Journal of Dental Research and Review

ORIGINAL ARTICLE
Year
: 2017  |  Volume : 4  |  Issue : 2  |  Page : 32--35

Gender determination in panoramic radiographs, utilizing mandibular ramus parameters: A cross-sectional study


Nimi Susan Mathew1, Laxmikanth Chatra1, Prashanth Shenoy1, KM Veena1, Rachana V Prabhu1, BK Sujatha2,  
1 Department of Oral Medicine and Radiology, Yenepoya Dental College, Mangalore, Karnataka, India
2 Depatment of Public Health Dentistry, Vydehi Institute of Dental Sciences and RC, Whitefield, Bengaluru, Karnataka, India

Correspondence Address:
Nimi Susan Mathew
Department of Oral Medicine and Radiology, Yenepoya Dental College, Yenepoya University, Derlakatte, Mangalore - 575 018, Karnataka
India

Abstract

Objective: The purpose of the present study is to determine the gender of individual using mandibular ramus parameters, namely, gonial flexure and minimum ramal breadth in panoramic radiographs. Materials and Methods: A cross-sectional study has been conducted using 100 panoramic radiographs from the archives of the Department of Oral Medicine and Radiology, Yenepoya Dental College, Mangalore. Two parameters, namely, gonial flexure and minimum ramal breadth were measured using Agfa Nx software for each digital radiograph. The mean values were calculated and compared between females and males using unpaired t-test and discriminant functional analysis. Results: It was observed that gonial flexure is more obtuse in females when compared to males (R gonial angle, t = 2.965, P = 0.004 L gonial angle t = 2.458, P = 0.016) and the minimum ramal breadth was wider in males compared to females (R ramus breadth, t = −2.846, P = 0.005, L ramus breadth, t = −2.478, P = 0.015) and also the discriminant function analysis was also found to be significant at P = 0.011, Wilks' lambda = 0.875 (Goodness of fit). Conclusion: Mandibular ramus parameters, namely, gonial flexure and minimum ramal breadth can be used efficiently to determine gender which has implication in forensic medicine.



How to cite this article:
Mathew NS, Chatra L, Shenoy P, Veena K M, Prabhu RV, Sujatha B K. Gender determination in panoramic radiographs, utilizing mandibular ramus parameters: A cross-sectional study.J Dent Res Rev 2017;4:32-35


How to cite this URL:
Mathew NS, Chatra L, Shenoy P, Veena K M, Prabhu RV, Sujatha B K. Gender determination in panoramic radiographs, utilizing mandibular ramus parameters: A cross-sectional study. J Dent Res Rev [serial online] 2017 [cited 2022 May 19 ];4:32-35
Available from: https://www.jdrr.org/text.asp?2017/4/2/32/216419


Full Text

 Introduction



The prime aspects of forensic investigations are determination of the gender, age, and identification of the ethnic population.[1] Estimation of gender is known as one of the four pillars of the anthropological protocol.[2] When the skeleton is available as a whole, gender analysis, and estimation is done almost 100% accurately, by examining the pelvic bone. However, in mass disaster scenarios were only fragmented bones are available; gender estimation becomes a tedious process. To tackle such situations gender determination should be done using fragmented bones.[3] One such bone that is available for analysis is the mandible as it is highly durable due to the presence of a dense layer of compact bone.[4]

Skull is the most dimorphic bone apart from the pelvis, but in situ ations were intact skull is not found the mandible is proven to play a vital role in determining the gender of an individual.[4] Dimorphism of the mandible is determined by the size and shape of the bone itself. Male bones are generally more in volume and robust when compared to female bones.[5] When considering the mandible, the condyle, and the ramus are the two areas which exhibit the highest dimorphism according to studies carried out by Humphrey et al., i.e., a marked dimorphism is noted regarding the mandibular ramus when compared with the mandibular body.[6]

In this digital era, Dentofacial Radiography has become one of the routine procedures in dental and medical hospitals as a part of primary investigations. Large segments of the population have these radiographs taken at different intervals of life, which contributes to the available antemortem data which can further help us in the identification of human remains.[7] The literature review states various studies that were conducted using dry mandibles for gender determination [1],[2],[3],[4],[5],[6],[7] and some studies were done on digital panoramic radiographs using 5 measurements which include maximum ramus breadth, minimum ramus breadth, condylar height, and projective ramus height.[8]

There were very limited data on gender determination using a single or the most dimorphic ramal parameter from a digital panoramic radiograph in Karnataka. Hence, a present study was conducted to determine gender of an individual considering the minimum ramus breadth and gonial flexure on panoramic radiographs in Mangalore population and there by assessing the potential use of these parameters in forensic analysis.

