morphologic evaluation of lingual concavity in posterior region of mandible: a cone beam computerized tomography study

Background: the present study aimed to assess the frequency, lingual concavity angle (lca) and the different types of lingual concavity in the posterior mandible.methods: 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.results: 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). conclusion: 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.