Masoumeh Johari; Farzad Esmaeili; Arman Saeedi vahdat; S. Naghinejad Ahmadi
Abstract
Background and aim: The aim of the present study was to measure the thicknesses of bone and soft issues in the mid palatal area at certain points for the placement of orthodontic mini-implants using CBCT and evaluate their relationships with age and gender.Materials and methods: A total of 161 subjects ...
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Background and aim: The aim of the present study was to measure the thicknesses of bone and soft issues in the mid palatal area at certain points for the placement of orthodontic mini-implants using CBCT and evaluate their relationships with age and gender.Materials and methods: A total of 161 subjects were evaluated in the present study, consisting of males (31.9%) with a mean age of 41.46±13.88 years and females (60.9%) with a mean age of 38.47±11.66 years. In all the samples 20 points were evaluated. First, the incisive foramen was located. Then para-coronal cross-sections were prepared at 4-, 8-, 16- and 24-mm distances from the posterior wall of the incisive foramen; in addition, on each cross-section, the mid-sagittal and para-sagittal areas were determined at 3- and 6-mm intervals bilaterally (5 points on the whole). The soft tissue and bone thickness were measured at these points. Results: The soft tissue thicknesses were significantly different at all the 20 sample points between males and females (P<0.05). In other words, at all the points the soft tissue thicknesses were significantly greater in males compared to females. In some areas there was a positive relationship between age and soft tissue thickness (P<0.01), i.e. the soft tissuethickness increased with age. In addition, in the majority of points the overall bone thickness was significantly higher in males compared to that in females; however, in the majority of points, no positive relationship was found between age and bone thickness.. Conclusion: Age was not a determining factor for bone thickness, while where was a stronger relationship between soft tissue thickness and age. In addition, the most appropriate locations for the placement of orthodontic mini-implants were paramedian area at 3- and 6-mm distances from the suture, 4 mm posterior to the incisive foramen.
Zohre Tabatabaei; Mohammad Danesh Ardakani
Abstract
Failure of multiple teeth eruption is a rare dental anomaly. Various local, systemic or genetic factors implicated in this condition, or it may be an Idiopathic phenomenon. Here we describe an Iranian young female with multiple teeth impaction who is free from any systemic disease or syndromic condition. ...
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Failure of multiple teeth eruption is a rare dental anomaly. Various local, systemic or genetic factors implicated in this condition, or it may be an Idiopathic phenomenon. Here we describe an Iranian young female with multiple teeth impaction who is free from any systemic disease or syndromic condition. This patient was managed successfully by interdisciplinary treatment. Based on clinical presentation and radiographic examination this paper discusses the differential diagnosis and management of this case.
Seyed Hosein Moslemzade; Mojgan Kachoei; Aydin Sohrabi; Ali Rafighi; S. Bahmani
Abstract
Background and aim: The frequency of exposure of dental personnel to infection and of patient to cross contaminated instruments has prompted concern about adequate sterilization of dental instruments. Aim of the present study was to evaluate the changes in the frictional properties of Ni-Ti orthodontic ...
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Background and aim: The frequency of exposure of dental personnel to infection and of patient to cross contaminated instruments has prompted concern about adequate sterilization of dental instruments. Aim of the present study was to evaluate the changes in the frictional properties of Ni-Ti orthodontic wires after sterilization with chemical agents.
Materials and methods: In the present study the friction between Ni-Ti wires measuring 16 mm in diameter and 18-slot stainless steel brackets were measured and compared in two groups as follows: 1) without sterilization (as received); 2) after chemical sterilization. Each group consisted of 30 specimens and friction was measured in a Universal testing machine.Results: Comparison of unsterilized samples with the group sterilized with chemical agents showed a significant difference (P=0.000) in shear stress.Conclusion: Based on the results of the present study, this sterilization techniques result in an increase in the friction of Ni-Ti orthodontic wires.
Mojgan Kachoei; Mohammad Hossein Ahangar Atashi; Amir Mohammadi; Sina BadamchiZadeh; Mehri Khobivand; Mahdieh Nourzadeh
Abstract
Introduction: Third molar impaction is usually related to lack of space for eruption. The aim of this study was to assess third molar angulation following extraction and non extraction orthodontic treatment.Methods: This study was carried out on pretreatment and post treatment panoramic and cephalometricradiographs ...
