This study aimed to evaluate the relationship between cranial base morphology and maxillofacial asymmetry.

Fifty female patients diagnosed with jaw deformities with or without maxillofacial asymmetry were included. Three-dimensional computed tomographic images taken before treatment were realigned using image processing software with three reference planes. The relationships between the amount of menton deviation from the mid-sagittal plane (SP) and measurements of maxillofacial and cranial morphology were investigated. The paired t -test was used to compare measurements between the deviated and un-deviated sides, while Pearson correlation analysis was used to assess the associations with menton deviation. Principal component analysis was subsequently performed to examine the overall relationships among measurements.

The results revealed significant correlations between menton deviation from the SP and several cranio-maxillofacial measurements, including the deviation of the most prominent point on the occipital bone, the midpoint of upper central incisors deviation from the SP and the occlusal cant. Significant correlations were also found in differences between the deviated and un-deviated sides of the transverse and posterior cranial distances, ramus length, mandibular body length, upper first molar and gonion positions. In a principal component analysis using all measurements, the first principal component was a factor related to craniomandibular asymmetry and the second principal component was a factor related to occlusal plane inclination associated with middle cranial asymmetry. The third principal component was a factor related to maxillary midline deviation.

Cranial base morphology is closely related to maxillofacial asymmetry in patients with jaw deformities.