Stylohyoid Ligament Syndrome –Solving the riddle ... - Ssdctumkur.org

CASE REPORTStylohyoid Ligament Syndrome –Solving the riddle with 3DComputed Tomography1 2 2 2 2Renu Tanwar , Chandrashekhar L. , Asha R. Iyengar K.S.Nagesh , Subhash BV1 Department of Oral Medicineand RadiologySGT Dental CollegeBudhera, Gurgaon 123505U.P., India2 Department of Oral Medicineand Radiology,D A P M R V Dental CollegeBangalore 560078Karnataka, IndiaJournal of Dental Sciences and ResearchVol. 2, Issue 2, Pages 1-5ABSTRACTOrofacial pain can be associated with stylohyiod ligament calcification or enlargement of styloidprocess. Calcification or ossification of the stylohyoid ligament is infrequent, often incidentalfinding on radiographs, however when the source of pain is from the styloid process or calcifiedstylohyoid ligaments it is referred to as Eagle's syndrome. This case report discusses the painpattern, clinical presentation, radiologic findings of stylohyoid ligament syndrome.Keywords: Stylohyoid Ligament Syndrome, 3D-CT, Eagle's SyndromeINTRODUCTIONPain in the orofacial region can result due to presence ofelongated styloid process unilaterally or bilaterally dueto pressure exerted on various vital structures in the neckregion. In conditions of hemifacial pain of obscurecausation, the oral diagnostician should considerStylohyoid syndrome as a possible diagnosis.Stylohyoid syndrome occurs due to elongation ofstylohyoid process or calcification of stylohyoidligament. In such cases, imaging helps in identifyingabnormally elongated styloid process or calcifiedstylohyoid ligament. Recent imaging modalitiesincluding three dimensional computed tomography aidin assessing the length and anatomical relationship ofelongated styloid process with vital structures and foroutlining the plane of incision for surgical treatment.CASE REPORTA 32 year old female patient came to the Department ofOral Medicine and Radiology, with chief complaint ofpain on right side of inside of the mouth since last threemonths. She was apparently well three months ago whenshe first experienced severe pain in right side of themouth on swallowing the food while having dinner. Painwas of primary incidence, severe in intensityparaoxysmal in nature and it lasted for two to threeminutes after swallowing ,and radiated towards the rightAddress for correspondence:Dr Renu TanwarE-mail: renuomdr@gmail.com, drashaiyengar@yahoo.co.inAccess this article onlineWebsite: http://www.ssdctumkur.org/jdsr.php.temporal region and side of the neck below the lower jawon the right side. Patient experienced similar episodes ofpain on swallowing and turning the head to the left side atthat time. The patient did not report any change in thenature of the pain since its first occurence and symptomsof pain were initiated on turning the head towards leftside. Patient did not gave history of decreased salivation,dryness of the mouth, trauma in head and neck region orsurgery with respect to the neck or tonsillar region. Onextraoral and intraoral examination no significantfindings were observed. On intraoral palpation, mildtenderness was observed on bidigital palpation of floorof the mouth on the posterior side. A provisionaldiagnosis of Stylohyoid syndrome was arrived at.Radiographic examinations included conventionalradiographs such as Mandibular true occlusal view,Panoramic radiograph, Lateral oblique view of the ramusof the mandible and advanced imaging as ComputedTomography of the head and neck including 3DComputed Tomography.Panoramic radiograph showed the elongated styloidprocesses bilaterally, with the right styloid processmeasuring 37 mm and the left styloid process measuring38 mm. The right styloid process showed uninterruptedelongation with calcified outline and the left styloidprocess showed uninterrupted elongation with nodularcomplex pattern of calcification (Figure 1).The lateral oblique view of of ramus of right side of themandible showed elongated styloid process with the tipof styloid process extending nearly upto the angle of themandible on the right side (Figure 2).46