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Introduction: Third molar impaction is usually related to lack of space for eruption. The aim of this study was to assess third molar angulation following extraction and non extraction orthodontic treatment.Methods: This study was carried out on pretreatment and post treatment panoramic and cephalometricradiographs of 70 CL I malocclusion patients. Thirty-five patients (24 female and 11 male) with mean age of 16.3±1.8 years had been treated with extraction of four first premolars (extraction group) and thirty-five patients (27 female and 8 male) with mean age of 16.9±2.6 years had been treated without extraction (nonextraction group). In each group, upper and lower third molar angulation, on pre and post treatment radiographs were assessed. Changes in third molar angulations from pretreatment to post treatment in each group were assessed with Mann- Whiteny U test. Changes in two groups were compared with Wilcoxon test.Results: statistical analysis revealed some degree of improvement in third molar angulation in both groups. changes of upper left third molars in extraction group and upper right and lower left third molars in non extraction group were statistically significant. The changes of third molar angulation between two groups were not statistically significant.
Conclusion: Extraction of first premolars during orthodontic treatments does not influence unerupted third molar angulation.
Esfandiar Akhavan Niaki; Tahereh HosseinZadeh Nik; B. Abbasian; Sedigheh SheikhZadeh
Abstract
Background and aim: G-axis which is defined by the angle between line S-N and S-G would be of great use in evaluation of the mandibular growth relative to other craniofacial structures the aim of this study was to evaluate the correlation of G-axis with vertical parameters in adult patients of different ...
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Background and aim: G-axis which is defined by the angle between line S-N and S-G would be of great use in evaluation of the mandibular growth relative to other craniofacial structures the aim of this study was to evaluate the correlation of G-axis with vertical parameters in adult patients of different malocclusions.Materials and methods: Lateral cephalograms of 90 patients with different malocclusions, were traced for evaluation of some horizontal and vertical cephalometric facial parameters. The patients were classified into three groups of 30 on the basis of clinical examination, ANB angle and wits appraisal. Pearson correlation test were conducted to compare the correlation of G axis with vertical parameters in different malocclusions.Results: Y-axis length showed significant and positive correlation with G-axis length. G-axis length and lower facial height had positive significant correlation in three categories. No significant correlation was found between G-axis length and ANB angle or wits. Conclusion: Application of the Y-axis and G-vector simultaneously seem to be more useful in cephalometric evaluation of mandibular growth pattern than emphasis on one.
Azita Tehranchi; Nazila Ameli; E. Hasanrezaee
Abstract
Background and aim: The objective of this study was to investigate the relationship between the gonial angle changes and occlusal plan steepness in patients underwent Bilateral Sagittal Split Osteotomy (BSSO) surgery.Materials and method: In this analytical retrospective clinical trial, 18 males and ...
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Background and aim: The objective of this study was to investigate the relationship between the gonial angle changes and occlusal plan steepness in patients underwent Bilateral Sagittal Split Osteotomy (BSSO) surgery.Materials and method: In this analytical retrospective clinical trial, 18 males and 12 females were studied who had been underwent BSSO surgery for mandibular advancement in. Cephalometric landmarks were calculated on the patients' lateral radiographs taken before and 1-6 months postsurgery using Dolphin software. The patients assigned into 3 groups according to different occlusal plan steepness. Landmarks' changes before and after surgery were analyzed by Paired t-test. The changes occurred regarding the normal and flat facial types assessed by Student t-test while the relationship between the presurgical occlusal plan and the landmark changes was evaluated using the Pearson Coefficient.Results: After BSSO, the gonial angle had increased in all patients with the mean value of 6.83ᴼ (P˂0.0001) but occlusal plan steepness increased to an insignificant value (mean 2.82ᴼ). Increased values of the gonial angle were similarly reported in the patients with normal occlusal plan steepness and flat occlusal plan while no significant relationship was found between occlusal plan steepness before the surgery and the gonial angle changes after surgery. However, fair more increase occurred in patients with normal steepness than lower ones. Conclusions: The results showed that there is no significant relationship between the gonial angle changes after surgery and the occlusal plan steepness prior the surgery of BSSO for mandibular advancement.
Mahdi Sazavar; Koroush Taheri Talesh; Javad Yazdani
Abstract
Aim: The BSSO is an excellent operation for a mandibular setback. Beyond 7-8 mm of posterior repositioning of the mandible with a BSSO is difficult, and consideration should be given to an inverted L osteotomy or intraoral vertical ramus osteotomy. (IVRO) Currently the period of immobilization ranges ...
