Carotid type of Eagle's syndrome.

Eyes don't see what mind does not know. It is important for a clinician to refresh his knowledge frequently to recognize some of the conditions that one may come across rarely no matter how insignificant the condition may seem. Especially in a dental outpatient department setting, individuals may complain of varied symptoms which the clinician, often tends to correlate to one of the oral diseases. We present a case of Eagle's syndrome with vague clinical presentation which could have easily gone undiagnosed if not for the application of simple diagnostic procedures and aids like Orthopantamogram (OPG).

INTRODUCTION

Styloid process is a slender pointed process in the temporal bone. It is in close relationship with tonsillar fossae and the mastoid bone. Eagle's syndrome is characterized by an elongated styloid process. This entity was first described by Eagle in the year 1937.[1] Prevalence of elongated styloid process or calcified stylohyoid ligament is about 4% of the general population, however; only a few of these cases are symptomatic. Eagle's syndrome may be associated with repeated pharyngalgia, sensation of foreign body in throat and tinnitus. In severe cases alterations in voice and taste also have been reported.[2] A case is reported here, which was initially diagnosed as only chronic periodontitis but after diagnostic procedures and radiographs as a case of Eagle's syndrome along with generalized chronic periodontitis.

CASE REPORT

A 50-year-old female reported to the Periodontology Department of our College with a complaint of dull pain on her left side of the lower jaw, which radiated to her neck since 2 years. The pain was generalized in nature and she felt it to be arising from the gums and deep within the lower jaw. It was intermittent in nature, recurring 2–3 times in succession in the past 3 months and had worsened for the past 15 days. It aggravated on bending forwards and flexing the neck. She also complained of loose teeth in her mouth but said the teeth were not hurting. Medical history revealed that the patient had hypertension and was on tab atenolol 10 mg once daily for the past 2 years. She was also a diagnosed case of type-II diabetes mellitus (fasting blood glucose level was 260 mg/dL) and was on oral hypoglycemic, tablet glibenclamide 500 mg once daily. The patient gave no history of any past trauma.

On extraoral examination, no abnormalities were detected with the temperomandibular joint and the regional lymph nodes were not palpable. However, the submandibular areas were tender on palpation bilaterally. Mouth opening was adequate, but patient reported irritation in her throat on opening the mouth wide. Intra-oral examination revealed presence of plaque and calculus. There was generalized bleeding on probing and deep periodontal pockets indicating generalized chronic periodontitis and the pocket formation were more in the maxillary than in the mandibular arch. The maxillary right first and second premolars showed Miller's Grade III mobility. Based on these clinical findings the case was diagnosed as generalized chronic periodontitis. An orthopantomogram (OPG) was taken, which revealed generalized alveolar bone loss and the mandibular right first molar showed advanced periapical bone destruction. Both the maxillary third molars and the mandibular right third molar were impacted. The OPG also revealed the presence of bilateral elongated styloid processes [Figure 1]. A lateral cephalogram was also taken to ascertain the presence and extent of the elongated styloid process [Figure 2]. However, re-examination and palpation of the tonsillar fossae could not detect any bony protuberances. Based on the clinical and radiographic findings, it was established as a case of Eagle's syndrome with associated generalized chronic periodontitis. Following phase-I therapy, the patient was kept under periodontal maintenance and simultaneously she was referred to the Department of Oral and Maxillofacial Surgery and Otorhinolaryngology for the management of the elongated styloid processes.

Figure 1

Orthopantomogram showing bilateral elongation of styloid processes (original magnification)

Figure 2

Lateral cephalogram revealing the elongated styloid processes (original magnification)

DISCUSSION

The average length of the styloid process ranges from 2 cm to 3 cm.[3] It is a part of the temporal bone lying anteromedial to the mastoid process. Embryologically the stylohyoid apparatus is derived from the Reichert's cartilage of the second brachial arch. This cartilage has four portions, which develop into the styloid process, the stylohyoid ligament, the lesser horn of the hyoid bone and the final portion giving rise to most of the hyoid bone. There is no specific sex predilection for elongation of the styloid process, but female patients are known to be more symptomatic as compared to the male counterparts.[4] There are two types of Eagle's syndrome reported, the classic type and the carotid artery type. The classic type usually presents with an elongated styloid process with a dull, persistent pain in the pharynx. Studies have reported increased incidence of classic type of Eagle's syndrome after tonsillectomy procedures.

