mechanical properties of the wires were evaluated by three point deflection test. Two way ANOVA and Tukey tests were used to compare groups.
Results: Persica caused significantly lower force in 2 and 3 mm deflection during loading compared to Peroxide, chlorhexidine and “as received”. Chlorhexidine also significantly reduced the loading force during 3mm deflection in comparison to saliva control. In 2 mm deflection during unloading Persica significantly reduced unloading force in comparison to all groups including: chlorhexidine, peroxide, saliva control and “as received”. It is also seen that chlorhexidine caused lower force compared to saliva control. Then, NiTi wires in 3 groups underwent 3200 tooth brushing cycles and were compared with each other and with 2 control groups (saliva + brushing and "as received" ) by Tukey test. The results showed that only in 3mm loading deflection there was significant difference between Persica and Peroxide, and also between peroxide and as received wires.Conclusion: Persica was the most effective mouthwash on mechanical properties of NITI wires.
Arezoo Jahanbin; Habibollah Esmaily; Yasaman Sardari; Maryam Poosti; Mahdiyeh Kazemian
Abstract
Aim: The aim of modem orthodontic treatments is to improve facial esthetics as well as dental occlusion and create an attractive smile. The purpose of the present study was to assess lip line in deep bite patients in comparison to the normal situation.Materials and methods: Twenty young (18-24 years) ...
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Aim: The aim of modem orthodontic treatments is to improve facial esthetics as well as dental occlusion and create an attractive smile. The purpose of the present study was to assess lip line in deep bite patients in comparison to the normal situation.Materials and methods: Twenty young (18-24 years) females with anterior deep bite (vertical overlap of upper teeth was more than one third of lower teeth height) participated in this study. Two Standard photographs in frontal view were taken in rest position and posed smile. Incisor show was measured in these two gestures in photoshop program. Descriptive statistical methods were used to analyze data.Results: The average incisor show in our deep bite patients was 76.5% of central tooth crown total height. In 35% of our patients less than 70% of the incisor height was exposed during posed smile, and in 75% of the cases incisor teeth were not seen in rest position.Conclusion: Incisor show was less than minimum level of smile attractiveness in 35% of deep bite patients and the incisors were not seen at rest in 75% of these patients.
Susan Sadeghian; Nasim Esnaashari; N. Ghoreishi
Abstract
Background and aim: The objective of this study is determining the correlation among the dental crowding and mesiodistal tooth width and dental arch dimensions.Materials and methods: In this case-control study dental casts of two groups of 40 subjects was investigated. Each group included 20 male and ...
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Background and aim: The objective of this study is determining the correlation among the dental crowding and mesiodistal tooth width and dental arch dimensions.Materials and methods: In this case-control study dental casts of two groups of 40 subjects was investigated. Each group included 20 male and 20 female subjects with the age range of 17 to 25 years old.
The first group had class I malocclusion with nominal or no crowding. (space deficiency ≤ 4).
The second group had class I malocclusion with significant crowding. (space deficiency ≥ 4).
The following parameters were measured and compared in both groups:The sum of mesiodistal tooth width, arch length in canine and molar spaces and arch perimeter. In order to compare the two group independent t-test with 95% confidence was applied.Results: In lower arch a significant difference was detected in both tooth size (P=0/02) and arch dimensions. The group with the significant crowding has smaller arch dimension and larger tooth size in comparison to the group with no crowding. In the upper arch a significant difference in intercanine width (P=0/01), arch perimeter (P=0/023), arch length (P=0/012), and intermolar width (P=0/03) was detected.Conclusion: The results of this study indicated that in upper arch the arch dimensions plays a significant role in crowding, and in the lower one both tooth size and arch dimensions have important role in crowding.
Susan Sadeghian
Abstract
Aim: The purpose of this study was toevaluate the relationship between the ultrasonographic thickness of masseter muscle and the width of dental arches.Materials and Methods: The sample comprised of 44 persons (22males, 22females), who did not undergo orthodontic treatment and they had at least 28 teeth ...
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Aim: The purpose of this study was toevaluate the relationship between the ultrasonographic thickness of masseter muscle and the width of dental arches.Materials and Methods: The sample comprised of 44 persons (22males, 22females), who did not undergo orthodontic treatment and they had at least 28 teeth with CL 1 occlusion. The thickness of the masseter muscle was measured ultrasonografically with the muscles both in relaxation and under contraction. Maxillary and madibular inter-molar and inter-canine width were measured with an digital caliper for the distance between the palatal surfaces of the permanent first molar and cingulumes of canines.Results: There was a significant association between mandibular inter-molar width and sex (PV=0.037). Masseter muscle thickness in both sides and either in relaxation or contraction showed a direct significant association with sex (PV=0.001). Maxillary inter-molar and inter- canine and mandibular inter-canine width showed a direct significant association with masseter thickness during contraction in tight side (PV=0.037), whereas in relaxation no statistically significant relationship was found (PV =0.07).Conclusions: The fmdings of this study indicated that the thickness and functional capacity of the masseter muscle may be considered as one of the factors influencing the width of the maxillary dental arch and inter canine mandibular dental arch width.
