Elongated styloid process in patients with temporomandibular disorders — Is there a link?

Eagle and Ernest syndromes: a scoping review

INTRODUCTION

Ossification disorders can affect the stylohyoid ligament as well the stylomandibular ligament. The symptomathology between those syndromes and other pathologies it has been a problem because there is not a guideline.

EVIDENCE ACQUISITION

With the aim to establish prevalence, diagnosis and etiopathogenesis of Eagle and Ernest syndromes, a scoping review was performed base on PRISMA criteria.

EVIDENCE SYNTHESIS

To review stylohyoid ligament and Eagle Syndrome 93 articles were selected. Three articles regarding the stylomandibular ligament and Ernest Syndrome were founded and selected.

CONCLUSIONS

Both syndromes should be clinically diagnosed and corroborate with imaging (2D or 3D), although imaging in Ernest Syndrome is not clear as well in Eagle Syndrome. A decisional algorithm for diagnosis of Eagle Syndrome and Ernest Syndrome is presented.

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

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.

Asymmetry of dental or joint anatomy or impaired chewing function contribute to chronic temporomandibular joint disorders

INTRODUCTION

The etiologies of most chronic temporomandibular joint disorders are unknown. However, an association between habitual chewing on a particular side and chronic temporomandibular joint disorders has been reported. The aim of this study was to investigate the differences between sides (affected vs unaffected) of biodynamic factors (including lateral dental guidance determined by dental anatomy) or condylar path angles (determined by temporomandibular joint morphology) and chewing function (physiological alternate chewing vs single habitual chewing side). The study scope was to investigate possible etiological factors to improve the understanding of temporomandibular joint disorders. The null hypothesis was that no difference would be found between sides that are or are not affected by chronic temporomandibular joint disorders in chewing function or in levels of dental or temporomandibular joint remodeling.

METHODS

This cross-sectional, double-blind study involved 24 adults with substantial, chronic, unilateral symptoms diagnosed as temporomandibular joint disorders. Chewing function, temporomandibular joint remodeling (using axiography) and dental anatomy (lateral guidance angles using kinesiography) were assessed.

RESULTS

Habitual chewing on one particular side was observed in 17 of 24 participants; significantly more (n=15) chewed on the affected side than on the unaffected side (P=0.002 in a two-tailed Fisher's exact test; risk estimate=4.5; 95% CI 1.326-15.277). The condylar path (CP) angle was steeper on the affected side than on the unaffected side (mean (standard deviation)=50.52° (9.98°) versus 45.50° (7.98°); P=0.002 in a two-tailed t-test). The lateral guidance (LG) angles were flatter on the affected side in all 24 participants.

CONCLUSION

Our results suggest that habitual chewing on one side may be associated with increasing condylar path, with flattening lateral guidance angles, and also with chronic temporomandibular joint disorder on the habitual chewing side.

[Protocol of cone beam computed tomography analysis for patients with craniomandibular dysfunction]

The article presents a detailed protocol of cone beam computed tomography (CBCT), which includes not only the classic analysis of dentoalveolar and skeletal disorders, but diagnosis of cranial patterns (craniocervical cephalometric analysis by M. Rocabado, cephalometric diagnosis by Sassouni PLUS), analysis of transverse jaw sizes (Penn analysis) and measuring the volume of the airway for screening of obstructive sleep apnea. The literature review was conducted using the PubMed in the Scopus and Medline electronic databases through April 2020. Combining several methods of interpretation of CBCT in a single protocol will allow doctors to obtain a more complete amount of information to make a complete plan of comprehensive treatment.

Eagle's syndrome, elongated styloid process and new evidence for pre-manipulative precautions for potential cervical arterial dysfunction

INTRODUCTION

Safety with upper cervical interventions is a frequently discussed and updated concern for physical therapists, chiropractors and osteopaths. IFOMPT developed the framework for safety assessment of the cervical spine, and this topic has been discussed in-depth with past masterclasses characterizing carotid artery dissection and cervical arterial dysfunction. Our masterclass will expand on this information with knowledge of specific anatomical anomalies found to produce Eagle's syndrome, and cause carotid artery dissection, stroke and even death. Eagle's syndrome is an underdiagnosed, multi-mechanism symptom assortment produced by provocation of the sensitive carotid space structures by styloid process anomalies. As the styloid traverses between the internal and external carotid arteries, provocation of the vessels and periarterial sympathetic nerve fibers can lead to various neural, vascular and autonomic symptoms. Eagle's syndrome commonly presents as neck, facial and jaw pain, headache and arm paresthesias; problems physical therapists frequently evaluate and treat.

