Relationship of stylohyoid chain and cervical internal carotid artery detected by 3D angiography.
OBJECTIVE
The calcification of the stylohyoid chain (SHC), elongated styloid process (SP), larger SP' angle and its shortened distance of cervical internal carotid artery (CICA) are risk factors for bony compression and the stylocarotid syndrome.


METHODS
3D-CTAs of 125 patients were analyzed in terms of the SP length, its angulations, type of the SHC and relationships of its proximity to the CICA.


RESULTS
Elongated SP was observed frequently both in females (47%) and males (55%). The mean distance of the CICA to the SP was calculated as 8.2 ± 3.3 mm. This short distance between the CICA and the SP was observed more frequently in males (28.1%) and females (10.7%). The anterior and medial angulations of the SP were calculated as 71.2 ± 4.3°, and 57.3 ± 9.3°, respectively. In the present study, the SHC was determined as normal SP (54.2%), absence of the SP (1%), duplication of the SP (1%), elongated SP (26%), complete ossification of the SHC (1%), segmentation of the SHC (9%), fracture of ossification of the SHC (1.6%) and pseudo articulations of the SHC (5.6%).


CONCLUSIONS
3D-CTA was the most appropriate radiological investigation analyzing and measuring SHC (elongated, larger angle, shorter distances with CICA) and identifying types (duplicated, segmented, complete and fractured) resulting from pressures on the CICA. Our study also revealed the pressure on the artery not only arose from the tip of the SP but could also result from types stretching over the artery wall. In those specimens, there is a higher probability of formation of the stylocarotid syndrome due to the long-term pressure on the sympathetic chain around the CICA.
Department of Radiology, Faculty of Medicine, Ege University, Izmir, Turkey.
Cenk
C
Eraslan
Department of Anatomy, Faculty of Medicine, Ege University, 35100, Izmir, Turkey.
Mehmet Asim
MA
Ozer
Department of Anatomy, Faculty of Medicine, Ege University, 35100, Izmir, Turkey. figen.govsa@ege.edu.tr.
Figen
http://orcid.org/0000-0001-9635-6308
F
Govsa
Faculty of Medicine, Ege University, Izmir, Turkey.
Ahmet Kemal
AK
Alagoz
Department of Radiology, Faculty of Medicine, Ege University, Izmir, Turkey.
Cem
C
Calli
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D059925:Anatomic Landmarks; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging* / Q000473:pathology*; D000072226:Computed Tomography Angiography / Q000379:methods*; D003287:Contrast Media; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009999:Ossification, Heterotopic / Q000000981:diagnostic imaging* / Q000473:pathology*; D011857:Radiographic Image Interpretation, Computer-Assisted; D013701:Temporal Bone / Q000002:abnormalities* / Q000000981:diagnostic imaging / Q000473:pathology
D003287:Contrast Media
Bony compression; Cervical internal carotid artery; Eagle syndrome; Stylohyoid chain; Styloid process; Three-dimensional angiography computed tomography (3D-CTA)