Bahman Seraj; Jale Mahmoudiyan; Sara Ghadimi
Abstract
Aim: The premature loss of primary molars and the failure to protect this site during normal growth and developmental events may put the normal occurrence of occlusion at risk in the permanent dentition. Protection of dental arch relations in the premature loss of teeth can only be ensured with placement ...
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Aim: The premature loss of primary molars and the failure to protect this site during normal growth and developmental events may put the normal occurrence of occlusion at risk in the permanent dentition. Protection of dental arch relations in the premature loss of teeth can only be ensured with placement of space maintainers. The purpose of this study was to evaluate the clinical performance of Fiber Reinforced Composite resin(FRC) as a space maintainer.Materials and Method: This study was conducted on 24 children applying 34 space maintainers. Old restorations in buccal surface were removed and grooves in mesiodistal direction were prepared on the decalcified or carious buccal surface of the abutment teeth. Teeth surfaces were etched, rinsed and dried. The required length of fiber was cut and then saturated with a few drops of bonding agent. The fiber was placed and a flowable composite was applied on the prepared grooves and fiber. The patients were followed up for 12 months.Results: Our results showed that median survival time was 11.65 months and the success rate of FRC as a space maintainer was 88.24%. At the end of the study, there was no significant statistical difference between linear and angular measurements in initial and final casts (P>0.05).Conclusion: This study revealed that FRC can be an appropriate substitute appliance in preserving the space of the premature loss of primary teeth to prevent space loss.
Mohamad Hosein Toodeh Zaeim; Soghra Yassaei; Hosein Aghili; Somaie Tefakh
Abstract
Aim: Nasopharyngeal space is estimated from a point on the posterior part of the soft palate till the nearest point on the wall of the pharynx and the aim of the present study was to study the nasopharyngeal indices in nasal breathers with class I and III malocclusions.Materials and Methods: This was ...
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Aim: Nasopharyngeal space is estimated from a point on the posterior part of the soft palate till the nearest point on the wall of the pharynx and the aim of the present study was to study the nasopharyngeal indices in nasal breathers with class I and III malocclusions.Materials and Methods: This was a descriptive analytical study done by the case - control method on 35 lateral cephalometries of patients with skeletal Class III malocclusion as the study group and 30 lateral cephalometries of patients with skeletal Class I malocclusion as the control group. The population under study included patients referring to the orthodontic clinic and their age range was between 10 and 20 years. The lateral cephalometric radiographies were traced and data was analyzed using coefficient relation and t test.Results: The bony height of the nasopharyngeal space had a statistically significant positive relationship with the anterior facial height. The bony area of nasopharyngeal space had a significant positive relationship with the anterior and lower facial height. There was no significant difference between the bony dimensions of the nasopharyngeal space and nasopharyngeal and oropharyngeal airway of the two groups.Conclusion: There was no significant difference between nasopharyngeal area parameters in skeletal Class I and Ill malocclusion. In nasal breather with skeletal Class III malocclusion, dimensions of nasopharyngeal area have no significant effect on facial growth pattern.
Tahereh Hosseinzadeh Nik; Elham Sadat Emdadian Razavi; Afsaneh Modarresi; Mobina Mollaei
Abstract
Introduction: A possible treatment option for non-growing patients with vertical maxillary excess (VME), is superior repositioning of maxilla with or without mandibular surgery. After maxillary impaction, mandible rotates around a center. A common assumption at the time of cephalometric prediction, is ...
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Introduction: A possible treatment option for non-growing patients with vertical maxillary excess (VME), is superior repositioning of maxilla with or without mandibular surgery. After maxillary impaction, mandible rotates around a center. A common assumption at the time of cephalometric prediction, is taking condyle as an unchangeable center of rotation. Any error in determination of center of mandibular autorotation (CMA) may lead to improper jaw positioning and unaesthetic results.
Materials and methods: In this study, before and after cephalometric radiographs from fourteen orthognathic patients with maxillary impaction were evaluated.
Results: showed that center of mandibular autorotation are not similar in different patients, partly because of individualized craniofacial morphology. Therefore, precise determination of center of mandibular autorotation is necessary for obtaining ideal results.
Saeid Sadeghian; Meysam Mahabadi; H. Saadat Hosseini; B. Sabagh
Abstract
Background and aim: Laser ablation as an alternative method for etching porcelain has been proposed. However,previous studies have reported contrasting results. This study is designed to investigate techniques that could obtain maximum bond strength and also modes of their fracture.Materials and method: ...
