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)
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 )
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)
Bahman Seraj; Hoorieh Bashizadeh; Arghavan Tonkaboni; Mohsen Shirazi
Abstract
Background and Aim: Assessment of skeletal maturity is an integral part of interceptive diagnosis and treatment planning. The present method of skeletal maturity assessment like handwrist or cervical vertebrae radiographies are expensive, require elaborate equipment and account for high radiation exposure, ...
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Background and Aim: Assessment of skeletal maturity is an integral part of interceptive diagnosis and treatment planning. The present method of skeletal maturity assessment like handwrist or cervical vertebrae radiographies are expensive, require elaborate equipment and account for high radiation exposure, especially for growing children. This study tried to consider the value of the 2nd primary molar in growth stage.
Material and Method: 40 samples aged 8-13 were tested by their panoramic and handwrist radiographs.
Result and Conclusion: there was a coincidence between presence calcified sesamoid and 2nd primary molar as the last tooth. The result showed that it could be a reliable index to predict the growth stage in 1st visit without radiography. (IJO 2006; 1: 58 - 60)
Fariborz Amini; Reyhaneh Hedayat
Abstract
Aim: The main goal of this research was to evaluate the sagittal and vertical effects of Hyrax (tooth born) and Haas (tooth-tissue born) rapid palatal expanders on dentoskeletal structures of patients with maxillary constriction characterized by bilateral posterior cross bite.
Materials and methods: ...
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Aim: The main goal of this research was to evaluate the sagittal and vertical effects of Hyrax (tooth born) and Haas (tooth-tissue born) rapid palatal expanders on dentoskeletal structures of patients with maxillary constriction characterized by bilateral posterior cross bite.
Materials and methods: A nonrondomized clinical trail of 22 patients 12 to 14 years old (mean age 12.5 years) with maxillary constriction, who were divided into two groups, was undertaken. Group-I consisted of 11 patients who received treatment by Hyrax type rapid palatal expander (RPE). Group- II composed 0111 patients who received treatment by Haas RPE. Two lateral cephalograms were taken, one before and the other after the palatal cusps of the upper posterior teeth reached the buccal cusps of lower posteriors consequent to expansion. The activation period lasted from 12-16 days with a mean value of 13.5 days. On each lateral cephalogram 8 linear and 10 angular parameters were measured, recorded and compared to a nearest of 0.5 mm and 0.5 degree respectively. Statistical analyses were performed using Kolomogrovsmirnov and paired t-test. A student t-test was used for comparison of two group.
Results: In both groups significant increases in lower anterior facial height were observed. The value (ANS-ME) was increased 1.30mm in Hyrax (P=0.009) and 1.80mm in Haas group (P=0.032). Statistically neither of the appliances showed a significant effects on sagital position of the maxilla. The mandible was rotated downward and backwards. SNB angle decreases 0.65 and 0.43 degrees in Hyrax and Haas group respectively. ANB angle was increased by means of 0.60 degree (p= 0.030) in Hyrax and 0.53 degree (p=0.08) in Haas group.
Conclussion: The maxilla kept its position sagitally, pre to post treatments, but showed inferior displacement in both groups. The mandible displayed a tendency to rotate downward and backward in both groups. Upper anteriors tipped palatally. (IJO 2006; 1: 61 - 65)
Amirfarhang Miresmaeili; Aliasghar Soleimani
Abstract
Aim: Malocclusion may be caused by tooth size discrepancy and it is impossible to achieve perfect treatment results without regarding this etiologic factor. The aim of present study was to determining and comparing the mesiodistal width of permanent teeth in normal occlusion group and patients with class ...
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Aim: Malocclusion may be caused by tooth size discrepancy and it is impossible to achieve perfect treatment results without regarding this etiologic factor. The aim of present study was to determining and comparing the mesiodistal width of permanent teeth in normal occlusion group and patients with class 1 crowding malocclusion in Hamedan.
