The vulnerability of lingual plate of the mesioangular impacted mandibular third molars: a measurement on CBCT images

Abstract

AbstractObjectivesThe innate fragility of lingual plate (LP) is assumed to be the main reason leading to injuries of lingual neurovascular bundles and surrounding fascial spaces during mandibular third molar (MTM) surgery. The aim of this study was to assess the LP and lingual cortical plate (LCP) thickness of mesioangular impacted MTM.MethodsA total of 130 cone beam computed topography images were collected and studied. The related landmarks of MTM roots and LP were identified for measurements. At three positions of each root, including middle third, apical third and apex, the integrity of LP together with thickness of LP and LCP were evaluated.ResultsThe results showed that mean values of LP and LCP thickness of the most lingual root at apical third were 0.89 and 0.57 mm respectively. The average values of LP and LCP thickness surrounding mesial root were significantly smaller than those of distal root at all examined positions, except LP thickness at the apex. Moreover, the thickness of LP presumably increased together with the horizontal and vertical impacted levels according to Pell–Gregory classification. The percentage of losing LP integrity was determined as 89.5%, 93.4% and 77.4% at middle third, apical third and apex, respectively.ConclusionIn conclusion, LP surrounding the mesioangular impacted MTM is considerably thin, which can be the reason of lingual neurovascular bundles traumas and fascial spaces damages, especially at the apical third of the mesial root and in class A MTM.