|Year : 2020 | Volume
| Issue : 1 | Page : 31-36
Mandibular ramus and gonial angle—Identification tool in age estimation and sex determination: A digital panoramic radiographic study in north indian population
Ashima Bali Behl1, Salvina Grewal2, Kavisha Bajaj3, Parvinder Singh Baweja4, Gurpreet Kaur5, Pavita Kataria6
1 Department of Oral Medicine, Diagnosis and Radiology, Baba Jaswant Singh (BJS) Dental College, Hospital and Research Institute, Ludhiana, Punjab, India
2 Practicing Dentist at The Dental Care Centre, Ludhiana, Punjab, India
3 Practicing Dentist at Bali Dental Clinic, Ludhiana, Punjab, India
4 Department of Conservative and Endodontics, Baba Jaswant Singh (BJS) Dental College, Hospital and Research Institute, Ludhiana, Punjab, India
5 Department of Prosthodontics, Baba Jaswant Singh (BJS) Dental College, Hospital and Research Institute, Ludhiana, Punjab, India
6 Department of Periodontics, Baba Jaswant Singh Dental College and Research Institute, Ludhiana, Punjab, India
|Date of Submission||02-Oct-2019|
|Date of Decision||20-Dec-2019|
|Date of Acceptance||06-Jan-2020|
|Date of Web Publication||17-Apr-2020|
Dr. Ashima Bali Behl
Department of Oral Medicine Diagnosis and Radiology, BJS Dental College, Hospital and Research Institute, Ludhiana, Punjab -141 001
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Background: Identification of the skeletal remains is of paramount importance in forensic dentistry and medico-legal investigations. Mandible may play a vital role in sex determination, as it is the most dimorphic bone of skull, which is often recovered intact. Mandibular ramus and gonial angle can be used to differentiate between sexes and age estimation. Aims and Objectives: The aim of the study was to assess the usefulness of digital panoramic radiographs to determine sex and age using linear measurements made with respect to gonial angle and ramus region in the population of north Indians. Materials and Methods: A total of 400 patients (North Indians: Males and females in equal number) were further divided into age groups 10-40 years. The linear measurements were made in ramus and gonial angle region, which were calculated by using Adobe Acrobat Reader, and findings were statistically analyzed. Results: Males showed a higher average value in terms of ramus breadth, condylar and coronoid ramus height than females. In addition, a significant positive correlation was seen between age and ramus linear measurements. Males have higher gonial angle than females and with increase in age, gonial angle decreases. In relation to gonial angle, females showed a higher gonial angle. “In addition, as age increases, decrease in gonial angle was found.”. Conclusion: In selected north Indian populace, mandibular ramus showed higher sexual dimorphism in relation with age and sex estimation. However, gonial angle can only be used as an additional tool to establish the identity of a person.
Keywords: Dentulous State, Mandibular Gonial Angle, Mandibular Linear Measurements, Mandibular Ramus, panoramic study
|How to cite this article:|
Behl AB, Grewal S, Bajaj K, Baweja PS, Kaur G, Kataria P. Mandibular ramus and gonial angle—Identification tool in age estimation and sex determination: A digital panoramic radiographic study in north indian population. J Indian Acad Oral Med Radiol 2020;32:31-6
|How to cite this URL:|
Behl AB, Grewal S, Bajaj K, Baweja PS, Kaur G, Kataria P. Mandibular ramus and gonial angle—Identification tool in age estimation and sex determination: A digital panoramic radiographic study in north indian population. J Indian Acad Oral Med Radiol [serial online] 2020 [cited 2020 Jun 1];32:31-6. Available from: http://www.jiaomr.in/text.asp?2020/32/1/31/282608
| Introduction|| |
According to Federation Dentaire Internationale (FDI), Forensic odontology is the branch of dentistry, which in the interest of justice deals with proper handling and examination of dental evidence and with proper evaluation, and presentation of dental findings.American Society of Forensic Odontology stated that Forensic odontology is by definition the application of dental science to law, i.e. the use of dental evidence in interest of justice. Keiser and Neilson in year 1970 defined Forensic odontology as that branch of dentistry which deals with proper handling and examination of dental evidence in interest of justice so that dental findings may be properly presented and evaluated. This branch has been utilized for many years for identification of victims and suspects in mass disasters, abuse, and organized crimes.
