Prevalence of Eruption of Third Molar Tooth among South Indians and Malaysians

Abstract

<strong>Introduction:</strong>In prehistoric humans, when the jaw size permitted space for normal dental development and position in the arches, third molar may have been a vital survival tool. However, as human evolution has progressed, jaw size has been gradually decreasing (Lamarckian Evolution). Hence due to the decrease in size of the jaw bone, it’s been reported that approximately 65% of the human population has at least one impacted third molar, and third molars that do erupt are often malposed in the arches and are consequently difficult to clean and prone for infection.<p><strong>Aim and Objective:</strong> To study the prevalence of eruption of third molar tooth among South Indians and Malaysians by observing the presence of third molars among them and to analyze the percentage of impacted third molars and congenital absence of third molar teeth among the Indian and Malaysian population.</p><p><strong>Materials and Methods:</strong>50 Malaysians and 50 Indians (25 males and 25 females in each population) aged between 17 to 25 years old were examined for the presence or absence of the third molars. To confirm the congenital absence of third molars, Orthopantomograms (OPG) were taken.</p><p> </p><p><strong>Results and Conclusion:</strong> In South Indian Population, it was noted that only 48% of males and 64% of females have congenital absence of third molar, and 52% of males and 36% of females have erupted third molars. 16% of males had partly impacted third molar whereas in case of female it was 28%. Congenital absence of third molars among females was 16% more than in males. More males (36%) had impacted third molars than females (24%). It was also noted that majority of them have their maxillary third molars erupted first before their mandibular third molars. In Malaysian Population, it was noted that only 28% of males and 20% of females had congenital absence of third molars, and 72% of males and 80% of females had erupted third molars. 40% of males had partly impacted third molar whereas in case of female it was 52%. Congenital absence of third molars among males was 8% more than females. More males (32%) had impacted third molars than females (28%). It was also noted that in majority of them their mandibular third molars had erupted before their maxillary third molars. When compared among south Indians and Malaysian population congenital absence and impacted third molars are more common in south Indians, whereas partly impacted third molar is more common among Malaysians.</p>

Morphologic and Demographic Predictors of Third Molar Agenesis

“…Some mutations have been shown to cause agenesis, but there are currently no known mutations that cause agenesis without other symptoms. While studies have long suggested a genetic component to agenesis (Garn and Lewis 1962;Shimizu et al 2013), environmental disturbances occurring before the M3 initiates have been shown to produce this pathology (Swee et al 2013 Odds ratio of female to male M3 agenesis Bansal, 2012Sandhu and Kaur, 2005Byahatti et al, 2011Ren and Kumar, 2014Shah and Parekh, 2014Garcia−Hernandez and Rodriguez, 2009Nicodemo, 1973Bhowmik, 2013Daito et al, 1992Hellman, 1936Haga et al, 2013Golovcencu and Geletu, 2012Shah and Boyd, 1979Lee et al, 2009Bhutta and Sadozai, 2013Hubenthal, 1989Sonnabend, 1966Raloti et al, 2013Nanda and Chawla, 1959Kirveskari et al, 1978Ghada, 2005Weise and Bruntsch, 1965Sarmiento and Herrera, 2004Garcia−Hernandez et al, 2008Elomaa and Elomaa, 1973Costa et al, 2007Godt and Greve, 1980Celikoglu and Kamak, 2012Celikoglu et al, 2010Krekeler et al, 1974Haga et al, 2013Speckin, 1981Hentisz, 2003Shinn, 1976Oliveira and Serra Negra, 1984Oliveira and Serra Negra, 1976Mok and Ho, 1996Afify and Zawawi, 2012Holzl, 1972Endo et al, 2015Kazanci et al, 2010Thompson et al, 1974Adler and Adler−Hradecky, 1963…”

“…Similarly, the relationship between M3 agenesis and impaction remains unexplored. Bansal, 2012Sandhu and Kaur, 2005Byahatti et al, 2011Ren and Kumar, 2014Shah and Parekh, 2014Garcia−Hernandez and Rodriguez, 2009Nicodemo, 1973Bhowmik, 2013Daito et al, 1992Hellman, 1936Haga et al, 2013Golovcencu and Geletu, 2012Shah and Boyd, 1979Lee et al, 2009Bhutta and Sadozai, 2013Hubenthal, 1989Sonnabend, 1966Raloti et al, 2013Nanda and Chawla, 1959Kirveskari et al, 1978Ghada, 2005Weise and Bruntsch, 1965Sarmiento and Herrera, 2004Garcia−Hernandez et al, 2008Elomaa and Elomaa, 1973Costa et al, 2007Godt and Greve, 1980Celikoglu and Kamak, 2012Celikoglu et al, 2010Krekeler et al, 1974Haga et al, 2013Speckin, 1981Hentisz, 2003Shinn, 1976Oliveira and Serra Negra, 1984Oliveira and Serra Negra, 1976Mok and Ho, 1996Afify and Zawawi, 2012Holzl, 1972Endo et al, 2015Kazanci et al, 2010Thompson et al, 1974Adler and Adler−Hradecky, 1963Grahnen, 1956Sandhu and Kapila, 1982Garcia−Hernandez and Beltran, 2008Haavikko, 1971Castilho et al, 1990Gravely, 1965Alam et al, 2014M...…”

“…There was, however, considerable variation in agenesis frequency among outcomes. The standard deviation of effect sizes was 9.97%, while the estimates ranged from 5.32% in a Ugandan population (Chagula 1960) to 56.0% in a South Indian cohort (Ren and Kumar 2014;Fig. 2).…”

Radiographic Assessment of Third Molars Agenesis Patterns in Young Adults

“…In a study on a relatively small sample size of 150 individuals, a prevalence rate of only 5.4% was reported [29]. On the contrary, another study on 50 individuals showed a prevalence rate of 56% [30]. A study involving a study population of 1005 showed a prevalence of mandibular M3 agenesis of 12%.…”

Third Molar Agenesis in Post-Medieval Chichester

“…Clinical accounts of third molar agenesis in Asia appear to be higher than most European groups: 30% in a Malaysian Malay population (Alam et al, 2014), 33% in a Chinese Malaysian population (Alam et al, 2014), 50% in Nepal (Upadhyaya et al, 2012), 32.3% in Japan (Endo et al, 2015) and 38.4% in Bangladesh (Sujon et al, 1984). Ren & Kumar (2014) also report a prevalence of agenesis of 48% of males and 64% of females from southern India, but only 25 individuals of each sex were analyzed, and therefore the small sample size may not be representative.…”