Localization of the First Mandibular Molar Roots in Relationship to the Mandibular Canal in Small Breed Dogs-A Tomography Imaging Study.

Han Chia,Kendall Taney,Don Hoover,James B Robertson,Lenin A Villamizar-Martinez

doi:10.3389/fvets.2021.684763

Han Chia, Kendall Taney + Show 3 more

Open Access

https://doi.org/10.3389/fvets.2021.684763

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Abstract

The intimate relationship between the mandibular canal (MC) and the first mandibular molar tooth presents challenges when performing dentoalveolar surgical procedures due to the probability of causing iatrogenic injury to the inferior alveolar neurovascular bundle. Superimposition between the MC and the first molar (M1) tooth roots is often observed on intraoral dental radiographs in small breed dogs. However, due to the radiograph's bidimensional nature, it is impossible to determine the buccal or lingual localization of the first molar roots with respect to the MC. Thus, this study's objective was to determine the localization of the first molar tooth's roots in relation to the position of the MC and their overlapping percentage with the canal in small-bodyweight dogs (<15 kg) using tomographic diagnostic images. For this, cone-beam computed tomography and high-definition computed tomography exams from 103 small breed dogs (under 15 kg) were retrospectively assessed to determine the lingual or buccal localization of the first molar tooth's roots with respect to the MC and the degree of overlap of the roots with the canal. In conclusion, most of the roots of M1 of dogs under 15 kg were located at the MC's lingual aspect (82.7%) with an overall superimposition median with the MC of 100 and 90% for the mesial and distal roots, respectively. Straddle tooth roots were not a common anatomical presentation in the dogs of this study.

Highlights

The mandibular canal (MC) is a hollow space that carries the inferior alveolar neurovascular bundle, which innervates and provides blood supply to the gingiva, teeth, and rostral soft tissue of the mandible [1, 2]
The first paper to describe the relationship between mandibular molar teeth and the MC was published in humans in 1986 based on intraoral dental radiographs [17]
We investigated the relationship between the M1 roots and the MC in small canine patients via tomographic images (CBCT and high-definition CT (HDCT))

Summary

Introduction

The mandibular canal (MC) is a hollow space that carries the inferior alveolar neurovascular bundle, which innervates and provides blood supply to the gingiva, teeth, and rostral soft tissue of the mandible [1, 2]. The mandibular first molar (M1) is the largest two-rooted tooth of the mandible in domestic canines, and portions of the roots are adjacent to the MC The cusps contain both a sharp edge and a flat edge for its function. The mesial end is sharp and intended for shearing, whereas the distal end is flat and used for grinding [6] Due to this tooth’s size, it is common to see the M1 tooth roots and MC overlapping on the intraoral dental radiographs. A previous intraoral radiographic study evaluated the relationship between patient body weight and the M1 size These authors showed that dogs under 10 kg presented larger M1s than the mandibular height, with the M1 tooth roots extending ventrally to the MC [7]

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