 Materials and Methods



Study design

A cross-sectional study was conducted at the Department of Oral Medicine and Radiology, Yenepoya Dental College and Hospital, Mangalore. After obtaining ethical clearance from institutional review board, 100 panoramic radiographs of patients within the age group 20–50 years were selected for the study.

Inclusion criteria

Panoramic radiographs of both dentulous and edentulous patients of age group 20–50 yearsPanoramic radiographs where both gonial flexure and minimum ramus breadth were clearly visibleOnly high-quality radiographs with no visible errors.

Exclusion criteria

Panoramic radiographs of patients with developmental anomalies, undergoing orthodontic treatments, or with a history of maxillofacial surgery/gross facial asymmetry.

All digital radiographs were taken from the same machine – Planmeca Promax, (Planmeca Oy, Helsinki, Finland) exposed under standard protocols (70 kVp, 10 mA) using phosphor plates, which were later digitized on a laser scanner, CR 30-X digitizer, (AGFA health care, Morstel – Belgium), and images were recorded by a computer-aided Agfa-NX drafting program.

The parameters used for the study were as follows:

Gonial flexure

A line traced tangential to the most inferior points at gonium and the lower border of the mandibular body (ML) and another line tangential to the posterior border of the ramus and condyle (RL). The intersection of these lines forms the gonial flexure. As given by Mattila et al.[9]

Minimum ramal breadth

It is the smallest anterior-posterior dimension of the ramus as mentioned by Sopher.[10]

The radiographs were analyzed using Agfa Nx software, were in the right and left sides were measured for the above parameters using a mouse driven method (by moving mouse and drawing lines using chosen points on the digital panoramic radiograph).

Statistical analysis

An independent t-test was done to determine the differences in measurements of right and left sides of the mandible and discriminant function analysis was carried out to find out whether the variables can be used for gender determination. The significance level was fixed at P < 0.05.

 Results



A cross-sectional study was conducted to determine the gender of individuals using mandibular ramus parameters on 100 panoramic radiographs.

In the present study, out of 100 panoramic radiographs 50 were of males, and 50 belong to females [Graph 1].[INLINE:1]

[Table 1] shows mean difference of gonial flexures and ramal breadth between males and females. R gonial flexure (4.032), L Gonial flexure (3.304), R ramal breadth (−0.21876), and L ramal breadth (−0.19590). The results are significant at P < 0.05.{Table 1}

[Table 2] shows the Goodness fit for the variables to determine gender using panoramic radiographs. The results were significant at P < 0.05.{Table 2}

 Discussion



Gender of an individual can be estimated up to 100% accurately from the adult skeleton available through a mass disaster. However, in situ ations where only fragmented parts are available the most commonly encountered bone is the mandible as it is the most durable owing to the presence of a dense layer of compact bone which keeps the bone well preserved.[8],[11]

In the reviews, there is evidence that male mandibles are large with prominent muscle attachment sites and slightly more robust than female mandibles. With features such as gonial flaring, broad ascending ramus, and high-symphysis metric analysis of mandible can be considered for gender determination.[12],[13] Most of the studies were conducted using the manual method of metric analysis on the dry bone, which is time-consuming and the technique is prone to error. As panoramic radiography is a part of routine radiographic examination for a large segment of population, as the emergence of digitization has image accuracy and has also simplified image storing and sharing and the advent of user friendly software has made metric analysis easy and less time-consuming adding the benefit that the analysis can be repeated to eliminate errors.[14] Hence, the use of personal computer-assisted analysis of panoramic radiographs can be considered reliable in the present study.

The use of panoramic radiography in the determination of gonial flexure has been studied by various authors and the results vary between age, gender, and race. This study, however, showed that gonial flexure is more obtuse in females than in males and the respective values were statistically significant.

Various other studies conducted on Indian and other ethnic populations have shown that gonial flexure is higher in females than in males as noted in studies conducted by Xie and Ainamo and Ghosh et al.[15],[16] Although many studies follow the general trend of gonial flexure being greater in males than in females, our study was in contrast with these showing similarity to the studies conducted by Xie and Ainamo and Ghosh et al.

