Mohsen Shirazi; Armin Soudi; Pedram Baghaeian; Yasamin Farajzadeh Jalali
Abstract
Background: The aim of this study was to investigate the crystal structure of mineral part in the Compact and Cancellous bones in different areas of alveolar bones.
Methods: In this study, 7 alveolar bone samples were prepared from buccal and distal plates of the jaws of three patients, and 4 samples ...
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Background: The aim of this study was to investigate the crystal structure of mineral part in the Compact and Cancellous bones in different areas of alveolar bones.
Methods: In this study, 7 alveolar bone samples were prepared from buccal and distal plates of the jaws of three patients, and 4 samples from Cortical and Cancellous bone of two other patients' palate. After converting all the samples into powder, the samples were examined by using the X-RD method. Diffractogram of 1-7 samples were compared with each other and Diffractogram of 8-11 samples also were compared with each other too. Results: Comparing two corresponding points in the jaws the crystallinity degree in the mandible is higher than the maxilla. In comparison of two corresponding points in the maxilla and mandible degree of crystallinity and the crystalline hydroxyapatite on the right has been more than on the left. The amount of crystalline hydroxyapatite phase in females is more than males and crystallinity degree of this phase in males is more than females, and in younger people, the hydroxyapatite crystalline phase is more than others and crystallinity of this phase in older subjects is higher than others.
Conclusions: Tooth movement, despite the influence of the same forces, is faster on left side than the right side and is faster on maxilla than mandible. Tooth movement is faster in younger people than in older subjects.
Navid Naseri; Pedram Baghaeian; Maryam Javaherimahd; Fatemeh Gorjizadeh
Abstract
Background: It has been proved that, there's craniofacial asymmetry but much of this skeletal asymmetries are clinically ignorable. This asymmetry may exist in teeth size arranged in right and left sides of human mouth too. Orthodontists should pay attention to bilateral tooth asymmetry in treatment ...
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Background: It has been proved that, there's craniofacial asymmetry but much of this skeletal asymmetries are clinically ignorable. This asymmetry may exist in teeth size arranged in right and left sides of human mouth too. Orthodontists should pay attention to bilateral tooth asymmetry in treatment planning stage.
Objectives: This study was conducted to demonstrate whether the difference between size of left and right side teeth is actual. Materials and Methods: A total of 200 plaster dental molds were used which were collected from a private practice in Tehran. A caliper with accuracy of 0.01 mm was used for measuring teeth and most teeth were measured twice and the average value was considered as the teeth size. In all cases, the Vernier calipers jaws were moved along the teeth longitudinal axis and the biggest width was measured in the contact point area. Results: In average 83.16% of left and right teeth in upper jaw and 83.66% of left and right teeth in the lower jaw were not symmetrical and teeth in the upper and lower jaws were completely similar 16.84% and 16.34%, respectively.
Conclusions: The result of the study showed that nearly 83% of teeth in maxilla and mandible are asymmetric in mesiodistal width. Mandibular second molar and canine showed the highest and lowest bilateral asymmetry respectively.