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Aim: The BSSO is an excellent operation for a mandibular setback. Beyond 7-8 mm of posterior repositioning of the mandible with a BSSO is difficult, and consideration should be given to an inverted L osteotomy or intraoral vertical ramus osteotomy. (IVRO) Currently the period of immobilization ranges between 7-21 days following the release of IMF, guiding elastics should be used to direct the mandible to maximal intercuspation.Materials and Methods: This study implied a 1 year follow- up on a group of 40 patients, who had undergone modified subcondylar osteotomy for mandibular setback. Relapse is measured as the distance from Sn perpendicular to Pog at the lateral cephalogram preoperative, one week, and one year postoperatively.Conclusion: Modified intra-oral subcondylar osteotomy with short term immobilization appeared to be a relatively safeeand reliable procedure.The mean skeletal horizontal relapse at Pog of the whole group, after one year was 0.6mm and neuro-senory disturbance (NSD) incidence alter 6 months was 2.5%.
Hamidreza Pakshir; R Rostami; AA Alavi
Abstract
Background and aim: Different adhesives have been used for bonding orthodontic brackets to teeth. The aim of this study was to evaluate the possibility of using Core Max II in bracket bonding by comparing it's shear bond strength with the two commonly used orthodontic adhesives; Transbond XT and Unite.
Subjects ...
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Background and aim: Different adhesives have been used for bonding orthodontic brackets to teeth. The aim of this study was to evaluate the possibility of using Core Max II in bracket bonding by comparing it's shear bond strength with the two commonly used orthodontic adhesives; Transbond XT and Unite.
Subjects and Methods: In this interventional study, 105 human premolars were divided into 3 groups of 35 each. After etching with 37% phosphoric acid, Dyna-Lock stainless steel brackets (3M Unitek, Monrovia, CA) with the average base surface area of 12.09 mm2 were bonded with three different adhesives: Core Max II (Sankin, Tokyo, Japan) Transbond XT (3M Unitek) and Unite (3M Unitek). The shear bond strength of 3 groups were measured by a universal testing machine (lnstron 3401, Canton, Mass) with cross- head speed of 0.5 mm/min. Adhesive Remnant Index (ARI) was determined under 10x magnification. For data analysis, SPSS statistical package was used.
Results: Mean shear bond strength of Core Max 11 (17.24± 3.2 MPa) was significantly higher than Transbond XT (15.44 ± 2.2 MPa) (P=0.009) but had not statistically difference with Unite (17.16 ± 3.7 MPa) (P=0.93). Evaluation of ARI indicated that 83% of Core Max II samples had score 0 or 1 and 17% had score 2 or 3. These percentages were 66% and 34% for Transbond XT and 77% and 23% for Unite, respectively.
Conclusion: In this study, it was concluded that: 1) Core Max II had a shear bond strength higher that Transbond XT and equal to Unite. 2) ARI of Core Max II showed a higher frequency of score 0 and 1, which indicated that after debonding, most of the adhesive remains on the bracket base. 3) Core Max II has the potential of being a good orthodontic adhesive. (IJO 2006; 1: 42 - 47)
Soghra Yassaei; Farzaneh Eslami; Roya Ghafouri fard
Abstract
Aim: Considering the importance of stability on the orthodontic treatment outcomes, the instability may cause dentoskeletal and soft tissue changes in patients after the treatment. The aim of this study was to evaluate dentoskeletal and facial soft tissue relapse in class II patients whom have been treated ...
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Aim: Considering the importance of stability on the orthodontic treatment outcomes, the instability may cause dentoskeletal and soft tissue changes in patients after the treatment. The aim of this study was to evaluate dentoskeletal and facial soft tissue relapse in class II patients whom have been treated with functional appliances. Materials and Methods: 23 patients with Class II Division 1 malocclusion who had received treatment with Farmand functional appliance and had at least two years of post treatment follow up, were evaluated using cephalometric analysis for dentoskeletal and soft tissue changes. The lateral cephalometric radiographs of the patients immediately after the treatment (T1) and two years follow up (T2) were traced and statistical analysis was performed to obtain the amount of occurred relapse between T1 and T2.Results: The mean decrease of ANB angle between T1 and T2 was 0.73 º, which was not statistically significant. Overall, the mean changes of skeletal and dental variables (FMA, GOGN-SN, U1 to SN, U1 to FH and IMPA) in T1 and T2 were not statistically significant. For the soft tissue variables, the mean increase of the nasolabial and mentolabial angle in T1 and T2 were not significant. The mean changes of Z and H angles in T1 and T2 were 0.53º and 0.63 º, which were not statistically significant. Conclusion: Dentoskeletal and soft tissue facial changes that occurred during treatment with Farmand functional appliance remained stable at least 2 years after treatment.
