Fig. 4

Anatomic points and linear measurements used in this study. P indicates the tip of the soft palate, C2 the most posterosuperior point on the odontoid process of the axis, C2i the most anteroinferior point on the body of the second cervical vertebra, C4 the most posteroinferior point on the body of the fourth cervical vertebra. 1 SPPS, 2 MPS, 3 IPS