Postoperative Change in the Positional Relationship between the Mandible and the Hyoid Bone in Patients with Mandibular Protrusion following Mandibular Osteotomy
2004 Volume 14 Issue 2 Pages 122-130
Details
2004 Volume 14 Issue 2 Pages 122-130
The purpose of this study was to clarify the positional relationship among the mandible, hyoid bone and cervical vertebrae in patients with mandibular protrusion.
Pre-and post-treatment records, including both CT images, of 11 patients were used to generate 12 angular measurements, to study the relationship among the mandible, hyoid bone and cervical vertebrae. Using a submental view of reconstructed 3DCT images obtained by CT data, an imaginary reference line was created perpendicular to the midpoint of a line tangential to the anterior borders of the right and left foramen ovale.
The results were as follows:
At the stage of pre-surgery, there was a positive correlation between the true mandible deviation and the long axis of the cervical vertebra. There was also a strong negative correlation between the true mandible deviation and the difference of the right and left axis of the mandible and cornu majus.
At the stage of post-surgery, there was a strong correlation between the angle of cornu majus change and the true mandible deviation, and the difference of the right and left axis of the mandible.
In conclusion, the results suggested that the positional relationship among the mandible, the hyoid bone, and cervical vertebrae tended to deviate in the same direction in patients with mandibular protrusion at the preoperative stage and that the cornu majus changed in the same direction as the mandible when mandibular osteotomy followed.
