ANATOMY

Detailed explanation-1: -The maxillary first premolar is the most commonly bi-rooted tooth with occasional presentation of three roots system; it is a transitional tooth between incisors and molars.

Detailed explanation-2: -The maxillary first premolar has variable morphology but is generally considered to have two roots and two canals (Fig. 1.58). The frequency of two roots is more than 55% in Caucasoids and less than 20% in Mongoloids.

Detailed explanation-3: -Majority (52.88%) of the maxillary first premolars were single rooted, 44.88% had two roots, and 2.22% had three roots. Ten teeth could not be assessed for root canal morphology as the canals were completely calcified and did not allow penetration of the dye during the procedure.

Detailed explanation-4: -Single roots, two roots, and three roots have been identified in maxillary first premolars, with the number of canals ranging from one to three per root. [12] The number and morphology of roots of Indian first premolars differ from those of Mongoloid first premolars, in which three roots are reported to be rare.

Detailed explanation-5: -It is now generally accepted that the most common form of maxillary first molar has three roots and four canals [4]; the mesiobuccal root has two root canals due to its wide buccolingual dimension and associated concavities and a single canal for distobuccal and palatal roots [5, 6].