Several classification systems have been proposed especially by Pruzansky (1982), Lauritzen et al (1985), David (1987), Vento et al (1991), and Horgan et al (1995). The most comprehensive classification system is OMENS+ as described by Horgan et al. However, surgeons find the classification of the skeletal deformity by Pruzansky, as modified by Kaban (which is incorporated in OMENS+) to be most useful in practice.
OMENS+ subdivides and grades each of the principal deformities. These are:
O = Orbit
M = Mandible
E = Ear
N = Nerves
S = Soft Tissues
+ = Extra-craniofacial features
Pruzansky subdivides the ear and the mandible deformities.
Mandible
This system has two weaknesses.
• It is possible to have a Pruzansky II with a functioning TMJ but with or without a zygomatic arch and glenoid fossa.
• It is possible to have a Pruzansky III with no condyle and no functioning TMJ with or without a zygomatic arch and a glenoid fossa.
3D-CT enables classification of this condition.
Pruzansky I
Pruzansky I
Pruzansky IIa
Pruzansky IIa
Pruzansky IIb
Pruzansky IIb
Pruzansky III
Pruzansky III