Predictive factors of the dimensions and location of mental foramen using cone beam computed tomography.

Juan Muinelo-Lorenzo,Juan Antonio Suárez-Quintanilla,Ana Fernández-Alonso,Ernesto Smyth-Chamosa,María Mercedes Suárez-Cunqueiro,Jesús Varela-Mallou,James J Cray

doi:10.1371/journal.pone.0179704

Juan Muinelo-Lorenzo, Juan Antonio Suárez-Quintanilla + Show 5 more

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https://doi.org/10.1371/journal.pone.0179704

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Abstract

ObjectiveThe mental foramen (MF) hosts main neurovascular structures, making it of crucial importance for surgical procedures. This study aimed to analyze the factors influencing the dimensions and location of the MF.Materials and methodsCone beam computed tomography (CBCT) scans of 344 patients were examined for MF dimensions, as well as for the distances from the MF to the alveolar crest (MF-MSB), and to the inferior mandibular border (MF-MIB).ResultsGender, mandibular side and presence of accessory mental foramina (AMF) significantly influence MF area. Males, left hemimandibles, and hemimandibles with no AMF had a higher rate of large MF areas (B = − 0.60; p = 0.003, females; B = 0.55; p = 0.005; B = 0.85; p = 0.038). Age, gender and dental status significantly influence MF-MSB distance. The distance decreased as age increased (B = −0.054; p = 0.001), females showed a lower rate of long MF-MSB distances (B = −0.94, p = 0.001), and dentate patients showed a higher rate of long MF-MSB distances (B = 2.27; p = 0.001). Age, gender and emerging angle significantly influenced MF-MIB distance. The distance decreased as age and emerging angle increased (B = −0.01; p = 0.001; B = −0.03; p = 0.001), and females had a lower rate of long MF-MIB distances (B = −1.94, p = 0.001).ConclusionsGeneral and local factors influence the dimensions and location of MF. MF dimensions are influenced by gender, mandibular side, anteroposterior position, and the presence of AMF. Distance from MF to alveolar crest is influenced by gender, age and dental status, while the relative MF position is influenced by age and dental status. CBCT images make it possible to analyze the MF in order to avoid complications during surgical procedures.

Highlights

The mental foramen (MF) is considered one of the main anatomic landmarks in the anterior region of the mandible because it constitutes the exit through which the terminal mandibular neurovascular branches pass
Left hemimandibles, and hemimandibles with no accessory mental foramina (AMF) had a higher rate of large MF areas (B = − 0.60; p = 0.003, females; B = 0.55; p = 0.005; B = 0.85; p = 0.038)
The distance decreased as age increased (B = −0.054; p = 0.001), females showed a lower rate of long MF-MSB distances (B = −0.94, p = 0.001), and dentate patients showed a higher rate of long MF-MSB distances (B = 2.27; p = 0.001)

Summary

Introduction

The mental foramen (MF) is considered one of the main anatomic landmarks in the anterior region of the mandible because it constitutes the exit through which the terminal mandibular neurovascular branches pass. There are anatomical variations affecting the MF and mental nerve regarding location, size, emerging direction, number, and shape [1,2]. The mandible of humans has undergone a decrease in its overall size compared to other primates [3,4]. The mental foramen (MF) has varied its size and location. The MF has shifted from the molar region in Neolithic skulls to its current premolar position in modern humans. The MF has increased in size since the Neolithic period [5]

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