Pruzansky IIa is a more severe subtype characterized by:
A small deformed hemi-mandible with a small ramus, pronounced antegonial notch and asymmetry of the chin (displaced to the affected side).
A hypoplastic TMJ with the glenoid fossa in an acceptable functional and anatomical position, that is approximately equidistant from the midline as the normal side but generally at a lower level.
Occlusal cant upwards on the affected side. Varying degrees of severity will be observed. The occlusion may be class I, II or III, but the class II pattern predominates.
In addition to the above, the following may be found:
Every range of ear presentation is possible from a completely normally shaped and positioned external ear with normal middle ear and inner ear structures and normal hearing all the way through to complete anotia with conduction hearing loss.
The position of the orbit and the eye on the affected side can be normal but varying degrees of vertical and horizontal dystopia can occur. Microphthalmia and anophthalmia can also occur.
The soft tissues on the affected side of the face can exhibit a range of severity from effectively normal to severely hypoplastic or absent.
The branches of the facial nerve on the affected side can function completely normally but can also show a varying range of reduced function (palsy) from mild to severe and affecting one or more of the nerve branches.