title: Prevalence of radix entomolaris in mandibular permanent first molars: a study in a South Indian population.
abstract: OBJECTIVE
  Anatomical racial variations are an acknowledged characteristic in permanent molars. Generally, mandibular first molars have 2 roots; however, the presence of a third root, radix entomolaris (RE), is a major anatomic variant among many population groups. This study evaluated the prevalence of permanent mandibular first molars featuring a distolingual root in a South Indian population.
  
  
  METHODS
  Five hundred patients of South Indian origin possessing bilateral mandibular first molars were selected. The radiographs of these patients were evaluated under optimal conditions. A total of 1000 mandibular first molars were screened and the incidence of 3-rooted mandibular first molars and the correlation between left and right side occurrence and between either gender was recorded.
  
  
  RESULTS
  The prevalence of 3-rooted mandibular first molars was 18.6% of the patients examined and 13.3% of the teeth examined. There was no statistically significant difference between genders or side of occurrence (P > .05). The bilateral incidence of a symmetric distribution was 43.01%.
  
  
  CONCLUSIONS
  RE is considered an Asiatic trait. The occurrence of this macrostructure in the South Indian population was 13.3%, which was lower than that of other patients of Mongoloid origin. The clinician must thoroughly examine the radiograph before initiation of endodontic therapy.
authors.affiliation: Department of Conservative Dentistry & Endodontics, School of Dental Sciences, Sharda University, Greater Noida, India. saurabhchandra@yahoo.com
authors.forename: Saurabh S
authors.initials: SS
authors.lastname: Chandra
authors.forename: Supriya
authors.initials: S
authors.lastname: Chandra
authors.forename: Padmanabhan
authors.initials: P
authors.lastname: Shankar
authors.forename: Rajamani
authors.initials: R
authors.lastname: Indira
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003786:Dental Pulp Cavity / Q000033:anatomy & histology*; D019229:Dentition, Permanent; D005260:Female; D006801:Humans; D007194:India / Q000453:epidemiology; D008297:Male; D008334:Mandible; D008875:Middle Aged; D008963:Molar / Q000033:anatomy & histology*; D015995:Prevalence; D014071:Tooth Abnormalities / Q000453:epidemiology*; D014092:Tooth Root / Q000033:anatomy & histology*; D044465:White People; D055815:Young Adult