The Pterygoid muscles, which move the under jaw forward and backward, do not connect with the larynx, so their action does not compress that organ or in any way impede the action of the vocal apparatus.
"Resonance in Singing and Speaking"
Thomas Fillebrown
Fractures of the angle and through the ramus are less common, and are not attended with deformity, as the fragments are retained in position by the masseter and internal Pterygoid muscles.
"Manual of Surgery Volume Second: Extremities--Head--Neck. Sixth Edition."
Alexander Miles Alexis Thomson
When the fracture is unilateral, the broken condyle is tilted inwards and forwards by the external Pterygoid, and can be palpated from the mouth, while the rest of the jaw is displaced towards the affected side, and not away from it, as happens in unilateral dislocation.
"Manual of Surgery Volume Second: Extremities--Head--Neck. Sixth Edition."
Alexander Miles Alexis Thomson