Through ages, the skull has remained useful for creation of biological profiles in mass disasters. However, in most cases when the entire skull is not available, the technical procedures have to be based on fragmented bones of skull. In such cases, mandible, which is the largest and the most dimorphic part of skull, plays a vital role in sex determination in corpse remains of the subjects.
Humphrey et al. in the year 1999 stated that sexual dimorphism is reflected in mandibular ramus than in the body. Similarly, variation in gonial angle with age, gender, and even dental status has been observed which is supported by radiographic and anthropometric studies.
Panoramic radiographs (OPG) are the most common extraoral radiographs that provide the maximum details with respect to hard tissue of maxilla and mandible and can be easily saved and stored in database for years. In forensic anthropology, calibrated measurement tool was used and antemortem radiographs provide cornerstone of positive identification of human remains. The presence of plenty of panoramic radiographs provides a great opportunity to study sexual dimorphism and age estimation of individuals in certain population. This was the idea of using panoramic images for various measurements in north Indian populace. OPGs were preferred diagnostic tools than cephalograms as there is no super imposition of structures and the measurements can be made bilaterally with more accuracy.
| Aims and Objectives|| |
- To measure various morphometric parameters of mandibular ramus and gonial angle in digital panoramic radiographs.
- To correlate these findings in the determination of
To find out which are the most reliable and accurate parameters in gender and age determination.
| Materials and Methods|| |
A sample of 400 antemortem orthopantomograms/OPG (200 males and 200 females) of north Indian population between 10 and 40 years of age was selected for study. The images were acquired using ORTHOPHOS XG5DS/CEPH system with exposure parameters of 60–90 Kvp, 3–16 mA, 14.1 s from radiology department of the institution. The digital panoramic images were saved in pdf format and exported to Adobe Acrobat Reader software where linear measurements in mandibular ramus and gonial angle were taken/done. The statistical analysis was done using Pearson correlation coefficient (P-value) and average values were also taken. A regression equation was also framed.
After image calibration, the following ramus linear and gonial angle measurements were performed.
- Upper ramus breadth (a): The horizontal distance between the most anterior to the most posterior point of the ramus passing through the sigmoid notch along a line parallel to the transverse plane [Figure 1].
- Lower ramus breadth (b): The horizontal distance between the most anterior to the most posterior point of the ramus at the level of the occlusal plane along a line parallel to the previous one. (An average ramus breadth value of (a) and (b) was calculated for each side and used for further analysis) [Figure 1]. For standardization, a horizontal orientation line (O) was digitally traced passing through the summit of the gonial angle and used for the following measurements
- Condylar ramus height (c): The distance from the condylion (A) to the intersection of the orientation line with the inferior border of the ramus (B) [Figure 2].
- Coronoid ramus height (d): The distance between coronion (C) and the intersection of the orientation line with the inferior border of the ramus (B) [Figure 2].
- Gonial angles (e): These were measured as the intersection between a digitally traced line tangential to the most inferior points at the angle and the lower border of the mandibular body and another line tangential to the posterior borders of the ramus and the condyle [Figure 3].
- Subjects between: 10 and 40 years
- Good quality standard panoramic images without any grade of exposure or positioning errors.
- Radiographs without any pathologies/fractures/trauma to the mandible/structural deformities/developmental disorders of head and neck region.
- Patients without any orthodontic treatment.
- Presence of pathological lesion, fracture or deformity
- Age group <10 years and >40 years
- Presence of splinting, bone plates, lag screws.
- Presence of developmental anomalies/disturbance/syndromes.
| Results|| |
Age (total): 26.179 + 3.856 Condylar Ramus (Left) – 0.127 Gonial Angle (Right)
Age (females): 10.784 + 3.725 Condylar Ramus (Left)
Age (males): 42.159 + 10.489 Upper Ramus (Right) – 7.14 Lower Ramus (Right) – 0.226 Gonial Angle (Right)
| Discussion|| |
What an evolution of dentistry for just managing tooth decay in ancient times to cosmetology, fighting cancer, and now to determine age and sex in forensic analysis. It has happened not as a miracle but because of hard work put in by thousands of dentists for millions of hours for the cause of society in general and dentistry in particular.
