The position of the hyoid bone is related to vi- tal functions. The aim of this research was to analyze the change in the position of the hyoid bone related to the surgical movement in orthognathic surgery. 52 subjects were included; the diagnosis was determined according to facial analysis, being identified as class II or class III facial deformity. The subjects were treated by maxillary and mandibular surgery without chin surgery; cone beam computed tomography were realized pre-surgical and post-surgical to perform the analyses. Statistical studies was according to the type of va- riable considering a value of p<0.05 to obtain significant differences. The results demonstrated changes in the position of the hyoid bone at different levels; in class II subjects a significant change was observed in the vertical position of the hyoid bone and there was a rise of 4.45 mm (p=0.001); in class III subjects, no significant relationships were observed in terms of horizontal or vertical position. The transverse distance showed significant changes, reducing by 3.62 mm in the post-surgical stage (p=0.008). It is possible to conclude that orthognathic surgery causes changes in the location of the hyoid bone.

KEY WORD: Hyoid bone, orthognathic surgery, osteotomy

According to the American Academy of Cranio-Maxillo-Facial Surgeons (AACMFS: American Academy of Cranio-Maxillo-Facial Surgeons, visit: https:/ /aacmfs.org/), reconstructive surgery implies surgery that seeks to rebuild, restore, or return to normality the hard and soft tissues of the cranio-maxillo-facial region that have become abnormal, dysfunctional or deformed due to an event. This event may be caused by trauma, tumor resection, or the result of a disease process. Cranio- maxillo-facial reconstructive surgery (including oral and dental) returns almost to normal those tissues and structures/body parts that were previously within the normal range, before the event. This contrasts with aesthetic and cosmetic surgery, for example, which seeks to improve an already normal facial or body appearance (also performed by some cranio-maxillo-facial surgeons). Therefore, reconstructive surgery is an integral part of cranio-maxillo-facial surgery and encompasses a wide range of interventional surgical procedures. Here, to rehabilitate patients with bone defects of critical size, for example, surgical reconstructions are required. However, surgical techniques are not enough. Successful bone reconstruction in the oral and maxillofacial region, using modern bone tissue engineering techniques, is applicable but requires innovative future research focusing on cells, grafts, growth factors, signaling pathways, and defect improvement. , as well as the vascularization of the graft. This brief communication attempts to provide some critical insights, highlighting recent advances, challenges and opportunities for research, development and innovation in this ever-growing and impactful area (quality of life) with a focus on system engineering. craniofacial bone tissue.