|FORENSIC ODONTOLOGY: ORIGINAL RESEARCH ARTICLE
|Year : 2020 | Volume
| Issue : 3 | Page : 266-270
Mandibular morphometric analysis for sex assessment: A retrospective radiographic study
Raghdaa A Mostafa1, Mona Abou El-Fotouh2
1 Lecturer of Oral and Maxillofacial Radiology, Faculty of Dentistry, Ain Shams University, Cairo, Egypt
2 Professor of Oral and Maxillofacial Radiology, Head Oral Medicine, Periodontology, and Oral Radiology department, Faculty of Dentistry, Ain Shams University, Cairo, Egypt
|Date of Submission||12-Apr-2020|
|Date of Decision||29-Jun-2020|
|Date of Acceptance||06-Jul-2020|
|Date of Web Publication||29-Sep-2020|
Dr. Raghdaa A Mostafa
Oral and Maxillofacial Radiology, Faculty of Dentistry, Ain Shams University, Cairo, Egypt, 5 Ahmed Hassan Elzayat Street, Nasr City, Cairo
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Objectives: The purpose of this study was to determine the value of mandibular morphometric measurements in sex assessment using digital panoramic radiographs in a sample of dentate Egyptian patients. Methods: A total of 200 digital panoramic radiographs (i.e.,100 males, 100 females) with age ranges between 20 and 60 years were selected. The samples were divided into 4 age groups with 10 years intervals. Maximum ramus width, minimum ramus width, condylar length, coronoid length, ramus length, gonial angle, ramus notch depth, bigonial width, horizontal length, and diagonal length were measured digitally for each subject. A comparison between different sex groups and age ranges was carried out and the mean values were calculated. Results: Mean results for minimum ramus width, condylar length, coronoid length, and ramus length were statistically significant for gender differences (P < 0.05).The mean of all measurements, except for gonial angle, ramus notch depth, and horizontal length, in males, was higher than that of females. Conclusions: Mandibular morphometric measurements assessed using panoramic radiographs can be used for sex assessment when compared to a known population standard.
Keywords: Forensic science, mandibular ramus, panoramic radiographs, sex assessment, sexual dimorphism
|How to cite this article:|
Mostafa RA, El-Fotouh MA. Mandibular morphometric analysis for sex assessment: A retrospective radiographic study. J Indian Acad Oral Med Radiol 2020;32:266-70
|How to cite this URL:|
Mostafa RA, El-Fotouh MA. Mandibular morphometric analysis for sex assessment: A retrospective radiographic study. J Indian Acad Oral Med Radiol [serial online] 2020 [cited 2020 Dec 3];32:266-70. Available from: https://www.jiaomr.in/text.asp?2020/32/3/266/296590
| Introduction|| |
Forensic odontology is a branch of dentistry which addresses issues related to human identification using dental evidence. The identification process begins with sex recognition followed by age and stature determination, as both factors are correlated to sex. Factors that impact sex identification include the percentage remaining from the skeleton while the other factor is the level of sexual dimorphism distinct within a population.
Sexual dimorphism is present in almost every bone. Pelvis and skull bones are considered to be the most significant, as both of them show the most dimorphic elements of the skeleton. The mandible can be useful in sex determination when the intact skull is not available.
Radiographs can be used in forensic anthropology. Compared to histological and biochemical methods, radiographs provide an inexpensive, simple, and less time-consuming tool for sex and age identification.
A panoramic radiograph is an important radiographic method that is used routinely in dental practices for jaws evaluation. It is considered to be a convenient tool for providing information about age and sex-related morphological variations in a single scan. Also, it allows vertical measurements and less accurate horizontal measurements for ramus and condyles.,
The mandible can be preserved compared to other bones, due to the existence of a layer of compact bone. Moreover, it shows sexual dimorphism in its shape and size as the growth rate of the mandible differs between both sexes.
The expression of mandibular sexual dimorphism can be seen in any place showing the process of bone deposition, resorption, or remodeling. These processes are greatly influenced by the size, strength, and angulation of the muscles of the mastication. These masticatory forces are different between males and females, therefore the mandibular condyle and ramus, in particular, are the most sexually dimorphic sites.,
Sexual dimorphism of the mandible is also affected by genetic or hormonal factors, skeletal characters, and socio-environmental factors including nutrition, food, climate, and pathologies. All of these factors lead to sexual dimorphic variations among various populations. Consequently, there is a need to develop and formulate population-specific standards for accurate sex determination.
