The evaluation of facial asymmetry in hyperdivergent patients with cone beam computed tomography

This retrospective study aims to determine if there is a difference in skeletal asymmetry between patients with hyperdivergent and normodivergent skeletal patterns via CBCT images. CBCT images of 104 subjects who presented for orthodontic care were examined. These patients were divided into two groups: Hyperdivergent group consisted of 52 patients (33 females and 19 males) with a mean age of 14,23±5,14 and normodivergent group consisted of 52 patients (24 females and 28 males) with a mean age of 14,98±6,22. Both groups were further divided into 2 subgroups (prepeak and postpeak) consisting of 26 patients according to their cervical vertebral maturation. Anatomic landmarks were defined and reference planes were established to determine the asymmetry of the landmarks using a coordinate plane system. Landmark asymmetries were analysed using an asymmetry index . Measurements of various anatomical structures contributing to craniofacial asymmetry with both right and left sides were performed and evaluated statistically as well. Hyperdivergent patients presented more significant differences between the right and left sides of the ramus length. ANS and Me landmarks were found more asymmetric in hyperdivergent patients. (p<0,01) There were no statistically significant differences between prepeak and post-peak maturation subgroups regarding asymmetry measurements in both divergent groups. Landmark asymmetry index values were not statistically different between the two divergent groups. Facial asymmetry is affected by the vertical skeletal pattern. Hyperdivergent patients are likely to present more mandibular asymmetry.