Three-dimensional evaluation of dentofacial transverse widths in adults with different sagittal facial patterns

The aim of this study was to evaluate the dentofacial transverse dimensions of subjects with different sagittal facial patterns using 3-dimensional cone-beam computed tomography images.

Cone-beam computed tomography images of 63 men and 80 women were divided into skeletal Class I, Class II, and Class III groups. Skeletal and dental evaluations were made on frontal views and coronal cross-sections of the images. Independent 2-sample t tests and 1-way analysis of variance followed by post hoc Tukey tests were used for sex and group differences. Pearson correlation analysis was used to identify factors related to changes in ANB angle.

The Class II subjects did not show differences in maxillomandibular width and maxillary width compared with Class I subjects; however, their maxillary molars were more lingually tipped. The Class III subjects showed greater maxillomandibular width differences and smaller maxillary widths and maxillary buccolingual alveolar widths at midroot level compared with Class I subjects. The maxillary molars were buccally inclined, and the mandibular molars were lingually compensated in Class III subjects. The ANB angle showed positive correlations with jugal process width, maxillary width, and maxillary buccolingual alveolar width at midroot level as well as mandibular molar buccal inclination; negative correlations were found in maxillomandibular width difference, mandibular width at midroot level, and maxillary molar buccal inclination.

A relative comparison of Class I, Class II, and Class III subjects showed that dental compensation had occurred to overcome the transverse skeletal discrepancies in the maxillary posterior segments of Class II and Class III subjects. This could escalate unidentified periodontal and functional problems in the long term. Future studies of transverse dentofacial dimensions, including periodontal evaluations and occlusal forces, would be useful for delivering proper orthodontic treatment for skeletal Class II and Class III subjects.