Restor Dent Endod.  2022 Feb;47(1):e1. 10.5395/rde.2022.47.e1.

Shape and anatomical relationship of the mental foramen to the mandibular premolars in an Indian sub-population: a retrospective CBCT analysis

• Sheth K
• Banga KS
• Pawar AM
• Gutmann JL
• Kim HC

• KMID: 2548110
• DOI: http://doi.org/10.5395/rde.2022.47.e1

Abstract

Objectives
This study assessed the shape and anatomical relationship of the mental foramen (MF) to mandibular posterior teeth in an Indian sub-population.
Materials and Methods
In total, 475 existing cone-beam computed tomography records exhibiting 950 MFs and including the bilateral presence of mandibular premolars and first molars were assessed. Images were evaluated 3-dimensionally to ascertain the position, shape, and anatomical proximity of MFs to mandibular teeth. The position and shape of MFs were measured and calculated. The Pythagorean theorem was used to calculate the distance between the root apex of the mandibular teeth and the MF.
Results
MFs exhibited a predominantly round shape (left: 67% and right: 65%) followed by oval (left: 30% and right: 31%) in both males and females and in different age groups. The root apices of mandibular second premolars (left: 71% and right: 62%) were closest to the MF, followed by distal to the first premolars and mesial to the second premolars. The mean vertical distance between the MF and the nearest tooth apex calculated on sagittal sections was 2.20 mm on the right side and 2.32 mm on the left side; no significant difference was found according to sex or age. The distance between the apices of the teeth and the MF was ≥ 4 mm (left; 4.09 ± 1.27 mm and right; 4.01 ± 1.15 mm).
Conclusions
These findings highlight the need for clinicians to be aware of the location of the MF in treatment planning and while performing non-surgical and surgical endodontic procedures.

Keyword

Anatomy; Endodontic procedures; Mandibular premolar; Mental nerve; Mental foramen; Nerve injury

Figure

• 

  Figure 1 Location and shapes of the mental foramen (MF). (A) Different locations of the MF found in the current study. 1) mFP: mesial to the first premolar, 2) FP: apex of the first premolar, 3) FPd-mSP: distal to the first premolar and mesial to the second premolar, 4) SP: apex of the second premolar, and 5) SPd-mFM: distal to the second premolar and mesial to the first molar. (B) Different shapes of the MF: round - both the diameters are the same; oval - long:short diameter ≥ 2; and irregular.

• 

  Figure 2 Measuring the distance of the mental foramen. (A) Vertical distance in a sagittal section; (B) horizontal distance in a coronal section; and (C) application of the Pythagorean theorem.

• 

  Figure 3 Position of the mental foramen. (A) FP; (B) FPd-mSP; (C) SP; and (D) SPd-mFM. FP: first premolar, SP: second premolar, FPd-mSP: between the distal FP and medial SP, SPd: distal to the SP.

• 

  Figure 4 Different shapes of the mental foramen. (A) Round; (B) oval (horizontal); (C) oval (vertical); and (D) irregular.

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