Amir Mohammadi; Saeid Foroughi Moghaddam
Abstract
Aim: Infectious complication which is reduced by chlorhexidine application may contribute to immediate orthodontic miniscrew failure. This study was determined to assess the influence of this agent on miniscrew immediate failure rate.
Materials and Methods: The study sample consisted of 62 miniscrews ...
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Aim: Infectious complication which is reduced by chlorhexidine application may contribute to immediate orthodontic miniscrew failure. This study was determined to assess the influence of this agent on miniscrew immediate failure rate.
Materials and Methods: The study sample consisted of 62 miniscrews inserted in 31 patients that their treatment plan consisted of placing one miniscrew on each side of their maxillary arch between first molar and second molar (2 screws for each patient). Fifteen patients were given a chlorhexidine regimen. Results: In the first six weeks after miniscrew insertion and before their loading 13.33 % of miniscrews in chlorhexidine group failed but the failure rate in non-chlorhexidine group was 6.25 %. According to Fisher's exact test the difference in failure rate was not statistically significant. Also there was no significant relation of failure rate to any category of the measured insertion torques or placement side (left or right) of miniscrews. Conclusion: Using chlorhexidine does not affect the miniscrew immediate failure rate. Also, insertion torque value and placement side (left or right side of the jaw) in the maxilla do not seem to have influence in miniscrew failure rate.
Koroush Taheri Talesh; Javad Yazdani; Amir Mohammadi; Azin Sohrabi; Aydin Sohrabi
Abstract
Introduction: It has been advocated that treatment of dentofacial deformities with jaw osieotomies may influence upper airway morphology, and several studies has shown that mandibular setback surgery has the potential to diminish airway size and alter the hyoid bone position.Objective: The purpose of ...
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Introduction: It has been advocated that treatment of dentofacial deformities with jaw osieotomies may influence upper airway morphology, and several studies has shown that mandibular setback surgery has the potential to diminish airway size and alter the hyoid bone position.Objective: The purpose of this study was to evaluate the effect of mandibular setback on the pharyngeal airway size, and hyoid bone position and to evaluate if a pre-surgical prediction on PAS can be made or not.Materials and methods: Twenty eight pre- and post-operative (3-4 months) lateral cephalograms of 28 individuals (16 females and 12 males older than 17) who had undergone vertical ramus ostetomy setback surgery to correct skeletal class III discrepancies. Cephalograms were traced and a paired-sample t-test was used to evaluate the difference between 11 linear variables pre- and post-operative measurements. Coefficient correlation was calculated for the amounts of setback and the change in airway size.Results: The vertical and horizontal position of hyoid and hyoid-mandible distance do not change significantly. Hyoid-2nd cervical vertebra and hyoid-pogonion distances reduced significantly. In the case of upper airway indicators, the width of pharynx was calculated at 4 different levels. In all 4 levels, statistical analysis revealed significant reduction but the correlation of reduction in the size of pharynx versus amount of setback is not significant (respectively from the most superior width to the most inferior one r=0.15, r=0.13, r=0.09, r=0.19).Conclusion: This study suggested that mandibular setback surgery can decrease the pharyngeal airway size.
