THE SYLOID PROCESS : MORPHOMETRY AND ITS CLINICAL IMPLICATIONS IN COSTAL REGION OF ANDRAPRADESH , INDIA

Address for Correspondence: Dr. Supriya Garapati, Associate professor, Department of Anatomy, MNR Medical College, Sangareddy, Telangana, India. E-Mail: garapati.supriya13@gmail.com Objective: Styloid process is a slender bony projection, pointing downwards from the temporal bone. An elongated styloid process can compress the vital vessels and nerves close to it. Aim of the present study was to emphasize the styloid process morphometry and its clinical importance in study population Materials and Methods: Styloid process of temporal bone was studied by using 52 three dimensional CT scans of both sexes. Results: The mean length of the styloid process on right and left side was 3.15± 0.52cm, 3.03 ± 0.55 cm. The mean width of the right and left styloid process was 0.74 ± 0.17 cm, 0.72 ± 0.19 cm. The mean medial angulation of right and left styloid process was 61.5° ± 8.17°, 61.6° ± 6.29° respectively. Conclusion: Morphometric evaluation of the styloid process is clinically important because of its closeness to important neurovascular structures. Data obtained from the present study may useful for physicians, surgeons, radiologists, otorhinolaryngologists, dentists and for anatomists as an academic interest.

contained within poststyloid space.The pain due to elongated styloid process is because of glossopharyngeal neuralgia, as the nerve is closely related to styloid process & may get stretched.This condition may be unilateral or bilateral.
Angiography studies [7] have demonstrated compression of the external carotid artery produced by the calcified stylohyoid ligament due to homolateral rotation of the head.
For the present study, computed tomography images of 52 individuals aged between 18-65 of both sexes were studied for styloid process morphometry.The CT scans were taken from the radiology department, Narayana general hospital, Nellore, A.P. following objectives were measured and analysed.
• Length of SP (SPL) • SP width (SPW) • SP's angulation All measurements were made with anteroposterior, right lateral and left lateral views in the 3D interactive module to the end point of ossification.The length was defined as the distance between the base of the SP and the tip of the ossified SHC on the anteroposterior view.If there was a segmental ossification of the SL, the distance was measured including the nonossified parts.The thickness of SHC ossification was defined as the distance where maximum thickness was seen.The mediolateral angle (MLA) was determined as the angle of intersection of the line connecting both bases of the SP and the longitudinal axis of the SHC on the anteroposterior view.The data were tabulated in Microsoft Excel 2007 for statistical analysis.

RESULTS
The mean length of the styloid process on right side was 3.15 ± 0.52cm.The maximum length which was measured in this study was 4.96cm.The mean length of left side styloid process was 3.03 ± 0.55 cm, the maximum length was 4. 95 cm.The mean width of right styloid process was 0.74 ± 0.17 cm.The maximum width was 1.09 cm).The mean width of styloid process on left side was 0.72 ± 0.19 cm.The maximum width was 1.23cm, the mean medial angulation of right styloid process was 61.5° ± 8.17° .The mean medial angulation of left styloid process was 61.6° ± 6.29°.Eagle considered tonsillectomy responsible for the formation of scar tissue around the styloid apex, with consequent compression or stretching of the vascular and nervous structures contained in the retro styloid compartment (in particular, the glossopharyngeal nerve and perivascular carotid sympathetic fibers) [13] However, ES is also discovered in patients who have never been subjected to tonsillectomy.
Variations in length of the styloid process were discussed by various researchers.It has been previously reported that the normal radiographic length of styloid process was 20 to 30 mm. whereas; Kaufman et al [14] reported that, the upper limit for the normal styloid processs as 30 mm.A wide range prevalence of ESP in different populations have been reported by many authors.The prevalence of elongated styloid process in the earlier studies was reported as 1% [15], 4% [16], and 8.2% [17].The 4% prevalence rate was observed by Eagle.The prevalence could be higher in the Iranian population, a study conducted by Ghafari-Abdollahpur [18] on 11-75-year-old patients from the Gilan province in which the prevalence was reported to be 36.4%.The prevalence of an elongated process in this study was greater than that of Ghafari-Abdollahpur study which was conducted over a wide range of ages.The present study showed 51.9% of prevalence of elongated styloid process on the right side, and 40% on the left side.
In most of the studies, the possibility of ESP involvement was reported equal in both sexes [19, 20, 21 and 22].In a study done in Saudi population, the prevalence of ESP in males was 63.2% and in female it was 36.8% [23].In contrast to these studies the present study showed the prevalence of ESP in females was 50% and in males it was 43%.
By selecting an equal sample size of edentulous males and females, Bozkir [24] demonstrated that statistically there was no significant difference between the two sexes.In a study by Ilguy [25], the ratio of female to male involvement was reported to be 3 to 1 which was correlate with the present study.
Sachin patil et al [26] showed that anterior angulation and distance between bases and tips of styloid process decreased in elongated styloid processes.They also mentioned in their study medial angulation showed no significant change with length increase of styloid process.Okabe et al [27] found a significant correlation between serum calcium concentration and the length of styloid process among 80 years old subjects.They noticed that, in longer styloid process, serum calcium concentration was higher.