Gholamreza Shirani; Mahnaz Arshad; Sohrab Asefi
Abstract
Supernumerary tooth is a rare event, which is usually found coincidentally in radiographic examination. The prevalence of this event is 1-3% with different prevalence for primary and permanent dentition. Supernumerary teeth may cause various clinical problems including: delayed or failure of eruption, ...
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Supernumerary tooth is a rare event, which is usually found coincidentally in radiographic examination. The prevalence of this event is 1-3% with different prevalence for primary and permanent dentition. Supernumerary teeth may cause various clinical problems including: delayed or failure of eruption, displacement or rotation of permanent teeth and cyst formation. The purpose of this study was to present the case of a 9-year-old boy who had a large dentigerous cyst around his primary mandibular left premolar that was enucleated with the tooth. A year after this enucleation, we have observed a supernumerary tooth in mesial of canine. It is a reasonable question that “can the supernumerary tooth formation relate to the dentigerous cyst around impacted tooth?” Therefore, it is necessary to perform more pathological investigation in this aspect to answer this question.
Mohammad Hossein Toode Zaeim; Soghra Yassaei; Hoori Mir Mohamad Sadeghi; Valiollah Rafiei
Abstract
Aim: A high percentage of the problems in finishing phase are due to tooth size imbalances that can be diagnosed in initial stages of treatment. The purpose of present study is to evaluate the frequency of anterior tooth size discrepancies by Bolton Analysis among class I, II and III malocclusions.Materials ...
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Aim: A high percentage of the problems in finishing phase are due to tooth size imbalances that can be diagnosed in initial stages of treatment. The purpose of present study is to evaluate the frequency of anterior tooth size discrepancies by Bolton Analysis among class I, II and III malocclusions.Materials and methods: The mesio-distal widths of six anterior teeth in 90 paired casts of patients (class I, II, and III), who were selected non-randomly, were measured. Chi-square test was performed to compare the frequency of anterior tooth size discrepancies between the three malocclusion groups. Analysis of variance was used to compare the mean anterior Bolton ratios as a function of skeletal anterior-posterior malocclusions and both genders. Mean mesio-distal width of six anterior teeth were compared by Analysis of variance in 3 skeletal malocclusion groups. Statistical differences were determined at the 95% confidence level.Results: Discrepancy was greater in class I and III than in class II. No sex difference was shown to exist in Bolton anterior ratio. mesio-distal width of upper laterals had greater variation coefficient.
Conclusion: Difference of mean anterior tooth size discrepancies among three skeletal class I, II and III malocclusions were not statistically significant.
Allahyar Geramy; Hannane Ghadirian
Abstract
Aim: Bent root forms are always a challenging point in an orthodontic treatment. The main aim of this study has been to assess the stress effects of a dilaceration in apical third of an upper central incisor in orthodontic movement.Materials and Methods: Three FEM models of an upper central incisor were ...
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Aim: Bent root forms are always a challenging point in an orthodontic treatment. The main aim of this study has been to assess the stress effects of a dilaceration in apical third of an upper central incisor in orthodontic movement.Materials and Methods: Three FEM models of an upper central incisor were designed with cortical and spongy bone, PDL, and teeth. The only difference between 3D models was the anatomy of the apical fourth of their root. A 30-deg (the first model) and a 60-degree (the second model) dilaceration in the apical fourth of the root were designed in a labial direction. The calculation was in ANSYS Workbench Ver. 11.0. A 1.0 N labio-palatal force was applied in 45 degrees to the horizontal plane in the labial side of the crown. Von mises stress was evaluated along a path of nodes starting at the mid root area at labial moving towards the apex and continuing to reach the mid root lingual region on root surface.
Results: The apical stress did not show a dramatic increase in dilacerated form models starting from 0.11 MPa in normal model to 0.17 MPa in a 60-degree dilacerations model. Moving away from the apex, the stress findings increased which was noticeable between the normal model (0.48 MPa) and the 60-degree model (2.11 MPa).Conclusion: Based on the findings of this FEN! study, It was shown that the increase in the stress in areas away from the apex can be interpreted as the reason to the start of the external root resorption. There may be other models of the pointed apex root forms to show an increase in the apical area stress which was not the case in this model.
Ali Rafighi; Aydin Sohrabi; Saeid Foroughi Moghaddam; Seyed Hossein Moslemzadeh; Reza Nemati; Leila Roshangar
Abstract
Background and aim: The aim of this study was to find out influence of the orthodontic devices on the oral epithelial cells.Materials and methods: Cells of lower lip oral mucosa from 32 orthodontic patients were collected by exfoliative cytology in three times: Day 0 (just before appliance placement), ...
