Impact of Twin Block and Motion Class II Appliances on Hyoid Bone Position - A Retrospective Clinical Study

All patients were submitted to preoperative and postoperative lateral teleradiography (Vatech D052SB, Puteaux, France), with the following exposure parameters: 75KV, Intensity10mA, exposition times 11s28, 112,8 mAs, using the Frankfort plane as reference parallel to the floor; moreover, patients were required to avoid moving and swallowing. Afterwards, digital datasets were uploaded and aligned into a digital therapeutic planning software (Orthalis®, Orqualceph®,group orqual) to accurately record the position changes of the hyoid bone at horizontal, vertical, and angular level, according the gender, facial biotype and airway complex, by measuring the following anatomical references: