Radiomorphometric analysis of the clivus – A soothsayer of age and gender

Karnam Shalini; Tejaswi Katne; Srikanth Gotoor; Ramlal Gantala; Alekhya Kanaparthi; Nivedhitha Parthasarathy

doi:10.4103/jomr.jomr_8_22

ORIGINAL ARTICLE

Year : 2022 | Volume : 10 | Issue : 3 | Page : 69-75

Radiomorphometric analysis of the clivus – A soothsayer of age and gender

Karnam Shalini¹, Tejaswi Katne², Srikanth Gotoor², Ramlal Gantala², Alekhya Kanaparthi³, Nivedhitha Parthasarathy⁴
¹ Department of Prosthodontics, GDC&H, Hyderabad, Telangana, India
² Department of Oral Medicine and Radiology, SVS Institute of Dental Sciences, Mahabubnagar, Telangana, India
³ Department of Oral Medicine and Radiology, MNR Dental College and Hospital, Sangareddy, Telangana, India
⁴ Department of Public Health, Prasanna School of Public Health, Manipal Academy of Higher Education, Manipal, Karnataka, India

Date of Submission	06-Apr-2022
Date of Decision	29-Jun-2022
Date of Acceptance	30-Jun-2022
Date of Web Publication	29-Dec-2022

Correspondence Address:
Tejaswi Katne
Department of Oral Medicine and Radiology, SVS Institute of Dental Sciences, Mahabubnagar - 509 002, Telangana
India

Source of Support: None, Conflict of Interest: None

Check

DOI: 10.4103/jomr.jomr_8_22

Abstract

Purpose: Skull is the most studied skeletal remaining as enamel and bones are the last ones to disintegrate after death. The clivus is one such dense part of the skull base and most of the time it is recovered intact from a damaged or incinerated skull and can be used as an indicator in identification. The present study is aimed to perform a radiomorphometric analysis of the clivus using cone-beam computed tomography (CBCT) and to assess its pertinence in age and gender estimation. Materials and Methods: The CBCT images of 254 (162 males, 92 females) subjects were obtained from New tom Giano HR (QR SRL Company, Verona, Italy) CBCT machine at 90 kVp, 6 mA for 7.2 s at the field of view (16 × 18), voxel size of 300 in the age group of 6–70 years were chosen. The clivus widths and lengths were measured using NNT software programs on axial and sagittal reconstructed images. Results: Mean clivus lengths and widths were significantly different in male and female patients. Bivariate correlations showed that there was a stronger association of the clivus lengths and widths to age when considered a linear combination as opposed to when taken individually in both female and male patients. Association between the linear combination of the clivus lengths and widths with age was found to be the highest in female patients among all the results (R = 0.553). All the above results were statistically significant (P < 0.05). Conclusion: CBCT measurements of clivus dimensions can be used reliably for anthropometric analysis as they are precisely associated with age and gender. Hence, it can be concluded that these dimensions can be used as a supplementary or only parameter when other parameters are uneventful in medicolegal cases.

Keywords: Age estimation, cone-beam computed tomography, clivus, foramen magnum

How to cite this article:
Shalini K, Katne T, Gotoor S, Gantala R, Kanaparthi A, Parthasarathy N. Radiomorphometric analysis of the clivus – A soothsayer of age and gender. J Oral Maxillofac Radiol 2022;10:69-75

How to cite this URL:
Shalini K, Katne T, Gotoor S, Gantala R, Kanaparthi A, Parthasarathy N. Radiomorphometric analysis of the clivus – A soothsayer of age and gender. J Oral Maxillofac Radiol [serial online] 2022 [cited 2023 Mar 29];10:69-75. Available from: https://www.joomr.org/text.asp?2022/10/3/69/366164

Introduction

In the recent past, forensic experts and anthropologists have been facing critical problems in the identification of deceased humans from hard tissues mainly bone. Conventionally, the skull is the most studied bone in physical anthropology.^[1] Gender determination is considered one of the most reliable tools for the identification of a deceased individual. Skeletal remains such as bones and enamel are the last to disintegrate after death and can be used as a tool for sex determination of an individual.^[2] The pelvis is the best and the skull is the second-best area for gender estimation as the craniofacial structures are less affected by environmental factors and comparatively remain undamaged.^[3] Age estimation is also needed for legal responsibilities and defining a living individual.^[4] Forensic experts are generally encountered with decomposed bodies and disintegrated skeletons which impose a need to look for alternative methods of sex determination.^[5]

The clivus is a part of the skull base situated between the foramen magnum (FM) and dorsum sellae. It is formed by the fusion of the synchondrosis between the exoccipital and basioccipital bones. After the fusion, it starts to grow and the process of ossification starts from the 3^rd year and continues until the age of 25 years to create basisphenoid and basiocciput.^[1],[6]

The clivus is bounded anteriorly by sphenoidal sinus, posteriorly by the anterior limit of prepontine and premedullary cisterns, inferiorly by posterior nasopharyngeal space, and laterally by petro-occipital fissure that begins near the cavernous sinus and extends inferiorly to the jugular foramen. Due to its dense nature and intactness even after incineration, the clivus can be alternatively used for gender determination medicolegally by anthropometric measurement.^[6]

The clivus can be evaluated very clearly using three-dimensional imaging technologies such as magnetic resonance imaging, computed tomography (CT), and cone-beam CT (CBCT) scans due to its central location. The clivus is located in the posterior cranial fossa and is related ventrally to the brainstem. Not only from anthropometric point of view but clinically also this is an important surgical site for related pathologies.^[7],[8],[9] On radiological examination using CT/CBCT, clivus, is best appreciated in axial and sagittal sectional view. Anterior and posterior boundaries are formed by compact cortical bone with the central portion consisting of cancellous bone with narrow fatty elements.^[10]

With the advent of newer technologies, CBCT has become a popular imaging technique due to better spatial resolution, quick scan time, isotropic image quality, and relatively low radiation dose compared to conventional CT making it, an alternative imaging modality. The visualization of cranial morphology and a three-dimensional approach to visualize and assess the morphology, and dimensions allow CBCT, as a potential tool for personal identification in forensic science and anthropometry.^[11]

Various studies in the literature pertaining to skull base have shown substantial evidence of the use of parts such as the FM, mastoid, maxillary sinus, frontal sinus, and occipital condyles as a forensic tool for age determination and sexual dimorphism. However, very few studies have evaluated clivus.^[1] Owing to the need to establish newer methods for determining sex and age from skeletal remains the proposed study was carried out with the objective to measure the relevant parameters of the clivus for age and sexual dimorphism using CBCT scans and to determine its forensic and medicolegal significance radiomorphometrically. Full-volume CBCT scans were used for this purpose.

Materials and Methods

This retrospective study was carried out in the department of oral medicine and radiology at a private dental college, during 2018–2019. The study was designed to measure the dimensions of the clivus for age determination and sexual dimorphism using CBCT. The study population comprised 254 images. They were previously referred to the radiology department for several other reasons. Informed consent was taken from all the participants at the time of taking the scan that required data from their CBCT scans can be used for further retrospective studies.

The CBCT images of subjects with no history of trauma and pathology and those diagnosed as normal were included in the study. Any CBCT with trauma, facial asymmetry, postsurgical, and obvious pathologies were excluded from the study. All the study subjects were examined on Newtom Giano HR CBCT machine (QR SRL Company, Verona, Italy). The axial and sagittal images were obtained at 90 kVp, 6 mA for 7.2 s at the field of view (16”×18)” voxel size of 300. The measurement of the clivus dimensions was done directly on DICOM images using NNT software program (Newtom, Verona, Italy). The measurements (width and length) were obtained from axial and sagittal sections using CBCT scans. All sections selected were aligned parallel to the plane of the FM to select the image for standardization [Figure 1].

Figure 1: Standardization with axial, coronal, and sagittal sections

Click here to view

The greatest measurement was taken after going through different slices in axial and sagittal sections of CBCT images.

The measurements were carried out as follows:

The axial reconstructed image was used to measure clivus width and was defined as the longest distance from left to right side near the anterior peripheral margin of FM inferiorly [Figure 2]
The sagittal reconstructed image was used to measure clivus length and was defined as the longest distance superio-inferiorly from the upper point of the dorsum sellae to the lowest point on the anterior margin of FM [Figure 3].

Figure 2: Axial reconstructed CBCT image demonstrating clivus width, CBCT: Cone-beam computed tomography

Click here to view

Figure 3: Sagittal reconstructed CBCT image demonstrating clivus width, CBCT: Cone-beam computed tomography

Click here to view

All the measurements obtained were entered into the Excel sheets and were subjected to statistical analysis.

Statistical analysis

Data were analyzed using SPSS version 21.0. Categorical variables were presented in number and percentage (%) and continuous variables were presented as mean and standard deviation quantitative variables were compared using the ANOVA test (i.e., clivus measurements and age) and independent t-test (i.e., clivus measurements and sex). Pearson correlation coefficients were used to determine the relationship between two scale parameters, whereas the correlation was defined as a measure of the strength of a linear relationship between two variables. Linear regression analysis was conducted to represent the correlation in the form of a mathematical equation: Y = mx + c. A P < 0.05 was considered statistically significant.

Results

The study sample comprised 254 subjects aged between 6 and 70 years with a mean age of 34 years. About 92 (36.2%) subjects were female and 162 (63.8%) of them were male. The male-to-female sex ratio was 1.7:1. The subjects were categorized into five age groups: <18 years, 19–30 years, 31–50 years, 51–65 years, and >65 years. The descriptive statistics of age and sex of the study sample are given in [Table 1].

Table 1: Distribution of patients by age and sex

Click here to view

Using an independent t-test, association of the clivus length and width was estimated between both genders. It was seen that the means of both the variables, clivus length, and clivus width were significantly higher in males compared to females (P < 0.05) [Table 2]. One-way ANOVA was applied to determine the association of the clivus length and width in different age groups of subjects. Both clivus length and width were found to be statistically significant for different age groups (<0.001). Mean clivus length (43.27 mm) was highest in the age group of 31–50 years. Mean clivus width (31.42 mm) was found to be highest in the age group of 51–65 years [Table 3].

Table 2: Descriptive statistics of the clivus length and width in different genders

Click here to view

Table 3: Descriptive statistics of the clivus length and width in different age groups

Click here to view

The bivariate correlation between age and clivus length and width was done to find out any linear relationship between the variables. Pearson correlation coefficient showed a positive correlation in all the cases. It is evident that a strong positive correlation is seen between the clivus width and age for female patients (r = 0.533) and a moderate positive correlation for male patients (r = 0.301), whereas a weak positive correlation is seen between the clivus length and age for both female (r = 0.259) and male patients (r = 0.195). In addition, it was also seen that the linear combination of the clivus length and width gives a stronger association than when taken individually in both female and male patients [Table 4].

Table 4: Bivariate Pearson correlation of the clivus length and width with age in different genders

Click here to view

Using linear regression analysis, when the clivus length is taken in relation to age, the mathematical equation derived in males is age = (2.68* clivus length) – 80.01 [Graph 1] and for females is age = (5.26* clivus length) – 190.29 [Graph 2]. When clivus width is taken in relation to age, the mathematical equation derived using linear regression analysis for males is age = (3.16* clivus width) – 58.41 [Graph 3] and for females is age = (6.99* clivus width) – 168.01 [Graph 4].

Linear regression analysis has been carried out for linear combination of the clivus length and width in relation to age and gender in males and the mathematical equation derived is age = (2.23* clivus length) + (2.96* clivus width) – 148.63 [Graph 5] and for females, it is age = (3.03* clivus length) + (6.56* clivus width) – 283.43 [Graph 6].

Hence, it can be concluded that if the clivus length and/or width of the patient are known, age can be predicted with the help of a mathematical equation derived from linear regression analysis.

