abnormal facial muscle morphology abnormal levator nasolabialis muscle morphology 2017-11-23T13:51:58Z any structural anomaly of the flat, thin muscle lying beneath the skin on the lateral surface of the maxillary bone; it arises from the maxillary bone, over the dorsum of the nose, and runs cranioventrally to insert partly on the wing of the nostril and partly into the lateral part of the upper lip; it acts to dilate the nostrils and elevate and retract the upper lip MP:0030429 abnormal levator nasolabialis morpholgy MPheno.ontology