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Background and aim: Laser ablation as an alternative method for etching porcelain has been proposed. However,previous studies have reported contrasting results. This study is designed to investigate techniques that could obtain maximum bond strength and also modes of their fracture.Materials and method: Fifty samples of porcelain fused to metal according to surface preparation were divided into five groups: 1.HF acid(9.6%) 2. HF acid+ silane 3. Co2 laser (2w, 30 s) 4. Co2 laser+silane 5.removing the glazed layer with diamond bur (controls). After bonding orthodontic brackets and thermocycling process, the shear bond strength (SBS) measured with Instron. Results analyzed by one way ANOVA and Least Significant Difference (p < 0.001). pattern of debonding was investigated with light microscope and results were analyzed by Kruskall wallis and Mann-whitney (p < 0.001).Results: results showed bond strength of Co2 laser (2 w) was clinically high although it was lower than HF acid samples, with better mode of fracture.Conclusion: HF acid in combination with silane showed the highest shear bond strength value while irradiation of grouped pulse Co2 laser for 30 s in combination with silane could be an alternative for HF acid etching.
Hossein Aghili; M.H Toode Zaeim; Mahdjoube Goldani moghadam; M.K. Jafari; A. Hedayati Fard; K. Guya
Abstract
Background and aim: The aim of this study was determining the prevalence of malocclusion amongst the male adolescents of Yazd province and comparing the results with that of other provinces of Iran. Materials and methods: The sample of this epidemiologic study consisted of 1980 male students with ...
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Background and aim: The aim of this study was determining the prevalence of malocclusion amongst the male adolescents of Yazd province and comparing the results with that of other provinces of Iran. Materials and methods: The sample of this epidemiologic study consisted of 1980 male students with age range of 14-17. The prevalence of class I, II, and III malocclusion according to the Angle’s classification was determined. Prevalence of Overbite, overjet, crowding and posterior crossbite was evaluated as well.Results: The prevalence of class I, II, and III malocclusion was 50.7, 19.5, and 16.6 percent respectively and normal occlusion was observed in 13.2% of cases. 47 percent of cases had normal overbite. Increased, reduced and edge to edge overbite was seen in 24, 11.9, and 13.1 percent respectively, and 4% had anterior open bite. Overjet was positive in 74.4% and negative in 12.4% of individuals. Prevalence of crowding and posterior crossbite was 40.5% and 10.5% respectively.
Conclusion: Class I malocclusion was the most common occlusal relationship in all of investigations done in different geographic districts of Iran. Clinical significance: Determining malocclusion prevalence in each population is prerequisite of making macro policy in health care systems, this study provides information about prevalence of malocclusion in Yazd province and comparing it with that of other geographical districts of Iran.
Zeinab Kadkhoda; Rahele Malekolkotab; Ahad Khoshzaban; Zahra Chinipardaz
Abstract
Aim: culture of human preiodontal mesenchymal stem cells to production osteoblast. This might be used for repair of human periodontal defects in future.Method: periodontal tissues were obtained from periodontium of patients who were candidate for periodontal surgery. They were 25-45 years old and had ...
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Aim: culture of human preiodontal mesenchymal stem cells to production osteoblast. This might be used for repair of human periodontal defects in future.Method: periodontal tissues were obtained from periodontium of patients who were candidate for periodontal surgery. They were 25-45 years old and had no systemic diseases, no smoking, and no drug treatment. Tissues were cultured in DMEM medium. Cells were by subsequently expanded by passages. 3 passages were done. Then cells were evaluated by inverted microscope and flowcytometry. We stained PDLstem cells with these markers: CD44, CD90 CD166,CD13, CD34,CD45 .Finding: PDL stem cells expressed MCSCs markers as shown in flowcytometry. The cells were negative by CD34 and CD45 markers and were positive by CD90, CD166, CD13, and CD44 markers .We saw a monolayer attached cells on the floor of flask macroscopically and we saw spindle cells by inverted microscope. In the microscopic finding we saw nuclear red calcified view with Alizarine staining in day 14th of culture.Conclusion: Our findings show that human PDL contains a population of multypotent postnatal stem cells can be isolated and expanded in vitro. It provides a reservoir of stem cells from an accessible tissue resource. These cells have capacity of proliferation ex vivo. Therefore tissue regeneration mediated by human PDL stem cells might have potency of practical cellular- based treatment of periodontal defects.
Hamed Mahmoud Hashemi; Manouchehr Rahmati Kamel; Siamak Hemmatpour
Abstract
The purpose of this review was to address the question whether mandibular distractionostegenesis (DO) has any effect on temporomandibular joint (TMJ). A literature survey from the pub Med database used the medical subject heading terms osteodistraction, T.M.J and 13 articles written in English were obtained. ...
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The purpose of this review was to address the question whether mandibular distractionostegenesis (DO) has any effect on temporomandibular joint (TMJ). A literature survey from the pub Med database used the medical subject heading terms osteodistraction, T.M.J and 13 articles written in English were obtained. mandibular DO may accompany with some resorption & remodeling of TMJ but apparently if correctly used produces less TMJ problems compared with conventional mandibular osteotomies and even according to some studies, It is beneficial to structure and position of TMJ. This technique has been proposed for advancement of mandible in patients with TMJ problem and for ramus lengthening for prevention of relaps and TMJ problems. Mandibular Do can be a valuable technique for reconstruction of ramus and condyle in severe mandibular deformities such as TMJ ankylosis and hemifacial microsomia. Transverse distraction of mandible may accompany with TMJ problems and should be used cautiously.
