3D-CT assessment of mandibular widths in young subjects with different underlying vertical facial patterns

Abstract

Abstract Aim This study was undertaken to evaluate the relationships among dental arch widths, mandibular bone widths, and masseter muscle dimensions in growing children with different underlying vertical facial patterns using three-dimensional computed tomography (3D-CT). Method Fifty-eight young subjects (32 male and 26 female) with a mean age of 13.27 (±1.59) years had undergone cranial CT examinations as part of medical diagnosis. 3D-CT images were reconstructed for the assessment of various mandibular dental and bone widths in relation to the vertical facial pattern and masseter muscle dimensions. Results The cross-sectional area and volume of the masseter muscle, mandibular plane angle, total posterior face height and lower posterior face height were significantly different among the vertical pattern groups. There were a number of significant positive and negative correlations among the muscular dimensions and the dental and bone widths with the different vertical patterns. Conclusions Dolichofacials are likely to have relatively smaller masseter cross-sectional areas and volumes than brachyfacials, and vice versa. There is likely to be a close association between mandibular intermolar width and the corresponding widths at the apical and lower border levels. There is not likely to be the same association between the intercanine width and the corresponding lower border width. Brachyfacials are likely to have a greater width of buccal cancellous bone through which the canines can potentially be expanded laterally.