Anomalous mandibular premolars: a mandibular first premolar with three roots and a mandibular second premolar with a C-shaped canal system

Int Endod J. 2008 Nov;41(11):1005-14. doi: 10.1111/j.1365-2591.2008.01451.x.

Abstract

Aim: To describe unusual variations in the root morphology and root canal systems of mandibular first and second premolar teeth extracted for orthodontic reasons.

Summary: Normally mandibular first and second premolar teeth have single roots with single canals. A 15-year-old patient presented for orthodontic treatment and two mandibular premolar teeth were examined post-extraction. The mandibular first premolar exhibited three distinct, separate roots and the mandibular second premolar exhibited a C-shaped root canal system. The coronal morphology of each of the mandibular premolars revealed dimensions and anatomy within normal limits. The incidence of a three-rooted mandibular first premolar is approximately 0.2%.

Key learning points: * Thorough clinical and radiographic interpretation is important in recognizing anomalous root and root canal systems. * The most common forms of root and canal systems and its aberrations must be understood to realize variations from normal do occur. * Successful root canal treatment requires an accurate diagnosis of the root canal system using all available aids. * Value of microcomputed tomography in the study of anatomy ex vivo and cone-beam tomography in clinical endodontics of complex premolar cases is increasing.

Publication types

  • Case Reports

MeSH terms

  • Adolescent
  • Bicuspid / abnormalities*
  • Dental Pulp Cavity / abnormalities*
  • Humans
  • Image Processing, Computer-Assisted
  • Imaging, Three-Dimensional
  • Male
  • Malocclusion / therapy
  • Mandible
  • Radiography, Dental, Digital
  • Serial Extraction
  • Tooth Root / abnormalities*
  • X-Ray Microtomography