Morphologic Evaluation of Lingual Concavity in Posterior Region of Mandible: A Cone Beam Computerized Tomography Study

The present study aimed to assess the frequency, Lingual Concavity Angle (LCA) and the different types of lingual concavity in the posterior mandible. In this study Cone Beam Computerized Tomography (CBCT) images of 670 mandibular bodies in the molar areas were evaluated. Cross-sectional images of the mandible were reconstructed at furcation points of first molar area. The LCA was measured. The subjects with LCA smaller than 85° were considered as concave. Then, the concave subjects were classified into three groups: angle less than 40°, angle between 40-60°, and angle between 60-85° were designated as extremely deep, deep, and mild deep, respectively. The most common type of lingual concavity was mild deep, followed by deep, and extremely deep. There was a significant positive correlation between the LCA and the age of participants (p<0.001). There was also significant relationship between the age of participants and the type of lingual concavity (p<0.001). The subjects in mild deep group were significantly older than deep group (p=0.032). Also, the non-concave subjects were significantly older than deep and mild deep subjects. (p=0.001 and 0.040, respectively). The LCA was significantly higher in males than females (p=0.020). The LCA was significantly larger on the left side (p<0.001).  The presence of deep lingual concavity was common (95%.). Also, mandibular lingual concavity types were found to vary by age, and laterality. Moreover, the LCA was significantly different according to patient age, sex, and laterality.