abnormal extrinsic tongue muscle morphology abnormal styloglossus muscle morphology 2017-09-28T09:49:01Z MPheno.ontology abnormal styloglossus morphology MP:0030211 any structural anomaly of the paired extrinsic tongue muscle that arises from the anterior surface of the styloid process of the mastoid bone and the proximal quarter of the stylohyoid ligament; it passes inferiorly and anteriorly to insert into the side and inferior aspects of the tongue; the muscle fibers of styloglossus merge with those of the hyoglossus; its action aids to retract the tongue and draw up the sides of the tongue to create a trough for swallowing