Discussion

In recent years, many disaster incidents have occurred that challenged forensic experts, globally with difficulties related to disaster management and victim identification. New technologies and anatomical markers have been developed constantly to make the working process faster and effective. In mass disasters, victim identification and sex determination are complex procedures and the study of anthropometric characteristics plays a pivotal role. Often, craniometric features are included among these characteristics that aid in identifying an individual from a skull remains found.^[12]

As mentioned earlier, the skull is the second-best sexually dimorphic portion of the body after the pelvis. If all of the bones that make up the skeleton are present, gender can be determined with 100% precision in contrast to cases of explosions, war fares, and other mass disasters.^[13] In the aforementioned scenario, radiography can assist in giving precise dimensions after applying specific formulae to determine age and gender. They can be accomplished using either morphological or radiomorphometric methodologies.^[14]

Previous studies on the clivus by Chaurasia et al.^[1],[15] and Bayrak et al.^[2] suggested the use of morphometric measurements on CBCT scans and found that the clivus shows sexual dimorphism and the length and width correlated with age.

In the present study, 254 CBCT images constituted the total sample. All the subjects were within the age range of 6–70 years with a mean age of 34 years. Both clivus length and width were higher in males and a statistically significant difference was found between all age groups in both clivus lengths and widths. In addition, the current study reported the difference in age determination when the clivus length and width were taken individually and together in both male and female sexes (P < 0.001). Furthermore, the clivus width showed a stronger correlation with age, suggesting it to determine age better than clivus length.

The results in the present study correspond with study conducted by Chaurasia et al.^[15] Based on the positive correlation between the clivus width and clivus length and reported that the mean clivus length was significantly higher in males compared to females. However, the same research group reported a study in 2018^[1] on a pediatric population of 150 subjects, with age range of 6–17 years (76 males and 74 females) and reported that statistically no significant difference was observed with clivus width in between male and female (P > 0.05). However, the clivus length was statistically significant (P < 0.001) in both male and female populations. They concluded that clivus width and clivus length were directly associated with age.

Jehan et al. in 2014^[5] conducted a study on 276 subjects to determine sexual dimorphism using clivus on CT scan. They suggested the mean clivus length and width of males were significantly (P < 0.0001) larger than those of females, respectively. The overall accuracy of correct diagnosis was 76.43% in males and 77.94% in females, Concluding that clivus can be used as a forensic tool in medicolegal cases.

Krmpotic-Nemanic et al.^[16] in 2005 reported studied 77 skull bases and reported that the final length of the clivus was reached by 11 years of life in both men and women, and then remained constant throughout life. The mean clivus length and width of males was larger than females and this difference was statistically significant (P < 0.0001) and these results are in accordance with our study.

Krogman et al.^[17] in their study stated that the shape of the cranial base as seen in the sellar angle was influenced by clefting, whereas the size, i.e., the clivus length and the anterior cranial base length were affected by sex and the results of our study suggested that both clivus length and width showed a significant correlation with age and gender.

Considering the predictability of clivus dimensions in the current study and the previous studies, these measurements can be used to supplement other evidence available, to precisely determine the age and gender of the skeletal remains. The current study also proves that the age determination is most accurate when clivus length and width are both taken together. Furthermore, the mathematical equations derived from linear regression analysis can be used in age prediction of an individual if the clivus width/clivus length is known, thereby making these measurements significant in forensic science and anthropology.

Limitations

The study has few limitations; first, the small sample size and inter or intraobserver variations were not calculated and it has to be kept in mind, that there may be scope for variations in the dimensions, owing to environmental or genetic factors. Therefore, we recommend further studies with a large sample size, and also in other populations to assess the accuracy level of clivus in sex and age determination.

