Department of Endodontics, University of Missouri-Kansas City, School of Dentistry, Kansas City, MO 64108, USA.
J Endod. 2010 Mar;36(3):434-7. doi: 10.1016/j.joen.2009.12.013.
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.
Fifty extracted, bifurcated, human maxillary first premolars were individually mounted and photographed under 10x magnification and oriented to simulate a clinical view.
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.
This knowledge can be used to clinically minimize the size of osteotomies required to locate P root apices during endodontic surgery.
尽管许多研究已经报道了上颌第一前磨牙的形态，但据我们所知，从未有研究报告过腭（P）根尖端相对于近中颊（B）根尖端在近远中（MD）、颊腭（BP）和根尖顶（AC）尺寸上的解剖位置。这些信息可以帮助临床医生更准确地定位根尖，减少手术并发症，并提高该牙根管治疗后根尖周手术的精度和预后。
将 50 个分叉的人上颌第一前磨牙单独固定并在 10 倍放大倍数下拍照，并定向以模拟临床观察。
在 50 个标本中，有 25 个标本的 P 根尖与 B 根尖重叠，24 个标本的 P 根尖位于 B 根尖的远侧，只有 1 个标本的 P 根尖位于 B 根尖的近侧。当 P 根尖不与 B 根尖重叠或位于 B 根尖的近侧时，P 根尖通常位于 B 根尖的远侧 1.4+/-0.7mm。在 98%的标本中，P 根尖位于 B 根尖的腭侧或腭侧远中。
这些知识可用于临床，以最小化在根管手术中定位 P 根根尖所需的截骨量。
