Abstract
Background: The removal of impacted lower third molars surgically can cause complications, and the lingual cortical bone thickness in this region becomes a determining factor in the risk of perforation and injury to the lingual nerve (LN). This study was conducted to assess the relationship between different angulations of impacted lower third molars based on Winter’s classification and the thickness of the lingual cortical bone. Variations in lingual cortical bone thickness among the genders were evaluated as well.
Methods: Cone-beam computed tomography (CBCT) scans of 50 impacted lower third molar teeth of 50 patients (26 men and 24 women) were evaluated in this study. The lingual bone thickness surrounding impacted lower mandibular teeth was measured at three key points, namely, the cemento-enamel junction of the second mandibular molar, the mid-root of the impacted third molar, and the root apex of the impacted third molar. Mesiodistal angulation and buccolingual angulations of the impacted mandibular third molars underwent investigation. Statistical analysis was conducted using SPSS 23. Data were analyzed using the independent sample t test, one-way ANOVA, multiple linear regression analysis, and Fisher’s exact test.
Results: There was a statistically significant relationship between the means of lingual cortical bone thickness surrounding the third molars based on Winter’s classification of third molars impacted at mesiodistal angulation (P=0.00). Regarding gender, buccolingual angulation demonstrated a statistically significant relationship among the means of lingual bone thickness around the third molars (P=0.022).
Conclusion: In our study, the thickness of the lingual cortical bone was notably affected in the middle and apical areas of the impacted third molar region. The variable position of the LN near the mandible third molar region was significant in dental procedures due to its proximity. Three-dimensional (3D) imaging CBCT provides preoperative risk assessment that reduces preventable complications that cannot be answered by 2D imaging.