Conclusion

The radiomorphometric evaluation of the clivus seemed to be a useful technique to determine gender and age of an individuals. There is a significant relationship between the gender and age of the individual and with length and width of the clivus. These parameters may be reliably used for sexual dimorphism and age estimation in anthropometric and forensic analysis. In our study, CBCT images could provide adequate measurements of the clivus with low radiation exposure, thereby can be used for evaluating radiomorphometric analysis of cranium in the field of forensic science.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1.	Chaurasia A, Patil R, Katheriya G. Radiomorphometeric evaluation of clivus in Indian paediatric population visiting a tertiary dental hospital – A cone beam computed tomography study. J Clin Diagn Res 2018;12:ZC05-8.
2.	Bayrak S. , Göller bulut d. Assessment of foramen magnum and clivus for estimation of age and gender using cone-beam ct. Atatürk üniversitesi diş hekimliği fakültesi dergisi. 2019; 29(2): 244-251.
3.	Uthman AT, Al-Rawi NH, Al-Timimi JF. Evaluation of foramen magnum in gender determination using helical CT scanning. Dentomaxillofac Radiol 2012;41:197-202.
4.	Bayrak S, Halıcıoglu S, Kose G, Halıcıoglu K. Evaluation of the relationship between mandibular condyle cortication and chronologic age with cone beam computed tomography. J Forensic Leg Med 2018;55:39-44.
5.	Jehan M, Kumar RK. Sexual dimorphism of clivus dimension by computed tomography scan. Indian J App Res 2014;4:379-81.
6.	Hofmann E, Prescher A. The clivus: Anatomy, normal variants and imaging pathology. Clin Neuroradiol 2012;22:123-39.
7.	Sallabanda K, Bustos JC, Gutiérrez-Díaz JA, Beltrán C, Peraza C, Delgado JM, et al. Long-term follow-up of 32 meningiomas of the clivus and foramen magnum subjected to stereotactic radiosurgery. In: McDermott MW, editor. Radiosurgery. Vol. 7. Basel: Karger; 2010. p. 202-11.
8.	Chen X, Dai J, Ai L, Ru X, Wang J, Li S, et al. Clival invasion on multi detector CT in 390 pituitary macroadenomas: correlation with sex, subtype and rates of operative complication and recurrence. AJNR Am J Neuroradiol 2011;32 (4):785 89. [PMID: 21436342].
9.	Mahale A, Dhananjaya KV, Pai M, Poornima V, Sahu KK. MRI sequence and characteristic features in 'Giant Cell Tumor' of clivus. J Clin Diagn Res 2013;7:1197-200.
10.	Bravo, A.P., Caceres, I.A., Sanz, L.I., Villoria, J.G., Ossaba, S., & Crespo, J.C. (2012). Tumors and tumor-like conditions of the clivus. A comprehensive review. ECR. 2012;C-1581 [cited 2022 Jan 6]. Available from: https://epos.myesr.org/esr/viewing/?module=viewing_ poster&pi=108634.
11.	Tambawala SS, Karjodkar FR, Sansare K, Prakash N, Dora AC. Sexual dimorphism of foramen magnum using cone beam computed tomography. J Forensic Leg Med 2016;44:29-34.
12.	Jaitley M, Phulambrikar T, Kode M, Gupta A, Singh SK. Foramen magnum as a tool for sexual dimorphism: A cone beam computed tomography study. Indian J Dent Res 2016;27:458-62. [PUBMED] [Full text]
13.	Gargi V, Prakash SM, Malik S, Nagaraju K, Goel S, Gupta S. Sexual dimorphism of foramen magnum between two different groups of Indian population: A cross-sectional cone-beam computed tomography study. J Forensic Sci Med 2018;4:150-5. [Full text]
14.	Di Vella G, Campobasso CP, Dragone M, Introna F Jr. Skeletal sex determination by scapular measurements. Boll Soc Ital Biol Sper 1994;70:299-305.
15.	Chaurasia A, Katheriya G, Patil R. Radio-morphometric evaluation of clivus in Indian Ethini city – A cone beam computed tomography study. J Oral Med Oral Surg Oral Pathol Oral Radiol 2017;3:35-41.
16.	Krmpotić-Nemanić J, Vinter I, Kelovizć Z, Marusić A. Postnatal changes of the clivus. Ann Anat 2005;187:277-80.
17.	Krogman WM, Jain RB, Long RE Jr. Sex differences in craniofacial growth from one month to ten years of cleft lip and palate. Cleft Palate J 1982;19:62-71.