Kinematic analysis of mandibular motion before and after orthognathic surgery for skeletal Class III malocclusion: A pilot study.

OBJECTIVES: The aim of the study was to detect the changes in 3D mandibular motion after orthognathic surgery for skeletal Class III malocclusion.

METHOD: Using a 3D motion analyzer, free mandibular border movements were recorded in nine patients successfully treated for skeletal Class III malocclusion and in nine patients scheduled for orthognathic surgery. Data were compared using Mann-Whitney non-parametric U-test.

RESULTS: The results showed no differences between the groups in the total amount of mouth opening, protrusion, and in lateral excursions, but the percentage of mandibular movement explained by condylar translation was significantly increased after surgery (20% vs. 23.6%). During opening, the post-surgery patients showed a more symmetrical mandibular interincisal point and condylar path than pre-surgery patients (p < 0.01).

DISCUSSION: Patients treated with orthognathic surgery for skeletal Class III malocclusion recover a good and symmetric temporomandibular joint function.