open access

Vol 81, No 1 (2022)
Original article
Submitted: 2020-11-09
Accepted: 2020-12-18
Published online: 2021-01-22
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Morphometric analysis of three-rooted mandibular first molars in a Slovene population: a macroscopic and cone-beam computed tomography analysis

L. Strmšek1, I. Štamfelj12
DOI: 10.5603/FM.a2021.0005
·
Pubmed: 33511624
·
Folia Morphol 2022;81(1):203-211.
Affiliations
  1. Department of Dental Diseases and Dental Morphology, Faculty of Medicine, University of Ljubljana, Slovenia
  2. Department of Operative Dentistry and Endodontics, University Medical Centre Ljubljana, Ljubljana, Slovenia

open access

Vol 81, No 1 (2022)
ORIGINAL ARTICLES
Submitted: 2020-11-09
Accepted: 2020-12-18
Published online: 2021-01-22

Abstract

Background: This study examined the root morphology of mandibular first molars (MFMs) with radix entomolaris (RE), which presents diagnostic and therapeutic challenges for clinicians.
Materials and methods: A total of 17 three-rooted MFMs were taken from a collection of extracted teeth. Root lengths and levels of furcations were measured with a digital calliper. The pulp floor configuration, root canal systems, and RE canal curvatures were evaluated using the cone-beam computed tomography scans.
Results: Radix entomolaris was either located disto-lingually, with its coronal portion fixed to the distal root (n = 16) or mid-lingually (n = 1). A literature search identified four additional cases of MFMs with RE located mid-lingually. In the present study, RE was significantly (p ≤ 0.001) shorter than the distal root (DR) and the mesial root, on average by 2.04 mm and 3.15 mm, respectively. The level of the distal furcation was significantly (p = 0.003) lower than that of the mesiodistal furcation, on average by 1.39 mm. The average divergence angle formed by the cervical portions of the RE and DR canals was 53.14°. All RE canals were severely curved (> 25°) in buccolingual direction. The RE orifice was located slightly disto-lingually to considerably mesio-lingually from the DR orifice.
Conclusions: The traditional assumption of a disto-lingually located RE needs to be changed, even though this is the most prevalently found variant of this anatomy. The additional variant includes the presence of a mid-lingually located RE, which has implications for the endodontic access cavity design.

Abstract

Background: This study examined the root morphology of mandibular first molars (MFMs) with radix entomolaris (RE), which presents diagnostic and therapeutic challenges for clinicians.
Materials and methods: A total of 17 three-rooted MFMs were taken from a collection of extracted teeth. Root lengths and levels of furcations were measured with a digital calliper. The pulp floor configuration, root canal systems, and RE canal curvatures were evaluated using the cone-beam computed tomography scans.
Results: Radix entomolaris was either located disto-lingually, with its coronal portion fixed to the distal root (n = 16) or mid-lingually (n = 1). A literature search identified four additional cases of MFMs with RE located mid-lingually. In the present study, RE was significantly (p ≤ 0.001) shorter than the distal root (DR) and the mesial root, on average by 2.04 mm and 3.15 mm, respectively. The level of the distal furcation was significantly (p = 0.003) lower than that of the mesiodistal furcation, on average by 1.39 mm. The average divergence angle formed by the cervical portions of the RE and DR canals was 53.14°. All RE canals were severely curved (> 25°) in buccolingual direction. The RE orifice was located slightly disto-lingually to considerably mesio-lingually from the DR orifice.
Conclusions: The traditional assumption of a disto-lingually located RE needs to be changed, even though this is the most prevalently found variant of this anatomy. The additional variant includes the presence of a mid-lingually located RE, which has implications for the endodontic access cavity design.

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Keywords

radix entomolaris, supernumerary root, dental morphology, dental anthropology, odontometrics

About this article
Title

Morphometric analysis of three-rooted mandibular first molars in a Slovene population: a macroscopic and cone-beam computed tomography analysis

Journal

Folia Morphologica

Issue

Vol 81, No 1 (2022)

Article type

Original article

Pages

203-211

Published online

2021-01-22

Page views

1837

Article views/downloads

614

DOI

10.5603/FM.a2021.0005

Pubmed

33511624

Bibliographic record

Folia Morphol 2022;81(1):203-211.

Keywords

radix entomolaris
supernumerary root
dental morphology
dental anthropology
odontometrics

Authors

L. Strmšek
I. Štamfelj

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