|Year : 2016 | Volume
| Issue : 4 | Page : 381-385
Evaluation of styloid process in Bareilly population on digital panoramic radiographs
Abhijeet Alok1, Indra Deo Singh2, Shivani Singh3
1 Department of Oral Medicine and Radiology, Sarjug Dental College and Hospital, Darbhanga, Bihar, India
2 Department of Psychiatry, Sri Krishna Medical College and Hospital, Muzaffarpur, Bihar, India
3 Department of Public Health Dentistry, Institute of Dental Sciences, Bareilly, Uttar Pradesh, India
|Date of Submission||15-Aug-2015|
|Date of Acceptance||03-Dec-2016|
|Date of Web Publication||21-Feb-2017|
Dr. Abhijeet Alok
Department of Oral Medicine and Radiology, Sarjug Dental College and Hospital, Hospital Road, Laheriasarai, Darbhanga - 846 003, Bihar
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Introduction: The styloid process is a long slender and pointed bony process projecting downwards, forwards and slightly medially from the temporal bone. Elongated styloid process is being more often seen in panoramic radiographs which are commonly used in dental practice. Aim: To assess the styloid process on digital panoramic radiographs. Materials and Methods: It is a cross-sectional study based on the panoramic radiographs of 2000 patients who reported to the department. The panoramic radiographs were available in the archives of our department as soft copies. These panoramic radiographs were obtained using Orthoralix DDE (GENDEX, USA) digital panoramic system. The length of the styloid process was measured radiographically on both sides of the maxillofacial region using the measurement toolbars on the accompanying analysis software. For statistical analysis, we used the unpaired t-test, Chi-square test, and one-way analysis of variance test, as necessary. Results: The average length of the right and left styloid process in males was 26.96 ± 8.748 and 26.76 ± 8.33 in females; right and left average length were 26.02 ± 5.86 and 26.59 ± 7.00 in males and females, respectively. The length of the styloid process on both sides increased with age; males had longer styloid process than females. Elongated styloid process was present in 26.5% of the patients. Langlais type I elongated styloids and type D calcification pattern were more common than others. Conclusion: Panoramic radiography is useful for the detection of an elongated styloid process in patients with or without symptoms, and helps avoid misdiagnosis of tonsillar pain or pain of dental, pharyngeal, or muscular origin.
Keywords: Eagle syndrome, elongated styloid process, panoramic radiography, stylohyoid ligament
|How to cite this article:|
Alok A, Singh ID, Singh S. Evaluation of styloid process in Bareilly population on digital panoramic radiographs. J Indian Acad Oral Med Radiol 2016;28:381-5
|How to cite this URL:|
Alok A, Singh ID, Singh S. Evaluation of styloid process in Bareilly population on digital panoramic radiographs. J Indian Acad Oral Med Radiol [serial online] 2016 [cited 2019 Oct 20];28:381-5. Available from: http://www.jiaomr.in/text.asp?2016/28/4/381/200623
| Introduction|| |
The term “styloid process” is derived from the Greek word “stylos” meaning a pillar which usually serves as a point of attachment for muscles and refers to the slender, pointed process (protrusion) of the temporal bone of the skull. The structures attached to the styloid process include stylopharyngeous, stylohyoid, styloglossus muscles, stylohyoid and stylomandibular ligaments. The entire stylohyoid apparatus is developed from four segments.
- Tympanohyal portion: The base of the styloid process.
- Stylohyal portion: Forms a large part of styloid process
- Ceratohyal portion: Precursor of the stylohyoid ligament
- Hypohyal portion: Development precedes the small horn of the hyoid bone.
The mechanism of the ossification of stylohyoid apparatus is not fully understood. It is suggested that some part of the cartilage is retained within the stylohyoid ligament during ossification, which results in varying degrees or patterns of ossification and elongation of stylohyoid chain. “Elongated styloid process,” is a term which was first used by Eagle. Various theories have been proposed to explain the ossification of stylohyoid/stylomandibular ligaments, namely, theory of reactive hyperplasia, reactive metaplasia, anatomic variance, and aging and developmental anomaly, due to a loss of elasticity in the ligament simulating tendinosis.,,, According to Eagle, normal styloid process measures between 2.5 and 3 cm. There are various variations of the styloid chain ranging from the thickness of segments, angle and direction of deviation, degree of calcification, and length of the styloid process, which need to be described radiographically according to its appearance on it.
