S. NaghiNejad Ahmadi; Mojgan Kochoei
Abstract
Aim: Orthodontic mini-implants have been incorporated into orthodontic treatment modalities. Adequate bone at mini-implant placement site can influence the success or failure of anchorage. The aim of the present study was to determine the thickness of bone in the maxillary mid-palatal area at predetermined ...
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Aim: Orthodontic mini-implants have been incorporated into orthodontic treatment modalities. Adequate bone at mini-implant placement site can influence the success or failure of anchorage. The aim of the present study was to determine the thickness of bone in the maxillary mid-palatal area at predetermined points for the placement of orthodontic mini-implants using Cone Beam CT technique in order to evaluate the relationship of these values with the facial height.
Materials and methods: A total of 161 patients, consisting of males (39.32%) and females (60.86%), were evaluated in the present study, 38% of the subjects had normal facial height, 29% had short face and 33% had long face. In order to determine which patient belonged to which facial height category, i.e. normal, long or short, two angular and linear evaluations were used: the angle between S-N and Go-Me lines and the S-Go to N-Me ratio. Twenty points were evaluated in all the samples. First the incisive foramen was located. The para-coronal cross-sections were prepared at distances of 4, 8, 16 and 24 mm from the distal wall of the incisive foramen and on each cross-section the mid-sagittal and para-sagittal areas were determined bilaterally at 3- and 6-mm distances (a total of 5 points). The thicknesses of the bone were determined at the predetermined points. Results: Statistical analysis did not show significant differences between three different facial height groups at none of the 20 points.Conclusion: The present study did not find any relationship between palatal bone thickness and facial height. Further studies with larger sample size are necessary to evaluate the relationship between the thickness of bone and facial height.
Mostafa Shahabi; Farzin Heravi; Naser Firoozi
Abstract
Aim: Some cphalometric angles change during growth and in accordance with facial height and other 'facial landmarks which make it less reliable for orthodontic diagnosis. The purpose of this study was to find out relationship between Beta Angle and the anterior-posterior position of jaws.
Materials ...
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Aim: Some cphalometric angles change during growth and in accordance with facial height and other 'facial landmarks which make it less reliable for orthodontic diagnosis. The purpose of this study was to find out relationship between Beta Angle and the anterior-posterior position of jaws.
Materials and Method: Sixty lateral cephalograms of 16 boys and 44 girls with class I, H or HI malocclusions were evaluated in our study. we traced all of the cephalograms to measure Beta angle and compare these values between different types of malocclusions. Data were annalized by means of T-student statistical test.
Results: Beta angle was 28.5° - 37.5° for class 1, less than 28.5° for class II and more than 37.5° for class III. There was no correlation between t3 angle and facial height.
Conclusion: Beta angle is independent from facial height. Beta Angle has an acceptable specificity and sensitivity for determining the anterior posterior position of Jaws (IJO 2006; 1: 184-7).