Table 1 Craniocervical posture measurement items and their definitions
| Â | Measuring items | Definition |
|---|---|---|
Linear Measurement | Ba-C3ia | The distance from the lowest anterior point of the third cervical vertebra (C3ia) to the midpoint of the anterior edge of the foramen magnum (Ba) |
C0-C1 | The distance from the base of occipital bone (C0) to posterior arch of atlas (C1) | |
C1-C2 | The distance from the posterior arch of the atlas (C1) to the spinous process of the second vertebra (C2) | |
Angular Measurement | NSL-CP | The angle between cervical vertebra plane (CP) and anterior skull base plane (NSL) |
NSL-OPT | The angle between the odontoid tangent (OPT) and the anterior skull base plane(NSL) | |
NL-OPT | The angle between the odontoid tangent (OPT) and the palatal plane (NL) | |
FH-OPT | The angle between the odontoid tangent (OPT) and Frankfort horizontal plane (FH) | |
ML-OPT | The angle between OPT and mandibular plane (ML) | |
RL-OPT | The angle between the odontoid tangent (RL) and the mandibular ramus (RL) | |
NSL-C2 | The anterior superior angle between the anterior skull base plane (NSL) and the tangent line (C2) of the lower edge of the second cervical vertebra | |
MGP-OP | The posterior-inferior angle of the intersection of the McGregor plane (MGP) and the odontoid plane (OP) |