PURPOSE

This masterclass aims to outline the safety concerns, assessment and management of patients with Eagle's syndrome and styloid anomalies. By providing evidence of this common anomaly found in almost one-third of the population, hypothesis generation and clinical reasoning with patients presenting with head and neck symptoms can improve.

IMPLICATIONS

Including styloid anomalies as potential hypotheses for patients with head and neck complaints can assist therapists in safe practice and expedite referral. The authors recommend updating the IFOMPT framework to incorporate Eagle's syndrome, a comprehensive autonomic assessment, and palpation of the stylohyoid complex to avoid potentially serious complications from conceivably hazardous interventions.

Evaluation of styloid chain calcification related to temporomandibular joint disc displacement: a retrospective cohort study

OBJECTIVES

The present study aimed to evaluate any relationship between elongated styloid process (ESP) and temporomandibular joint disc displacement (TMJD).

STUDY DESIGN

A retrospective cohort study.

SETTING

Dentomaxillofacial Radiology division of Erciyes University Dental Hospital.

PARTICIPANTS

Ninety-four temporomandibular joints (TMJs) of 47 patients were allocated in this study. Intervention-disease: Two experienced dentomaxillofacial radiologists have interpreted all CBCT and MR images. Patients who referred with TMJ disorders were classified according to temporomandibular joint's disc status as normal disc position (ND), displacement with reduction (DWR) and displacement without reduction (DWoR).

METHODS

Main outcome measures: Interpretation of styloid chain calcification pattern and styloid processes length measured linearly on reconstructed sagittal slices of CBCT. Randomization: Cone beam computed tomography (CBCT) and magnetic resonance (MR) images of 154 patients who were admitted between September 1, 2012 and September 1, 2019. Only 47 of them fulfilled the study requirements. Blinding: Single blind of the outcome measurements and interpretations of MR images.

RESULTS

Total 94 TMJs of 47 patients disc status groups were analyzed and defined as DWoR (n = 25), DWR (n = 32), and ND (n = 37). On multivariate analysis, no statistical significant differences were found between groups in terms of styloid process lengths. Mean SP length and standard deviation of disc status groups (DWoR, DWR, and ND) are 35.5 (± 9.8) mm, 34.6 (± 9.2) mm, and 38.3 (± 8.9) mm, respectively. When patients were grouped individually according to their post-MRI diagnosis, the mean styloid process length in the non-temporomandibular joint disc displacement (non-TMJD) patients (47.9 ± 10.8) was significantly higher than the TMJD patients (36.1 ± 9.3). In this study, there is no intervention to cause any harm or side effects.

CONCLUSION

Our results indicate that styloid-stylohyoid syndrome may be misdiagnosed with temporomandibular joint disorder (TMD).

TRIAL REGISTRATION

Clinical Trials NCT04280107.

Cone-Beam Computed Tomographic Evaluation of Styloid Process in Patients With Temporomandibular Disorders and Asymptomatic Individuals

OBJECTIVES

Elongated styloid processes (ESP) may show clinical symptoms that are readily confused with symptoms associated with temporomandibular disorders (TMDs). The purpose of study was to compare the prevalance and characteristics of ESP in patients with TMD and asymptomatic individuals are examined by cone beam computed tomography.

METHODS

Angulations and length of the styloid process (SP) were evaluated in CBCT images of 100 patients with TMD symptoms and 100 control patients, retrospectively. Differences between the patient and control groups were assessed by analysis independent sample t test. Pearson correlation test was used to evaluate between length and angulation of SP relationship.

RESULTS

The mean length of SP in the TMD group was 38.19 ± 8.6 mm for the right and 38.99 ± 8.1 mm for the right side. The mean length of SP in the control group was 36.80 ± 6.3 for the right side and 36.18 ± 6.5 mm for the left side. The mean anterior angulation of the SP in the TMD group was 22.08 ± 5.5 degree in the TMD group and 23.97 ± 4.1 degree in the control group. The mean medial angulation of the SP in the TMD group was 30.57 ± 4.9 degree and 29.89 ± 4.4 degree in the control group. There was no significant difference in length and angle between the groups (P > 0.05).

CONCLUSION

No correlation was found in terms of length and angulations of SP between TMD and control groups.

The dentomaxillary apparatus from molecular biology to variational anatomy-Underpinning interdisciplinary research

Over the past decades, the research environment in anatomy has dramatically changed. Studies have become more interdisciplinary and complex, with many components required, from basic to clinical research. Within this framework, this special issue was designed to create a link between fundamental fields such as developmental and molecular biology, dental materials, anatomy, histology, and their applications in the clinical research of the dentomaxillary apparatus.