Frequency of four-rooted molars in 1,775 extracted upper molar teeth: A biological explanation of this challenging clinical anomaly

Abstract

Background:  Tooth development starts after the rupture of the buccopharyngeal membrane, establishing communication with the primitive digestive tract.  Tooth development undergoes descriptive stages of initiation, bud, cap, bell and apposition.  Root formation begins after crown formation by the Hertwig's epithelial root sheath.
Methodology:  The study material was the extracted 1,775 upper molar teeth.  Each tooth was examined for the occurrence of four roots, using the clinical index for upper molar; possession of three roots; an extra root is an anomaly.  The normal positions of the roots are two buccally and one palatal root.
Result:  Out of a total of 1,775 upper molar teeth examined 8 (0.451%) were four-rooted.  This makes a frequency of 0.451%.
Conclusion:  We conclude that endodontist should have a pre-knowledge of anatomic variation in root canals, especially an awareness and understanding of the possible presence of an additional root and unusual root canal morphology.  This is essential in determining the successful outcome of endodontic treatment.