CONCLUSION
Styloid process elongation may often be a coincidental asymptomatic radiographic finding.Therefore, proper clinical and radiographic evaluation can detect an elongated styloid process.The radiological picture of the anomalous styloid process may be beneficial for the surgeons, neurologists and radiologists in daily clinical practice.Anomalies related to styloid process may help in arriving at a correct diagnosis and help in avoiding erroneous interpretation of radiographs.
It is clearly understood that there is a lot of variation in the prevalence rate of elongated styloid process reported by different studies.In this situation, the present study would surely add the necessary data and highlights the importance of further studies on styloid process and we also emphasize that there is always a need of correlation of this data with symptomatic eagle syndrome patients.

INTRODUCTION
International Journal of Anatomy and Research, Int J Anat Res 2017, Vol 5(2.2):3796-99.ISSN 2321-4287 DOI: https://dx.doi.org/10.16965/ijar.2017.181approximately 20-30 mm.Although there are cases in which it has reached 8 cm [1-5].The space around the styloid process (parapharyngeal space) is divided by styloid process and muscles arising from it into prestyloid a poststyloid space.Prestyloid space is bounded medially by buccopharyngeal fascia & laterally by medial pterygoid muscle.The glossopharyngeal nerve is situated within the prestyloid space [6] ICA, IJV, Superior Sympathetic, ganglion, CN VII, CN IX, CNX, CNXI, CNXII are The styloid process (SP) is a cylindrical, long cartilaginous bone located in the temporal bone of skull.The muscles and ligaments are attached to the SP which has a role in mastication and swallowing.There are many nerves and vessels such as the carotid arteries adjacent to the SP.The SP and the stylohyoid ligament develop from the Reichert's cartilage (second pharyngeal arch).The normal SP length is Supriya Garapati, Ch.Santhi, Pentyala Suneetha .THE SYLOID PROCESS: MORPHOMETRY AND ITS CLINICAL IMPLICATIONS IN COSTAL REGION OF ANDRAPRADESH, INDIA.

Table 1 :
Showing the Mean length, width and medial angulation on both sides.Supriya Garapati, Ch.Santhi, Pentyala Suneetha .THE SYLOID PROCESS: MORPHOMETRY AND ITS CLINICAL IMPLICATIONS IN COSTAL REGION OF ANDRAPRADESH, INDIA.
The stylohyoid process and ligament are derived from Reichert's cartilage.During fetal development, Reichert's cartilage links the styloid bone to the hyoid bone.If these structures solidify, they can cause the pain and suffering present in.Eagle, who described this syndrome complex, divided it into two categories.The classical type is presented as foreign body sensation in the throat, pain in the throat and the ear ache.The other type is the styloid process compressing the carotid arterial system and presenting as DISCUSSION dizziness and headache[12].