Anatomical Analysis of Mandibular Posterior Teeth using CBCT: An Endo-Surgical Perspective

Eur Endod J. 2021 Dec;6(3):264-270. doi: 10.14744/eej.2021.40427.

Abstract

Objective: This study sought to analyse the relationship between mandibular posterior teeth and the surrounding anatomical structures.

Methods: A total of 170 CBCT images were examined to obtain measurements regarding the following: buccolingual (BL) and mesiodistal (MD) root thickness at the standard level of resection (3 mm from the apex), the thickness of the overlying buccal and lingual bone at the same level, the proximity of the mandibular canal (MC) to the apices of the mandibular posterior teeth, as well as the horizontal location of the mental foramen (MF).

Results: The BL root width at 3 mm from the apex was the broadest at the mesial roots of the first molars with males: 5.33±0.99 mm and females: 5.16±0.88 mm (mean±SD). The root width was narrowest at the second premolars (males: 3.80±0.83 mm; females: 3.61±0.60 mm). At the same level; the buccal bone was thickest over the distal roots of the second molars (males: 6.92±1.85 mm; females: 6.95±1.95 mm) and thinnest over the first premolars (males: 1.73±0.93 mm; females: 1.49±1.01 mm), while the lingual bone was thickest over the distal roots of the first molars (males: 5.58±1.36 mm; females: 4.52±1.24 mm) and thinnest over the distal roots of the second molars (males: 3.13±1.50 mm; females: 2.60±1.46 mm). The nearest root apices to the MC were the distal roots of the second molars (male: 1.21±1.45 mm; female: 1.75±1.97 mm), while the furthest were the mesial roots of the first molars (male: 4.00±2.39 mm; female: 4.77±2.58 mm). The most common horizontal location of the MF was between the first and second premolars (51.8%). The lingual bone was significantly thinner over both roots of first molars in females (P<0.05).

Conclusion: As the position of the teeth became more posterior, the buccal bone thickness increased, the lingual bone thickness decreased, and the distance to the MC became closer. CBCT analysis provides distortion- and superimposition-free images of the relevant anatomic structures.