Predicting the anatomical position of the palatal root apex in maxillary first premolars during surgical endodontic treatment.

Introduction: Although many studies have reported on the morphology of maxillary first premolars, to our knowledge, there has never been an investigation reporting the anatomic position of the palatal (P) root tip relative to the B root tip in mesiodistal (MD), buccopalatal (BP), and apicocoronal (AC) dimensions. Such information could help clinicians more accurately locate root apices, reduce surgical morbidity, and improve the precision and prognosis of endodontic periradicular surgery for this tooth.

Methods: Fifty extracted, bifurcated, human maxillary first premolars were individually mounted and photographed under 10x magnification and oriented to simulate a clinical view.

Results: The P apex was superimposed by the B apex in 25 of 50 specimens, distal to the B apex in 24 of 50, and mesial to the B apex in only 1 instance. When not superimposed by or mesial to the B apex, the P apex was usually 1.4+/-0.7 mm distal to the B apex. In 98% of specimens, the P apex was positioned palatocoronal or palatocoronodistal to the B apex.

Conclusions: This knowledge can be used to clinically minimize the size of osteotomies required to locate P root apices during endodontic surgery.