EVALUATION OF ELONGATED STYLOID PROCESS IN NORMAL ADULT POPULATION- A DIGITAL PANORAMIC RADIOGRAPHIC STUDY.
BRIEF RESUME OF THE INTENDED WORK : 6.1Need for the study : The word Styloid process is derived from the Greek word “Stylos” means a pillar. It is a slender bony projection that originates from the inferior aspect of the temporal bone, anterior and medial to the stylomastoid foramen1 or it is in the lateral part of the tonsil fossa and the lateral wall of the pharynx. The external and internal carotid arteries lay on either side.2 The mean radiographic length of the process in a normal state is 20-30 mm. The tip of the styloid process is continuous with the stylohyoid ligament, which extends to the lesser cornu of the hyoid bone.3
When the length of the styloid process is beyond 30mm, then it is called as elongated styloid process (ESP). The elongation of this styloid process or ossification of stylohyoid ligament can result in Eagle’s syndrome. This was first described in 1652 by Italian surgeon Pietro Marchetti. In 1937, Eagle coined the term Stylalgia to describe the pain associated with elongation of the styloid process caused due to compression on some neural and vascular structures.4 It has been estimated that between 2% and 4% of the general population presents radiographic evidence of an ossified portion of the stylohyoid chain. Majority of these patients are asymptomatic.5
More commonly, panoramic radiographs are used to determine the elongation of the styloid process. However, computed tomography is used as an adjunct for the information provided by panoramic radiographs.5,6
The aim of this study is to determine the prevalence of elongated styloid process in healthy adult population and to investigate the prevalence, morphology and pattern of calcification of elongated styloid process in relation to gender and sub age groups and measurement of interstyloid distance in relation to gender and age groups with the help of digital panoramic radiograph.
6.2Review of literature: A study was done by T Jung, H Tschernitschek et al (2004)8 to investigate the natural variation of the length of the Styloid Process. 1000 consecutive Panoramic radiographs of normal population were analysed. Both right and left side measurements were combined to give a total of 837 measurements, the distribution depended significantly on age and gender. The 90th percentile varied between 42 mm for women under 35 years and 49 mm for men aged over 35 years. The study concluded that the Styloid process should be considered to be elongated only if its length exceeds 45 mm, which corresponds to the average of the 90th percentiles for different sex and age groups.
A retrospective study was conducted by Shah SP et al (2012)9 to investigate the number of asymptomatic styloid process elongation (ESP) in relation to gender, type of elongation and calcification pattern. 517 panoramic radiographs of patients were analysed out of which 80 patients (15.47%) had elongated styloid process; 31 were females (38.75%), and 49 were male (61.25%). Among ESPs Type 1 was most frequent (65.85%), followed by Type 2 (18.29%), Type 3 (15.85%). Among calcifications the most frequent was calcified outline (40.64%), partially calcified (29.14%), nodular calcification (17.11%) and completely calcified (13.10%).
A study was conducted by Bhagga MB et al ( 2012)10 to study prevalence, elongation and calcification patterns of styloid process in Mathura population and its relation to gender, age and mandibular positions. Digital panoramic radiographs of 2,706 adult patients were analysed and the elongated styloid process was classified with the radiographic appearance based on the morphology and calcification pattern. Study showed higher prevalence of elongated styloid process in the population of the Mathura region when compared with other Indian populations. The calcification of the styloid process was more common in the older age group with no correlation to gender, mandibular movement and site. “Type I” with a “partially calcified” styloid process was observed more frequently in the population.
A study was conducted by Shaik MA et al (2013)1 , to investigate the prevalence, morphology and calcification pattern of elongated styloid process in Saudi population of Aseer (Southern) region and its relation to gender and sub age groups. 1,085 digital panoramic radiographs were analysed. Study stated that the elongated styloid process was most prevalent in elderly aged male patients with type I morphology and calcified outline.
A study was conducted by Sudhakara Reddy R et al (2013)7 on 600 digital panoramic radiographs of patients with dental problems. Out of 520 measurable styloid processes (260 panoramic radiographs), 154 styloid processes had length greater than 3cm. The mean average length of elongated styloid process was 3.67±0.62 cm. No significant association was obtained between age and length of styloid process. The type of elongation pattern had no effect on the calcification pattern. Study suggested that Type I elongated styloid processes were most likely to be completely calcified (type D), but statistically non-significant.
6.3 Objectives of the study :
To study the prevalence, morphology, calcification pattern of elongated styloid process on panoramic radiographs.
To determine the variation in age, sex, type and sides (right and left) of styloid process.
To determine the interstyloid distance in relation to age and sex.
MATERIALS AND METHODS 7.1. Source of the data:
Out Patients visiting the Department of Oral Medicine and Radiology of Dr. Syamala Reddy Dental College, Hospital and Research centre, Bengaluru.
7.2. Method of collection of data:
The study group will be consisting of 1000 healthy adult patients between age groups 20-70 years, divided into 20-29, 30-39, 40-49, 50-59 and 60-69 sub age groups.