Vol. 2, Issue 2, September 2011Fig. 1: Panoramic radiograph showing enlargement ofstyloid process on either sidesFig. 3: coronal and sagittal sections demonstratingprominent styloid processFig. 2: Lateral oblique view of the ramus of mandible –right sideComputed Tomography was done and volume scans wereperformed from skull base down to the level of C6e m p l o y i n g 0 . 6 2 5 m m s e c t i o n s . M u l t i p l a n a rreconstructions were also performed for 3Dreconstruction (Figure 3 & 4).The following observations were made :1) Presence of elongated styloid process were seenbilaterally.2) Right styloid process measured 3.9mm.3) Left styloid process measuerd 4.2mm.4) No obvious evidence of calcification of stylohyoidligament was found on CT images.Based on Patient's history,clinical and radiologicalfindings,a final diagnosis of Stylohyoid Syndrome wasarrived at. Patient was advised non steroidal analgesicsthree times a day for five days and was referred to oralsurgeon for surgical management.DISCUSSIONThe stylohyoid chain consists of the styloid process, thelesser cornu of the hyoid bone and its connectingligament. The stylohyoid chain is derived from Secondbranchial arch or Hyoid arch known as Reichert'scartilage. The styloid process is a small, taperingprojection of the temporal bone located anterior to thestylomastoid foramen..The styloid process lies betweenthe internal and external carotid arteries, posterior to thetonsillar fossa and lateral to the pharyngeal wall. Thestyloid process has attachments to three muscles and twoligaments. The stylohyoid ligament itself, extends fromthe tip of the styloid process to the lesser cornu of thehyoid bone. The stylomandibular ligament extends fromthe styloid process to the angle of the mandible. The threemuscles include the stylopharyngeous, stylohyoid, andstyloglossus. The nerve supply comes from theglossopharyngeal, facial, and hypoglossal nerves,respectively. The internal jugular vein and the accessory,47

hypoglossal, vagus, and glossopharyngeal nerves arelocated medial to the styloid process. Theglossopharyngeal nerve emerges from the anterior partof the jugular foramen, medial to the styloid process,where it then curves around the posterior border at thelevel of the origin of the stylohyoid muscle. Thisanatomic relationship is important as a cause ofglossopharyngeal neuralgia in reported cases with anelongated and ,or fractured styloid process as the[1]etiologic cause .In 1937,Eagle proposed that the average length of the[2]styloid process ranges from 2.5 to 3.0 centimeters .In 1964, Developmental theory was proposed by Lengeleand Dhem3 for the elongation of styloid process based onmorphogenesis of of Reichert's cartilage. According tothem, elongation of styloid process should becongenital. However it was also agreed by them thatfurther growth was possible through the cartilaginouscap of the tip of the styloid process.Langlais et al4 proposed a radigraphic classification ofelongated and mineralized stylohyoid ligamentcomplex.This classification was based on types ofelongation and patterns of calcification of stylohyoidligament. (Table 1 & 2) (Figure 4).Because of an elongated styloid process or a calcifiedstylohyoid ligament, a patient with Eagle's syndromemay develop non-specific pain, which may change withhead movements at the ear or neck. Additionally, apatient with an elongated styloid process may havereferred pain to the jaw joint or upper extremities, ordysphagia or foreign body-like irritation throughout the[5]pharynx .There are several different theories, which try to explainthe etiopathology of Eagle's syndrome such ascongenital elongation of the styloid process andcalcification and ossification of the stylohyoidligament6. Fini et al. reported that past tonsillectomy is[7]related to Eagle's syndrome .In differential diagnosis, laryngopharyngeal dysesthesiahas to be considered as well as dental malocclusion,TABLE 1: MORPHOLOGIC CHARACTERISTICS OF STYLOID PROCESSTYPES NOMENCLATURE RADIOGRAPHIC APPEARANCESI ELONGATED Uninterrupted integrity of styloid image(>25-28mm).II PSEUDOARTICULATED Styloid process is