Table 5 This OMENS form used for this study was adapted from prior studies to enhance usability and optimize complete data collection for clinical studies

Vento, A. R., et al. The O.M.E.N.S. classification of hemifacial microsomia. The Cleft palate-craniofacial journal. 28, 68–76; discussion 77, (1991).

Horgan, J. E., et al..OMENS-Plus: analysis of craniofacial and extracraniofacial anomalies in hemifacial microsomia. The Cleft palate-craniofacial journal: 32, 405–412, (1995).

Gougoutas AJ, Singh DJ, Low DW, Bartlett SP. Hemifacial microsomia: Clinical features and pictographic representations of the OMENS classification system. Plast Reconstr Surg. 2007;120:112e–120e.)

Birgfeld CB, et al. A phenotypic assessment tool for craniofacial microsomia. Plast Reconstr Surg 2011, 127(1):313–320.

Birgfeld CB, et al. Comparison of Two-Dimensional and Three-Dimensional Images for Phenotypic Assessment of Craniofacial Microsomia. Cleft Palate Craniofac J 2012.

Heike CL, et al. Photographic Protocol for Image Acquisition in Craniofacial Microsomia. Head Face Med 2011, 7(1):25.

Malformations of the orbit in CFM commonly include small size, and/or displacement. The appearance of the orbit may be impacted by multiple factors, such as challenges identifying the midline plane in a child with significant facial asymmetry. This rating scale does not distinguish between degree of variation in size or displacement, and some degree of orbital asymmetry is common in the general population.

Adequate classification requires use of a tongue blade; however, the appearance of the tongue blade angle in the photos may not accurately reflect the degree of maxillary asymmetry. The ultimate classification should be based on the rater’s interpretation of the most appropriate angle.

S/p surgery: Mark "yes" if evidence to suggest prior surgery. OK to rate severity on current image, despite history of surgery.

Unable to rate: Mark this category if the tongue blade is not used or not properly positioned and the rater is unable to reliabilty approximate the symmetry of the maxillae.

Mandibular asymmetry is a hallmark of CFM and is classically attributable to hypoplasia of the ramus. Mandibular hypoplasia can be difficult to evaluate on two-dimensional images. Our protocol incorporates multiple views of the mandible to enhance the rater’s ability to characterize the mandible. Mild mandibular asymmetry can be common in the general population.

S/p surgery: Mark “yes” if evidence to suggest prior mandibular surgery. OK to rate on current image, despite history of surgery

Unable to rate: if feature is not well-visualized

CFM is frequently associated with various grades of microtia with or without absence of the external auditory meatus. We have incorporated profile, oblique, and frontal views to allow for assessment of ear size, shape, and position. This system relies on assessment of morphology, and does not account for measurements. Must see all parts of the ear to rate.

S/p surgery: should be used for all instances in which the original appearance of the ear has been modified by surgery. This feature cannot be rated if the ear has been significantly altered surgically.

Unable to rate: applied to all ears in which features (such as the helix) are obscured by hair, or the feature has been signicantly altered surgically

Facial palsies can involve any or all branches of the facial nerve and may be unilateral or bilateral. The photographic protocol includes series of images designed to capture the participant in a neutral expression, and well as animation (following instructions by the photographer) that requires function of each branch of the facial nerve. It can be challenging on images to distinguish between asymmetric movement related to nerve function, and asymmetry that occurs as a result of the underlying structural malformations. Movement does not have to be symmetric to be considered functional. Given the challenges identifying nerve function on a series of static images, we classify “present” if images suggest true paralysis.

S/p surgery: typically unable to determine based on images

Unable to rate: Low threshold for not rating if inadequate images of animation are obtained

Deficiency of the soft tissue is common in CFM. As described for the mandible, capturing soft tissue deficiency and the resultant facial asymmetry can be challenging using a 2D images. For this reason, we’ve included several views of the face to allow for assessment of soft tissue asymmetry.

S/p surgery: Any evidence of scarring that could indicate prior surgery affecting this feature; OK to rate feature with or without evidence of prior surgery

Unable to rate: if feature is not well-visualized

S/p surgery: OK to rate degree based on the location of the scar

Unable to rate: inadequate information to complete the rating with confidence, based on poor image or scarring that is not clearly related to prior cleft repair

S/p surgery: often challenging to identify on images

Unable to rate: Inadequate information to complete the rating with confidence

Typically based on the identification of an asymmetric corneal light reflex

S/p surgery: Not applicable to ratings based on photos

Unable to rate: Can be difficult to assess on photos

Can be difficult to assess on photos, particularly if eyes are not fully open and/or the dermoids have been treated surgically. Artifact on images is also common and may interfere with an accurate assessment

S/p surgery: often challenging to identify on images

Unable to rate: Inadequate information to complete the rating with confidence

Can be challenging to obtain an adequate view of the ear canal on photos. Raters cannot identify ear canal stenosis on photos

S/p surgery: Mark this category if evidence of surgical ear/canal reconstruction

Unable to rate: Mark this category if the rater is unable to determine with certainty the presurgical appearance of the canal

S/p surgery: Mark this category if the rater identifys scars suggesting prior ear or soft tissue surgery in the location of preauricular or facial tags. If the surgical scars are characteristic for preauricular or facial tag removal, OK to also mark “present” and “s/p” surgery for these features.

Unable to rate: if evidence of prior surgery and the rater cannot identify the presurgical state.

S/p surgery: OK to rate degree based on the scar

Unable to rate: Inadequate information to complete the rating with confidence

S/p surgery: OK to rate degree based on the appearance of the scar

Unable to rate: Inadequate information to complete the rating with confidence

Unable to rate: Mark this category if the views are insufficient to confidently classify the morphology of the tongue