Anterior Vibrating Line:
At the junction of immovable hard palate & slightly movable soft palate (cupid bow shape)

RECORDING ANT. VIBRATING LINE:
- During border-molding – short & vigorous “hah”
- Ask the patient to blow through closed nostrils – Valsavan Maneuver
- Soft palate should be depressed & inferior
- Hold head at 30° flexion
- Fox plane angulation – 30°
- While recording soft palate should fall gradually for easy recording

Posterior Vibrating Line: At the junction of slightly movable soft palate & highly movable soft palate
- PPS recording angulation – 30°
- It is a straight line, from one hamular notch to the other
- Anatomically – the junction between aponeurosis of tensor veli palatini & muscular portion of soft palate