Malposition of teeth and jaws in patients with congenital superior oblique palsy

Background: Patients with congenital superior oblique palsy tend to adopt a head tilt to the contralateral side to maintain binocular single vision. It has long been recognised that facial asymmetries may be caused by a head tilt. The aim of this study was to describe the effect of habitual head tilt due to congenital superior oblique palsy on dental occlusion. Patients and methods: The study was designed as a descriptive cohort study. Ten patients with congenital superior oblique palsy (3 female, 7 male; mean age 51.7 (y) ± 15.8 SD, ranging from 19 to 69 (y)) underwent orthodontic examination. Orthodontic findings and values for vertical, torsional and horizontal deviation measured with the Harms tangent screen and stereopsis using a random dot test were compared. Results: Three orthodontic parameters were found to correlate significantly or at least as trend with orthoptic parameters. Midline deviation of the upper jaw to the face (rho = 0.623; p = 0.054) and anterior positioning of upper first molar in the sagittal plane (rho = 0.594; p = 0.07) correlate with the vertical deviation; overbite correlates with horizontal deviation measured in the primary position (rho = 0.768; p = 0.016). Conclusions: In this small study, three orthodontic parameters correlated with orthoptic findings in patients with congenital superior oblique palsy. Further studies are needed to establish whether congenital superior oblique palsy is more frequent in patients exhibiting abnormal values of these orthodontic parameters