Journal of Indian Academy of Oral Medicine and Radiology

FORENSIC ODONTOLOGY: ORIGINAL ARTICLE
Year
: 2019  |  Volume : 31  |  Issue : 2  |  Page : 152--154

Determination of gender by using mandibular flexure – A radiographic study


Leena James, Tejavathi Nagaraj, Sita Gogula, CK Sumana, Haritma Nigam, Swati Saxena 
 Department of Oral Medicine and Radiology, Sri Rajiv Gandhi College of Dental Sciences and Hospital, Bengaluru, Karnataka, India

Correspondence Address:
Dr. Sita Gogula
Department of Oral Medicine and Radiology, Sri Rajiv Gandhi College of Dental Sciences and Hospital, Bengaluru, Karnataka
India

Abstract

Introduction: In forensic medicine identification of age, gender is an initial step in determining one's identity. After the pelvis, mandible plays an important role in determining gender when the whole body is not present. Forensic dentists require knowledge encompassing a number of disciplines since the dental records obtained can identify an individual or afford the information needed by the authorities to establish neglect, fraud, or abuse. Aim: Determination of gender by using mandibular ramus flexure. Materials and Methods: The study was conducted on 50 male and 50 female orthopantomographs taken in the Department of Oral Medicine and Radiology. Each image was examined for the presence of flexure on the posterior margin of the ramus at the occlusal plane. The posterior margin of the ramus was carefully traced graphically and the occlusal plane level was delineated as guided by the height of cusp tips at the occlusal surfaces of the mandibular molars. Results: In the present study, it was proved 64% accuracy in determination of gender with P value of 0.005. Conclusion: By using ramus flexure, sex can be determined moderately and can be used as a supplementary in determining the sex.



How to cite this article:
James L, Nagaraj T, Gogula S, Sumana C K, Nigam H, Saxena S. Determination of gender by using mandibular flexure – A radiographic study.J Indian Acad Oral Med Radiol 2019;31:152-154


How to cite this URL:
James L, Nagaraj T, Gogula S, Sumana C K, Nigam H, Saxena S. Determination of gender by using mandibular flexure – A radiographic study. J Indian Acad Oral Med Radiol [serial online] 2019 [cited 2019 Oct 21 ];31:152-154
Available from: http://www.jiaomr.in/text.asp?2019/31/2/152/261097


Full Text



 Introduction



Forensic dentistry involves the processing, review, evaluation, and presentation of dental evidence with the purpose of contributing scientific and objective data in legal processes. Forensic dentists require knowledge encompassing a number of disciplines because the dental records obtained can identify an individual or afford the information needed by the authorities to establish neglect, fraud, or abuse.

In the identification of human remains, skeleton plays a crucial role where the gender can be determined with 100% accuracy. When the entire skeleton is not available as in case of mass disasters to identify the persons, identity with the available skeletal remains, mandibular ramus flexure also plays a prominent role.[1]

To consider the skeletal remains as an indicator of gender the following criteria should be fulfilled:[2]

The anatomic and physiologic gender differences should be reflected in the morphologyIt should withstand the extreme climatic changes of skeletonization and fossilizationThrough time the trait should be recognizable.

Among skull bones, mandible plays a crucial role in determining gender. It consists of dense compact bone that is very durable, hence preserved when compared to other bones. The expression of mandibular dimorphism is influenced by muscles of mastication, and the masticatory forces are different for males and females.[3]

 Materials and Methods



The present study was conducted on randomly selected 50 males and 50 females orthopantomograph images of patients who reported to SRI RAJIV GANDHI COLLEGE OF DENTAL SCIENCES AND HOSPITAL.

Inclusion criteria: Age group between 20 and 45 years are considered.

Exclusion criteria: Developmental abnormalities, fractures, systemic conditions like hyperparathyroidism, and edentulous patients are excluded.

Radiographs taken by Kodak 8000C Digital Panoramic and Cephalometric System (73 kVp, 12 mA, 13.9 s) were used for the study.

By guidelines described by Loth and Henneberg (1996). Adult human males exhibit an angulation of the posterior border of the mandibular ramus at the level of the occlusal surface, whereas females display generally a straight posterior border of the ramus. When a flexure is present on female mandibles, the feature is never at the same level as in males: The flexure is nearby the condylar process or close above the gonial angle. A score of +1 is assigned if the flexure is visible at the occlusal level and −1 in other cases as shown in [Figure 1] and [Figure 2]. If the trait is badly expressed, a score of 0 is assigned. For each mandible, the scores for the left and right ramus are added and mandibles with the score of 0, +1, and +2 are identified as males, and mandibles with scores of −1 or −2 are identified as females.{Figure 1}{Figure 2}

Statistics

The examination results of the entire sample were analyzed using SPSS version-21 (Statistical Package for Social Studies; SPSS Ltd, Fountain Valley, CA 92708 USA); the “Chi-squared test,” of the package, was employed at a probability level of P < 0.01, indicating significant differences would be evaluated at 99% level of confidence.

 Results



Among the 50 female patients, 33 OPG were proved correct, and among 50 male patients, 31 were proved correct with a Chi-square test value 7.853 and P value 0.005 as shown in [Table 1] and [Graph 1].{Table 1}[INLINE:1]

Sex correctly predicted by the observer and subjects of misdiagnosed sex.

As P < 0.05, there is statistically significant difference between sexes identified by the observer and misdiagnosed sex.

Distribution of predicted sex and its percentage, indicated by ramus shape as shown in the [Table 2] and [Graph 2].{Table 2}[INLINE:2]

 Discussion



The mandibular ramus flexure was used as an indicator for identification of gender was introduced first by Loth and Henneberg in 1996.[2] Before the growth of temporomandibular joint ceases, during the growth spurt period, the growth of the mandible is rapid and the sex hormones and forces of mastication influence the dimorphism of the mandibular ramus.[2],[4] According to some studies, it was predicted that it was more accurate for males than females.[5] Some authors considered that it has more sensitivity to females.[6]

In our study, overall, it was proved 64% accurate with a significance of 0.005, but in the study conducted by Loth and Henneberg in 1996, they proved by taking a single indicator i.e., mandibular ramus flexure an accuracy of 94.2% and they confirmed that flexure of the posterior border of the ramus at the level of occlusal plane of the teeth help in identification of the gender.[2]

In 1998, a study conducted by Muller gonial flaring can be considered as an indicator of gender, and in his study, it was proved about 76% accurate than the chin shape or ramus flexure.[6]

In 1998, Donelly et al. performed the double-blind test, and they identified that there is an association between sex and mandibular gonial flexure.[4]

In 2008, Ivan Claudio SG et al. performed double-blind test and the results showed accuracy between 57.5% and 60.5%, and the most sensitive test for determining male 70% and for females is 38–46%.[7] However, in our study, it was proved more accurate for females 66% when compared to males i.e., 62%.

There is a controversy regarding the accuracy of the ramus flexure as an indicator of gender because few cases have pathological conditions such as paget's disease, acromegaly, and other systemic diseases.[8]

The forces of mastication acts on the muscles of mastication especially elevating muscles and these forces are involved in remodeling of the ramus.[9] According to study conducted by many researchers, they correlated that environmental functional factors such as chewing habits and food habits.[10]

 Conclusion



Mandibular ramus flexure can be considered as one of the indicators of the sex as it provides moderately acceptable accuracy. In determining the sex of unknown trait, it is better to include as many parameters as possible for attaining the accuracy.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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