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Background and aim: The aim of this study was to find out influence of the orthodontic devices on the oral epithelial cells.Materials and methods: Cells of lower lip oral mucosa from 32 orthodontic patients were collected by exfoliative cytology in three times: Day 0 (just before appliance placement), and 14 and 60 days after appliance insertion. Nuclear (NA) and cytoplasmic (CA) areas, NA/CA ratio, cell morphology, and cellularity of smears were analyzed by using cytologic and cytomorphometric methods.Results: The NA of the cells adjacent to orthodontic devices diminished after appliance placement, and reached to its lower level in day 60 (p = 0.000). Investigated epithelial cells showed insignificant changes in CA. Type II inflammatory smears, according to Papanicolau, increased insignificantly after the treatment initiation. Superficial epithelial cells, were predominant cell type in day 14 and 60 (p= 0.002)..Conclusion: Orthodontic appliances cause reduction in NA and induce epithelial hyperkeratosis in lower lip mucosa.
Seyed Mohammad Hosseinikhah; Zahra Ebrahimi Nik; Soghra Yassaei; Seyed Morteza Saadat Mostafavi; F. Faghir
Abstract
Background and aim: There are no strict criteria in determining the need for orthodontic treatment and dentists often have different opinion on assessing the orthodontic treatment needs. Making an appropriate estimation of the need and demand for orthodontic treatments is necessary to organize and provide ...
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Background and aim: There are no strict criteria in determining the need for orthodontic treatment and dentists often have different opinion on assessing the orthodontic treatment needs. Making an appropriate estimation of the need and demand for orthodontic treatments is necessary to organize and provide meaningful orthodontic services. In this study, the orthodontic treatment needs were evaluated in highschool boys of Yazd.Materials and methods: 420 students who were studying in 14 different high schools were randomly selected. All participants were examined under normal white light and DHC(dental health component) ruler. To assess the orthodontic treatment needs, the dental health component of IOTN index was used. The data were analyzed by Chi-square test and p-value was 0.05.Results: Measurements showed that 44.8% of students scored 1, 15.1% scored 2, 13.6% scored 3, 15.3% scored 4 and 10.7% scored 5 in DHC records. The most frequent malocclusions observed in this study population were contact point displacement (27.3%), crossbite (13.3%), hypodontia (12.8%) and increased overjet (9.3%).Conclusion: Based on the results, approximately one fourth of participants had definite need for orthodontic treatments (IOTN Grades 4 and 5) which is a warning sign. More studies are needed to be done on different populations of the country to make the governors able for organizing oral health programs and providing beneficial dental insurance.
Mohammad Karim Soltani; N. Mollaie; O. Mohammadi
Abstract
Background and aim: The maxillary canine is the second most frequently impacted tooth following third molars. The etiology of the impacted canine is obscure, but probably multifactorial. There are some evidences that patients with a few certain features of occlusion may be at higher risk to the ...
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Background and aim: The maxillary canine is the second most frequently impacted tooth following third molars. The etiology of the impacted canine is obscure, but probably multifactorial. There are some evidences that patients with a few certain features of occlusion may be at higher risk to the development of impacted canine. The aim of this study was to investigate the association between occurrence of canine impaction and other aspects of occlusion.
Materials and Methods: This study was conducted with patients aged 14 years or older who consequently presented to Orthodontics clinic, School of Dentistry, Hamedan. The patients with impacted canine were examined for occlusal condition clinically . Data were recorded and analyzed statistically.Results: 28 males and 69 females withcanine impaction were found among 600 evaluated patients. Of 97 patients with impacted canine, 48.5% had occlusal relation of Class I, 21.6% of Class II D1, 18.6% of Class II D2, and 11.3% of Class III. The statistical analysis showed that there is no relation of impacted canine to occlusion, as well as to crowding, agenesis, anterior or posterior cross bite (P> 0.05), but canine impaction presented a significant correlation to smaller size of lateral incisors and spacing (P< 0.05). Conclusion: The study concluded that there was anassociation between canine impaction and the small size of lateral incisor and spacing.
Mahtab Nouri; Sara Alijani; Alireza Akbarzade
Abstract
Background and aim: Number of studies evaluating the changes in head position following mandibular setback surgery (MSS) is scarce. This study sought to assess the craniofacial morphology, head and neck posture following mandibular setback surgery.Materials and methods: This retrospective, longitudinal, ...
