Dental Communication Biosc.Biotech.Res.Comm. Special Issue Vol 13 No 8 2020 Pp-104-107 Morphometric Analysis of Chin Shape in Inverted Mandible and Mid Symphysis Menti Angle Sachin Aditya B1 and Yuvaraj Babu K2* 1Saveetha Dental college and Hospitals, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai - 600077, India 2Assistant professor, Department of Anatomy, Saveetha Dental college and Hospitals, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai - 600077, India ABSTRACT In human anatomy, the skull 's facial skeleton, the outer surface of the mandible, is distinguished by a slight ridge in the median line, suggesting the mandibular symphysis or junction line in which the two lateral halves of the mandible usually unite at an early life (1-2 years). This is not a true symphysis, since there is no cartilage between the mandible's two hands. The main aim of the study is to measure the mid symphysis menti angle in the inverted aspect. 30 unsexed dry human skulls were taken from the Department of Anatomy, Saveetha Dental College and Hospital. Protractor was used to measure the mid symphysis menti angle in the inverted aspect of the mandible. The average measurement of mid symphysis menti angle was 76.16° and the shape of the mental protuberance for most of the samples were oval shaped. Our study has tried to analyse the mid symphysis menti angle and chin shape in the inverted aspect of mandibles, this data may be useful for surgeons in planning their surgery in the mandibular region. KEY WORDS: MID SYMPHYSIS MENTI ANGLE, MENtaL PROTUBERANCE, MANDIBLE, CHIN SHAPE. INTRODUCTION they show sexual dimorphism(G and Vinay, 2013). It is the largest and strongest bone in the face with horizontally The human mandible is routinely utilised as a part curved body that is convexed forwards with two broad of the assessment of biological identity in forensic rami, which ascend from the posterior end of the body, anthropological and odontological practice (Fouhil and Therefore it remains the most durable bone of the facial El Fouhil, 2012; Rehman, Parveen and Ishaq, 2016). skeleton and retains its shape better than other bones(G It is morphologically distinct from other primates and Vinay, 2013; Batel et al., 2014). The human mandible both in terms of proportions and specific anatomical is also found to resist post mortem damage and forms features(Bennack, 1981). They are also being used since an important source of information about the sexual olden time to ascertain the sex of an individual, because dimorphism. It forms the chief articulating segment of the skull(Posso and Donatelli, 2006), Thus it is the platform for dental surgeons to work with. ARTICLE INFORMATION Different authors have highlighted the utility of *Corresponding Author: [email protected] odontological strategies in morphological, metric Received 4th Aug 2020 Accepted after revision 23rd Sep 2020 Print ISSN: 0974-6455 Online ISSN: 2321-4007 CODEN: BBRCBA highlights and non-metric qualities in the mandible, including discrete regions, for example, symphyseal Thomson Reuters ISI Web of Science Clarivate Analytics USA and morphology and shape, gonial edge, gonial reversal and Crossref Indexed Journal eversion, ramus flexure, generally shape from circular fourier analysis(7) and separating capacities dependent NAAS Journal Score 2020 (4.31) SJIF: 2020 (7.728) A Society of Science and Nature Publication, Bhopal India 2020. All rights reserved. Online Contents Available at: http//www.bbrc.in/ 104 Doi: http://dx.doi.org/10.21786/bbrc/13.8/119 Aditya B & Babu K on their measurements among others in the appraisal mean value of mid symphysis menti angle is 76.16°+ of biological sex and ancestry(8,9). Most recently, 2.43° , in which the largest mid symphysis menti angle a number of studies used geometric morphometric was 85° and smallest mid symphysis menti angle was approaches(Fabre et al., 2014) address issues of biological 71°. identity. Previous studies on dried mandibles include study of their angle in mixed population in which the angle varied between 110 degrees to 142 degrees from old Table 1. Minimum, Maximum and average Midsymphysis to young age people and facial height was also calculated menti angle in mandible with this bone(Malik et al., 2017). Mid Symphysis menti Although measurements of several thousands of angle in degrees mandibles taken for anthropological purposes have been published, they are actually of little value in some cases. Maximum Angle 85° Primarily this can be due to the fact that the technique Minimum Angle 71° of measurement has never been standardised and many of the data obtained by those techniques which have been most widely used cannot be compared accurately in Average value of Mid 76.16° + 2.43° cases where direct comparison should be possible. There symphysis menti angle are only a few publications related to inverted aspect of mandible and midsymphis menti angle, the present study Roy in his study of chin shape evaluated the proportion of is aimed at morphometrically analysing the chin shape in external chin to identify those with diverse morphology, inverted mandible and mid symphysis menti angle. The he used protuberantia mentalis for differentiation but need for such type of study is due to increased incidence we considered mid symphysis menti angle and mental of accidents where a number of unidentified cases are protuberance, subjects falling between the age group of obtained and these measurements may be useful for their 18-25 years were selected because most of the mandible reconstructive procedures. growth was completed by that time and SN-MP (facial divergence angle) was the parameter used were mean Our department is passionate about child care, we have value for males was 23±5.9° and for females it was published numerous high quality articles in this domain 24.2±5°. (Roy et al., 2012). over the past 3 years (Govindaraju, Jeevanandan and Subramanian, 2017a, 2017b; Panchal, Gurunathan and In a similar study by Maneesha Sharma on morphometric Shanmugaavel, 2017; Ravikumar, Jeevanandan and analysis of mandible in Indian population, the author Subramanian, 2017; Jeevanandan and Govindaraju, focused on helping in identification of mutilated bodies 2018; Nair et al., 2018; Ravikumar et al., 2018, 2019; by determining the sex of the obtained mandible, they Ravindra et al., 2018, 2019; Subramanyam et al., 2018; also tried to set up some parameters of mandible as Vishnu Prasad et al., 2018; Jeevanandan, Ganesh indicators of sex in Indian population, for this the length, and Arthilakshmi, 2019; Ramadurai et al., 2019; angle and minimum breadth of mandible were considered Ramakrishnan, Dhanalakshmi and Subramanian, 2019; and the mean length was 17.22cm, this study gave 60% Veerale Panchal, Jeevanandan and Subramanian, 2019; accuracy in sex determination (Sharma et al., 2016). A Vignesh et al., 2019; V. Panchal, Jeevanandan and well established racial difference in the facial mandibular Subramanian, 2019; Samuel, Acharya and Rao, 2020). dimension had been found to exist by various researchers With this inspiration we planned to pursue research in various facial types. on morphometric analysis of chin shape in inverted mandible and mid symphysis menti angle. CONCLUSION MATERIAL AND METHODS Since most of the research are not being done on mid symphysis menti angle, thus knowing the accurate For the current study 30 dried unsexed mandibles chin shape and mid symphysis menti angle may prove of the South Indian population were examined from to be helpful in mandibular surgical procedures for the Department of Anatomy, Saveetha Dental College people at a particular area in case of accidents and in and Hospital. The shape of mental protuberance and case of corrective jaw surgeries performed to enhance mid symphysis menti-angle was measured using a appearance. protractor keeping the mandible in inverted aspect, the measurements were recorded separately for each ACKNOWLEDGEMENTS parameter and the readings were tabulated and statistically analysed. We acknowledge Department of Anatomy for allowing us to use bones from their collection for this study RESULTS AND DISCUSSION Conflict of Interest: The author declares that there is no In this study out of the 30 samples used, 13 samples had conflict of interest in the present study. round shaped mental protuberance and the remaining 17 mandibles had oval shaped mental protuberance. The 105 Aditya B & Babu K REFERENCES files and mtwo files in deciduous molars -a randomized Batel, A. et al. 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