The relationship of medial sigmoid depression and sigmoid notch morphology with vertical and sagittal growth patterns in Turkish population

Medial sigmoid depression (MSD) is an anatomical variation located just below the deepest point of the sigmoid notch (SN). The etiology of MSD is unknown. It has been reported that increased maximum bite force affects the occurrence of MSD, and vertical growth pattern affects SN morphology. The aim of this study was to investigate the effects of these malocclusions on the presence and morphology of MSD and SN, since bite force can change with vertical and sagittal growth patterns. This is the first study to investigate the effects of vertical growth pattern on the presence and morphology of MSD, and the effects of sagittal growth pattern on SN morphology. Panoramic and lateral cephalometric radiographs of a total of 634 (427 female, 207 male) patients aged from 18 to 35 years (mean 19.58) were included in this retrospective study. MSD and SN shapes, SN depth and width were evaluated on panoramic radiographs. Mann Whitney-U, Kruskal-Wallis and Chi-square tests were used for data analysis. Sagittal and vertical growth patterns were not significantly associated with the presence and shape of MSD (p>0.05). SN depth was greater in individuals with class III malocclusion, and both SN depth and width were lower in hyperdivergent individuals. There was no significant relationship between SN shapes and vertical and sagittal growth patterns (p>0.05). SN depth is affected by both vertical and sagittal growth pattern, and SN width is affected only by vertical growth pattern. The presence of MSD was not associated with growth pattern.