Age estimation and sex determination are one of the important duties of medicolegal officers in recent times as crimes of varied nature are increasing. Mandibular condyle, ramus, and angle (gonial) in particular are generally most sexually dimorphic as they are sites associated with greatest dimorphic morphological changes in size and remodeling during growth.
Cross-sectional studies have promoted the concept that mandibular ramus and angle could be used as an indicator of age and gender.
The present study showed a statistically significant difference between males and females gonial angles [Figure 3]. Females showed greater mean values as compared to males, i.e. approximately 3°–4°. Females–120.98 (R), 121.57 (L); Males–117.28 (R), 121.01 (L) [Table 1] and [Figure 4]. Our results correlated with Huumonen et al. who found significantly larger gonial angle in females as compared to males. Raustia and Salonen et al. also showed no correlation of gonial angle with gender. Al-Faleh could not establish any significant difference between sexes and gonial angle.
Our results did not correlate with studies by Shahabi et al. which showed no statistically significant difference between gonial angle of two sexes; Jensen and Palling showed increase in gonial angle of male than females. A study done on Anatolian population by Gungor et al. showed no significant difference between right and left gonial angles but significant difference between left gonial angle between sexes, whereas in our study, a difference between right and left gonial angle of males and females with significant difference between right gonial angles between sexes was noted.
Our study showed a decrease in gonial angle with advancing age [Table 2], intergroup analysis following a significant pattern which correlated with study by Upadhyay. which showed decrease in gonial angle with increasing age but intergroup analysis does not follow a significant pattern. Our result did not correlate with studies done by Izard which showed gonial angle increase with age and Ohm and Silness which also showed the same results as Izard.
Mandibular ramus used as age [Table 3] and sex determination tool in the present study showed a statistically significant positive (direct) correlation between age and ramus linear measurements, i.e. an increase in age [Figure 5], [Figure 6], [Figure 7], [Figure 8] is associated with increase in these measurements and vice-versa, which was in accordance with the study conducted on Egyptian population. No statistically significant difference was found between right and left side regarding linear measurements, which was in favor with the previous studies. Subsequently, mean of two sides was further used for further statistical analysis.
The present study [Table 4] revealed that males had statistically significant higher mean values regarding all mandibular ramus linear measurements than females [Figure 9], [Figure 10], [Figure 11], [Figure 12]. Ramus breadth –upper = 1.66(M), 1.59(F); lower = 1.40(M), 1.45(F); condylar ramus height = 3.01(M), 2.74(F); coronoid ramus height = 2.89(M), 2.68(F). Discriminant function [Table 5] analysis revealed that condylar ramus height and coronoid ramus height are significant indicators for predictors of sex estimation which favors the study conducted on Egyptian population in which only condylar ramus height was significant predictor of sex estimation.
|Table 4: Association of gender with various mean mandibular measurements|
Click here to view
This was in agreement with Saini et al. in study of mandible of North Indian population who found ramus metric parameters were higher in males than in females. Rai et al. in their study on human dentate dry mandible of Indian population found that height of ramus male mandibles showed a significant difference than that of females' mandible; however, there was no significant difference in breadth of ramus between both sexes.
| Conclusion|| |
Our study showed that gonial angle is influenced by both gender and age. As gonial angle decreases with increasing age, there seems to be the difference in gonial angle with different age groups but little significant and definitely reliable. Gonial angle can serve as an adjunct and additional forensic parameter which guides for age group assessment and sex determination.
In selected North Indian population sample, the mandibular ramus showed a high sexual dimorphism with condylar and coronoid ramus heights as the most significant predictor for age and sex estimation. Hence, in the present study, mandibular ramus was selected for age and sex estimation. The study of sex estimation is not only important from a forensic point of view but also for regional variations and population history. However, such views hold little significance as increasing literature shows contrary and variable results.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8], [Figure 9], [Figure 10], [Figure 11], [Figure 12]
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5]