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Background and aim: Number of studies evaluating the changes in head position following mandibular setback surgery (MSS) is scarce. This study sought to assess the craniofacial morphology, head and neck posture following mandibular setback surgery.Materials and methods: This retrospective, longitudinal, semi-experimental study was performed on 35 patients with Class III malocclusion. Radiographs taken at baseline and one year after surgery were retrieved from the medical records of patients. Lateral cephalograms were scanned and landmarks were marked on the first (baseline) radiograph. The second radiograph was superimposed on the first radiograph, true vertical lines or a ruler were considered as parallel images and a line was drawn along the SN from the point S. After superimposition, cephalometric variables were measured using Orthosurger X software (Iran). The mean, standard deviation (SD) and range of changes in each group were calculated. The significance of differences caused by surgery was analyzed using paired t-test.Results: The total mandibular length, mandibular body length, ramus length, SNB, SN-Pog, A-N-Pog, the angle between the body and ramus and the mandibular plane inclination significantly decreased; while, ANB angle, overjet and overbite significantly increased. No significant change occurred in the head position or cervical vertebra following MSS.
Conclusions: Since changes in the positions of cervical hard tissue were not significant, decreased airway volume following MSS seems to be related to the soft tissue structures namely the tongue, the soft palate and the suprahyoid and cervical muscles.
Massoud Seifi; Mina Mahdian
Abstract
Aim: Quality management in orthodontics is a complex issue which aims at providing high quality services to patients. Development of a well established quality control policy according to regional characteristics and socio-economic features of the consumers, is of great importance. However, there is ...
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Aim: Quality management in orthodontics is a complex issue which aims at providing high quality services to patients. Development of a well established quality control policy according to regional characteristics and socio-economic features of the consumers, is of great importance. However, there is also an inevitable need for careful supervision regarding the implementation of the quality control program. This study is to evaluate and improve standards in removable orthodontic treatment.Materials and Methods: Data was retrieved from students, patients, orthodontists and technicians filled the relevant fields of questionnaires. The patients were chosen from those who had passed their second follow up session. The following health service modules were assessed in the questionnaires: "The pre-admission phase for patients", "The pmcass of admission". "The treatment, the follow up and the retention phase", and "The laboratory".Results: The results were analyzed in two categories; the patient related questions (clinic) including modules from entrance to dismissal and the technician related questions (appliance construction). The pattern of the answers in the first category was: 8.1% "Very poor", 12.7% "Poor', 32.5% "Moderate", 48.8% "Good" and 0% "Very good". The second category of questions yielded the following pattern of response: 16.1% voted "Very poor", 61.2% voted "Poor" and 12.6% voted "Moderate", 9.6% "Good" and 0% "Very good". In general, the majority of participants (38.4%) marked the answer choice "Good".Conclusions: Generally, the treatment provided for patients seemed to be of "good" standard. However, further attention has to be devoted to laboratory-related aspects of Orthodontic services.
Atefe Saffar Shahroudi; Amir-Hossein Mirhashemi; Hassan Noroozi; Hannane Ghadirian; Tahereh Hosseinzadeh Nik
Abstract
One of the most important characteristic of dentition is dental arch form. In orthodontic treatment, it is crucial to understand each individual dental arch for diagnosis and treatment planning and try to preserve it throughout the treatment to achieve a higher stability. Additionally, it is important ...
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One of the most important characteristic of dentition is dental arch form. In orthodontic treatment, it is crucial to understand each individual dental arch for diagnosis and treatment planning and try to preserve it throughout the treatment to achieve a higher stability. Additionally, it is important to maintain a wellestablished coordination between maxillary and mandibular dental arch to have a perfect functional occlusion. In orthodontics up to now, different definitions have been proposed for human dental arch form and methods for coordinating dental arches. The aim of this study was to gather and compare these concepts. The available data were categorized and discussed in five different domains: Arch Form (history and recent concepts), Factors affecting dental arch form, Characterization of arch form, Coordination of upper and lower arches and arch wire selection and arch form.
Tahereh Hosseinzadeh Nik; Shahin Nourozi; Seyed Mehdi Hosseinizade
Abstract
Aim: The purpose of this study was to investigate skeletal and dental changes during anterior tooth retrac-tion as well as upper lip response to this orthodontic treatment.
Materials and Methods: Pretreatment and post treatment lateral cephalograms of 15 post-pubertal female patients (mean age 18.2) ...
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Aim: The purpose of this study was to investigate skeletal and dental changes during anterior tooth retrac-tion as well as upper lip response to this orthodontic treatment.
