Comparative Anatomy of Mandibular Neurovascular Canals in Modern Human and Great Apes: A Pilot Study with Cone Beam Computed to Mography

Xin Liang,Patrick Semal,Hesham N. Mustafa,Livia Corpas,Yan Huang,Jacobs Reinhilde,Bassant Mowafey,Politis Constantinus,Lambrichts Ivo

doi:10.14302/issn.2577-2279.ijha-17-1903

Abstract

The aim of the present study was to compare mandibular neurovascular canal anatomy in human and great apes by using cone beam computed tomography (CBCT). The anatomical variability of mandibular neurovascular canals (mandibular, incisive and lingual canals) of 129 modern humans and great apes (Homo, Pan and Gorilla) were analyzed by linear measurements on CBCT images. The Kruskal-Wallis non-parametric test and Dunnâs all pairs for joint ranks were applied to compare the variability of mandibular canals among these groups. Human, Chimpanzee and Gorilla groups showed significant differences in the dimensions of the mandibular canal, mental foramen, incisive canal, lingual canal and anterior mandibular bone width. Bifid mandibular canals and anterior loops were the anatomical variations most frequently observed in the Gorilla. Humans had a larger mental foramen and a distinctive incisive canal. The latter could not be identified in the Gorilla group. The variability in the anatomy within mandibles of human and non-human primates, shows different forms in the neurovascular structures. In comparison to the mandible of great apes, the incisive canal is suggested to be a feature unique to the human mandible.

Highlights

The anatomy of the human mandible has been widely studied by means of advanced imaging technologies such as cone beam computed tomography (CBCT)[1,2,3,4], which is able to provide accurate, essentially immediate and non-invasive 3D radiographic images of teeth, soft-tissues, nerve paths and bone structures in the craniofacial region
The typical images from modern human and great apes with different anatomical features were shown in Figure 1 and Figure 2
Interspecific variability was determined by comparing contemporary human and great ape mandibles

Summary

Introduction

The anatomy of the human mandible has been widely studied by means of advanced imaging technologies such as cone beam computed tomography (CBCT)[1,2,3,4], which is able to provide accurate, essentially immediate and non-invasive 3D radiographic images of teeth, soft-tissues, nerve paths and bone structures in the craniofacial region. The mandibular form may reflect functional adaptation to forces experienced during mastication[16], the mandibular neurovascular canal has been considered as the most stable structure guiding mandibular development[17,18] It may be a relevant structure to indicate nerves intra- and inter- specific patterning related to mandibular anatomy. It was considered that the diversities related to nerves are cranial discrete traits of the modern human skull[19] These anatomy variations in the mandible canal may result from a process of adaptation to various environmental and subsistence patterns as well as random drift by population size, network and isolation, leading to the development of regional frequency patterns[20,21,22]. Dimensional variability, eg., larger canal diameter and proximity to root apices, should be considered so as to avoid, or at least anticipate as high risk factors for inferior alveolar nerve injuries during the treatment planning and oral maxillofacial surgery[23]

Objectives

Methods

Results

Discussion

Conclusion