Mental Foramen Position in Class I, II, III Malocclusion on Vertical and Horizontal Dimensions by using CBCT

Abstract Purpose: Mental foramen (MF) is characterised as a funnel-like opening of the mental canal onto the lateral surface of mandible, it serves as a pathway for vessels and nerves.The present study aimed to determine the position of the mental foramen (MF) in CBCT images in Class I, Class II, and Class III malocclusions with different growth patterns. Material and Methods : In this descriptive-cross-sectional study, 150 CBCT images of individuals with Class I, Class II, and Class III malocclusions were selected. Each sagittal malocclusion had 50 samples, with 25 participants exhibiting a vertical growth pattern and 25 participants exhibiting a horizontal growth pattern for each type of malocclusion.The age range was 18-35 years, and they had no history of specific oral and dental diseases, previous surgeries, or orthodontic treatment. Using CBCT images, measurements were performed on both the left and right sides. MF Shape and MF Position relative to the Nearest Tooth were evaluated. And also MF Length, Hieght, Distance from MF to Inferior Border, Distance from MF to Bone Crest and Mental Canal Angle were measured. The variables of different types of malocclusions were evaluated using one-way analysis of variance (ANOVA). The frequency of MF shape and its position in relation to the nearest tooth, were analysed by using the chi-square test. Results: No significant differences were observed in terms of shape of MF among different types of malocclusion in sagittal relationship and type of growth pattern. Significant differences in location of MF were observed in terms of growth pattern P=0/0028. However there was not any significant changes in location of MF in sagittal malocclusions. The distance from MF to the inferior border (p<0.001), distance to the crest of the bone (p<0.001), and mental canal angle (p=0.008) were significantly greater in individuals with a vertical growth pattern compared to those with horizontal growth pattern. Distance of MF to inferior border of mandible was 15/96± 0/63 in class II vertical growth pattern which was higher than in class I and II vertical growers. And also the same distance in class II horizontal growers was 13/56± 0/89 which was greater than in class I and II horizontal growers. Conclusion: Greater distance between the mental foramen (MF) and the inferior border of the mandible was observed in Class II vertical growth pattern compared to Class I and Class II vertical growers. Similarly, in Class II horizontal growers, the distance was higher compared to Class I and Class II horizontal growers of MF to inferior border of mandible was greater in class II vertical growth pattern in relationship to class I and II vertical growers. And the same distance in class II horizontal growers was higer than in class I and II horizontal growers.