As mentioned in the studies conducted by Jensen and Palling, Ohm and Silness and Upadhyay et al.[17],[18],[19] contributing to the effect of masticatory muscles that is masseter and medial pterygoid whose insertion is into the gonion affects the size of the gonion and there by the gonial flexure.[1],[20],[21]

Minimum ramal breadth parameters were stated to exhibit the best dimorphism. In the present study, it was found to be wider in males when compared to females, which is consistent with the osteometric studies conducted by Vodanović and Dumančć and Giles.[7],[22]

These differences in the musculoskeletal development and to the differences related to different growth trajectories in males and females.[6]

It has been established that socio-environmental factors such as food, climate, nutrition, and pathologies influence the development and there by affecting the growth and appearance of the bone.[4]

Numerous studies have demonstrated that skeletal characteristics differ in each population and thus emphasized the need for population specific osteometric standards for gender determination.[4],[7],[22]

In the view of these findings, further studies on more diverse populations to assess the significance of these parameters are recommended.

 Conclusion



Mandibular ramus was found to be a valuable tool for gender determination as the bone is resistant to damage and disintegration. Hence, we strongly suggest the use of minimum ramal breadth as an aid in the forensic analysis of gender determination.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1Franklin D, Oxnard CE, O'Higgins P, Dadour I. Sexual dimorphism in the subadult mandible: Quantification using geometric morphometrics. J Forensic Sci 2007;52:6-10.
2Kimmerle EH, Ross A, Slice D. Sexual dimorphism in America: Geometric morphometric analysis of the craniofacial region. J Forensic Sci 2008;53:54-7.
3Raj JD, Ramesh S. Sexual dimorphism in mandibular ramus of South Indian population. Antrocom Online J Anthropol 2013;9:253-8.
4Saini V, Srivastava R, Rai RK, Shamal SN, Singh TB, Tripathi SK. Mandibular ramus: An indicator for sex in fragmentary mandible. J Forensic Sci 2011;56 Suppl 1:S13-6.
5Scheuer L. Application of osteology to forensic medicine. Clin Anat 2002;15:297-312.
6Humphrey LT, Dean MC, Stringer CB. Morphological variation in great ape and modern human mandibles. J Anat 1999;195(Pt 4):491-513.
7Vodanović M, Dumančć J. Determination of sex by discriminant function analysis of mandibles from two croatian archaeological sites. Acta Stomatol Croat 2006;40:263-77.
8Indira AP, Markande A, David MP. Mandibular ramus: An indicator for sex determination – A digital radiographic study. J Forensic Dent Sci 2012;4:58-62.
9Mattila K, Altonen M, Haavikko K. Determination of the gonial angle from the orthopantomogram. Angle Orthod 1977;47:107-10.
10Samatha K, Byahatti SM, Ammanagi RA, Tantradi P, Sarang CK, Shivpuje P. Sex determination by mandibular ramus: A digital orthopantomographic study. Journal of Forensic Dental Sciences 2016;8:95-8.
11Duric M, Rakocevic Z, Donic D. The reliability of sex determination of skeletons from forensic context in the Balkans. Forensic Sci Int 2005;147:159-64.
12Thakur KC, Choudhary AK, Jain SK, Lalit K. Racial architecture of human mandible – An anthropological study. J Evol Med Dent Sci 2013;2:4177-88.
13Kumar MP, Lokanadham S. Sex determination and morphometric parameters of human mandible. Int J Res Med Sci 2013;1:93-6.
14Tsorovas G, Karsten AL. A comparison of hand-tracing and cephalometric analysis computer programs with and without advanced features – Accuracy and time demands. Eur J Orthod 2010;32:721-8.
15Xie QF, Ainamo A. Correlation of gonial angle size with cortical thickness, height of the mandibular residual body, and duration of edentulism. J Prosthet Dent 2004;91:477-82.
16Ghosh S, Vengal M, Pai KM. Remodeling of the human mandible in the gonial angle region: A panoramic, radiographic, cross-sectional study. Oral Radiol 2009;25:2-5.
17Jensen E, Palling M. The gonial angle. Am J Orthod 1954;40:120-33.
18Ohm E, Silness J. Size of the mandibular jaw angle related to age, tooth retention and gender. J Oral Rehabil 1999;26:883-91.
19Upadhyay RB, Upadhyay J, Agrawal P, Rao NN. Analysis of gonial angle in relation to age, gender, and dentition status by radiological and anthropometric methods. J Forensic Dent Sci 2012;4:29-33.
20Ingervall B, Thilander B. Relation between facial morphology and activity of the masticatory muscles. J Oral Rehabil 1974;1:131-47.
21Rando C, Hillson S, Antoine D. Changes in mandibular dimensions during the mediaeval to post-mediaeval transition in London: A possible response to decreased masticatory load. Arch Oral Biol 2014;59:73-81.
22Giles E. Sex determination by discriminant function analysis of the mandible. Am J Phys Anthropol 1964;22:129-35.