The carotid artery type of Eagle's syndrome does not have any history of surgery. This type occurs when an elongated styloid process produces symptoms by compressing the internal or external carotid artery when the head is turned or flexed, which causes pain in the pharyngeal region due to compression of the perivascular sympathetic fibers. The present case falls into the second category. The cause of elongated styloid process is not well understood, but several theories have been put forward. The most popular one is the growth of the osseous tissue along stylohyoid ligament. The pathophysiological mechanisms for the pain of Eagle's syndrome as explained by Ceylan et al. include:[5]

Compression of the neural elements, the glossopharyngeal nerve, the lower branch of the trigeminal nerve, and/or the chorda tympani nerve by the elongated styloid process

Fracture of the ossified stylohyoid ligament, followed by proliferation of granulation tissue that causes pressure on surrounding structures and results in pain

Impingement on the carotid vessels by the styloid process producing irritation of the sympathetic nerves in the arterial sheath

Degenerative and inflammatory changes in the tendinous portion of the stylohyoid insertion, a condition called an insertion tendinosis

Irritation of the pharyngeal mucosa by direct compression by the styloid process

Stretching and fibrosis involving the 5th, 7th, 9th, and 10th cranial nerves in the post-tonsillectomy period.

Diagnosis of Eagle's syndrome is primarily based on clinical findings and radiological appearance. A simple orthopantomogram can reveal elongation of the styloid process. The length of the styloid process is better demonstrated on lateral views as there is less superimposition. Computed tomography (CT) scans can provide excellent images of the region and relationship of the styloid process to adjacent soft tissues. Three-dimensional reconstruction of the region with cone beam CT (three-dimensional) can help in the diagnosis as well as the surgical planning. In the differential diagnosis for Eagle's syndrome, myofascial pain dysfunction syndrome, migraine headaches, laryngopharyngeal dysesthesia, dental related diseases and neuralgias have to be considered.[6]

Styloid process is considered to be elongated if it is more than 3 cm. As measured on OPG, styloid process in this case was 8.2 cm on the right side and 8.5 cm on the left. When styloid process is more than 7.5 cm in length, palpation of elongated styloid process in the tonsillar fossa is usually positive.[7] The relationship of the elongated styloid process to various anatomic structures in the present case is schematically illustrated in Figure 3. In the present case, in spite of its length, the styloid processes were not palpable in the tonsillar fossa. There is no agreement among researchers if length of the styloid process determines the presentations of the symptoms in Eagle's syndrome. Because of location of the styloid process and based on the available data on the subject, it can be logically deduced that symptoms of Eagle's syndrome is definitely associated with the relationship of the styloid process to cranial nerves 5, 7, 9 and 10, the external carotid artery and the internal carotid artery.[8]

Figure 3

Diagrammatic representation of elongated styloid process (schematic diagram)

Treatment for Eagle's syndrome is essentially surgical. Styloidectomy can be performed by intraoral or extraoral approaches. Injection of steroids into the tonsillar fossa has been reported to alleviate the symptoms, and the same has been followed in patients unfit for surgery.[9] In the present case, nonsurgical periodontal therapy was carried out for addressing the periodontal condition, and she was put on periodontal maintenance. For the management of the elongated styloid processes, she has been referred to the Department of Oral and Maxillofacial Surgery and Otorhinolaryngology for evaluation of her medical parameters and surgical treatment.

CONCLUSION

Eagle's syndrome is a rare clinical entity, which has varied presentations. The clinical presentations could be overlapping as in the present case where the chief complaint was orofacial pain and loose teeth. This makes us recommend that the awareness among dental practitioners about Eagle's syndrome needs to be increased to successfully diagnose and treat cases of pain arising from head and neck region as these cases may go undiagnosed or misdiagnosed for a long time.