fa Effectiveness of twin-block and Mandibular Protraction Appliance-IV in the improvement of pharyngeal airway passage dimensions in Class II malocclusion subjects with a retrognathic mandible ارتودنسی Orthodontics پژوهشي Research <p> <strong>Objective:</strong></p><p>  To test the hypothesis that twin-block and Mandibular Protraction Appliance-IV (MPA-IV) are not effective in improving the pharyngeal airway passage (PAP) dimensions among Class II malocclusion subjects with a retrognathic mandible. </p><p> <strong>Materials and Methods:</strong></p><p>  Eighty-three subjects ranging in age from 8 to 14 years were divided into four groups. Group I included 30 Class I malocclusion subjects (healthy controls) group II consisted of 16 Class II malocclusion subjects (Class II controls) group III had 16 subjects in whom Class II malocclusion was treated by MPA-IV and the remaining 21 subjects formed group IV, whose Class II malocclusions were corrected by twin-block appliance. Lateral cephalograms recorded at the beginning of orthodontic treatment in group I subjects and at the beginning and end of follow-up/treatment with functional appliance in group II, III, and IV subjects were analyzed to determine the PAP dimensions. Paired t-test, one-way analysis of variance, and Tukey tests were applied for statistical analysis, and a P-value .05 was considered statistically significant.</p><p> <strong> Results:</strong></p><p>  Soft palate length was decreased significantly in group III (P < .05) and group IV (P < .001) subjects. Soft palate thickness in group IV subjects was increased significantly as compared to group II (P < .05) and group III (P < .01) subjects. The improvement in soft palate inclination in group III and group IV subjects was significant (P < .01). The oropharynx depth was increased significantly in group III (P < .05) and group IV (P < .001) subjects. The depth of the hypopharynx was increased significantly (P < .01) in group IV subjects. </p><p> <strong>Conclusions:</strong></p><p>  The twin-block appliance was more efficient than the MPA-IV in the improvement of PAP dimensions among Class II malocclusion subjects with retrognathic mandible. </p><hr><p></p><p> <strong>Source: </strong>The Angel Orthodontists</p><p><a href="http://www.angle.org/doi/abs/10.2319/083112-702.1" target="_blank"><font color="#0000ff"> Full Text</font></a></p> Functional appliance, Twin-block, Mandibular Protraction Appliance, Pharyngeal airway passage 0 0 http://idai.ir/browse.php?a_code=A-10-32-2006&slc_lang=fa&sid=1 Ashok Kumar Jena ashokkjena@yahoo.co.in 10031947532846009415 10031947532846009415 Yes Unit of Orthodontics, Oral Health Sciences Centre, Post Graduate Institute of Medical Education and Research, Chandigarh, India Satinder Pal Singh 10031947532846009416 10031947532846009416 No Unit of Orthodontics, Oral Health Sciences Centre, Post Graduate Institute of Medical Education and Research, Chandigarh, India Ashok Kumar Utreja 10031947532846009417 10031947532846009417 No Unit of Orthodontics, Oral Health Sciences Centre, Post Graduate Institute of Medical Education and Research, Chandigarh, India