fa Three-dimensional changes of the hyoid bone and airway volumes related to its relationship with horizontal anatomic planes after bimaxillary surgery in skeletal Class III patients ارتودنسی Orthodontics پژوهشي Research <p> <strong>Objective:</strong></p><p>  To evaluate longitudinal changes of the hyoid bone position and pharyngeal airway space after bimaxillary surgery in mandibular prognathism patients. </p><p> <strong>Materials and Methods:</strong></p><p>  Cone-beam computed tomography scans were taken for 25 mandibular prognathism patients before surgery (T0), 2 months after surgery (T1), and 6 months after surgery (T2). The positional displacement of the hyoid bone was assessed using the coordinates at T0, T1, and T2. Additionally, the volume of each subject's pharyngeal airway was measured. </p><p> <strong>Results:</strong></p><p>  The mean amount of posterior maxilla impaction was 3.76 ± 1.33 mm as the palatal plane rotated 2.04° ± 2.28° in a clockwise direction as a result of bimaxillary surgery. The hyoid bone moved backward (P < .05, P < .001) and downward (P > .05, P < .05) at 2 months and 6 months after surgery, while the total volume of the pharyngeal airway significantly decreased at the same time points (P < .001, P < .001). There was significant relationship between the changes of the hyoid bone position and airway volume at 2 months after surgery (P < .05). The change of the palatal plane angle was positively correlated to the decrease in the total airway volume (P < .001). </p><p> <strong>Conclusions:</strong></p><p>  The null hypothesis was rejected. The hyoid bone moved inferoposteriorly, and the pharyngeal airway volume decreased for up to 6 months after bimaxillary surgery. The decrease in the pharyngeal airway volume was correlated to the changes in the palatal plane inclination and the positional change of the hyoid bone. </p><hr><p></p><p> <strong>Source: </strong>The Angel Orthodontists</p><p><a href="http://www.angle.org/doi/abs/10.2319/083112-700.1" target="_blank"><font color="#0000ff"> Full Text</font></a></p> Hyoid bone, Pharyngeal airway, Orthognathic surgery, Skeletal Class III malocclusion, CBCT 0 0 http://idai.ir/browse.php?a_code=A-10-32-1990&slc_lang=fa&sid=1 Min-Ah Kim 10031947532846009344 10031947532846009344 No Department of Orthodontics, Kangdong Sacred Heart Hospital, Hallym University Medical Center, Seoul, Korea Bo-Ram Kim 10031947532846009345 10031947532846009345 No Department of Orthodontics, Kangdong Sacred Heart Hospital, Hallym University Medical Center, Seoul, Korea Jin-Young Choi 10031947532846009346 10031947532846009346 No Graduate School of Hallym University, Seoul, Korea Jong-Kuk Youn 10031947532846009347 10031947532846009347 No Graduate School of Hallym University, Seoul, Korea Yoon-Ji R.Kim 10031947532846009348 10031947532846009348 No Department of Orthodontics, Kangdong Sacred Heart Hospital, Hallym University Medical Center, Seoul, Korea Yang-Ho Park dentpark64@hanmail.net 10031947532846009349 10031947532846009349 Yes Department of Orthodontics, Kangdong Sacred Heart Hospital, Hallym University Medical Center, Seoul, Korea