The styloid process, the thin and long osseous part of the temporal bone, lies caudally, medially and anteriorly toward the maxilla vertebropharyngeal recess, which involves the carotid arteries, internal jugular vein, facial, glossopharyngeal, vagal and hypoglossal nerves. It developed from Reichert's cartilage of 2nd branchial arch. Studies have estimated that, in approximately 2–28% of general population, there is radiographic evidence of an elongated styloid process, however, most cases are asymptomatic.,, Symptoms associated with Eagle's syndrome are dull, aching pain with or without referred pain to the ear and mastoid region on the affected side. Some patients may complain of pain on swallowing (dysphasia) or an abnormal sensation of a foreign body in the pharynx or neck and cervicofacial pain. There are only few studies reported on the elongation and calcification patterns of styloid process. Authors such as Langlais et al., MacDonald-Jankowski, and Correll et al. have classified elongated styloid process.,, In the present study, our aim was to investigate the prevalence of elongation and calcification patterns of elongated styloid process in patients presenting to our institution using digital panoramic radiographs.
| Materials and Methods|| |
The present study was conducted in the Department of Oral Medicine and Radiology. A total of 2000 digital panoramic radiographs of patients with dental problems were obtained from the archives of our department as soft copies. Radiographs with positioning and magnification errors were excluded during the evaluation process. Panoramic radiographs were obtained from Orthoralix DDE (GENDEX, USA) digital panoramic system using standard exposure parameters, as recommended by the manufacturer. The magnification factor used for the machine was 1.25. The selected radiographs were of patients aged above 18 years. All panoramic radiographs were made and evaluated in the same manner by a single oral radiologist with the help of measuring tools on the accompanying software. The length of the styloid process was measured as the distance from the point where the styloid left the tympanic plate to the tip of the process, regardless of whether or not the styloid process was segmented, similar to method described by Ilgüy et al. Styloid process measuring more than 30 mm was considered as elongated. The type of elongation and calcification of each styloid process on both sides were classified as per Langlais et al., with a few modifications.
In our study, few panoramic radiographs showed calcification of the styloid process which were not continuous with the base of the skull. Similar finding was reported by MacDonald-Jankowski  in his classification. Hence, in the present study, we modified Langlais classification by adding a fourth variant of the elongation pattern. It mainly included styloid process similar to type “H to J” patterns (proposed by MacDonald-Jankowski) of calcified stylohyoid chain, which was not continuous with the base of skull. The elongation patterns were graded as
- Type I: Uninterrupted integrity of styloid process (>30 mm)
- Type II: Styloid process joined to the mineralized stylomandibular or stylohyoid ligament by a single pseudoarticulation
- Type III: Segmented styloid process containing multiple pseudoarticulations
- Type IV: Elongation of the styloid process due to distant ossification.
The calcification patterns were divided into four types. They are as follows
- Type A: Styloid process showing calcified outline
- Type B: Partially calcified styloid process with discontinuous radiolucent core
- Type C: Nodular appearance of styloid process with varying degrees of central radiolucency
- Type D: Completely calcified styloid process with no evidence of a radiolucent interior.
All the collected data were entered in a spreadsheet (Excel 2007, Microsoft office) and was analyzed using statistical analysis software (SPSS version 16.01, Chicago, Illinois, USA). Student t-test, Chi-square test, and analysis of variance were used to analyze any significant differences between the groups.
| Results|| |
A total of 2000 panoramic radiographs were evaluated, out of which 1320 belonged to males (66%) and 680 belonged to females (34%) [Table 1]. A total of 530 radiographs (26.5%) showed an increase in the length of styloid process, either unilateral or bilateral. A total of 345 showed unilateral elongated styloid process and 185 showed bilateral elongated styloid process. Thus, a total of 530 radiographs showed elongation.
