Vento et al developed the OMENS (orbit, mandible, ear, nerve, soft tissue) classification to help describe patients with hemifacial microsomia. This is a condition known by many names including Ocular-Auriculo-Vertebral Spectrum and the First and Second Branchial Arch Syndrome. The OMENS classification is helpful in coding patients for data storage and statistical analysis.
Coding:
(1) The primary letter is in capitals.
(2) The subtype is a numerical subscript.
(3) Since a variety of cranial nerves may be affected, the number for the cranial nerve (5, 7 or 12) is entered as a superscript after the letter and before the subtype.
|
Group |
Description |
Code |
|
O |
normal orbital size and position |
O0 |
|
|
abnormal orbital size |
O1 |
|
|
abnormal orbital position. An additional arrow can be used to indicate the relative position of the affected side (an upward arrow for superior; a downward arrow for inferior) |
O2 |
|
|
abnormal orbital size and position |
O3 |
|
M |
normal mandible |
M0 |
|
|
the mandible and glossoid fossa are small with a short ramus |
M1 |
|
|
mandibular ramus short and abnormally shaped; the glenoid fossa is in anatomically acceptable position with reference to the opposite TMJ |
M2A |
|
|
mandibular ramus short and abnormally shaped; the TMJ is inferiorly, medially and anteriorly displaced, with a severely hypoplastic condyle |
M2B |
|
|
complete absence of ramus, glenoid fossa, and TMJ |
M3 |
|
E |
normal ear |
E0 |
|
|
mild hypoplasia and cupping with all structures present |
E1 |
|
|
absence of external auditory canal with variable hypoplasia of concha |
E2 |
|
|
malpositioned lobule with absent auricle, lobular remnant usually inferiorly and anteriorly displaced |
E3 |
|
N |
no facial nerve involvement |
N70 |
|
|
upper facial nerve involvement (temporal and zygomatic branches) |
N71 |
|
|
lower facial nerve involvement (buccal, mandibular, and cervical branches) |
N72 |
|
|
all branches of the facial nerve affected |
N73 |
|
S |
no obvious soft tissue or muscle deficiency |
S0 |
|
|
minimal subcutaneous tissue or muscle deficiency |
S1 |
|
|
moderate subcutaneous tissue or muscle deficiency |
S2 |
|
|
severe soft tissue deficiency due to subcutaneous and muscular hypoplasia |
S3 |
where:
• Involvement of the trigeminal nerve would be classified N50, N51, etc. (with the 5 a superscript and the 0, 1, etc as subscripts).
Specialty: Genetics
ICD-10: ,