Material and Method: Based on Andrews normal occlusion criteria among 3335 students of Hamedan pre-university schools 32 persons were selected as normal group. In matched sex and range of age , 32 patients with class 1 crowding malocclusion were selected from a private office . Orthodontic dental casts of all samples were prepared. Mesiodistal width of all teeth (except 2nd molars), overbite, over-jet and Bolton indices were measured 3 times. Student t test and Mann whiteny u test were used for analysis.
Results: In crowding group the mesiodistal width of all teeth except for the first molars, were significantly greater than normal group specially in upper lateral incisors and lower premolars. Maxillary tooth material was 5.3 millimeter (p=0.0005) and mandibular tooth material was 5.4 millimeter (p=0.0036) greater in crowding patients. In crowding patients, overjet was significantly less and overbite was significantly more than normal group (p=0.0001) There was not significant difference in Bolton index between 2 groups.
Conclusion: It seems there is more crowding tendency in cases with large teeth. According to results. Bolton discrepancy (tooth size discrepancy) cannot be considered as a frequent factor in developing class 1 crowding. 2006; 1: 66 - 69)
Allahyar Geramy
Abstract
Aim: Introduction of new bracket designs in market and use with a range of inciso-apical dimension and base thickness arises a question in mind as "Is it necessary to standardize various bracket bases from torque delivery efficiency?"
Materials and Methods: Two bracket bases of different incio-apical ...
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Aim: Introduction of new bracket designs in market and use with a range of inciso-apical dimension and base thickness arises a question in mind as "Is it necessary to standardize various bracket bases from torque delivery efficiency?"
Materials and Methods: Two bracket bases of different incio-apical dimension (3 and 6 mm.) and also two different base thicknesses (1.6 and 3.5 mm.) were modeled and moments were applied. All displacements along a defined incio-apical path were monitored to be evaluated.
Results and Conclusion: No difference was found between the displacements along the defined path in each phase of study. In this way, it was concluded that torque delivery of different brackets is not related to their base size (inciso-apical) and dimenson which is in complete agreement and confirmation of the principle of free vectors. (IJO 2006; 1: 71 - 74)
Nasrin Farhadian; Amir H. Momeni
Abstract
Aim: Everyday because of developing new materials and techniques, more adults become interested in orthodontic treatments. Soft positioner and its new generation in the name of Invisalign System is an example. The present case report was designed to study the effects of soft elastic foils as serial aligners ...
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Aim: Everyday because of developing new materials and techniques, more adults become interested in orthodontic treatments. Soft positioner and its new generation in the name of Invisalign System is an example. The present case report was designed to study the effects of soft elastic foils as serial aligners on treat-ing the mild to moderate crowding.Materials and Method: Three teenage patients with crowding not more than 6 millimeters were select-ed. After the preparation of orthodontic diagnostic records and filling the periodontal chart, manual teeth setup was carried out on working casts with a maximum 0.5 millimeter displacement. Aligners were made up of bioplast foils. The appliance was worn by patient full time for at least 2 weeks. Then the new one was made and this procedure was continued until complete tooth alignment. The last aligner was used as retainer for three months later. These variables were evaluated after treatment : dental alignment , over jet . overbite, inclination of upper & lower incisors, lips relation to E line, mandibular plan angle, clicking in TMJ, periodontal status and tooth pain. Active treatment period lasted between 3-5 months.Results: Anterior crowding was completely corrected in all patients. Protrusion of upper & lower incisors were seen in lateral cephalograms. Overbite, mandibular plan angle and lips relation to E line did not change. Improvement of periodontal status were recorded in all patients. Low to moderate toothache was reported during the first 2 days .Conclusion: Mild to moderate crowding could be corrected successfully with soft elastic foils (Serial Aligners) without deleterious effects on TMJ and periodontium however manual tooth setup was time consuming. (IJO 2006; 1: 75 - 78)
Faramarz Mojtahedzadeh
Hossein Ravanmehr; Amir Hossein Mirhashemi; Allahyar Geramy; Ahmad Sodagar
Ahmad Sodagar; Allahyar Geramy; Ehsan Karimian
