Intraoral and extraoral approach for surgical treatment of Eagle's syndrome: a retrospective study

Abstract

Background and purpose: Eagle's syndrome is not uncommon in clinical work. Because of its atypical symptoms, it is easy to be misdiagnosed as other diseases, further leading to misdiagnosis and mistreatment. At present, there is no expert consensus or treatment guidelines for the disease. We evaluated the clinical characteristics and postoperative efficacy of 103 patients with Eagle's syndrome based on their clinical symptoms, radiological studies, and physical examination. Through the multicenter clinical study of Tongji Medical College and Dalian Medical University, we found some characteristics of Eagle's syndrome in operation and imaging.

Methods: In total, 103 patients with Eagle's syndrome (treated from January 2010 to January 2020) were retrospectively enrolled. The postoperative curative effect was analyzed by three surgical methods: styloid process resection through the external cervical approach (styloid process could not be touched through the mouth or could be touched under the jaw or when the CT scan showed that the inclination angle was not large), tonsillectomy + styloidectomy, and preservation of the tonsil for styloidectomy (the styloid process bone could be touched directly during intraoral palpation or in whom the distal part of the styloid process could not be directly touched, but the CT scan showed that the bone inclined toward the oropharynx and its distal part was relatively close to the oropharynx cavity; whether tonsillectomy was performed depended on whether the patient's tonsil was too large to affect the surgical incision). According to the Quality of Well-Being Scale (QWB), we calculated the W value of the scale before operation and 30 days, 3 months, 6 months and 12 months after operation, and compared the W value of each group.

Results: The average length of the styloid process was 33 mm (range 25-61 mm). The patients were followed up for 12-36 months (average 15 months). Of the 103 patients, 21 underwent styloid process resection through the external cervical approach, 49 underwent tonsillectomy and styloidectomy, and 33 underwent styloidectomy with preservation of the tonsil. The treatment cured 48 (46%) cases, was effective in 35 (34%) and was ineffective in 20 (20%). The R language 3.6.3 software was used to perform the nonparametric rank sum test, differences in characteristics between groups were analyzed using the Kruskal-Wallis test with Dunn post hoc tests ( R package FSA) for categorical variables, and there was no significant difference between the three types of operations (H = 0.491, P = 0.782). QWB showed that the quality of life after operation was improved compared with that before operation.

Conclusions: Operation is an effective method for treating Eagle's syndrome. There were no significant differences between the effects of the intraoral and external cervical approaches. Imaging examination-especially CT scanning and 3D reconstruction of the styloid process-is very helpful for diagnosis, but not an absolute criterion for the selection of surgery protocol.

Keywords: Eagles syndrome; Styloidectomy; Three-dimensional computed tomography.