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

Abstract

Objectives: The 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. Methods: A 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. Results: The 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. Conclusion: In 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. Clinical relevance Scientific rationale for studyThe width of lingual plate (LP) is one of the most vital factors associated with lingual nerve trauma and tooth displacement to submandibular spaces in third molars extraction. Principle findingsLingual plate surrounding mesioangular impacted third molars is particularly thin in the majority of cases. LP of mesioangular impacted tooth is more vulnerable than that of distoangular one. The thickness of LP is also correlated to vertical and horizontal levels of impaction by Pell-Gregory classification.

Análisis de terceros molares y sus estructuras anatómicas adyacentes mediante CBCT: meta-análisis

“…En cuanto a la clasificación de Winter se concluyó una prevalencia significativa de impactación de 3MM en posición mesioangular entre cinco estudios analizados (de Almeida Barros et al, 2018;Ishii et al, 2017;Nguyen et al, 2021 La imagen CBCT a diferencia de una RP permite observar el estado de la cortical ósea en relación al 3MM, este dato permitió establecer que los 3MM distoangulados y horizontales presentan una cortical lingual más delgada, además la posición vestibulolingual se relaciona con una perforación de la cortical lingual a nivel medio radicular (Menziletoglu et al, 2019); mientras que los autores Nguyen y Cols., refieren una cortical lingual delgada a nivel del tercio apical de la raíz mesial de un 3MM (Nguyen et al, 2021).…”

“…Encontraron que la posición más común fue mesioangular; la cortical lingual es la única barrera de tejido duro entre el 3MM impactado y las estructuras anatómicas en la cara lingual de la mandíbula. Se determinó que la cortical lingual era notablemente delgada observándose con mayor frecuencia a nivel del tercio apical de la raíz mesial y en los 3MM de clase A según Pell y Gregory (Nguyen et al, 2021).…”

Chart selection appropriate for articles in the field of medicine, dentistry and health sciences

“…charts can be grouped (figure 4), 13 displaying the same data on absolute and proportional variables, study and experimental groups, 14 different years, genders, 15 etiology, 16 or age range. 17 Horizontal or vertical bar charts can be used for the same purpose 18 but a horizontal bar chart is usually employed when many data are available. A minor modification of line chart is addition of a single dot on time; this chart is a control chart (figure 5).…”