A Study on Metopic Suture in Cadaveric Skulls of Assamese People

Abstract

Metopic suture is formed due to failure of union of the two halves of the frontal bone. Usually the suture disappears by early childhood, but in some cases it persists as complete or incomplete metopic suture throughout life. A complete metopic suture extends from anterior aspect of bregma to the nasion which is known as metopism. The present study is carried out in 126 dry human cadaveric skulls collected from the Dept. INTRODUCTION:The metopic suture is a vertical suture running between the two halves of frontal bone from the anterior aspect of anterior fontanelle to nasion. It is formed due to failure of fusion between the two halves of frontal bones. At birth the two halves of frontal bone remain separated by the metopic suture and the suture closes before puberty. According to Keith, (1) the metopic suture disappears at the end of first year or beginning of second year of life.According to Romanes, (2) the metopic suture normally closes by fifth or sixth year. Warwick & Williams (3) states that the two halves of the frontal bone begin to unite in second year and the suture is generally obliterated by the eighth year. Hamilton (4) claims that the metopic suture disappears by seventh year of life. Fusion of this suture commences at the anterior fontanelle i.e., bregma and terminates at nasion. Sometimes when it fails to ossify and persists as a complete suture extending from bregma to nasion, it is called metopism.The incidences of metopism vary among population of different regions and different races as reported by various workers. In the present study a humble attempt has been made to know the incidence of metopic suture in Assamese population of Assam, India. This study was carried out on 126 dry human skulls collected from the Dept. of Anatomy, Dept. of Forensic science & Institute of Pharmacy at Assam Medical College and Hospital, Dibrugarh, Assam, India. The skulls were observed macroscopically for metopic suture and divided into three groups.The first group included skulls without any metopic suture, second group included the skulls with complete metopic suture i.e., metopism and the third group included the skulls with incomplete metopic suture. The skulls of the third group were further sub grouped according to the shape of the suture as -Linear, U shaped, Inverted U shaped, H shaped, V shaped and Y shaped. Data found on examination was recorded, tabulated, photographed and compared with the findings of other studies.

Coexistence of Complete Metopic Suture and Inca Bone in Thai Skulls: Incidence, Morphology and Clinical Applications

“…The incidence of the persistent metopic suture, reported by previous studies, was found to be 1.8% in Lebanese, 3.3% in British, 7.5% in Northeastern Thai, 7.0 -9.7% in Brazilian, 2.0 -85.0% in Indian subpopulations, 11.5% in Nepalese, 35.0% in Nigerians, and 3.3 -75.0 % in Anatolian. The incomplete type is more commonly found than the complete type (Berry, 1975;Ajmani et al, 1983;Baaten et al, 2003;Bilodi et al, 2003;Castilho et al, 2006;Eroğlu, 2008;Hussain Saheb et al, 2010;Manalgiri et al, 2010;Yadav et al, 2010;Chandrasekaran and Shastri., 2011;Murlimanju et al, 2011;Chakravarthi and Venumadhav, 2012;da Silva et al, 2013;Nallathamby et al, 2013;Masih et al, 2013;Pilli and Sunder, 2013;Aksu et al, 2014;Khandare et al, 2014;Kumar and Rajasekar, 2014;Saikia 2014;Santhosh et al, 2014;Wadekar et al, 2014;Arumugam and Arrchana, 2015;Basha and Sugavasi, 2015;Khamanarong et al, 2015;Kumar and Rajshekar, 2015;Hemalatha and Rao, 2016;Nayakanati et al, 2016;Kundu et al, 2017. Shrestha et al, 2017Singh et al, 2017).…”

Metopism in adult South Africans and its relationship to frontal sinus size

“…Thus, Agarwal et al (1979) noted that it was situated “almost exclusively” in the lower part of the frontal above nasion and Yadav et al (2010) reported it to be just above nasion in 95.95% (142/148) of specimens examined by them. In all other studies in which the incomplete suture has been documented, it is clearly located immediately superior to nasion in all cases (Ajmani et al, 1983; Aksu et al, 2014; Andrade et al, 2019; Burrell et al, 2016; Castilho et al, 2006; Chandrasekaran & Shastri, 2011; del Sol et al, 1989; Kumar & Rajshekar, 2015; Maneenin et al, 2013; Mangalgiri et al, 2010; Pilli & Sunder, 2013; Saikia, 2014; Santhosh et al, 2014; Surekha et al, 2016; Vinoth et al, 2014; Zanaty, 2017).…”

“… Note : Studies: 1, Ajmani et al (1983); 2, Castilho et al (2006); 3, Mangalgiri et al (2010); 4, Chandrasekaran and Shastri (2011); 5, Maneenin et al (2013); 6, Pilli and Sunder (2013); 7, Aksu et al (2014); 8, Kumar and Rajshekar (2015); 9, Saikia (2014); 10, Santhosh et al (2014); 11, Vinoth et al (2014); 12, Burrell et al (2016); 13, Surekha et al (2016); 14, Zanaty (2017); 15, Andrade et al (2019). …”