joined to the mineralized stylomandibularor stylohyoid ligament by a single pseudoarticulation,usually located superior to inferior border of the mandible.III SEGMENTED Short or long continuous portions of the styloid process oruninterrupeted segments of mineralized ligament.TABLE 2 : PATTERNS OF CALCIFICATIONSPATTERNSCALCIFIED OUTLINEPARTIALLY CALCIFIEDNODULAR COMPLEXCOMPLETELY CALCIFIEDRADIOGRAPHIC APPEARANCESThin radiopaque cortex and a central lucency that constitutes mostof the process.Thicker radiopaque outline with almost complete opacification aswell as small and occasionally discontinuous radiolucent core.Knobby or scalloped outline which may be partially calcified withvarying degree of central radiolucency.Totally radiopaque with no evidence of a radiolucent interior.48

REFERENCESFig. 4: Three dimensional reconstruction demonstratingenlargement of styoid process on either sidesn e u r a l g i a o f s p h e n o p a l a t i n e g a n g l i a ,temporomandibular arthritis, glossopharyngeal andtrigeminal neuralgia, chronic tonsillo-pharyngitis, hyoidbursitis, Sluder's syndrome, histamine cephalgia, clustertype headache, esophageal diverticula, temporalarteritis, cervical vertebral arthritis, benign or malign[8, 9]neoplasms, and migraine type headache .Several imaging modalities have been used for thediagnosis of Eagle's syndrome thus far, including lateralhead and neck radiograph, Towne radiograph, panoramicradiograph, lateral-oblique mandible plain film,anteroposterior head radiograph, and CT. Also, bariumswallow studies can show the indentation of the[10]elongated styloid process as a filling defect .1) Frommer J. Anatomic variations in the stylohyoid chain andtheir possible clinical significance. Oral Surg 1974;38:659–667.2) Eagle WW.Elongated styloid process :Report of twocases.Arch Otolaryngol 1937;25:584-587.3) Lengele B,Dhem A.Microradiographic and histological studyof styloid process of temporal bone.Acta Anat1989;135;193-199.4) Langlais RP,Langland OE,Nortje CJ.Soft tissueradiopacities.Chapter 19. Diagnostic imaging of thejaws.Philadelphia : A Lea and Febiger.1995. p.617-621 '5) K.C.Prasad et al, “Elongated styloid process (Eagle'ssyndrome): a clinical study,” Journal of Oral andMaxillofacial Surgery, vol. 60, no. 2, pp. 171–175, 2002..6) Balbuena L, Hayes D, Ramirez SG, Johnson R. Eagle'ssyndrome (elongated styloid process). South Med J 1997;90:331-334.7) Fini et al. The long styloid proc- ess syndrome or Eagle'ssyndrome J Craniomaxillofac Surg 2000; 28:123-127.8) Harma R. Stylalgia: clinical experiences of 52 cases. ActaOtolaryngol 1966; 224:149.9) Politi M, Toro C, and Tenani G.A Rare Cause for CervicalPain: Eagle's Syndrome. International Journal of DentistryVolume 2009, Article ID 781297, 1-3.10) A Savranlar, L Uzun, M Birol Uður, T Özer.ThreedimensionalCT of Eagle's syndrome. Diagn Interv Radiol2005; 11:206-209.11) Chiang C, Liao Y, Yang W. Three-DimensionalReconstruction CT in Diagnosis of Eagle's Syndrome: aRetrospective Study. Chin J Radiol 2006; 31: 221-225.12) LEE S K. Eagle's syndrome with 3-D Reconstructed CT:twocases report .Chin J Radiol 2004; 29: 353-357.Superimposition of several osseous structures, anddistortion and magnifications secondary to angulationsare the potential disadvantages of conventionalradiographs and, in particular, panoramic films. 3D-CTimages reformatted from the raw data obtained with aspiral scanner provide all the information about thestyloid process, including its length, direction, andanatomical relations. 3D-CT is an objective diagnostictool to outline the anatomy, tailor the surgical plan, andoffer a detailed explanation to the patients as well.Another advantage of the 3D-CT images is threedimensional length measurements, which are impossible[11,12]in 2D images .In conclusion, 3D-CT is a valuable diagnostic imagingtool in patients with Eagle's syndrome that allowsclinicians to evaluate the styloid process in spatialgeometry, make accurate length measurements, andexplain the problem in detail to patients, all of whichmake this technique superior to conventional imagingmodalities.49