Abstract:

Objective To observe the occlusal contacts during protrusion and lateral movements in adolescent patients after orthodontic treatment. Methods Sixteen adolescent patients who achieved normal dentition after orthodontic treatment were selected as experimental group and 17 healthy adolescents and young adults with normal occlusion were selected as control group. The occlusal contacts during protrusion and lateral movements in the two groups were recorded with T-Scan Ⅱ system and compared. Results The prevalence of occlusal interferences in the posterior segment in the experimental group was high and most of them were on the second molars. The value of disclusion time during left lateral movements, right lateral movements and protrusion in the experimental group were （1.504±0.681）, （1.532±0.913）, （1.358±0.791）s. The value of disclusion time during left lateral movements, right lateral movements and protrusion in the control group were（0.470±0.059）,（0.483±0.045）,（0.482±0.047）s. The results in the experimental group were significantly longer than those of control group（P＜0.01）. Conclusion Although the patients achieved normal dentition after orthodontic treatment, their disclusion time were longer than those in healthy adolescents and young adults with normal occlusion.

Key words: orthodontics, malocclusion, disclusion time, occlusal interferences