Materials and Methods: Pretreatment and post treatment lateral cephalograms of 15 post-pubertal female patients (mean age 18.2) with class II division I malocclusion or bialveolar protrusion who required upper first premolar (P1) extraction were evaluated using a series of 5 linear and 9 angular measurements. All the cases were treated using combination edgewise technique. Point A displacement was then analyzed, and then the effect of orthodontic correction was determined using single variant regression analysis.
Results: On average, the maxillary incisors retraction was found to be 4.8mm which cause significant changes in SNA angle due to backward and downward movement of point A.
Conclusion: Preoral region hard tissue changes can be produced by surgical intervention, growth, ortho-pedic forces, and orthodontic movement of teeth. According to this study point A movement in post-puber-tal patients is possible but it seems surgical intervention is inevitable in severe cases. Also palatal and occlusal plane rotation occur consequent to the tooth retraction. (IJO 2006; 1: 48 - 52 )
Mohammad Hosseinikhah; Soghra Yassaie; Navid Rezaie
Abstract
Background and aim: This study is aimed at specifying the indices of soft tissues of the face in male subjects 18-25 years old with proportional faces in Yazd, and comparing it to the northern European race using photography and anthropometry.Materials and methods: 80 male individuals in age range of ...
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Background and aim: This study is aimed at specifying the indices of soft tissues of the face in male subjects 18-25 years old with proportional faces in Yazd, and comparing it to the northern European race using photography and anthropometry.Materials and methods: 80 male individuals in age range of 18-25 were selected from among university students of yazd who had normal occlusion and proportional faces with no background of Truma, mandible-face surgery, rhinoplasty or orthodontic treatment. Standard photography of “natural head position” (NHP) and half face position was shot on subjects. Then the facial anthropometric indices were measured directly using a caliper with long jaws. All the photographs were printed out in color, and facial angles were drawn and measured. Acquired data was analyzed using the statistical software of SPSS II.Results: This study shows that that face form in Iranian race is different from that of northern Europeans. The Ala-Ala, Zy'-Zy', Go'-Go' indices, nasofrontal angle, upper and lower lips’ vermilion, facial index, and mandible-face widthes were significantly different from the study on northern European race carried out by Farkas.Conclusion: Considering less cheek (malar) width and more facial index in our study compared to that of Farkas, Iranian samples were more inclined to the dolichofacial form of the face.
Masoud Davoudian
Abstract
Introduction: Cephalometric radiographs have become an indispensable tool in the orthognathic setting. Traditionally, cephalometric images have been analyzed by manually tracing the radiograph, which was time-consuming. The development of computer technology has made digital tracing possible. The purpose ...
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Introduction: Cephalometric radiographs have become an indispensable tool in the orthognathic setting. Traditionally, cephalometric images have been analyzed by manually tracing the radiograph, which was time-consuming. The development of computer technology has made digital tracing possible. The purpose of this study was to examine and compare the reliability and reproducibility of digitization using Viewbox imaging software (version 3.0) with traditional manual technique.Materials and methods: The sample consisted of cephalograms from 30 randomly selected patients after orthodontic treatment. Twenty one cephalometric measurements calculated by 1 operator, both manually and with digital tracing software. Measurement error was assessed for each method by duplicating measurements of 15 randomly selected radiographs and by using Pearson's coefficient of determination. A paired t-test was used to detect differences between the manual and the digital method.Results: An overall greater variability in the digital cephalometric measurements was found. Differences between the two methods for saddle angle, gonial angle, nasolabial angle and upper lip to E line were statistically significant (P<0.05), but the last one showed a mean difference lower than two units.Conclusions: The two tracing methods provide accurate and similar clinical results except for some measurements, especially nasolabial angle; therefore, version 3.0 of this digital cephalometric software can be reliably chosen as a routine diagnostic tool with knowledge of its limited errors.
Masoud Davoudian; Mohammad Hossein Shahpasandzadeh; Mohammad Seif Safari
Abstract
Supernumerary teeth occur in both the deciduous and the permanent dentition. Reported prevalence in permanent and primary dentition is between 1% and 3.5% and between 0.3% and 0.6%, respectively. Supernumerary teeth occur more frequently in the maxilla. The present case is extremely unusual in that a ...
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Supernumerary teeth occur in both the deciduous and the permanent dentition. Reported prevalence in permanent and primary dentition is between 1% and 3.5% and between 0.3% and 0.6%, respectively. Supernumerary teeth occur more frequently in the maxilla. The present case is extremely unusual in that a supernumerary premolar in the right maxilla distal to first molar is functionally erupted but caused impaction of second and third molars.
