Elongated styloid process: literature review and morphometric data on a collection of dried skulls

Abstract

The styloid process is a subtle process of variable length that originates from the petrous part of temporal bone . From the process originate three muscles: the stylopharyngeus,the styloglossus, the stylohyoideus and two ligaments :stylohyoid and stylomandibular . The styled process of the temporal bone has a variable length as demonstrated for studies conducted in three-dimensional computed tomography or dental panoramic three-dimensional scanning,and in dried skulls The normal length of the styloid process is particularly important to establish for the relations of closeness with vascular and nervous structures and their possible compression by an elongated styloid process.Several studies have focused on the effects of changes in length and course of the styloid process, highlighting the relations of the carotid artery and the glossopharyngeal nerve to explain cerebrovascular symptoms or Eagle’s syndrome characterized by neck pain and dysphagia .However the association for the abnormal length of styloid process and Eagle’s syndrome is not always present and many cases are asymptomatic. In the present study we propose a review of the studies performed with different in vivo radiological techniques and on dried skull collections on the normal and pathological length of the stiloyd process and on its association with the Eagle’s syndrome. We also present a morphometric study carried out in dried skulls of our museum collection.The results are discussed in light of the possible variations in the muscular and ligamentous structures consequent to the elongation of the styloid process.