Inclusion criteria: 1) The radiographs of normal and asymptomatic patients will be included.
2) The radiographs with proper patient positioning and without any magnification errors will be included.
3) Radiographs of both the genders will be included.
Exclusion criteria: 1) The radiographs with questionable stylohyoid complex will be excluded.
2) Radiographs of patients of age groups less than 20 years and more than 70 years will be excluded.
3) The radiographs with superimposed normal anatomical structures will be excluded from the study.
Methodology: All the out patients visiting to Department of Oral Medicine and Radiology, Dr.Syamala Reddy Dental College will be undergoing thorough routine examination and a brief case history will be recorded. Demographic details will be recorded on imaging request form and the informed consent will be taken. All the patients satisfying the inclusion criteria will be selected as the study sample.
The subjects of the study will be examined according to the protocol for the presence or absence of elongated styloid process based on objective and subjective signs. All the subjects will be examined by palpation in the tonsillar fossa region to analyze any symptoms of elongated styloid process and for any sharp bony projections in that region. Subjects will be examined for the mandibular protrusive movement, which is the position of the mandible anterior to centric relation for evaluating any restriction in the movement. Subjects will be questioned about any foreign body sensation in the neck, hyper salivation and dysphagia.
Extra oral panoramic images will be taken using SORODEX CRANEX EXCEL CEPH and SOREDEX PSP Digital extra oral system phosphor imaging plate (15×30) with exposure parameters 73 Kvp; 6 mA. After processing, the images will be digitally stored using software DfW 2.6 and observed on a monitor.
The following will be measured or determined for each styloid process identified: prevalence, type and the pattern of calcification and also both the right and left styloid process will be analyzed independently. The length measurement will be initiated proximally at the point where the styloid process extends from the temporal bone using software DfW 2.6 (DIGORA PCT) with a magnification factor of 1.4 in a similar way as described by Ilguy et al.13 The morphology, type of elongation and calcification of styloid process on the right and left sides will be evaluated according to Langlais et al.12
Statistical analyses: The results obtained will then be tabulated, analyzed and concluded using SPSS 13.0 software.
7.3 Does the study require any investigations or interventions to be conducted on patients or other humans or animals? If so, please describe briefly
Yes, digital panoramic radiographs will be taken for the subjects
7.4 Has ethical clearance been obtained from your institution in case of 7.3?
LIST OF REFERENCES:
Shaik MA, N, Kaleem SM, Wahab A, Hameed S. Prevalence of elongated styloid process in Saudi population of Aseer region. Eur J Dent 2013; 7:449-54.
Ghafari R, Hosseini B, Shirani AM, Manochehrifar H, Saghaie S. Relationship between the elongated styloid process in panoramic radiographs and some of the general health conditions in patients over 40 years of age in the Iranian population. Dent Res J 2012; 9:S52-6.
Frommer J. Anatomic variations in the stylohyoid chain and their possible clinical significance. Oral Surg Oral Med Oral Pathol 1974; 38:659 67.
Eagle WW. Symptomatic elongated styloid process; report of two cases of styloid process carotid artery syndrome with operation. Arch Otolaryngol 1949; 49:490 503.
Prasad KC, Kamath MP, Reddy KJ, Raju K, Agarwal S. Elongated styloid process (Eagle’s syndrome): A clinical study. J Oral Maxillofacial Surg 2002; 60:171-5.
Jaju PP, Suvarna P, Parikh N. Eagles syndrome: An enigma to dentists. J Indian Acad Oral Med Radiol 2007; 19:424-9.
Sudhakara Reddy R, Sai Kiran Ch, Sai Madhavi N, Raghavendra MN, Satish A. Prevalence of elongation and calcification patterns of elongated styloid process in south India. J Clin Exp Dent. 2013(1):e30-5.
T Jung, H Tschernitschek, H Hippen, B Schneider, L Borchers. Elongated styloid process: When is it really elongated? Dentomaxillofacial radiology 2004; 33; 119-124.
Shah SP, Praveen NB, Syed V, Subhashini AR. Elongated Styloid Process: A Retrospective Panoramic Radiography Study. World J Dent 2012; 3(4):316-319.
Bagga MB, Anand C, Garima Y. Clinicoradiologic evaluation of styloid process calcification. Imaging Science in Dentistry 2012; 42: 155-61.
Shah SP, Praveen NB, Syed V, Subhashini AR. Elongated styloid process: A retrospective Panoramic Radiographic Study. World J Dent 2012; 3(4):316-319.
Langlais RP, Miles DA, Van Dis ML. Elongated and mineralized stylohyoid ligament complex: A proposed classification and report of a case of Eagle’s syndrome. Oral Surg Oral Med Oral Pathol 1986; 61:527 32.
Ilgüy M, Ilgüy D, Güler N, Bayirli G. Incidence of the type and calcification patterns in patients with elongated styloid process. J Int Med Res 2005; 33:96 102.