en orthodontic orthodontic Original article Original article <div> <table align="center" hspace="0" vspace="0"> <tbody> <tr> <td style="padding: 0cm 12px; text-align: justify;" valign="top"><span style="font-size:13pt"><span new="" roman="" style="font-family:" times=""><b><span style="font-size:9.0pt"><span style="font-family:" verdana=""><span style="color:#2e74b5">Background and Aim</span></span></span></b><b><span style="font-size:9.0pt"><span style="font-family:" verdana=""><span style="color:#2e74b5">:</span></span></span></b> <span style="font-size:9.0pt"><span style="font-family:" verdana="">The bite force changes due to alterations in the lever system of the jaw following orthognathic surgery. This study aimed to assess the changes in the maximum bite force of skeletal Class II patients between 18-30 years after orthognathic surgery compared with the preoperative state. </span></span></span></span><br> <span style="font-size:13pt"><span new="" roman="" style="font-family:" times=""><b><span style="font-size:9.0pt"><span style="font-family:" verdana=""><span style="color:#2e74b5">Materials and Methods: </span></span></span></b><span style="font-size:9.0pt"><span style="font-family:" verdana="">This inception cohort study evaluated 17 patients with skeletal Class II malocclusion (mandibular deficiency) and normal vertical dimension between 18-30 years who underwent mandibular advancement surgery. The maximum bite force on the mandibular first molars was measured preoperatively and at 6 weeks, and 3 and 6 months, postoperatively. The overjet and overbite were also measured on diagnostic casts. Data were analyzed by the Shapiro-Wilk test, Mauchly&rsquo;s test, the Greenhouse&ndash;Geisser correction, and the Spearman and Pearson&rsquo;s correlation coefficients.&nbsp; </span></span></span></span><br> <span style="font-size:13pt"><span new="" roman="" style="font-family:" times=""><b><span style="font-size:9.0pt"><span style="font-family:" verdana=""><span style="color:#2e74b5">Results: </span></span></span></b><span style="font-size:9.0pt"><span style="font-family:" verdana="">The mean maximum bite force preoperatively was significantly higher than that at 6 weeks (P<0.001), 3 months (P<0.001), and 6 months (P<0.001), postoperatively. No significant difference was noted in the mean bite force in the right and left sides of the jaw (P=0.589). The overbite and maximum bite force were not significantly correlated in the right (P=0.181) or the left (P=0.134) side, preoperatively. The overjet had no significant correlation with the maximum bite force in the right (P=0.881) or the left (P=0.677) side, preoperatively.</span></span></span></span><br> <span style="font-size:13pt"><span new="" roman="" style="font-family:" times=""><b><span style="font-size:9.0pt"><span style="font-family:" verdana=""><span style="color:#2e74b5">Conclusion:</span></span></span></b> <span style="font-size:9.0pt"><span style="font-family:" verdana="">Mandibular advancement surgery in skeletal Class II patients with mandibular deficiency decreases the maximum bite force in the first 6 months, postoperatively. </span></span></span></span></td> </tr> </tbody> </table> </div> <div style="text-align: justify;"></div> Malocclusion, Angle Class II, Bite Force, Mandibular Osteotomy, Micrognathism 236 242 http://jrdms.dentaliau.ac.ir/browse.php?a_code=A-10-980-1&slc_lang=en&sid=1 Golnoosh Golestaneh golestanehgolnoosh@gmail.com 100319475328460011551 100319475328460011551 No Department of Endodontics, School of Dentistry, Shahid Sadoughi University of Medical Sciences, Yazd, Iran Mehdi Rafiei mehdi.rafiei@khuisf.ac.ir 100319475328460011552 0000000216116193 Yes Department of Orthodontics, Faculty of Dentistry, Islamic Azad University, Isfahan (Khorasgan) Branch, Isfahan, Iran Arash Golestaneh drgolestaneh@gmail.com 100319475328460011553 100319475328460011553 No Department of Oral & Maxillofacial Surgery, Faculty of Dentistry, Islamic Azad University, Isfahan (Khorasgan) Branch, Isfahan, Iran