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.
Behnam Mirzakouchaki; Shirin Shahrbaf; S. Naghinejad Ahmadi
Abstract
Background and aim: Adjusting the retention of orthodontic appliances and the patient’s comfort are important factors for the efficacy of orthodontic treatment using removable appliances. The aim of the present study was to introduce a new technique for adjusting Adams clasp, which is the most ...
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Background and aim: Adjusting the retention of orthodontic appliances and the patient’s comfort are important factors for the efficacy of orthodontic treatment using removable appliances. The aim of the present study was to introduce a new technique for adjusting Adams clasp, which is the most important component involved in the retention of removable appliances, to provide greater retention and patient comfort. Materials and methods: The subjects in the present study consisted of 45 patients referring to the Department of Orthodontics. Four removable maxillary plates were fabricated for each patient. One plate was adjusted from the area of both Adams clasps at overhead areas in the conventional technique. In the three remaining plates, the Adams clasp was bent in the middle area of the bridge under three vertical angles of 8, 15 and 20 degrees. The plates were placed in each patient’s mouth and the retention, overbite change and patient pain scores were determined. Results: The adjustment under a vertical bend of 15° in the middle area of the bridge resulted in maximum retention, followed by 8°, 20° and zero degree (the conventional technique). There were no significantly differences in the mean overbite change values between the four study groups. In addition, mean pain scores did not exhibit significant differences between the four study groups. Conclusion: By creating a bend of 15° in the vertical direction in the bridge area of Adams clasp, the tip of the overheads moved 2 mm toward each other based on trigonometry principles, resulting in maximum retention without increasing patient discomfort.
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.