Main group of our patients belonged to 21–50-year age group, comprising a total of 69.8% out of the total 2000 patients [Table 2]. Elongated styloid process was more prevalent in the age group of 51–70 years. Mean length of the styloid process was more in males than females in both the right and left side.
68.8% of styloid process had Type I elongation pattern on the right side [Table 3] whereas on left side 65.7% of styloid process showed Type I elongation pattern [Table 4]. In males, 70.74% of patients had Type I elongation pattern. Type II, III, and IV elongation patterns were seen in 12.60%, 3.25%, and 13.41%, respectively. In females, 65.12% of patients had Type I elongation pattern. Type II, III, and IV elongation patterns were seen in 22.48%, 4.65%, and 7.75%, respectively.
|Table 3: Distribution according to age group and elongation (right side)|
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Type D calcification pattern was most common on the right side (39.09%) followed by Type A calcification which was noted in 34% [Table 5]. On the left side, most common pattern of calcification was Type D pattern (39.01%), followed by Type B (31.41%) and Type A (24.61%).
|Table 5: Distribution according to age group and calcification type (right side)|
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| Discussion|| |
In the present study, the average length of the right and left styloid process in males was 26.96 ± 8.748 and 26.76 ± 8.33, respectively, whereas in females right and left average length was 26.02 ± 5.86 and 26.59 ± 7.00, respectively. The normal styloid process, as reported by Eagle, measured 2.5–3 cm, whereas Kaufman et al. reported 30 mm as the upper limit for the normal styloid process anything above this will be considered as elongated., In various studies, different investigators have reported the incidence of elongated styloid as 4, 1.4, 7, and 18.2% respectively.,,,
It has been found in various researches that, with advancing age, there is progression in the length of calcification. The findings of the present study were similar to those obtained in different studies by More and Asrani and Ferrario et al., We reported that males had longer styloid process compared to females. This finding was similar to the study conducted by More and Asrani, and Sudhakara et al. In our study, unilateral elongation was seen in 65.1% whereas bilateral elongation was seen in 34.9% of panoramic radiographs, which is similar to the study conducted by Scaf et al., however, it differed from the study by More and Asrani  who found an unilateral elongation of 31.95% and bilateral elongation of 68.05% and Bozkir et al. who reported unilateral elongation in 25% and bilateral elongation in 75% of the cases. Bozkir et al. studied 200 panoramic radiographs of edentulous patients aged above 50 years. They found elongated styloid processes in 8 patients; among these 8 patients, 2 had unilateral and 6 had bilateral elongated styloid processes. The average length of the elongated styloid processes in the study conducted by Bozkir et al. was 53 mm. They found that 42% were of uninterrupted Type I and 58% were of interrupted Type III.
In the present study, no significant association was found between age-elongation patterns and calcification patterns, which was in accordance to the study of Sudhakara et al. In the present study, a relatively high prevalence of Type IV elongation pattern was obtained when compared to Type III, which can be attributed to the following reasons:
- Hypomineralization of styloid process in the region of the base of skull resulting in the loss of structural appearance in the panoramic radiograph.
- Increased density of the soft tissue structure (ear lobe) masking the presence of a portion of radiopaque styloid process, in the radiograph.
- Presence of carotid artery calcifications in the region of styloid process simulating the presence of Type IV styloid process.
- Artefactual presence of radiopaque structures in the region of styloid process masking its presence.
The presence of type IV styloid process should be confirmed only by higher diagnostic imaging modalities such as computed tomography or cone beam computed tomography. However, being a retrospective study, the advantage of reanalyzing these structures in our study was very minimal.
| Conclusion|| |
Panoramic radiography is useful for the detection of an elongated styloid process in patients with or without symptoms, and can thus help in avoiding misinterpretation of the symptoms as tonsillar pain or pain of dental, pharyngeal or muscular origin while measuring the length of the styloid process. Therefore, further researches are required to correlate the symptoms of elongated styloid process with the different types and patterns of elongation of the styloid process.
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Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3], [Table 4], [Table 5]