en Clinical Medicine Clinical Medicine مقاله پژوهشی Original Research Article <span style="font-size:10pt"><span new="" roman="" style="font-family:" times=""><b><span style="font-size:9.0pt"><span style="background:#2d7f8f"><span style="color:white">Background & Objective:</span></span></span></b><b> </b><b>&nbsp;</b><span style="font-size:9.0pt"><span style="color:black">Class II malocclusion is one of the most common types of malocclusion, and if untreated, can lead to speech and health problems, temporomandibular discomfort, trauma risk to maxillary incisors, and psychological issues. Early treatment with appliances like Maxillary splint headgear (MSH) or Twin block can, therefore, be highly impactful. The present study aimed to compare the effects of MSH and Twin block on cephalometric landmarks to make an informed decision for optimal treatment planning. </span></span></span></span><br> <span style="font-size:10pt"><span new="" roman="" style="font-family:" times=""><b><span style="font-size:9.0pt"><span style="background:#2d7f8f"><span style="color:white"><span style="letter-spacing:-.1pt">&nbsp;Materials & Methods:</span></span></span></span></b> &nbsp;<span style="font-size:9.0pt"><span style="color:black"><span style="letter-spacing:-.1pt">The research comprised sixteen patients treated with a maxillary headgear splint and sixteen patients treated with a Twin block, and lateral cephalometric radiographs were evaluated before and after treatment. These two groups were compared due to orthodontic parameters using an independent t-test or Mann-Whitney test.</span></span></span></span></span><br> <span style="font-size:10pt"><span new="" roman="" style="font-family:" times=""><b><span lang="EN-IN" style="font-size:9.0pt"><span style="background:#2d7f8f"><span style="color:white">Results: </span></span></span></b><b>&nbsp;</b><span style="font-size:9.0pt"><span style="color:black"><span style="letter-spacing:-.1pt">The results indicate that age and gender had no effect on the final treatment outcome. No significant differences were observed in cephalometric parameters (<i>P</i>>0.05) except for pre-treatment &quot;ANB&quot; and &quot;Lip Competency at rest,&quot; which were higher in the MSH group (<i>P</i>=0.035 and 044, respectively). </span></span></span><span dir="RTL" lang="FA" style="font-size:9.0pt"><span style="color:black"><span style="letter-spacing:-.1pt"></span></span></span></span></span><br> <span style="font-size:10pt"><span new="" roman="" style="font-family:" times=""><b><span style="font-size:9.0pt"><span style="background:#2d7f8f"><span style="color:white">Conclusion: </span></span></span></b><b>&nbsp;</b><span style="font-size:9.0pt"><span style="color:black">MSH and Twin block are equally effective in treating Class II malocclusion.</span></span></span></span><br> &nbsp; Extraoral Traction Appliances – Functional Orthodontic Appliance – Removable Orthodontic Appliance – Malocclusion Class II 397 404 http://journal.zums.ac.ir/browse.php?a_code=A-10-7070-1&slc_lang=en&sid=1 Sheida Shafiee Sheida98sh@gmail.com 5200319475328460082271 5200319475328460082271 No School of Dentistry, Zanjan University of Medical Sciences, Zanjan, Iran Sina Mohammadzadeh sinamohammadzadeh1377@gmail.com 5200319475328460082272 5200319475328460082272 No School of Dentistry, Zanjan University of Medical Sciences, Zanjan, Iran HasaanAli Shafiee Hashfriee@yahoo.com 5200319475328460082273 5200319475328460082273 No Department of Orthodontics, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran Anahita Dehghani Soltani Anahita_dehghani@yahoo.com 5200319475328460082274 5200319475328460082274 No Department of Orthodontics, School of Dentistry, Shahid Beheshti University of Medical Science, Tehran, Iran Farzane Ahmadi ahmadi.farzane@zums.ac.ir 5200319475328460082275 5200319475328460082275 No Department of Biostatistics and Epidemiology, Faculty of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran Azin Nourian azin.nourian@gmail.com 5200319475328460082276 5200319475328460082276 Yes Department of Orthodontics, School of Dentistry, Zanjan University of Medical Sciences, Zanjan, Iran