ABSTRACT
A study of 428 endodontically treated 1st permanent molar teeth of both jaws was performed to identify the variation in tooth length of Bangladeshi people. In this study, radiographic method, Ingle's method was used and mathematical calculation as purposed by Messing was used to measure the length of the individual canal. The method involves measurement of the length in preoperative radiograph followed by clinical evaluation with diagnostic radiograph. The working length of each canal was finally calculated comparing both pre-operative and diagnostic radiograph. Study revealed that average length of upper 1st molar is 20.62mm and for lower 1st molar is 20.28mm; the range of length for upper 1st molar is 17.16mm - 25.33mm and for lower 16mm - 24mm. The study also revealed that the tooth length has no significance on the sex of the people of same race. To verify the results of the study, statistical tools were applied on a randomly selected sample of 100 patients and the statistical tests also supports the findings of the study. The results also indicate that the tooth length of Bangladeshi people is shorter than their Caucasoid counterpart. In previous studies performed by different researcher and given in different textbook of Endodontic shows that the length of tooth of Caucasian people is longer than this study.