Therefore, this study aimed to determine the value of mandibular morphometric measurements in sex assessment using digital panoramic radiographs in a sample of dentate Egyptian subjects.
| Methods and Patients|| |
The present retrospective study was conducted on 850 randomly collected panoramic radiographs stored in the archive of the Oral and Maxillofacial Radiology department, Faculty of Dentistry, Ain shams university, Cairo, Egypt during the period from January 2019 to August 2019.
A total of 200 radiographs (i.e.,100 males, 100 females) matched the inclusion criteria which included; high-quality panoramic radiographs, free from distortion and artifacts, and only radiographs of dentate patients of Egyptian origin were included.
The exclusion criteria for this study were as follows: no history of trauma to the maxillofacial region, no history of orthodontic or maxillofacial surgery, no abnormal dental condition, i.e., impaction, transposition and congenitally missing teeth, no pathology or congenital anomaly in the mandible that could affect the interpretation of the radiographic image, and no history of any systemic disease that might affect bone metabolism.
The study population was divided into four age groups; 20 to <30 years, 30 to <40 years, 40 to <50 years, and 50–60 years.
All digital panoramic radiographs were acquired using the department's panoramic machine Pax-I- (VATECH® Digital X-ray Imaging System, Korea) which uses the following parameters: 70 kVp and 10 mA, with a scanning time of 13 seconds with the standard protocol of patients positioning according to the manufacturer's instructions.
EzDent imaging software® provided by the same machine was used to digitally trace lines on the panoramic radiographs to assess the following measurements:
- Maximum Ramus Width: is the distance between the most anterior point on the mandibular ramus and the most posterior point on the condyle as described by Chalkoo et al. [Figure 1]
- Minimum Ramus Width: is the smallest anterior – posterior diameter of the ramus.[Figure 1]
- Condylar length: is the distance between the most superior point on the mandibular condyle and the deepest point in the concavity of the antigonial notch.[Figure 1]
- Coronoid length: is the distance between the coronoid and the deepest point in the concavity of the antigonial notch.[Figure 1]
- Ramus length: is the height of the ramus of the mandible measured from the most superior point on the mandibular condyle to the lower margin of the bone. This line was obtained by drawing a tangent backward from the deepest point in the concavity of the antigonial notch to meet a vertical line from the most superior point on the mandibular condyle down.[Figure 1]
- Gonial angle: Was assessed by tracing a line tangent to the lower border of the mandible and another line tangent to the posterior border of the ramus as described by Upadhyay et al.[Figure 2]
- Ramus notch depth: It Was measured as the perpendicular distance between a line tangent to the posterior border of the ramus line and the deepest point of the ramus concavity as described by Sairam et al.[Figure 1]
- Bigonial width: Measured as the horizontal distance from the right to the left of the gonial which is the most inferior, posterior, and lateral points on the external angle of the mandible as described by Lux et al.[Figure 3]
- Horizontal length: was measured as the distance between two horizontal lines, the first line tangent to the base of the mandible at the level of the symphysis menti and the other line connecting the posterior- most points at the angle at the junction of the body and the ascending rami of the mandible as described by Sharma et al.[Figure 3]
- The Diagonal length of the mandible body: this was measured between the point of the symphysis menti to the posterior- most point at the angle of the junction of the body and the ascending rami of the mandible. [Figure 3]
|Figure 1: Panoramic radiograph showing Maximum Ramus Width = 36.55 mm, Minimum Ramus Width = 29.62 mm, Condylar length = 68.06 mm, Coronoid length = 55.51 mm, Ramus length = 65.13 mm, Ramus notch depth = 2.05 mm|
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|Figure 2: Panoramic radiograph showing gonial angle; right side = 121.14°, left side 122.53°|
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|Figure 3: Panoramic radiograph showing Bigonial width = 174.75mm, Horizontal length = 38.27mm, Diagonal length of the mandible body (right side = 96.04mm, left side = 95.58)|
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All measurements were assessed bilaterally by one oral and maxillofacial radiologist with more than 10 years of experience, then the mean of both sides was calculated and used for further statistical analysis.
The analyses were performed using SPSS for windows version 24. The mean of the left and the right sides was calculated and used in further statistical analysis. Descriptive statistics for each variable were calculated. Independent sample 2-tailed t-tests were used for male-female comparison in all age groups. Results with P < 0.05 were considered statistically significant.
| Results|| |
In the present study, 850 panoramic radiographs were evaluated, with 200 radiographs meeting the criteria for inclusion. Descriptive statistics of the values of the ten different mandibular measurements in the four age groups of both males and females are summarized in [Table 1].
|Table 1: Descriptive statistics for the ten measurements in all age groups for both male (m) and female (f)|
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The mean of all measurements, except for gonial angle, ramus notch depth, and horizontal length, in males was higher than that of females. Bigonial width increased by age in both sexes. While measurements for ramus notch depth and diagonal length increased by age in males only.