Rahman Showkatbakhsh; Abdolreza Jamilian; Ladan Eslamian
Abstract
Aim: The main goal of this study was to compare the effects of a differently designed functional appliance (R-appliance) with a bionator treated group in Class II Division I (C1 II Div I) cases.Materials and Methods: 22 patients (12 girls, 10 boys) treated with R-Appliance were selected as experimental ...
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Aim: The main goal of this study was to compare the effects of a differently designed functional appliance (R-appliance) with a bionator treated group in Class II Division I (C1 II Div I) cases.Materials and Methods: 22 patients (12 girls, 10 boys) treated with R-Appliance were selected as experimental group. Control group consisted of 22 patients (11 boys, 11 girls) treated with a bionator. All of the patients had a C1 II Div I malocclusion due to mandibular deficiency. Lateral cephalograms were analyzed at the beginning (T1, T 1) and the end of the study (T 2, T 2).Results: Paired T-test showed that SNB significantly increased in both groups. The same test revealed that IMPA was reduced in the R-appliances treated group by 4.5°±3.5° (P<0.001) but it was increased by 1.9°±3.9° (P<0.03) in the bionator group. Analysis utilizing T-test showed that the inter group difference of IMPA was statistically significant (P<0.01). SNA showed an increase of 0.1°±1.6° (P<0.9) in the R-appliance treated group; while, it was decreased for 0.4°±0.9° (P<0.1) in the bionator treated group.
Conclusions: Both groups were successful in advancement of mandible; however, the R-appliance achieved this result without retroclination of the lower incisors.
Farzin Heravi; Maryam Rezaee
Abstract
Aim: An appropriate occlusal relationship, when there is a significant tooth size discrepancy between the lower and upper dental arches, is impossible. In this way, it is necessary to assess the Bolton's anterior and overall ratios. But it seems too difficult to Measure 24 teeth for each patient routinely. ...
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Aim: An appropriate occlusal relationship, when there is a significant tooth size discrepancy between the lower and upper dental arches, is impossible. In this way, it is necessary to assess the Bolton's anterior and overall ratios. But it seems too difficult to Measure 24 teeth for each patient routinely. in this research our aim was to find an appropriate substitute for the Bolton ratio.
Material and Methods: One hundred pairs of dental casts were selected and the mesiodistal width of each tooth was measured by a sharpened gauge. Then correlation between lateral ratio (mesiodestal width of lower lateral incisors/ upper lateral incisors) and Bolton's anterior ratio (AR) and overall ratio (OR) was evaluated by paired T test and regression models.
Results: Mean overall ratio was 91:3 %, anterior ratio 79.0% and lateral ratio 88.4%correspondingly. No significant difference was found between males and females. A well correlation was found between LR and AR (r=0.70) and OR.
Conclusion: Strong correlation between LR and AR and OR was established. Mean value of 88.4% for LR was correspondent to normal Bolton ratios. (IJO 2006; 1: 53 - 57)
Maryam Poosit; Mohammad Basafa; Farzaneh Ahrari; Amin Reza Movahedian
Abstract
Aim: There is little information about the diagnostic ability of SNB and Facial angles in class II malocclusion. The aim of this study was to evaluate sensitivity and specificity of SNB and Facial angle in diagnosing anteroposterior position of mandible in patients with skeletal class II malocclusion.Material ...
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Aim: There is little information about the diagnostic ability of SNB and Facial angles in class II malocclusion. The aim of this study was to evaluate sensitivity and specificity of SNB and Facial angle in diagnosing anteroposterior position of mandible in patients with skeletal class II malocclusion.Material and Methods: Pretreatment cephalograms of 76 patients with skeletal class II malocclusion were assessed in this study. Sensitivity and specificity of SNB and Facial angles were determined using SPSS and ROC (Receiver Operative Characteristics) curves.Results: Sensitivity and specificity of Facial angle were 61 and 70 percent, respectively. The corresponding values for SNB angle were 40 and 86 percent. The highest sensitivity and specificity for SNB and Facial angles related to 75.5 and 79.5 degrees, respectively.Conclusion: The findings showed that in diagnosing mandibular anteroposterior position of class II patients, Facial angle is more sensitive and SNB angle is more specific. Moreover, it is suggested that in cephalometric analysis, patients with Facial and SNB angles less than 79.5 and 75.5 degree respectively, be assumed to have skeletal class II malocclusion.
