Abstract
CGL was performed on thirty adults who complained of sleep disorder. We studied the following six items by head and neck X-ray before and after CGL. The results are shown parentheses at the end of each item.
1) The shortest vertical length between the hyoid bone and mandible (+10.3mm)
2) Vertical length between the hyoid bone and the tangent of C2-4 (+4.6mm)
3) The shortest length between the hyoid bone and the chin (+2.9mm)
4) The angle of the hyoid bone and the tangent of C2-4 (+3.3 degrees)
5) The length of H-M (H is an intersection of a tangent of C2-4, vertical from the hyoid bone. M is an intersection of a tangent of C2-4 and mandibular.) (+7.4mm)
6) Width of the narrowest part of the hypopharynx (+3.0mm)
Every items showed a significant difference between before and after the CGL, (p<0.05).
After the operation, the hyoid bone moved downward and the cranial bone rotated forward. As a result, the hypopharynx and the oropharynx expanded. Expansion of the hypopharynx calculated that the resistance of flow decreased, whereas the airflow increase.
