Anatomical considerations on the extrinsic tongue muscles for articulatory modeling

Abstract

Physiological articulatory models have evolved from simpler forms to complex ones, while recent models preserve traits of oversimplification and anatomical unreality. This work combines MRI observations at ATR-BAIC and Johns Hopkins University to point to the issue for advancing extrinsic tongue muscle modeling. The genioglossus, previously thought to arise from the genial tubercle of the mandible, has direct fiber attachments on the short tendon of the tongue. The posterior genioglossus, being regarded as a functional division of the muscle, can be given anatomical definition to the horizontal bundle arising from the inferior aspect of the short tendon. The styloglossus has been modeled as linear strings traveling 'free in air' before inserting into the tongue, but the extralingual part is actually restrained by the surrounding soft tissues to lack mobility. The intralingual styloglossus forms anterior and posterior slings in the tongue tissue, possibly with the distal fibers of the hyoglossus. Combined styloglossus and hyoglossus shortening via the slings may be a factor shaping the tongue into various forms.