Journal of Oral Medicine Open Access

Keywords

Elongation; Styloid process; Eagle’s syndrome; Calcification

Introduction

Elongated styloid process was first described by Eagle in 1937 [1]. Eagle’s syndrome consists of elongation of the styloid process or stylohyoid ligament with associated pain. The normal length of the styloid process is around 30mm and if it is longer than 30mm it is considered elongated [2]. Not all morphological changes in the styloid process produce symptoms of Eagles syndrome. Misdiagnosis of Eagle’s syndrome ultimately result in attributing it to some other cause [3,4].

Around 2% and 4% presents radiographic evidence of an ossified potion of the styloid process [5] and are usually asymptomatic [6]. Panoramic radiographs are widely used to determine the elongation of styloid process [7]. The objectives of our study were 1. To evaluate the prevalence of styloid process elongation in South Kerala population and also to determine the common calcification patterns using panoramic radiographs.

Methodology

A retrospective study of 100 digital OPGs of subjects from 20 to 80 years, who visited Oral Medicine and Radiology department, Pushpagiri College of Dental Sciences, Thiruvalla, Kerala, South India over a 2-month period was done. Panoramic radiographs were styloid process, was not clearly visible were excluded from the study. All panoramic radiographs were digitally generated on a Kodak 9000c Digital Panoramic and Cephalometric System.

A single trained examiner oral radiologist performed the radiographic examinations of the panoramic radiographs. The length of the styloid process in the radiograph was measured by a line drawn from the lowest point of the external acoustic meatus to the apex of the process.

Langlais [8] classification was used for assessing styloid process elongation in 1986.

Three types according to the degree of elongation.

• Type 0 - normal styloid process [8].

• Type 1- elongated greater than 30 mm.

• Type 2- pseudo segmented styloid process.

• Type 3- segmented, consists of length greater than 30 mm [8].

Classified according to the calcification pattern, four types Langlais (1986).

A. External calcification (boundary) where the image of the styloid process is continuous with no signs of calcification [8].

B. Partial calcification where the image of the styloid process with the presence of radiopaque calcified segments.

C. Nodular calcification: styloid process image with nodular areas, radiopaque calcification.

D. Completely calcified image: image of the styloid process radiopaque, calcified or totally homogeneous [8].

Results

Out of the 110 digital panoramic radiographs were examined, 10 radiographs with questionable styloid process were excluded. 100 radiographs were examined for elongated styloid process and calcification pattern. Out of the 100 patients examined 51 were males and 49 were females. Styloid process was normal in 33 males and in 38 females. The results of our study revealed a prevalence of 35% elongation of styloid process. Elongation of styloid process was noticed more in males 24(68.6%) as compared to females 11(31.4%). Elongation was more 19(54.4%) in the 41-60 year age group, followed by 61-80 and 20-40 age group. Table 1 External calcification was the common calcification pattern seen 67(67%) in our study, followed by partial calcification 23(23%), complete calcification in 8(8%) and nodular calcification in 2(2%). External calcification was seen more in males 40(59.7%) as compared to females 27(40.29%) (Table 2).

Table 1 Distribution of cases of elongation of styloid process according to gender and age group.

Type of elongation	Gender	Age groups (years)			Total cases according to gender	Total cases according to type of elongation
		20-40	41-60	61-80
Normal	F	18	13	7	38	65
	M	11	10	6	27
Elongated	F	1	7	3	11	34
	M	7	11	5	23
Pseudo-segmented	F	0	0	0	0	0
	M	0	0	0	0
Segmented	F	0	0	0	0	1
	M	0	1	0	1
Total		37	42	21	100

Table 2 Distribution of cases of calcification of styloid process according to gender and age group.

Type of calcification	Gender	Age Group (in years)			Total cases according to gender	Total cases according to type of calcification
		20-40	41-60	61-80
External	F	14	11	4	29	67
	M	15	14	9	37
Partial	F	2	8	4	14	23
	M	3	4	2	9
Nodular	F	1	1	0	2	2
	M	0	0	0	0
Complete	F	2	0	2	4	8
	M	1	3	0	4
Total		38	41	21	100

Discussion

Term styloid process is derived from stylos means a pillar. It is derived mostly from the first and second brachial arches. It is attached to the stylopharnygeous, stylohyoid and to the styloglossus muscles and to the stylohyoid and stylomandibular ligaments.

Mechanism of ossification is not clearly understood [9,10]. Eagel’s syndrome is a rare disease that develops because of the compression of the elongated or calcified stylohyoid ligament on the neural and vascular structures, commonly associated with persistent throat pain, foreign body sensation, dysphagia, referred otalgia, neck and facial pain [11-13].

Our study showed 35% prevalence of elongation of styloid process in a South Kerala population. This is greater than those recorded by Rizzatti-Barbosa et al. (20%) [14] and Leite et al. (19.56%) [15]. Radiographic studies have observed a prevalence of elongated styloid process from 1.4 to 83.6% [16-20]. The difference in the prevalence of elongated styloid process can be due to the diagnostic, image interpretation criteria and geographical location [11,19,21,22].

Styloid process elongation was found more in males than in females. This finding is in accordance with other authors who also identified a male predilection in different geographic locations [18,23-25].

High prevalence of elongated styloid process was observed in the 41-60 age group, but less in the 61-80 and 21-40 year old age groups. Anbiaee and Javadzadeh [26], Al- Khateeb et al. [12], and Ekici et al. [19] also reported elongation of the styloid process with advancing age.

External calcification was the common calcification pattern seen in our study 67(67%). It was seen more in males than in females. This is in accordance to the study conducted in Saudi population by Shaik et al. [25] but not in accordance to Ilguy et al. [27] in Turkey. According to Reddy et al. [24] and Bagga et al. [28] completely calcified and partially calcified were the most prevalent calcification pattern in South and North Indian population.

Conclusion

Oral physicians should be aware of the styloid process elongation, which is often a coincidental asymptomatic radiographic finding. Panoramic radiographs are economical and useful diagnostic tool for early detection of elongated styloid process with or without symptoms. To our best knowledge this is the first type of study in terms of prevalence of styloid process and calcification patterns in South Kerala. Further studies are required with a larger sample size should be performed to support this result.

Oral physicians should be aware of the styloid process elongation, which is often a coincidental asymptomatic radiographic finding. Panoramic radiographs are economical and useful diagnostic tool for early detection of elongated styloid process with or without symptoms. To our best knowledge this is the first type of study in terms of prevalence of styloid process and calcification patterns in South Kerala. Further studies are required with a larger sample size should be performed to support this result.

Acknowledgement

We would like to acknowledge Mrs. Nisha Kurian, Assistant professor, Biostatics, Pushpagiri Institute of Medical Sciences for her help.

Conflict of Interest

The authors declare no conflict of interest.

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