Independent sample 2-tailed t-test was used for male-female comparison regardless of the age groups. Statistically significant gender differences were observed for minimum ramus width, condylar length, coronoid length, and ramus length (P < 0.05) as shown in [Table 2].
|Table 2: Male-female comparison for the ten studied mandibular measurements|
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Furthermore, male-female comparison within the same age group for each of the four groups revealed that in age group (20 to < 30), ramus depth was found to be statistically significant (P = 0.013) while in age group (30 to <40), minimum ramus width, condylar length, ramus length, and gonial angle were a statistically significant (P < 0.05). In the age group of (30 to <40), minimum ramus width, condylar length, ramus length, and gonial angle were statistically significant (P < 0.05). Coronoid length was statistically significant in the age group between 40 to <50 (P = 0.020). In the age group (50 to <60), condylar length, coronoid length, ramus length, and diagonal length were statistically significant (P < 0.05).
| Discussion|| |
Studying mandibular morphology has been used by anthropologists and forensic dentists.
 Panoramic radiographs are frequently used in these fields and are considered as a dependable technique. Despite the limitations of panoramic radiograph related to positioning errors, its accuracy in providing anatomic measurements has been established.
In the present study, the minimum ramus width, condylar length, coronoid length, and ramus length showed a significant difference between sexes. Those results were in agreement with the investigations was done by Rad et al., Behl et al. and Indira, et al. Another investigation was done by Samatha K., et al. on the same five variables as Indira, et al. reported significant differences in 3 of the 5 morphometric variables evaluated that is, maximum ramus width, condylar height, and height of ramus. Also, the authors stated that males showed higher values for the other variables, but the difference was not significant. In the current study, although the difference in maximum ramus width was not significant, higher mean values for males was observed.
Moreover, following a study by El-Shafey et al. the authors found a significant difference in all the parameters under investigation. Furthermore, they concluded that coronoid height and ramus height are the most dimorphic measurement.
Our results also correlated with the study done by Damera et al. In this study, condylar height, the height of ramus, and coronoid height showed significant differences. Kumar and Deepthi found statistically significant sex differences for maximum ramus width, minimum ramus width, maximum ramus height, and coronoid height.
Additionally, Chalkoo et al. reported that the coronoid height, condylar height, and height of ramus were statistically significant between sexes. Whereas, Bhuyan et al. reported that only the ramus height was statistically significant among the five variables assessed in a sample of 50 dentulous participants.
About the gonial angle, Upadhya et al. reported no correlation between the genders and the mandibular angle. The same results were reported by Sharma et al. However, this study was done on a sample of 126 dried mandibles belonging to the Indian population grouped into an adult and elderly groups.
On the other hand, the gender difference in the gonial angle was statistically significant in a study done by Bhuyan et al. Similar findings were also recorded by El-Shafey et al. and Rai et al.
Rad et al. and Levershaet al. found that females have a significantly higher value of gonial angle than their male counterpart. Behl et al. reported the same results. Our results showed that females had higher mean values compared to males. However, the difference was not statistically significant. This may be attributed to the difference in the populations under investigation. The age group for the study sample as reported by Behl et al. was 10-40 years old from the north Indian population. Whereas, the study sample in Leversha et al. was from Far North Queensland.
In the present study, ramus notch depth, bigonial width, horizontal length, and diagonal length showed non-significant malefemale differences. Damera et al. reported similar results for the bigonial width. Shamount, et al. showed disagreement with the above observations. Rad et al. reported significant results for the horizontal distance (bigonial width) and chain height. Singh et al. also stated significant sex differences in bigonial width and horizontal length, however, their study was conducted on dry human mandibles.
A clear trend of a consistent increase in the values of bigonial width with age in both sexes was observed in the current study. Similar findings were reported by Leversha et al. On the other hand, Sandeepa et al. reported that no correlation of the measurements with the age of the person was found. The authors' conclusions are also in agreement with the current results in the present study where no specific pattern was observed for the ramus notch depth, horizontal width, and diagonal length with age.
| Conclusion|| |
Based on the results of this study, the minimum ramus width, condylar length, coronoid length, and ramus length showed differences between both males and females. These mandibular morphometric measurements can be used for sex assessment when compared to a known population standard.
Furthermore, the results of this study should be applied cautiously on dry mandibular remains as it was conducted on living individuals.
Further research is recommended on a larger sample from different geographic regions to improve the effectiveness of these measurements.
Our study was exempted from the Review of the Ethics Committee as all included panoramic radiographs were retrieved from the records of the Oral and Maxillofacial Radiology Department and were taken for reasons other than the purpose of this study.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3]
[Table 1], [Table 2]