Anterior and medial angulations of the styloid process in subjects with TMD: clinical and radiographic findings

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.

Prevalence of morphological and structural changes in the stylohyoid chain

Background

Total or partial calcification of the stylohyoid chain, elongation of the stylohyoid process of the temporal bone and/or calcification of the stylohyoid ligament are usually incidental radiographic findings. The purpose of this study was to evaluate the prevalence of morphological and structural changes within the stylohyoid chain in 4413 digital panoramic radiographs.

Material and Methods

The images were evaluated for the presence or absence of changes in the stylohyoid chain by a specialist in dentofacial radiology and the information collected comprised gender, age, side, right and left measurements and classification of the chain side elongated or calcified stylohyoid process, as well as type and pattern of right or left calcification.

Results

275 (6.2%) subjects presented alterations, mostly bilateral, in the stylohyoid chain, being 186 females (67.6%) and 89 males (32.4%), with a higher proportion elongation. Partial calcification was more prevalent than total calcification. The right side was most affected and the frequency of events increased with age.

Conclusions

The findings of the present study demonstrate that the commonest alterations in the stylohyoid chain are bilateral, mainly elongation, with a clear trend to increased prevalence with increasing age, presenting a low incidence. Noneless, the clinicians must be aware of these alterations in the routinely radiographic examination.

Key words:Stylohyoid process, Stylohyoid ligament calcification, Stylohyoid chain, Eagle’s syndrome.

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.

Morphometric examination of the styloid process by 3D-CT in patients with Eagle syndrome

PURPOSE

This study aimed to obtain the length, medial-anterior angulation and basis-apex coordinates of the styloid process in patients with Eagle syndrome by three-dimensional computed tomography.

METHODS

This study was performed on three-dimensional computed tomography images obtained from the hospital picture archiving and communication system (by obtaining 3D images by a RadiAnt DICOM viewer 4.6.9 version). In this study, the anterior and lateral lengths of the styloid process, its anterior and medial angulation, and the coordinate values on the x, y, and z-axes of 24 patients (14 males, 10 females) diagnosed with Eagle syndrome were examined.

RESULTS

The mean anterior lengths were found to be 41.45 mm on the right and 36.07 mm on the left sides, while the mean lateral lengths were found to be 42.15 mm on the right and 37.59 mm on the left sides. The mean medial angulation was measured to be 62.91° on the right and 63.42° on the left, while mean anterior angulation was measured to be 28.01° on the right and 30.43° on the left. The styloid process basis coordinates were determined as (right: x = - 41.30, y = 0, z = 0, left: x = 40.79, y = 0, z = 0), and apex coordinates were determined as (right: x = - 22.61, y = - 36.86, z = - 19.52, left: x = 24.90, y = - 32.14, z = - 18.65).

CONCLUSION

Knowing the styloid process basis and apex coordinates in addition to knowing the its length and angulation will be useful in diagnosing Eagle syndrome. We think that these results in relation to the coordinates of the styloid process will bring a new perspective to clinicians who investigate the length and angulation of the styloid process.

Evaluation of the styloid process in a Sri Lankan population using digital panoramic radiographs

OBJECTIVE

The objectives of this study were to evaluate the normal radiographic length of the styloid process (SP), prevalence and type of elongation, and angulation of the styloid process in relation to sex and side on digital panoramic radiographs in a Sri Lankan population.

METHODS

A total of 100 digital panoramic images selected from the database at the Division of Oral Medicine and Radiology, Faculty of Dental Sciences, University of Peradeniya, Sri Lanka were evaluated for the radiological features of the styloid process. Lengths greater than 30 mm were consider as elongated. Elongated styloid processes were also classified into three types based on Langlais classification (elongated, pseudo articulated; and segmented).

RESULTS

The mean radiological length of the SP on the right and left side was 25.8 mm ± 7.5 mm and 23.2 mm ± 9.0 mm respectively. The prevalence of elongated styloid process in males and female were 34.9% and 24.6%. The maximum length observed on right and left sides were 43.2 mm and 41 mm respectively. However, the differences between the genders and the sides were statistically not significant (P = 0.199). The most frequently observed type of elongation was type I (elongated) according to the Langlais classification.

CONCLUSION

This study provides valuable knowledge of the anatomical variations of the SP which may help clinicians from various specialties to diagnose the Eagle syndrome.