Abstract
Purpose: To examine the effect of lateral head tilt on mandibular position, we measured the positions of the condylar and incisal points in three dimensions after lateral tilting of the head. The relationship between head tilt angle and mandibular position was subsequently investigated.
Methods: Thirty healthy adults with normal occlusion and suffering no stomatognathic dysfunction were examined. An anterior jig was attached to the maxilla and a paraocclusal clutch was attached to the mandible. Left and right condylar and incisal points were measured by the Win Jaw System® at the following head tilt angles: 0°, 5°, 10°, 15°, 20°, 25°, and 30° (toward either side). Anteroposterior, horizontal, and vertical shifts of the condylar and incisal points from the corresponding reference positions were calculated at each tilt angle. Differences in head tilt angle were analyzed by one-way repeated measures ANOVA and Bonferroni’s method.
Results: In the condylar points on the side of the flexed neck, anteroposterior, horizontal, and vertical shifts were not significantly different. Lateral head tilt caused significant anteroposterior and vertical shifts in the condylar points on the side of the extended neck, and the shift increased in line with head tilt angle of 10º or more. Lateral head tilt caused significant anteroposterior and horizontal shift in the incisal points, and the shift increased in line with head tilt angle of 10º or more.
Conclusions: Lateral head tilt causes a shift in the mandibular position which increases with increasing head tilt angle.
